text: // https://d3js.org Version 4.8.0. Copyright 2017 Mike Bostock.
  (function (global, factory) {
      typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
          typeof define === 'function' && define.amd ? define(['exports'], factory) :
              (factory((global.d3 = global.d3 || {})));
  }(this, (function (exports) { 'use strict';
  
      var version = "4.8.0";
  
      var ascending = function(a, b) {
          return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
      };
  
      var bisector = function(compare) {
          if (compare.length === 1) compare = ascendingComparator(compare);
          return {
              left: function(a, x, lo, hi) {
                  if (lo == null) lo = 0;
                  if (hi == null) hi = a.length;
                  while (lo < hi) {
                      var mid = lo + hi >>> 1;
                      if (compare(a[mid], x) < 0) lo = mid + 1;
                      else hi = mid;
                  }
                  return lo;
              },
              right: function(a, x, lo, hi) {
                  if (lo == null) lo = 0;
                  if (hi == null) hi = a.length;
                  while (lo < hi) {
                      var mid = lo + hi >>> 1;
                      if (compare(a[mid], x) > 0) hi = mid;
                      else lo = mid + 1;
                  }
                  return lo;
              }
          };
      };
  
      function ascendingComparator(f) {
          return function(d, x) {
              return ascending(f(d), x);
          };
      }
  
      var ascendingBisect = bisector(ascending);
      var bisectRight = ascendingBisect.right;
      var bisectLeft = ascendingBisect.left;
  
      var pairs = function(array, f) {
          if (f == null) f = pair;
          var i = 0, n = array.length - 1, p = array[0], pairs = new Array(n < 0 ? 0 : n);
          while (i < n) pairs[i] = f(p, p = array[++i]);
          return pairs;
      };
  
      function pair(a, b) {
          return [a, b];
      }
  
      var cross = function(values0, values1, reduce) {
          var n0 = values0.length,
              n1 = values1.length,
              values = new Array(n0 * n1),
              i0,
              i1,
              i,
              value0;
  
          if (reduce == null) reduce = pair;
  
          for (i0 = i = 0; i0 < n0; ++i0) {
              for (value0 = values0[i0], i1 = 0; i1 < n1; ++i1, ++i) {
                  values[i] = reduce(value0, values1[i1]);
              }
          }
  
          return values;
      };
  
      var descending = function(a, b) {
          return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
      };
  
      var number = function(x) {
          return x === null ? NaN : +x;
      };
  
      var variance = function(values, valueof) {
          var n = values.length,
              m = 0,
              i = -1,
              mean = 0,
              value,
              delta,
              sum = 0;
  
          if (valueof == null) {
              while (++i < n) {
                  if (!isNaN(value = number(values[i]))) {
                      delta = value - mean;
                      mean += delta / ++m;
                      sum += delta * (value - mean);
                  }
              }
          }
  
          else {
              while (++i < n) {
                  if (!isNaN(value = number(valueof(values[i], i, values)))) {
                      delta = value - mean;
                      mean += delta / ++m;
                      sum += delta * (value - mean);
                  }
              }
          }
  
          if (m > 1) return sum / (m - 1);
      };
  
      var deviation = function(array, f) {
          var v = variance(array, f);
          return v ? Math.sqrt(v) : v;
      };
  
      var extent = function(values, valueof) {
          var n = values.length,
              i = -1,
              value,
              min,
              max;
  
          if (valueof == null) {
              while (++i < n) { // Find the first comparable value.
                  if ((value = values[i]) != null && value >= value) {
                      min = max = value;
                      while (++i < n) { // Compare the remaining values.
                          if ((value = values[i]) != null) {
                              if (min > value) min = value;
                              if (max < value) max = value;
                          }
                      }
                  }
              }
          }
  
          else {
              while (++i < n) { // Find the first comparable value.
                  if ((value = valueof(values[i], i, values)) != null && value >= value) {
                      min = max = value;
                      while (++i < n) { // Compare the remaining values.
                          if ((value = valueof(values[i], i, values)) != null) {
                              if (min > value) min = value;
                              if (max < value) max = value;
                          }
                      }
                  }
              }
          }
  
          return [min, max];
      };
  
      var array = Array.prototype;
  
      var slice = array.slice;
      var map = array.map;
  
      var constant = function(x) {
          return function() {
              return x;
          };
      };
  
      var identity = function(x) {
          return x;
      };
  
      var sequence = function(start, stop, step) {
          start = +start, stop = +stop, step = (n = arguments.length) < 2 ? (stop = start, start = 0, 1) : n < 3 ? 1 : +step;
  
          var i = -1,
              n = Math.max(0, Math.ceil((stop - start) / step)) | 0,
              range = new Array(n);
  
          while (++i < n) {
              range[i] = start + i * step;
          }
  
          return range;
      };
  
      var e10 = Math.sqrt(50);
      var e5 = Math.sqrt(10);
      var e2 = Math.sqrt(2);
  
      var ticks = function(start, stop, count) {
          var reverse = stop < start,
              i = -1,
              n,
              ticks,
              step;
  
          if (reverse) n = start, start = stop, stop = n;
  
          if ((step = tickIncrement(start, stop, count)) === 0 || !isFinite(step)) return [];
  
          if (step > 0) {
              start = Math.ceil(start / step);
              stop = Math.floor(stop / step);
              ticks = new Array(n = Math.ceil(stop - start + 1));
              while (++i < n) ticks[i] = (start + i) * step;
          } else {
              start = Math.floor(start * step);
              stop = Math.ceil(stop * step);
              ticks = new Array(n = Math.ceil(start - stop + 1));
              while (++i < n) ticks[i] = (start - i) / step;
          }
  
          if (reverse) ticks.reverse();
  
          return ticks;
      };
  
      function tickIncrement(start, stop, count) {
          var step = (stop - start) / Math.max(0, count),
              power = Math.floor(Math.log(step) / Math.LN10),
              error = step / Math.pow(10, power);
          return power >= 0
              ? (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1) * Math.pow(10, power)
              : -Math.pow(10, -power) / (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1);
      }
  
      function tickStep(start, stop, count) {
          var step0 = Math.abs(stop - start) / Math.max(0, count),
              step1 = Math.pow(10, Math.floor(Math.log(step0) / Math.LN10)),
              error = step0 / step1;
          if (error >= e10) step1 *= 10;
          else if (error >= e5) step1 *= 5;
          else if (error >= e2) step1 *= 2;
          return stop < start ? -step1 : step1;
      }
  
      var sturges = function(values) {
          return Math.ceil(Math.log(values.length) / Math.LN2) + 1;
      };
  
      var histogram = function() {
          var value = identity,
              domain = extent,
              threshold = sturges;
  
          function histogram(data) {
              var i,
                  n = data.length,
                  x,
                  values = new Array(n);
  
              for (i = 0; i < n; ++i) {
                  values[i] = value(data[i], i, data);
              }
  
              var xz = domain(values),
                  x0 = xz[0],
                  x1 = xz[1],
                  tz = threshold(values, x0, x1);
  
              // Convert number of thresholds into uniform thresholds.
              if (!Array.isArray(tz)) {
                  tz = tickStep(x0, x1, tz);
                  tz = sequence(Math.ceil(x0 / tz) * tz, Math.floor(x1 / tz) * tz, tz); // exclusive
              }
  
              // Remove any thresholds outside the domain.
              var m = tz.length;
              while (tz[0] <= x0) tz.shift(), --m;
              while (tz[m - 1] > x1) tz.pop(), --m;
  
              var bins = new Array(m + 1),
                  bin;
  
              // Initialize bins.
              for (i = 0; i <= m; ++i) {
                  bin = bins[i] = [];
                  bin.x0 = i > 0 ? tz[i - 1] : x0;
                  bin.x1 = i < m ? tz[i] : x1;
              }
  
              // Assign data to bins by value, ignoring any outside the domain.
              for (i = 0; i < n; ++i) {
                  x = values[i];
                  if (x0 <= x && x <= x1) {
                      bins[bisectRight(tz, x, 0, m)].push(data[i]);
                  }
              }
  
              return bins;
          }
  
          histogram.value = function(_) {
              return arguments.length ? (value = typeof _ === "function" ? _ : constant(_), histogram) : value;
          };
  
          histogram.domain = function(_) {
              return arguments.length ? (domain = typeof _ === "function" ? _ : constant([_[0], _[1]]), histogram) : domain;
          };
  
          histogram.thresholds = function(_) {
              return arguments.length ? (threshold = typeof _ === "function" ? _ : Array.isArray(_) ? constant(slice.call(_)) : constant(_), histogram) : threshold;
          };
  
          return histogram;
      };
  
      var threshold = function(values, p, valueof) {
          if (valueof == null) valueof = number;
          if (!(n = values.length)) return;
          if ((p = +p) <= 0 || n < 2) return +valueof(values[0], 0, values);
          if (p >= 1) return +valueof(values[n - 1], n - 1, values);
          var n,
              i = (n - 1) * p,
              i0 = Math.floor(i),
              value0 = +valueof(values[i0], i0, values),
              value1 = +valueof(values[i0 + 1], i0 + 1, values);
          return value0 + (value1 - value0) * (i - i0);
      };
  
      var freedmanDiaconis = function(values, min, max) {
          values = map.call(values, number).sort(ascending);
          return Math.ceil((max - min) / (2 * (threshold(values, 0.75) - threshold(values, 0.25)) * Math.pow(values.length, -1 / 3)));
      };
  
      var scott = function(values, min, max) {
          return Math.ceil((max - min) / (3.5 * deviation(values) * Math.pow(values.length, -1 / 3)));
      };
  
      var max = function(values, valueof) {
          var n = values.length,
              i = -1,
              value,
              max;
  
          if (valueof == null) {
              while (++i < n) { // Find the first comparable value.
                  if ((value = values[i]) != null && value >= value) {
                      max = value;
                      while (++i < n) { // Compare the remaining values.
                          if ((value = values[i]) != null && value > max) {
                              max = value;
                          }
                      }
                  }
              }
          }
  
          else {
              while (++i < n) { // Find the first comparable value.
                  if ((value = valueof(values[i], i, values)) != null && value >= value) {
                      max = value;
                      while (++i < n) { // Compare the remaining values.
                          if ((value = valueof(values[i], i, values)) != null && value > max) {
                              max = value;
                          }
                      }
                  }
              }
          }
  
          return max;
      };
  
      var mean = function(values, valueof) {
          var n = values.length,
              m = n,
              i = -1,
              value,
              sum = 0;
  
          if (valueof == null) {
              while (++i < n) {
                  if (!isNaN(value = number(values[i]))) sum += value;
                  else --m;
              }
          }
  
          else {
              while (++i < n) {
                  if (!isNaN(value = number(valueof(values[i], i, values)))) sum += value;
                  else --m;
              }
          }
  
          if (m) return sum / m;
      };
  
      var median = function(values, valueof) {
          var n = values.length,
              i = -1,
              value,
              numbers = [];
  
          if (valueof == null) {
              while (++i < n) {
                  if (!isNaN(value = number(values[i]))) {
                      numbers.push(value);
                  }
              }
          }
  
          else {
              while (++i < n) {
                  if (!isNaN(value = number(valueof(values[i], i, values)))) {
                      numbers.push(value);
                  }
              }
          }
  
          return threshold(numbers.sort(ascending), 0.5);
      };
  
      var merge = function(arrays) {
          var n = arrays.length,
              m,
              i = -1,
              j = 0,
              merged,
              array;
  
          while (++i < n) j += arrays[i].length;
          merged = new Array(j);
  
          while (--n >= 0) {
              array = arrays[n];
              m = array.length;
              while (--m >= 0) {
                  merged[--j] = array[m];
              }
          }
  
          return merged;
      };
  
      var min = function(values, valueof) {
          var n = values.length,
              i = -1,
              value,
              min;
  
          if (valueof == null) {
              while (++i < n) { // Find the first comparable value.
                  if ((value = values[i]) != null && value >= value) {
                      min = value;
                      while (++i < n) { // Compare the remaining values.
                          if ((value = values[i]) != null && min > value) {
                              min = value;
                          }
                      }
                  }
              }
          }
  
          else {
              while (++i < n) { // Find the first comparable value.
                  if ((value = valueof(values[i], i, values)) != null && value >= value) {
                      min = value;
                      while (++i < n) { // Compare the remaining values.
                          if ((value = valueof(values[i], i, values)) != null && min > value) {
                              min = value;
                          }
                      }
                  }
              }
          }
  
          return min;
      };
  
      var permute = function(array, indexes) {
          var i = indexes.length, permutes = new Array(i);
          while (i--) permutes[i] = array[indexes[i]];
          return permutes;
      };
  
      var scan = function(values, compare) {
          if (!(n = values.length)) return;
          var n,
              i = 0,
              j = 0,
              xi,
              xj = values[j];
  
          if (compare == null) compare = ascending;
  
          while (++i < n) {
              if (compare(xi = values[i], xj) < 0 || compare(xj, xj) !== 0) {
                  xj = xi, j = i;
              }
          }
  
          if (compare(xj, xj) === 0) return j;
      };
  
      var shuffle = function(array, i0, i1) {
          var m = (i1 == null ? array.length : i1) - (i0 = i0 == null ? 0 : +i0),
              t,
              i;
  
          while (m) {
              i = Math.random() * m-- | 0;
              t = array[m + i0];
              array[m + i0] = array[i + i0];
              array[i + i0] = t;
          }
  
          return array;
      };
  
      var sum = function(values, valueof) {
          var n = values.length,
              i = -1,
              value,
              sum = 0;
  
          if (valueof == null) {
              while (++i < n) {
                  if (value = +values[i]) sum += value; // Note: zero and null are equivalent.
              }
          }
  
          else {
              while (++i < n) {
                  if (value = +valueof(values[i], i, values)) sum += value;
              }
          }
  
          return sum;
      };
  
      var transpose = function(matrix) {
          if (!(n = matrix.length)) return [];
          for (var i = -1, m = min(matrix, length), transpose = new Array(m); ++i < m;) {
              for (var j = -1, n, row = transpose[i] = new Array(n); ++j < n;) {
                  row[j] = matrix[j][i];
              }
          }
          return transpose;
      };
  
      function length(d) {
          return d.length;
      }
  
      var zip = function() {
          return transpose(arguments);
      };
  
      var slice$1 = Array.prototype.slice;
  
      var identity$1 = function(x) {
          return x;
      };
  
      var top = 1;
      var right = 2;
      var bottom = 3;
      var left = 4;
      var epsilon = 1e-6;
  
      function translateX(x) {
          return "translate(" + x + ",0)";
      }
  
      function translateY(y) {
          return "translate(0," + y + ")";
      }
  
      function center(scale) {
          var offset = scale.bandwidth() / 2;
          if (scale.round()) offset = Math.round(offset);
          return function(d) {
              return scale(d) + offset;
          };
      }
  
      function entering() {
          return !this.__axis;
      }
  
      function axis(orient, scale) {
          var tickArguments = [],
              tickValues = null,
              tickFormat = null,
              tickSizeInner = 6,
              tickSizeOuter = 6,
              tickPadding = 3,
              k = orient === top || orient === left ? -1 : 1,
              x, y = orient === left || orient === right ? (x = "x", "y") : (x = "y", "x"),
              transform = orient === top || orient === bottom ? translateX : translateY;
  
          function axis(context) {
              var values = tickValues == null ? (scale.ticks ? scale.ticks.apply(scale, tickArguments) : scale.domain()) : tickValues,
                  format = tickFormat == null ? (scale.tickFormat ? scale.tickFormat.apply(scale, tickArguments) : identity$1) : tickFormat,
                  spacing = Math.max(tickSizeInner, 0) + tickPadding,
                  range = scale.range(),
                  range0 = range[0] + 0.5,
                  range1 = range[range.length - 1] + 0.5,
                  position = (scale.bandwidth ? center : identity$1)(scale.copy()),
                  selection = context.selection ? context.selection() : context,
                  path = selection.selectAll(".domain").data([null]),
                  tick = selection.selectAll(".tick").data(values, scale).order(),
                  tickExit = tick.exit(),
                  tickEnter = tick.enter().append("g").attr("class", "tick"),
                  line = tick.select("line"),
                  text = tick.select("text");
  
              path = path.merge(path.enter().insert("path", ".tick")
                  .attr("class", "domain")
                  .attr("stroke", "#000"));
  
              tick = tick.merge(tickEnter);
  
              line = line.merge(tickEnter.append("line")
                  .attr("stroke", "#000")
                  .attr(x + "2", k * tickSizeInner)
                  .attr(y + "1", 0.5)
                  .attr(y + "2", 0.5));
  
              text = text.merge(tickEnter.append("text")
                  .attr("fill", "#000")
                  .attr(x, k * spacing)
                  .attr(y, 0.5)
                  .attr("dy", orient === top ? "0em" : orient === bottom ? "0.71em" : "0.32em"));
  
              if (context !== selection) {
                  path = path.transition(context);
                  tick = tick.transition(context);
                  line = line.transition(context);
                  text = text.transition(context);
  
                  tickExit = tickExit.transition(context)
                      .attr("opacity", epsilon)
                      .attr("transform", function(d) { return isFinite(d = position(d)) ? transform(d) : this.getAttribute("transform"); });
  
                  tickEnter
                      .attr("opacity", epsilon)
                      .attr("transform", function(d) { var p = this.parentNode.__axis; return transform(p && isFinite(p = p(d)) ? p : position(d)); });
              }
  
              tickExit.remove();
  
              path
                  .attr("d", orient === left || orient == right
                      ? "M" + k * tickSizeOuter + "," + range0 + "H0.5V" + range1 + "H" + k * tickSizeOuter
                      : "M" + range0 + "," + k * tickSizeOuter + "V0.5H" + range1 + "V" + k * tickSizeOuter);
  
              tick
                  .attr("opacity", 1)
                  .attr("transform", function(d) { return transform(position(d)); });
  
              line
                  .attr(x + "2", k * tickSizeInner);
  
              text
                  .attr(x, k * spacing)
                  .text(format);
  
              selection.filter(entering)
                  .attr("fill", "none")
                  .attr("font-size", 10)
                  .attr("font-family", "sans-serif")
                  .attr("text-anchor", orient === right ? "start" : orient === left ? "end" : "middle");
  
              selection
                  .each(function() { this.__axis = position; });
          }
  
          axis.scale = function(_) {
              return arguments.length ? (scale = _, axis) : scale;
          };
  
          axis.ticks = function() {
              return tickArguments = slice$1.call(arguments), axis;
          };
  
          axis.tickArguments = function(_) {
              return arguments.length ? (tickArguments = _ == null ? [] : slice$1.call(_), axis) : tickArguments.slice();
          };
  
          axis.tickValues = function(_) {
              return arguments.length ? (tickValues = _ == null ? null : slice$1.call(_), axis) : tickValues && tickValues.slice();
          };
  
          axis.tickFormat = function(_) {
              return arguments.length ? (tickFormat = _, axis) : tickFormat;
          };
  
          axis.tickSize = function(_) {
              return arguments.length ? (tickSizeInner = tickSizeOuter = +_, axis) : tickSizeInner;
          };
  
          axis.tickSizeInner = function(_) {
              return arguments.length ? (tickSizeInner = +_, axis) : tickSizeInner;
          };
  
          axis.tickSizeOuter = function(_) {
              return arguments.length ? (tickSizeOuter = +_, axis) : tickSizeOuter;
          };
  
          axis.tickPadding = function(_) {
              return arguments.length ? (tickPadding = +_, axis) : tickPadding;
          };
  
          return axis;
      }
  
      function axisTop(scale) {
          return axis(top, scale);
      }
  
      function axisRight(scale) {
          return axis(right, scale);
      }
  
      function axisBottom(scale) {
          return axis(bottom, scale);
      }
  
      function axisLeft(scale) {
          return axis(left, scale);
      }
  
      var noop = {value: function() {}};
  
      function dispatch() {
          for (var i = 0, n = arguments.length, _ = {}, t; i < n; ++i) {
              if (!(t = arguments[i] + "") || (t in _)) throw new Error("illegal type: " + t);
              _[t] = [];
          }
          return new Dispatch(_);
      }
  
      function Dispatch(_) {
          this._ = _;
      }
  
      function parseTypenames(typenames, types) {
          return typenames.trim().split(/^|\s+/).map(function(t) {
              var name = "", i = t.indexOf(".");
              if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
              if (t && !types.hasOwnProperty(t)) throw new Error("unknown type: " + t);
              return {type: t, name: name};
          });
      }
  
      Dispatch.prototype = dispatch.prototype = {
          constructor: Dispatch,
          on: function(typename, callback) {
              var _ = this._,
                  T = parseTypenames(typename + "", _),
                  t,
                  i = -1,
                  n = T.length;
  
              // If no callback was specified, return the callback of the given type and name.
              if (arguments.length < 2) {
                  while (++i < n) if ((t = (typename = T[i]).type) && (t = get(_[t], typename.name))) return t;
                  return;
              }
  
              // If a type was specified, set the callback for the given type and name.
              // Otherwise, if a null callback was specified, remove callbacks of the given name.
              if (callback != null && typeof callback !== "function") throw new Error("invalid callback: " + callback);
              while (++i < n) {
                  if (t = (typename = T[i]).type) _[t] = set(_[t], typename.name, callback);
                  else if (callback == null) for (t in _) _[t] = set(_[t], typename.name, null);
              }
  
              return this;
          },
          copy: function() {
              var copy = {}, _ = this._;
              for (var t in _) copy[t] = _[t].slice();
              return new Dispatch(copy);
          },
          call: function(type, that) {
              if ((n = arguments.length - 2) > 0) for (var args = new Array(n), i = 0, n, t; i < n; ++i) args[i] = arguments[i + 2];
              if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
              for (t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
          },
          apply: function(type, that, args) {
              if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
              for (var t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
          }
      };
  
      function get(type, name) {
          for (var i = 0, n = type.length, c; i < n; ++i) {
              if ((c = type[i]).name === name) {
                  return c.value;
              }
          }
      }
  
      function set(type, name, callback) {
          for (var i = 0, n = type.length; i < n; ++i) {
              if (type[i].name === name) {
                  type[i] = noop, type = type.slice(0, i).concat(type.slice(i + 1));
                  break;
              }
          }
          if (callback != null) type.push({name: name, value: callback});
          return type;
      }
  
      var xhtml = "http://www.w3.org/1999/xhtml";
  
      var namespaces = {
          svg: "http://www.w3.org/2000/svg",
          xhtml: xhtml,
          xlink: "http://www.w3.org/1999/xlink",
          xml: "http://www.w3.org/XML/1998/namespace",
          xmlns: "http://www.w3.org/2000/xmlns/"
      };
  
      var namespace = function(name) {
          var prefix = name += "", i = prefix.indexOf(":");
          if (i >= 0 && (prefix = name.slice(0, i)) !== "xmlns") name = name.slice(i + 1);
          return namespaces.hasOwnProperty(prefix) ? {space: namespaces[prefix], local: name} : name;
      };
  
      function creatorInherit(name) {
          return function() {
              var document = this.ownerDocument,
                  uri = this.namespaceURI;
              return uri === xhtml && document.documentElement.namespaceURI === xhtml
                  ? document.createElement(name)
                  : document.createElementNS(uri, name);
          };
      }
  
      function creatorFixed(fullname) {
          return function() {
              return this.ownerDocument.createElementNS(fullname.space, fullname.local);
          };
      }
  
      var creator = function(name) {
          var fullname = namespace(name);
          return (fullname.local
              ? creatorFixed
              : creatorInherit)(fullname);
      };
  
      var nextId = 0;
  
      function local$1() {
          return new Local;
      }
  
      function Local() {
          this._ = "@" + (++nextId).toString(36);
      }
  
      Local.prototype = local$1.prototype = {
          constructor: Local,
          get: function(node) {
              var id = this._;
              while (!(id in node)) if (!(node = node.parentNode)) return;
              return node[id];
          },
          set: function(node, value) {
              return node[this._] = value;
          },
          remove: function(node) {
              return this._ in node && delete node[this._];
          },
          toString: function() {
              return this._;
          }
      };
  
      var matcher = function(selector) {
          return function() {
              return this.matches(selector);
          };
      };
  
      if (typeof document !== "undefined") {
          var element = document.documentElement;
          if (!element.matches) {
              var vendorMatches = element.webkitMatchesSelector
                  || element.msMatchesSelector
                  || element.mozMatchesSelector
                  || element.oMatchesSelector;
              matcher = function(selector) {
                  return function() {
                      return vendorMatches.call(this, selector);
                  };
              };
          }
      }
  
      var matcher$1 = matcher;
  
      var filterEvents = {};
  
      exports.event = null;
  
      if (typeof document !== "undefined") {
          var element$1 = document.documentElement;
          if (!("onmouseenter" in element$1)) {
              filterEvents = {mouseenter: "mouseover", mouseleave: "mouseout"};
          }
      }
  
      function filterContextListener(listener, index, group) {
          listener = contextListener(listener, index, group);
          return function(event) {
              var related = event.relatedTarget;
              if (!related || (related !== this && !(related.compareDocumentPosition(this) & 8))) {
                  listener.call(this, event);
              }
          };
      }
  
      function contextListener(listener, index, group) {
          return function(event1) {
              var event0 = exports.event; // Events can be reentrant (e.g., focus).
              exports.event = event1;
              try {
                  listener.call(this, this.__data__, index, group);
              } finally {
                  exports.event = event0;
              }
          };
      }
  
      function parseTypenames$1(typenames) {
          return typenames.trim().split(/^|\s+/).map(function(t) {
              var name = "", i = t.indexOf(".");
              if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
              return {type: t, name: name};
          });
      }
  
      function onRemove(typename) {
          return function() {
              var on = this.__on;
              if (!on) return;
              for (var j = 0, i = -1, m = on.length, o; j < m; ++j) {
                  if (o = on[j], (!typename.type || o.type === typename.type) && o.name === typename.name) {
                      this.removeEventListener(o.type, o.listener, o.capture);
                  } else {
                      on[++i] = o;
                  }
              }
              if (++i) on.length = i;
              else delete this.__on;
          };
      }
  
      function onAdd(typename, value, capture) {
          var wrap = filterEvents.hasOwnProperty(typename.type) ? filterContextListener : contextListener;
          return function(d, i, group) {
              var on = this.__on, o, listener = wrap(value, i, group);
              if (on) for (var j = 0, m = on.length; j < m; ++j) {
                  if ((o = on[j]).type === typename.type && o.name === typename.name) {
                      this.removeEventListener(o.type, o.listener, o.capture);
                      this.addEventListener(o.type, o.listener = listener, o.capture = capture);
                      o.value = value;
                      return;
                  }
              }
              this.addEventListener(typename.type, listener, capture);
              o = {type: typename.type, name: typename.name, value: value, listener: listener, capture: capture};
              if (!on) this.__on = [o];
              else on.push(o);
          };
      }
  
      var selection_on = function(typename, value, capture) {
          var typenames = parseTypenames$1(typename + ""), i, n = typenames.length, t;
  
          if (arguments.length < 2) {
              var on = this.node().__on;
              if (on) for (var j = 0, m = on.length, o; j < m; ++j) {
                  for (i = 0, o = on[j]; i < n; ++i) {
                      if ((t = typenames[i]).type === o.type && t.name === o.name) {
                          return o.value;
                      }
                  }
              }
              return;
          }
  
          on = value ? onAdd : onRemove;
          if (capture == null) capture = false;
          for (i = 0; i < n; ++i) this.each(on(typenames[i], value, capture));
          return this;
      };
  
      function customEvent(event1, listener, that, args) {
          var event0 = exports.event;
          event1.sourceEvent = exports.event;
          exports.event = event1;
          try {
              return listener.apply(that, args);
          } finally {
              exports.event = event0;
          }
      }
  
      var sourceEvent = function() {
          var current = exports.event, source;
          while (source = current.sourceEvent) current = source;
          return current;
      };
  
      var point = function(node, event) {
          var svg = node.ownerSVGElement || node;
  
          if (svg.createSVGPoint) {
              var point = svg.createSVGPoint();
              point.x = event.clientX, point.y = event.clientY;
              point = point.matrixTransform(node.getScreenCTM().inverse());
              return [point.x, point.y];
          }
  
          var rect = node.getBoundingClientRect();
          return [event.clientX - rect.left - node.clientLeft, event.clientY - rect.top - node.clientTop];
      };
  
      var mouse = function(node) {
          var event = sourceEvent();
          if (event.changedTouches) event = event.changedTouches[0];
          return point(node, event);
      };
  
      function none() {}
  
      var selector = function(selector) {
          return selector == null ? none : function() {
              return this.querySelector(selector);
          };
      };
  
      var selection_select = function(select) {
          if (typeof select !== "function") select = selector(select);
  
          for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
                  if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
                      if ("__data__" in node) subnode.__data__ = node.__data__;
                      subgroup[i] = subnode;
                  }
              }
          }
  
          return new Selection(subgroups, this._parents);
      };
  
      function empty$1() {
          return [];
      }
  
      var selectorAll = function(selector) {
          return selector == null ? empty$1 : function() {
              return this.querySelectorAll(selector);
          };
      };
  
      var selection_selectAll = function(select) {
          if (typeof select !== "function") select = selectorAll(select);
  
          for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                  if (node = group[i]) {
                      subgroups.push(select.call(node, node.__data__, i, group));
                      parents.push(node);
                  }
              }
          }
  
          return new Selection(subgroups, parents);
      };
  
      var selection_filter = function(match) {
          if (typeof match !== "function") match = matcher$1(match);
  
          for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
                  if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
                      subgroup.push(node);
                  }
              }
          }
  
          return new Selection(subgroups, this._parents);
      };
  
      var sparse = function(update) {
          return new Array(update.length);
      };
  
      var selection_enter = function() {
          return new Selection(this._enter || this._groups.map(sparse), this._parents);
      };
  
      function EnterNode(parent, datum) {
          this.ownerDocument = parent.ownerDocument;
          this.namespaceURI = parent.namespaceURI;
          this._next = null;
          this._parent = parent;
          this.__data__ = datum;
      }
  
      EnterNode.prototype = {
          constructor: EnterNode,
          appendChild: function(child) { return this._parent.insertBefore(child, this._next); },
          insertBefore: function(child, next) { return this._parent.insertBefore(child, next); },
          querySelector: function(selector) { return this._parent.querySelector(selector); },
          querySelectorAll: function(selector) { return this._parent.querySelectorAll(selector); }
      };
  
      var constant$1 = function(x) {
          return function() {
              return x;
          };
      };
  
      var keyPrefix = "$"; // Protect against keys like “__proto__”.
  
      function bindIndex(parent, group, enter, update, exit, data) {
          var i = 0,
              node,
              groupLength = group.length,
              dataLength = data.length;
  
          // Put any non-null nodes that fit into update.
          // Put any null nodes into enter.
          // Put any remaining data into enter.
          for (; i < dataLength; ++i) {
              if (node = group[i]) {
                  node.__data__ = data[i];
                  update[i] = node;
              } else {
                  enter[i] = new EnterNode(parent, data[i]);
              }
          }
  
          // Put any non-null nodes that don’t fit into exit.
          for (; i < groupLength; ++i) {
              if (node = group[i]) {
                  exit[i] = node;
              }
          }
      }
  
      function bindKey(parent, group, enter, update, exit, data, key) {
          var i,
              node,
              nodeByKeyValue = {},
              groupLength = group.length,
              dataLength = data.length,
              keyValues = new Array(groupLength),
              keyValue;
  
          // Compute the key for each node.
          // If multiple nodes have the same key, the duplicates are added to exit.
          for (i = 0; i < groupLength; ++i) {
              if (node = group[i]) {
                  keyValues[i] = keyValue = keyPrefix + key.call(node, node.__data__, i, group);
                  if (keyValue in nodeByKeyValue) {
                      exit[i] = node;
                  } else {
                      nodeByKeyValue[keyValue] = node;
                  }
              }
          }
  
          // Compute the key for each datum.
          // If there a node associated with this key, join and add it to update.
          // If there is not (or the key is a duplicate), add it to enter.
          for (i = 0; i < dataLength; ++i) {
              keyValue = keyPrefix + key.call(parent, data[i], i, data);
              if (node = nodeByKeyValue[keyValue]) {
                  update[i] = node;
                  node.__data__ = data[i];
                  nodeByKeyValue[keyValue] = null;
              } else {
                  enter[i] = new EnterNode(parent, data[i]);
              }
          }
  
          // Add any remaining nodes that were not bound to data to exit.
          for (i = 0; i < groupLength; ++i) {
              if ((node = group[i]) && (nodeByKeyValue[keyValues[i]] === node)) {
                  exit[i] = node;
              }
          }
      }
  
      var selection_data = function(value, key) {
          if (!value) {
              data = new Array(this.size()), j = -1;
              this.each(function(d) { data[++j] = d; });
              return data;
          }
  
          var bind = key ? bindKey : bindIndex,
              parents = this._parents,
              groups = this._groups;
  
          if (typeof value !== "function") value = constant$1(value);
  
          for (var m = groups.length, update = new Array(m), enter = new Array(m), exit = new Array(m), j = 0; j < m; ++j) {
              var parent = parents[j],
                  group = groups[j],
                  groupLength = group.length,
                  data = value.call(parent, parent && parent.__data__, j, parents),
                  dataLength = data.length,
                  enterGroup = enter[j] = new Array(dataLength),
                  updateGroup = update[j] = new Array(dataLength),
                  exitGroup = exit[j] = new Array(groupLength);
  
              bind(parent, group, enterGroup, updateGroup, exitGroup, data, key);
  
              // Now connect the enter nodes to their following update node, such that
              // appendChild can insert the materialized enter node before this node,
              // rather than at the end of the parent node.
              for (var i0 = 0, i1 = 0, previous, next; i0 < dataLength; ++i0) {
                  if (previous = enterGroup[i0]) {
                      if (i0 >= i1) i1 = i0 + 1;
                      while (!(next = updateGroup[i1]) && ++i1 < dataLength);
                      previous._next = next || null;
                  }
              }
          }
  
          update = new Selection(update, parents);
          update._enter = enter;
          update._exit = exit;
          return update;
      };
  
      var selection_exit = function() {
          return new Selection(this._exit || this._groups.map(sparse), this._parents);
      };
  
      var selection_merge = function(selection) {
  
          for (var groups0 = this._groups, groups1 = selection._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
              for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
                  if (node = group0[i] || group1[i]) {
                      merge[i] = node;
                  }
              }
          }
  
          for (; j < m0; ++j) {
              merges[j] = groups0[j];
          }
  
          return new Selection(merges, this._parents);
      };
  
      var selection_order = function() {
  
          for (var groups = this._groups, j = -1, m = groups.length; ++j < m;) {
              for (var group = groups[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
                  if (node = group[i]) {
                      if (next && next !== node.nextSibling) next.parentNode.insertBefore(node, next);
                      next = node;
                  }
              }
          }
  
          return this;
      };
  
      var selection_sort = function(compare) {
          if (!compare) compare = ascending$1;
  
          function compareNode(a, b) {
              return a && b ? compare(a.__data__, b.__data__) : !a - !b;
          }
  
          for (var groups = this._groups, m = groups.length, sortgroups = new Array(m), j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, sortgroup = sortgroups[j] = new Array(n), node, i = 0; i < n; ++i) {
                  if (node = group[i]) {
                      sortgroup[i] = node;
                  }
              }
              sortgroup.sort(compareNode);
          }
  
          return new Selection(sortgroups, this._parents).order();
      };
  
      function ascending$1(a, b) {
          return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
      }
  
      var selection_call = function() {
          var callback = arguments[0];
          arguments[0] = this;
          callback.apply(null, arguments);
          return this;
      };
  
      var selection_nodes = function() {
          var nodes = new Array(this.size()), i = -1;
          this.each(function() { nodes[++i] = this; });
          return nodes;
      };
  
      var selection_node = function() {
  
          for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
              for (var group = groups[j], i = 0, n = group.length; i < n; ++i) {
                  var node = group[i];
                  if (node) return node;
              }
          }
  
          return null;
      };
  
      var selection_size = function() {
          var size = 0;
          this.each(function() { ++size; });
          return size;
      };
  
      var selection_empty = function() {
          return !this.node();
      };
  
      var selection_each = function(callback) {
  
          for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
              for (var group = groups[j], i = 0, n = group.length, node; i < n; ++i) {
                  if (node = group[i]) callback.call(node, node.__data__, i, group);
              }
          }
  
          return this;
      };
  
      function attrRemove(name) {
          return function() {
              this.removeAttribute(name);
          };
      }
  
      function attrRemoveNS(fullname) {
          return function() {
              this.removeAttributeNS(fullname.space, fullname.local);
          };
      }
  
      function attrConstant(name, value) {
          return function() {
              this.setAttribute(name, value);
          };
      }
  
      function attrConstantNS(fullname, value) {
          return function() {
              this.setAttributeNS(fullname.space, fullname.local, value);
          };
      }
  
      function attrFunction(name, value) {
          return function() {
              var v = value.apply(this, arguments);
              if (v == null) this.removeAttribute(name);
              else this.setAttribute(name, v);
          };
      }
  
      function attrFunctionNS(fullname, value) {
          return function() {
              var v = value.apply(this, arguments);
              if (v == null) this.removeAttributeNS(fullname.space, fullname.local);
              else this.setAttributeNS(fullname.space, fullname.local, v);
          };
      }
  
      var selection_attr = function(name, value) {
          var fullname = namespace(name);
  
          if (arguments.length < 2) {
              var node = this.node();
              return fullname.local
                  ? node.getAttributeNS(fullname.space, fullname.local)
                  : node.getAttribute(fullname);
          }
  
          return this.each((value == null
              ? (fullname.local ? attrRemoveNS : attrRemove) : (typeof value === "function"
                  ? (fullname.local ? attrFunctionNS : attrFunction)
                  : (fullname.local ? attrConstantNS : attrConstant)))(fullname, value));
      };
  
      var window = function(node) {
          return (node.ownerDocument && node.ownerDocument.defaultView) // node is a Node
              || (node.document && node) // node is a Window
              || node.defaultView; // node is a Document
      };
  
      function styleRemove(name) {
          return function() {
              this.style.removeProperty(name);
          };
      }
  
      function styleConstant(name, value, priority) {
          return function() {
              this.style.setProperty(name, value, priority);
          };
      }
  
      function styleFunction(name, value, priority) {
          return function() {
              var v = value.apply(this, arguments);
              if (v == null) this.style.removeProperty(name);
              else this.style.setProperty(name, v, priority);
          };
      }
  
      var selection_style = function(name, value, priority) {
          var node;
          return arguments.length > 1
              ? this.each((value == null
                  ? styleRemove : typeof value === "function"
                      ? styleFunction
                      : styleConstant)(name, value, priority == null ? "" : priority))
              : window(node = this.node())
                  .getComputedStyle(node, null)
                  .getPropertyValue(name);
      };
  
      function propertyRemove(name) {
          return function() {
              delete this[name];
          };
      }
  
      function propertyConstant(name, value) {
          return function() {
              this[name] = value;
          };
      }
  
      function propertyFunction(name, value) {
          return function() {
              var v = value.apply(this, arguments);
              if (v == null) delete this[name];
              else this[name] = v;
          };
      }
  
      var selection_property = function(name, value) {
          return arguments.length > 1
              ? this.each((value == null
                  ? propertyRemove : typeof value === "function"
                      ? propertyFunction
                      : propertyConstant)(name, value))
              : this.node()[name];
      };
  
      function classArray(string) {
          return string.trim().split(/^|\s+/);
      }
  
      function classList(node) {
          return node.classList || new ClassList(node);
      }
  
      function ClassList(node) {
          this._node = node;
          this._names = classArray(node.getAttribute("class") || "");
      }
  
      ClassList.prototype = {
          add: function(name) {
              var i = this._names.indexOf(name);
              if (i < 0) {
                  this._names.push(name);
                  this._node.setAttribute("class", this._names.join(" "));
              }
          },
          remove: function(name) {
              var i = this._names.indexOf(name);
              if (i >= 0) {
                  this._names.splice(i, 1);
                  this._node.setAttribute("class", this._names.join(" "));
              }
          },
          contains: function(name) {
              return this._names.indexOf(name) >= 0;
          }
      };
  
      function classedAdd(node, names) {
          var list = classList(node), i = -1, n = names.length;
          while (++i < n) list.add(names[i]);
      }
  
      function classedRemove(node, names) {
          var list = classList(node), i = -1, n = names.length;
          while (++i < n) list.remove(names[i]);
      }
  
      function classedTrue(names) {
          return function() {
              classedAdd(this, names);
          };
      }
  
      function classedFalse(names) {
          return function() {
              classedRemove(this, names);
          };
      }
  
      function classedFunction(names, value) {
          return function() {
              (value.apply(this, arguments) ? classedAdd : classedRemove)(this, names);
          };
      }
  
      var selection_classed = function(name, value) {
          var names = classArray(name + "");
  
          if (arguments.length < 2) {
              var list = classList(this.node()), i = -1, n = names.length;
              while (++i < n) if (!list.contains(names[i])) return false;
              return true;
          }
  
          return this.each((typeof value === "function"
              ? classedFunction : value
                  ? classedTrue
                  : classedFalse)(names, value));
      };
  
      function textRemove() {
          this.textContent = "";
      }
  
      function textConstant(value) {
          return function() {
              this.textContent = value;
          };
      }
  
      function textFunction(value) {
          return function() {
              var v = value.apply(this, arguments);
              this.textContent = v == null ? "" : v;
          };
      }
  
      var selection_text = function(value) {
          return arguments.length
              ? this.each(value == null
                  ? textRemove : (typeof value === "function"
                      ? textFunction
                      : textConstant)(value))
              : this.node().textContent;
      };
  
      function htmlRemove() {
          this.innerHTML = "";
      }
  
      function htmlConstant(value) {
          return function() {
              this.innerHTML = value;
          };
      }
  
      function htmlFunction(value) {
          return function() {
              var v = value.apply(this, arguments);
              this.innerHTML = v == null ? "" : v;
          };
      }
  
      var selection_html = function(value) {
          return arguments.length
              ? this.each(value == null
                  ? htmlRemove : (typeof value === "function"
                      ? htmlFunction
                      : htmlConstant)(value))
              : this.node().innerHTML;
      };
  
      function raise() {
          if (this.nextSibling) this.parentNode.appendChild(this);
      }
  
      var selection_raise = function() {
          return this.each(raise);
      };
  
      function lower() {
          if (this.previousSibling) this.parentNode.insertBefore(this, this.parentNode.firstChild);
      }
  
      var selection_lower = function() {
          return this.each(lower);
      };
  
      var selection_append = function(name) {
          var create = typeof name === "function" ? name : creator(name);
          return this.select(function() {
              return this.appendChild(create.apply(this, arguments));
          });
      };
  
      function constantNull() {
          return null;
      }
  
      var selection_insert = function(name, before) {
          var create = typeof name === "function" ? name : creator(name),
              select = before == null ? constantNull : typeof before === "function" ? before : selector(before);
          return this.select(function() {
              return this.insertBefore(create.apply(this, arguments), select.apply(this, arguments) || null);
          });
      };
  
      function remove() {
          var parent = this.parentNode;
          if (parent) parent.removeChild(this);
      }
  
      var selection_remove = function() {
          return this.each(remove);
      };
  
      var selection_datum = function(value) {
          return arguments.length
              ? this.property("__data__", value)
              : this.node().__data__;
      };
  
      function dispatchEvent(node, type, params) {
          var window$$1 = window(node),
              event = window$$1.CustomEvent;
  
          if (event) {
              event = new event(type, params);
          } else {
              event = window$$1.document.createEvent("Event");
              if (params) event.initEvent(type, params.bubbles, params.cancelable), event.detail = params.detail;
              else event.initEvent(type, false, false);
          }
  
          node.dispatchEvent(event);
      }
  
      function dispatchConstant(type, params) {
          return function() {
              return dispatchEvent(this, type, params);
          };
      }
  
      function dispatchFunction(type, params) {
          return function() {
              return dispatchEvent(this, type, params.apply(this, arguments));
          };
      }
  
      var selection_dispatch = function(type, params) {
          return this.each((typeof params === "function"
              ? dispatchFunction
              : dispatchConstant)(type, params));
      };
  
      var root = [null];
  
      function Selection(groups, parents) {
          this._groups = groups;
          this._parents = parents;
      }
  
      function selection() {
          return new Selection([[document.documentElement]], root);
      }
  
      Selection.prototype = selection.prototype = {
          constructor: Selection,
          select: selection_select,
          selectAll: selection_selectAll,
          filter: selection_filter,
          data: selection_data,
          enter: selection_enter,
          exit: selection_exit,
          merge: selection_merge,
          order: selection_order,
          sort: selection_sort,
          call: selection_call,
          nodes: selection_nodes,
          node: selection_node,
          size: selection_size,
          empty: selection_empty,
          each: selection_each,
          attr: selection_attr,
          style: selection_style,
          property: selection_property,
          classed: selection_classed,
          text: selection_text,
          html: selection_html,
          raise: selection_raise,
          lower: selection_lower,
          append: selection_append,
          insert: selection_insert,
          remove: selection_remove,
          datum: selection_datum,
          on: selection_on,
          dispatch: selection_dispatch
      };
  
      var select = function(selector) {
          return typeof selector === "string"
              ? new Selection([[document.querySelector(selector)]], [document.documentElement])
              : new Selection([[selector]], root);
      };
  
      var selectAll = function(selector) {
          return typeof selector === "string"
              ? new Selection([document.querySelectorAll(selector)], [document.documentElement])
              : new Selection([selector == null ? [] : selector], root);
      };
  
      var touch = function(node, touches, identifier) {
          if (arguments.length < 3) identifier = touches, touches = sourceEvent().changedTouches;
  
          for (var i = 0, n = touches ? touches.length : 0, touch; i < n; ++i) {
              if ((touch = touches[i]).identifier === identifier) {
                  return point(node, touch);
              }
          }
  
          return null;
      };
  
      var touches = function(node, touches) {
          if (touches == null) touches = sourceEvent().touches;
  
          for (var i = 0, n = touches ? touches.length : 0, points = new Array(n); i < n; ++i) {
              points[i] = point(node, touches[i]);
          }
  
          return points;
      };
  
      function nopropagation() {
          exports.event.stopImmediatePropagation();
      }
  
      var noevent = function() {
          exports.event.preventDefault();
          exports.event.stopImmediatePropagation();
      };
  
      var dragDisable = function(view) {
          var root = view.document.documentElement,
              selection$$1 = select(view).on("dragstart.drag", noevent, true);
          if ("onselectstart" in root) {
              selection$$1.on("selectstart.drag", noevent, true);
          } else {
              root.__noselect = root.style.MozUserSelect;
              root.style.MozUserSelect = "none";
          }
      };
  
      function yesdrag(view, noclick) {
          var root = view.document.documentElement,
              selection$$1 = select(view).on("dragstart.drag", null);
          if (noclick) {
              selection$$1.on("click.drag", noevent, true);
              setTimeout(function() { selection$$1.on("click.drag", null); }, 0);
          }
          if ("onselectstart" in root) {
              selection$$1.on("selectstart.drag", null);
          } else {
              root.style.MozUserSelect = root.__noselect;
              delete root.__noselect;
          }
      }
  
      var constant$2 = function(x) {
          return function() {
              return x;
          };
      };
  
      function DragEvent(target, type, subject, id, active, x, y, dx, dy, dispatch) {
          this.target = target;
          this.type = type;
          this.subject = subject;
          this.identifier = id;
          this.active = active;
          this.x = x;
          this.y = y;
          this.dx = dx;
          this.dy = dy;
          this._ = dispatch;
      }
  
      DragEvent.prototype.on = function() {
          var value = this._.on.apply(this._, arguments);
          return value === this._ ? this : value;
      };
  
  // Ignore right-click, since that should open the context menu.
      function defaultFilter$1() {
          return !exports.event.button;
      }
  
      function defaultContainer() {
          return this.parentNode;
      }
  
      function defaultSubject(d) {
          return d == null ? {x: exports.event.x, y: exports.event.y} : d;
      }
  
      var drag = function() {
          var filter = defaultFilter$1,
              container = defaultContainer,
              subject = defaultSubject,
              gestures = {},
              listeners = dispatch("start", "drag", "end"),
              active = 0,
              mousemoving,
              touchending;
  
          function drag(selection$$1) {
              selection$$1
                  .on("mousedown.drag", mousedowned)
                  .on("touchstart.drag", touchstarted)
                  .on("touchmove.drag", touchmoved)
                  .on("touchend.drag touchcancel.drag", touchended)
                  .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
          }
  
          function mousedowned() {
              if (touchending || !filter.apply(this, arguments)) return;
              var gesture = beforestart("mouse", container.apply(this, arguments), mouse, this, arguments);
              if (!gesture) return;
              select(exports.event.view).on("mousemove.drag", mousemoved, true).on("mouseup.drag", mouseupped, true);
              dragDisable(exports.event.view);
              nopropagation();
              mousemoving = false;
              gesture("start");
          }
  
          function mousemoved() {
              noevent();
              mousemoving = true;
              gestures.mouse("drag");
          }
  
          function mouseupped() {
              select(exports.event.view).on("mousemove.drag mouseup.drag", null);
              yesdrag(exports.event.view, mousemoving);
              noevent();
              gestures.mouse("end");
          }
  
          function touchstarted() {
              if (!filter.apply(this, arguments)) return;
              var touches$$1 = exports.event.changedTouches,
                  c = container.apply(this, arguments),
                  n = touches$$1.length, i, gesture;
  
              for (i = 0; i < n; ++i) {
                  if (gesture = beforestart(touches$$1[i].identifier, c, touch, this, arguments)) {
                      nopropagation();
                      gesture("start");
                  }
              }
          }
  
          function touchmoved() {
              var touches$$1 = exports.event.changedTouches,
                  n = touches$$1.length, i, gesture;
  
              for (i = 0; i < n; ++i) {
                  if (gesture = gestures[touches$$1[i].identifier]) {
                      noevent();
                      gesture("drag");
                  }
              }
          }
  
          function touchended() {
              var touches$$1 = exports.event.changedTouches,
                  n = touches$$1.length, i, gesture;
  
              if (touchending) clearTimeout(touchending);
              touchending = setTimeout(function() { touchending = null; }, 500); // Ghost clicks are delayed!
              for (i = 0; i < n; ++i) {
                  if (gesture = gestures[touches$$1[i].identifier]) {
                      nopropagation();
                      gesture("end");
                  }
              }
          }
  
          function beforestart(id, container, point, that, args) {
              var p = point(container, id), s, dx, dy,
                  sublisteners = listeners.copy();
  
              if (!customEvent(new DragEvent(drag, "beforestart", s, id, active, p[0], p[1], 0, 0, sublisteners), function() {
                      if ((exports.event.subject = s = subject.apply(that, args)) == null) return false;
                      dx = s.x - p[0] || 0;
                      dy = s.y - p[1] || 0;
                      return true;
                  })) return;
  
              return function gesture(type) {
                  var p0 = p, n;
                  switch (type) {
                      case "start": gestures[id] = gesture, n = active++; break;
                      case "end": delete gestures[id], --active; // nobreak
                      case "drag": p = point(container, id), n = active; break;
                  }
                  customEvent(new DragEvent(drag, type, s, id, n, p[0] + dx, p[1] + dy, p[0] - p0[0], p[1] - p0[1], sublisteners), sublisteners.apply, sublisteners, [type, that, args]);
              };
          }
  
          drag.filter = function(_) {
              return arguments.length ? (filter = typeof _ === "function" ? _ : constant$2(!!_), drag) : filter;
          };
  
          drag.container = function(_) {
              return arguments.length ? (container = typeof _ === "function" ? _ : constant$2(_), drag) : container;
          };
  
          drag.subject = function(_) {
              return arguments.length ? (subject = typeof _ === "function" ? _ : constant$2(_), drag) : subject;
          };
  
          drag.on = function() {
              var value = listeners.on.apply(listeners, arguments);
              return value === listeners ? drag : value;
          };
  
          return drag;
      };
  
      var define = function(constructor, factory, prototype) {
          constructor.prototype = factory.prototype = prototype;
          prototype.constructor = constructor;
      };
  
      function extend(parent, definition) {
          var prototype = Object.create(parent.prototype);
          for (var key in definition) prototype[key] = definition[key];
          return prototype;
      }
  
      function Color() {}
  
      var darker = 0.7;
      var brighter = 1 / darker;
  
      var reI = "\\s*([+-]?\\d+)\\s*";
      var reN = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)\\s*";
      var reP = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)%\\s*";
      var reHex3 = /^#([0-9a-f]{3})$/;
      var reHex6 = /^#([0-9a-f]{6})$/;
      var reRgbInteger = new RegExp("^rgb\\(" + [reI, reI, reI] + "\\)$");
      var reRgbPercent = new RegExp("^rgb\\(" + [reP, reP, reP] + "\\)$");
      var reRgbaInteger = new RegExp("^rgba\\(" + [reI, reI, reI, reN] + "\\)$");
      var reRgbaPercent = new RegExp("^rgba\\(" + [reP, reP, reP, reN] + "\\)$");
      var reHslPercent = new RegExp("^hsl\\(" + [reN, reP, reP] + "\\)$");
      var reHslaPercent = new RegExp("^hsla\\(" + [reN, reP, reP, reN] + "\\)$");
  
      var named = {
          aliceblue: 0xf0f8ff,
          antiquewhite: 0xfaebd7,
          aqua: 0x00ffff,
          aquamarine: 0x7fffd4,
          azure: 0xf0ffff,
          beige: 0xf5f5dc,
          bisque: 0xffe4c4,
          black: 0x000000,
          blanchedalmond: 0xffebcd,
          blue: 0x0000ff,
          blueviolet: 0x8a2be2,
          brown: 0xa52a2a,
          burlywood: 0xdeb887,
          cadetblue: 0x5f9ea0,
          chartreuse: 0x7fff00,
          chocolate: 0xd2691e,
          coral: 0xff7f50,
          cornflowerblue: 0x6495ed,
          cornsilk: 0xfff8dc,
          crimson: 0xdc143c,
          cyan: 0x00ffff,
          darkblue: 0x00008b,
          darkcyan: 0x008b8b,
          darkgoldenrod: 0xb8860b,
          darkgray: 0xa9a9a9,
          darkgreen: 0x006400,
          darkgrey: 0xa9a9a9,
          darkkhaki: 0xbdb76b,
          darkmagenta: 0x8b008b,
          darkolivegreen: 0x556b2f,
          darkorange: 0xff8c00,
          darkorchid: 0x9932cc,
          darkred: 0x8b0000,
          darksalmon: 0xe9967a,
          darkseagreen: 0x8fbc8f,
          darkslateblue: 0x483d8b,
          darkslategray: 0x2f4f4f,
          darkslategrey: 0x2f4f4f,
          darkturquoise: 0x00ced1,
          darkviolet: 0x9400d3,
          deeppink: 0xff1493,
          deepskyblue: 0x00bfff,
          dimgray: 0x696969,
          dimgrey: 0x696969,
          dodgerblue: 0x1e90ff,
          firebrick: 0xb22222,
          floralwhite: 0xfffaf0,
          forestgreen: 0x228b22,
          fuchsia: 0xff00ff,
          gainsboro: 0xdcdcdc,
          ghostwhite: 0xf8f8ff,
          gold: 0xffd700,
          goldenrod: 0xdaa520,
          gray: 0x808080,
          green: 0x008000,
          greenyellow: 0xadff2f,
          grey: 0x808080,
          honeydew: 0xf0fff0,
          hotpink: 0xff69b4,
          indianred: 0xcd5c5c,
          indigo: 0x4b0082,
          ivory: 0xfffff0,
          khaki: 0xf0e68c,
          lavender: 0xe6e6fa,
          lavenderblush: 0xfff0f5,
          lawngreen: 0x7cfc00,
          lemonchiffon: 0xfffacd,
          lightblue: 0xadd8e6,
          lightcoral: 0xf08080,
          lightcyan: 0xe0ffff,
          lightgoldenrodyellow: 0xfafad2,
          lightgray: 0xd3d3d3,
          lightgreen: 0x90ee90,
          lightgrey: 0xd3d3d3,
          lightpink: 0xffb6c1,
          lightsalmon: 0xffa07a,
          lightseagreen: 0x20b2aa,
          lightskyblue: 0x87cefa,
          lightslategray: 0x778899,
          lightslategrey: 0x778899,
          lightsteelblue: 0xb0c4de,
          lightyellow: 0xffffe0,
          lime: 0x00ff00,
          limegreen: 0x32cd32,
          linen: 0xfaf0e6,
          magenta: 0xff00ff,
          maroon: 0x800000,
          mediumaquamarine: 0x66cdaa,
          mediumblue: 0x0000cd,
          mediumorchid: 0xba55d3,
          mediumpurple: 0x9370db,
          mediumseagreen: 0x3cb371,
          mediumslateblue: 0x7b68ee,
          mediumspringgreen: 0x00fa9a,
          mediumturquoise: 0x48d1cc,
          mediumvioletred: 0xc71585,
          midnightblue: 0x191970,
          mintcream: 0xf5fffa,
          mistyrose: 0xffe4e1,
          moccasin: 0xffe4b5,
          navajowhite: 0xffdead,
          navy: 0x000080,
          oldlace: 0xfdf5e6,
          olive: 0x808000,
          olivedrab: 0x6b8e23,
          orange: 0xffa500,
          orangered: 0xff4500,
          orchid: 0xda70d6,
          palegoldenrod: 0xeee8aa,
          palegreen: 0x98fb98,
          paleturquoise: 0xafeeee,
          palevioletred: 0xdb7093,
          papayawhip: 0xffefd5,
          peachpuff: 0xffdab9,
          peru: 0xcd853f,
          pink: 0xffc0cb,
          plum: 0xdda0dd,
          powderblue: 0xb0e0e6,
          purple: 0x800080,
          rebeccapurple: 0x663399,
          red: 0xff0000,
          rosybrown: 0xbc8f8f,
          royalblue: 0x4169e1,
          saddlebrown: 0x8b4513,
          salmon: 0xfa8072,
          sandybrown: 0xf4a460,
          seagreen: 0x2e8b57,
          seashell: 0xfff5ee,
          sienna: 0xa0522d,
          silver: 0xc0c0c0,
          skyblue: 0x87ceeb,
          slateblue: 0x6a5acd,
          slategray: 0x708090,
          slategrey: 0x708090,
          snow: 0xfffafa,
          springgreen: 0x00ff7f,
          steelblue: 0x4682b4,
          tan: 0xd2b48c,
          teal: 0x008080,
          thistle: 0xd8bfd8,
          tomato: 0xff6347,
          turquoise: 0x40e0d0,
          violet: 0xee82ee,
          wheat: 0xf5deb3,
          white: 0xffffff,
          whitesmoke: 0xf5f5f5,
          yellow: 0xffff00,
          yellowgreen: 0x9acd32
      };
  
      define(Color, color, {
          displayable: function() {
              return this.rgb().displayable();
          },
          toString: function() {
              return this.rgb() + "";
          }
      });
  
      function color(format) {
          var m;
          format = (format + "").trim().toLowerCase();
          return (m = reHex3.exec(format)) ? (m = parseInt(m[1], 16), new Rgb((m >> 8 & 0xf) | (m >> 4 & 0x0f0), (m >> 4 & 0xf) | (m & 0xf0), ((m & 0xf) << 4) | (m & 0xf), 1)) // #f00
              : (m = reHex6.exec(format)) ? rgbn(parseInt(m[1], 16)) // #ff0000
                  : (m = reRgbInteger.exec(format)) ? new Rgb(m[1], m[2], m[3], 1) // rgb(255, 0, 0)
                      : (m = reRgbPercent.exec(format)) ? new Rgb(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, 1) // rgb(100%, 0%, 0%)
                          : (m = reRgbaInteger.exec(format)) ? rgba(m[1], m[2], m[3], m[4]) // rgba(255, 0, 0, 1)
                              : (m = reRgbaPercent.exec(format)) ? rgba(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, m[4]) // rgb(100%, 0%, 0%, 1)
                                  : (m = reHslPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, 1) // hsl(120, 50%, 50%)
                                      : (m = reHslaPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, m[4]) // hsla(120, 50%, 50%, 1)
                                          : named.hasOwnProperty(format) ? rgbn(named[format])
                                              : format === "transparent" ? new Rgb(NaN, NaN, NaN, 0)
                                                  : null;
      }
  
      function rgbn(n) {
          return new Rgb(n >> 16 & 0xff, n >> 8 & 0xff, n & 0xff, 1);
      }
  
      function rgba(r, g, b, a) {
          if (a <= 0) r = g = b = NaN;
          return new Rgb(r, g, b, a);
      }
  
      function rgbConvert(o) {
          if (!(o instanceof Color)) o = color(o);
          if (!o) return new Rgb;
          o = o.rgb();
          return new Rgb(o.r, o.g, o.b, o.opacity);
      }
  
      function rgb(r, g, b, opacity) {
          return arguments.length === 1 ? rgbConvert(r) : new Rgb(r, g, b, opacity == null ? 1 : opacity);
      }
  
      function Rgb(r, g, b, opacity) {
          this.r = +r;
          this.g = +g;
          this.b = +b;
          this.opacity = +opacity;
      }
  
      define(Rgb, rgb, extend(Color, {
          brighter: function(k) {
              k = k == null ? brighter : Math.pow(brighter, k);
              return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
          },
          darker: function(k) {
              k = k == null ? darker : Math.pow(darker, k);
              return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
          },
          rgb: function() {
              return this;
          },
          displayable: function() {
              return (0 <= this.r && this.r <= 255)
                  && (0 <= this.g && this.g <= 255)
                  && (0 <= this.b && this.b <= 255)
                  && (0 <= this.opacity && this.opacity <= 1);
          },
          toString: function() {
              var a = this.opacity; a = isNaN(a) ? 1 : Math.max(0, Math.min(1, a));
              return (a === 1 ? "rgb(" : "rgba(")
                  + Math.max(0, Math.min(255, Math.round(this.r) || 0)) + ", "
                  + Math.max(0, Math.min(255, Math.round(this.g) || 0)) + ", "
                  + Math.max(0, Math.min(255, Math.round(this.b) || 0))
                  + (a === 1 ? ")" : ", " + a + ")");
          }
      }));
  
      function hsla(h, s, l, a) {
          if (a <= 0) h = s = l = NaN;
          else if (l <= 0 || l >= 1) h = s = NaN;
          else if (s <= 0) h = NaN;
          return new Hsl(h, s, l, a);
      }
  
      function hslConvert(o) {
          if (o instanceof Hsl) return new Hsl(o.h, o.s, o.l, o.opacity);
          if (!(o instanceof Color)) o = color(o);
          if (!o) return new Hsl;
          if (o instanceof Hsl) return o;
          o = o.rgb();
          var r = o.r / 255,
              g = o.g / 255,
              b = o.b / 255,
              min = Math.min(r, g, b),
              max = Math.max(r, g, b),
              h = NaN,
              s = max - min,
              l = (max + min) / 2;
          if (s) {
              if (r === max) h = (g - b) / s + (g < b) * 6;
              else if (g === max) h = (b - r) / s + 2;
              else h = (r - g) / s + 4;
              s /= l < 0.5 ? max + min : 2 - max - min;
              h *= 60;
          } else {
              s = l > 0 && l < 1 ? 0 : h;
          }
          return new Hsl(h, s, l, o.opacity);
      }
  
      function hsl(h, s, l, opacity) {
          return arguments.length === 1 ? hslConvert(h) : new Hsl(h, s, l, opacity == null ? 1 : opacity);
      }
  
      function Hsl(h, s, l, opacity) {
          this.h = +h;
          this.s = +s;
          this.l = +l;
          this.opacity = +opacity;
      }
  
      define(Hsl, hsl, extend(Color, {
          brighter: function(k) {
              k = k == null ? brighter : Math.pow(brighter, k);
              return new Hsl(this.h, this.s, this.l * k, this.opacity);
          },
          darker: function(k) {
              k = k == null ? darker : Math.pow(darker, k);
              return new Hsl(this.h, this.s, this.l * k, this.opacity);
          },
          rgb: function() {
              var h = this.h % 360 + (this.h < 0) * 360,
                  s = isNaN(h) || isNaN(this.s) ? 0 : this.s,
                  l = this.l,
                  m2 = l + (l < 0.5 ? l : 1 - l) * s,
                  m1 = 2 * l - m2;
              return new Rgb(
                  hsl2rgb(h >= 240 ? h - 240 : h + 120, m1, m2),
                  hsl2rgb(h, m1, m2),
                  hsl2rgb(h < 120 ? h + 240 : h - 120, m1, m2),
                  this.opacity
              );
          },
          displayable: function() {
              return (0 <= this.s && this.s <= 1 || isNaN(this.s))
                  && (0 <= this.l && this.l <= 1)
                  && (0 <= this.opacity && this.opacity <= 1);
          }
      }));
  
      /* From FvD 13.37, CSS Color Module Level 3 */
      function hsl2rgb(h, m1, m2) {
          return (h < 60 ? m1 + (m2 - m1) * h / 60
                  : h < 180 ? m2
                      : h < 240 ? m1 + (m2 - m1) * (240 - h) / 60
                          : m1) * 255;
      }
  
      var deg2rad = Math.PI / 180;
      var rad2deg = 180 / Math.PI;
  
      var Kn = 18;
      var Xn = 0.950470;
      var Yn = 1;
      var Zn = 1.088830;
      var t0 = 4 / 29;
      var t1 = 6 / 29;
      var t2 = 3 * t1 * t1;
      var t3 = t1 * t1 * t1;
  
      function labConvert(o) {
          if (o instanceof Lab) return new Lab(o.l, o.a, o.b, o.opacity);
          if (o instanceof Hcl) {
              var h = o.h * deg2rad;
              return new Lab(o.l, Math.cos(h) * o.c, Math.sin(h) * o.c, o.opacity);
          }
          if (!(o instanceof Rgb)) o = rgbConvert(o);
          var b = rgb2xyz(o.r),
              a = rgb2xyz(o.g),
              l = rgb2xyz(o.b),
              x = xyz2lab((0.4124564 * b + 0.3575761 * a + 0.1804375 * l) / Xn),
              y = xyz2lab((0.2126729 * b + 0.7151522 * a + 0.0721750 * l) / Yn),
              z = xyz2lab((0.0193339 * b + 0.1191920 * a + 0.9503041 * l) / Zn);
          return new Lab(116 * y - 16, 500 * (x - y), 200 * (y - z), o.opacity);
      }
  
      function lab(l, a, b, opacity) {
          return arguments.length === 1 ? labConvert(l) : new Lab(l, a, b, opacity == null ? 1 : opacity);
      }
  
      function Lab(l, a, b, opacity) {
          this.l = +l;
          this.a = +a;
          this.b = +b;
          this.opacity = +opacity;
      }
  
      define(Lab, lab, extend(Color, {
          brighter: function(k) {
              return new Lab(this.l + Kn * (k == null ? 1 : k), this.a, this.b, this.opacity);
          },
          darker: function(k) {
              return new Lab(this.l - Kn * (k == null ? 1 : k), this.a, this.b, this.opacity);
          },
          rgb: function() {
              var y = (this.l + 16) / 116,
                  x = isNaN(this.a) ? y : y + this.a / 500,
                  z = isNaN(this.b) ? y : y - this.b / 200;
              y = Yn * lab2xyz(y);
              x = Xn * lab2xyz(x);
              z = Zn * lab2xyz(z);
              return new Rgb(
                  xyz2rgb( 3.2404542 * x - 1.5371385 * y - 0.4985314 * z), // D65 -> sRGB
                  xyz2rgb(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z),
                  xyz2rgb( 0.0556434 * x - 0.2040259 * y + 1.0572252 * z),
                  this.opacity
              );
          }
      }));
  
      function xyz2lab(t) {
          return t > t3 ? Math.pow(t, 1 / 3) : t / t2 + t0;
      }
  
      function lab2xyz(t) {
          return t > t1 ? t * t * t : t2 * (t - t0);
      }
  
      function xyz2rgb(x) {
          return 255 * (x <= 0.0031308 ? 12.92 * x : 1.055 * Math.pow(x, 1 / 2.4) - 0.055);
      }
  
      function rgb2xyz(x) {
          return (x /= 255) <= 0.04045 ? x / 12.92 : Math.pow((x + 0.055) / 1.055, 2.4);
      }
  
      function hclConvert(o) {
          if (o instanceof Hcl) return new Hcl(o.h, o.c, o.l, o.opacity);
          if (!(o instanceof Lab)) o = labConvert(o);
          var h = Math.atan2(o.b, o.a) * rad2deg;
          return new Hcl(h < 0 ? h + 360 : h, Math.sqrt(o.a * o.a + o.b * o.b), o.l, o.opacity);
      }
  
      function hcl(h, c, l, opacity) {
          return arguments.length === 1 ? hclConvert(h) : new Hcl(h, c, l, opacity == null ? 1 : opacity);
      }
  
      function Hcl(h, c, l, opacity) {
          this.h = +h;
          this.c = +c;
          this.l = +l;
          this.opacity = +opacity;
      }
  
      define(Hcl, hcl, extend(Color, {
          brighter: function(k) {
              return new Hcl(this.h, this.c, this.l + Kn * (k == null ? 1 : k), this.opacity);
          },
          darker: function(k) {
              return new Hcl(this.h, this.c, this.l - Kn * (k == null ? 1 : k), this.opacity);
          },
          rgb: function() {
              return labConvert(this).rgb();
          }
      }));
  
      var A = -0.14861;
      var B = +1.78277;
      var C = -0.29227;
      var D = -0.90649;
      var E = +1.97294;
      var ED = E * D;
      var EB = E * B;
      var BC_DA = B * C - D * A;
  
      function cubehelixConvert(o) {
          if (o instanceof Cubehelix) return new Cubehelix(o.h, o.s, o.l, o.opacity);
          if (!(o instanceof Rgb)) o = rgbConvert(o);
          var r = o.r / 255,
              g = o.g / 255,
              b = o.b / 255,
              l = (BC_DA * b + ED * r - EB * g) / (BC_DA + ED - EB),
              bl = b - l,
              k = (E * (g - l) - C * bl) / D,
              s = Math.sqrt(k * k + bl * bl) / (E * l * (1 - l)), // NaN if l=0 or l=1
              h = s ? Math.atan2(k, bl) * rad2deg - 120 : NaN;
          return new Cubehelix(h < 0 ? h + 360 : h, s, l, o.opacity);
      }
  
      function cubehelix(h, s, l, opacity) {
          return arguments.length === 1 ? cubehelixConvert(h) : new Cubehelix(h, s, l, opacity == null ? 1 : opacity);
      }
  
      function Cubehelix(h, s, l, opacity) {
          this.h = +h;
          this.s = +s;
          this.l = +l;
          this.opacity = +opacity;
      }
  
      define(Cubehelix, cubehelix, extend(Color, {
          brighter: function(k) {
              k = k == null ? brighter : Math.pow(brighter, k);
              return new Cubehelix(this.h, this.s, this.l * k, this.opacity);
          },
          darker: function(k) {
              k = k == null ? darker : Math.pow(darker, k);
              return new Cubehelix(this.h, this.s, this.l * k, this.opacity);
          },
          rgb: function() {
              var h = isNaN(this.h) ? 0 : (this.h + 120) * deg2rad,
                  l = +this.l,
                  a = isNaN(this.s) ? 0 : this.s * l * (1 - l),
                  cosh = Math.cos(h),
                  sinh = Math.sin(h);
              return new Rgb(
                  255 * (l + a * (A * cosh + B * sinh)),
                  255 * (l + a * (C * cosh + D * sinh)),
                  255 * (l + a * (E * cosh)),
                  this.opacity
              );
          }
      }));
  
      function basis(t1, v0, v1, v2, v3) {
          var t2 = t1 * t1, t3 = t2 * t1;
          return ((1 - 3 * t1 + 3 * t2 - t3) * v0
              + (4 - 6 * t2 + 3 * t3) * v1
              + (1 + 3 * t1 + 3 * t2 - 3 * t3) * v2
              + t3 * v3) / 6;
      }
  
      var basis$1 = function(values) {
          var n = values.length - 1;
          return function(t) {
              var i = t <= 0 ? (t = 0) : t >= 1 ? (t = 1, n - 1) : Math.floor(t * n),
                  v1 = values[i],
                  v2 = values[i + 1],
                  v0 = i > 0 ? values[i - 1] : 2 * v1 - v2,
                  v3 = i < n - 1 ? values[i + 2] : 2 * v2 - v1;
              return basis((t - i / n) * n, v0, v1, v2, v3);
          };
      };
  
      var basisClosed = function(values) {
          var n = values.length;
          return function(t) {
              var i = Math.floor(((t %= 1) < 0 ? ++t : t) * n),
                  v0 = values[(i + n - 1) % n],
                  v1 = values[i % n],
                  v2 = values[(i + 1) % n],
                  v3 = values[(i + 2) % n];
              return basis((t - i / n) * n, v0, v1, v2, v3);
          };
      };
  
      var constant$3 = function(x) {
          return function() {
              return x;
          };
      };
  
      function linear(a, d) {
          return function(t) {
              return a + t * d;
          };
      }
  
      function exponential(a, b, y) {
          return a = Math.pow(a, y), b = Math.pow(b, y) - a, y = 1 / y, function(t) {
              return Math.pow(a + t * b, y);
          };
      }
  
      function hue(a, b) {
          var d = b - a;
          return d ? linear(a, d > 180 || d < -180 ? d - 360 * Math.round(d / 360) : d) : constant$3(isNaN(a) ? b : a);
      }
  
      function gamma(y) {
          return (y = +y) === 1 ? nogamma : function(a, b) {
              return b - a ? exponential(a, b, y) : constant$3(isNaN(a) ? b : a);
          };
      }
  
      function nogamma(a, b) {
          var d = b - a;
          return d ? linear(a, d) : constant$3(isNaN(a) ? b : a);
      }
  
      var interpolateRgb = ((function rgbGamma(y) {
          var color$$1 = gamma(y);
  
          function rgb$$1(start, end) {
              var r = color$$1((start = rgb(start)).r, (end = rgb(end)).r),
                  g = color$$1(start.g, end.g),
                  b = color$$1(start.b, end.b),
                  opacity = nogamma(start.opacity, end.opacity);
              return function(t) {
                  start.r = r(t);
                  start.g = g(t);
                  start.b = b(t);
                  start.opacity = opacity(t);
                  return start + "";
              };
          }
  
          rgb$$1.gamma = rgbGamma;
  
          return rgb$$1;
      }))(1);
  
      function rgbSpline(spline) {
          return function(colors) {
              var n = colors.length,
                  r = new Array(n),
                  g = new Array(n),
                  b = new Array(n),
                  i, color$$1;
              for (i = 0; i < n; ++i) {
                  color$$1 = rgb(colors[i]);
                  r[i] = color$$1.r || 0;
                  g[i] = color$$1.g || 0;
                  b[i] = color$$1.b || 0;
              }
              r = spline(r);
              g = spline(g);
              b = spline(b);
              color$$1.opacity = 1;
              return function(t) {
                  color$$1.r = r(t);
                  color$$1.g = g(t);
                  color$$1.b = b(t);
                  return color$$1 + "";
              };
          };
      }
  
      var rgbBasis = rgbSpline(basis$1);
      var rgbBasisClosed = rgbSpline(basisClosed);
  
      var array$1 = function(a, b) {
          var nb = b ? b.length : 0,
              na = a ? Math.min(nb, a.length) : 0,
              x = new Array(nb),
              c = new Array(nb),
              i;
  
          for (i = 0; i < na; ++i) x[i] = interpolateValue(a[i], b[i]);
          for (; i < nb; ++i) c[i] = b[i];
  
          return function(t) {
              for (i = 0; i < na; ++i) c[i] = x[i](t);
              return c;
          };
      };
  
      var date = function(a, b) {
          var d = new Date;
          return a = +a, b -= a, function(t) {
              return d.setTime(a + b * t), d;
          };
      };
  
      var reinterpolate = function(a, b) {
          return a = +a, b -= a, function(t) {
              return a + b * t;
          };
      };
  
      var object = function(a, b) {
          var i = {},
              c = {},
              k;
  
          if (a === null || typeof a !== "object") a = {};
          if (b === null || typeof b !== "object") b = {};
  
          for (k in b) {
              if (k in a) {
                  i[k] = interpolateValue(a[k], b[k]);
              } else {
                  c[k] = b[k];
              }
          }
  
          return function(t) {
              for (k in i) c[k] = i[k](t);
              return c;
          };
      };
  
      var reA = /[-+]?(?:\d+\.?\d*|\.?\d+)(?:[eE][-+]?\d+)?/g;
      var reB = new RegExp(reA.source, "g");
  
      function zero(b) {
          return function() {
              return b;
          };
      }
  
      function one(b) {
          return function(t) {
              return b(t) + "";
          };
      }
  
      var interpolateString = function(a, b) {
          var bi = reA.lastIndex = reB.lastIndex = 0, // scan index for next number in b
              am, // current match in a
              bm, // current match in b
              bs, // string preceding current number in b, if any
              i = -1, // index in s
              s = [], // string constants and placeholders
              q = []; // number interpolators
  
          // Coerce inputs to strings.
          a = a + "", b = b + "";
  
          // Interpolate pairs of numbers in a & b.
          while ((am = reA.exec(a))
          && (bm = reB.exec(b))) {
              if ((bs = bm.index) > bi) { // a string precedes the next number in b
                  bs = b.slice(bi, bs);
                  if (s[i]) s[i] += bs; // coalesce with previous string
                  else s[++i] = bs;
              }
              if ((am = am[0]) === (bm = bm[0])) { // numbers in a & b match
                  if (s[i]) s[i] += bm; // coalesce with previous string
                  else s[++i] = bm;
              } else { // interpolate non-matching numbers
                  s[++i] = null;
                  q.push({i: i, x: reinterpolate(am, bm)});
              }
              bi = reB.lastIndex;
          }
  
          // Add remains of b.
          if (bi < b.length) {
              bs = b.slice(bi);
              if (s[i]) s[i] += bs; // coalesce with previous string
              else s[++i] = bs;
          }
  
          // Special optimization for only a single match.
          // Otherwise, interpolate each of the numbers and rejoin the string.
          return s.length < 2 ? (q[0]
              ? one(q[0].x)
              : zero(b))
              : (b = q.length, function(t) {
                  for (var i = 0, o; i < b; ++i) s[(o = q[i]).i] = o.x(t);
                  return s.join("");
              });
      };
  
      var interpolateValue = function(a, b) {
          var t = typeof b, c;
          return b == null || t === "boolean" ? constant$3(b)
              : (t === "number" ? reinterpolate
                  : t === "string" ? ((c = color(b)) ? (b = c, interpolateRgb) : interpolateString)
                      : b instanceof color ? interpolateRgb
                          : b instanceof Date ? date
                              : Array.isArray(b) ? array$1
                                  : isNaN(b) ? object
                                      : reinterpolate)(a, b);
      };
  
      var interpolateRound = function(a, b) {
          return a = +a, b -= a, function(t) {
              return Math.round(a + b * t);
          };
      };
  
      var degrees = 180 / Math.PI;
  
      var identity$2 = {
          translateX: 0,
          translateY: 0,
          rotate: 0,
          skewX: 0,
          scaleX: 1,
          scaleY: 1
      };
  
      var decompose = function(a, b, c, d, e, f) {
          var scaleX, scaleY, skewX;
          if (scaleX = Math.sqrt(a * a + b * b)) a /= scaleX, b /= scaleX;
          if (skewX = a * c + b * d) c -= a * skewX, d -= b * skewX;
          if (scaleY = Math.sqrt(c * c + d * d)) c /= scaleY, d /= scaleY, skewX /= scaleY;
          if (a * d < b * c) a = -a, b = -b, skewX = -skewX, scaleX = -scaleX;
          return {
              translateX: e,
              translateY: f,
              rotate: Math.atan2(b, a) * degrees,
              skewX: Math.atan(skewX) * degrees,
              scaleX: scaleX,
              scaleY: scaleY
          };
      };
  
      var cssNode;
      var cssRoot;
      var cssView;
      var svgNode;
  
      function parseCss(value) {
          if (value === "none") return identity$2;
          if (!cssNode) cssNode = document.createElement("DIV"), cssRoot = document.documentElement, cssView = document.defaultView;
          cssNode.style.transform = value;
          value = cssView.getComputedStyle(cssRoot.appendChild(cssNode), null).getPropertyValue("transform");
          cssRoot.removeChild(cssNode);
          value = value.slice(7, -1).split(",");
          return decompose(+value[0], +value[1], +value[2], +value[3], +value[4], +value[5]);
      }
  
      function parseSvg(value) {
          if (value == null) return identity$2;
          if (!svgNode) svgNode = document.createElementNS("http://www.w3.org/2000/svg", "g");
          svgNode.setAttribute("transform", value);
          if (!(value = svgNode.transform.baseVal.consolidate())) return identity$2;
          value = value.matrix;
          return decompose(value.a, value.b, value.c, value.d, value.e, value.f);
      }
  
      function interpolateTransform(parse, pxComma, pxParen, degParen) {
  
          function pop(s) {
              return s.length ? s.pop() + " " : "";
          }
  
          function translate(xa, ya, xb, yb, s, q) {
              if (xa !== xb || ya !== yb) {
                  var i = s.push("translate(", null, pxComma, null, pxParen);
                  q.push({i: i - 4, x: reinterpolate(xa, xb)}, {i: i - 2, x: reinterpolate(ya, yb)});
              } else if (xb || yb) {
                  s.push("translate(" + xb + pxComma + yb + pxParen);
              }
          }
  
          function rotate(a, b, s, q) {
              if (a !== b) {
                  if (a - b > 180) b += 360; else if (b - a > 180) a += 360; // shortest path
                  q.push({i: s.push(pop(s) + "rotate(", null, degParen) - 2, x: reinterpolate(a, b)});
              } else if (b) {
                  s.push(pop(s) + "rotate(" + b + degParen);
              }
          }
  
          function skewX(a, b, s, q) {
              if (a !== b) {
                  q.push({i: s.push(pop(s) + "skewX(", null, degParen) - 2, x: reinterpolate(a, b)});
              } else if (b) {
                  s.push(pop(s) + "skewX(" + b + degParen);
              }
          }
  
          function scale(xa, ya, xb, yb, s, q) {
              if (xa !== xb || ya !== yb) {
                  var i = s.push(pop(s) + "scale(", null, ",", null, ")");
                  q.push({i: i - 4, x: reinterpolate(xa, xb)}, {i: i - 2, x: reinterpolate(ya, yb)});
              } else if (xb !== 1 || yb !== 1) {
                  s.push(pop(s) + "scale(" + xb + "," + yb + ")");
              }
          }
  
          return function(a, b) {
              var s = [], // string constants and placeholders
                  q = []; // number interpolators
              a = parse(a), b = parse(b);
              translate(a.translateX, a.translateY, b.translateX, b.translateY, s, q);
              rotate(a.rotate, b.rotate, s, q);
              skewX(a.skewX, b.skewX, s, q);
              scale(a.scaleX, a.scaleY, b.scaleX, b.scaleY, s, q);
              a = b = null; // gc
              return function(t) {
                  var i = -1, n = q.length, o;
                  while (++i < n) s[(o = q[i]).i] = o.x(t);
                  return s.join("");
              };
          };
      }
  
      var interpolateTransformCss = interpolateTransform(parseCss, "px, ", "px)", "deg)");
      var interpolateTransformSvg = interpolateTransform(parseSvg, ", ", ")", ")");
  
      var rho = Math.SQRT2;
      var rho2 = 2;
      var rho4 = 4;
      var epsilon2 = 1e-12;
  
      function cosh(x) {
          return ((x = Math.exp(x)) + 1 / x) / 2;
      }
  
      function sinh(x) {
          return ((x = Math.exp(x)) - 1 / x) / 2;
      }
  
      function tanh(x) {
          return ((x = Math.exp(2 * x)) - 1) / (x + 1);
      }
  
  // p0 = [ux0, uy0, w0]
  // p1 = [ux1, uy1, w1]
      var interpolateZoom = function(p0, p1) {
          var ux0 = p0[0], uy0 = p0[1], w0 = p0[2],
              ux1 = p1[0], uy1 = p1[1], w1 = p1[2],
              dx = ux1 - ux0,
              dy = uy1 - uy0,
              d2 = dx * dx + dy * dy,
              i,
              S;
  
          // Special case for u0 ≅ u1.
          if (d2 < epsilon2) {
              S = Math.log(w1 / w0) / rho;
              i = function(t) {
                  return [
                      ux0 + t * dx,
                      uy0 + t * dy,
                      w0 * Math.exp(rho * t * S)
                  ];
              };
          }
  
          // General case.
          else {
              var d1 = Math.sqrt(d2),
                  b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2 * w0 * rho2 * d1),
                  b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2 * w1 * rho2 * d1),
                  r0 = Math.log(Math.sqrt(b0 * b0 + 1) - b0),
                  r1 = Math.log(Math.sqrt(b1 * b1 + 1) - b1);
              S = (r1 - r0) / rho;
              i = function(t) {
                  var s = t * S,
                      coshr0 = cosh(r0),
                      u = w0 / (rho2 * d1) * (coshr0 * tanh(rho * s + r0) - sinh(r0));
                  return [
                      ux0 + u * dx,
                      uy0 + u * dy,
                      w0 * coshr0 / cosh(rho * s + r0)
                  ];
              };
          }
  
          i.duration = S * 1000;
  
          return i;
      };
  
      function hsl$1(hue$$1) {
          return function(start, end) {
              var h = hue$$1((start = hsl(start)).h, (end = hsl(end)).h),
                  s = nogamma(start.s, end.s),
                  l = nogamma(start.l, end.l),
                  opacity = nogamma(start.opacity, end.opacity);
              return function(t) {
                  start.h = h(t);
                  start.s = s(t);
                  start.l = l(t);
                  start.opacity = opacity(t);
                  return start + "";
              };
          }
      }
  
      var hsl$2 = hsl$1(hue);
      var hslLong = hsl$1(nogamma);
  
      function lab$1(start, end) {
          var l = nogamma((start = lab(start)).l, (end = lab(end)).l),
              a = nogamma(start.a, end.a),
              b = nogamma(start.b, end.b),
              opacity = nogamma(start.opacity, end.opacity);
          return function(t) {
              start.l = l(t);
              start.a = a(t);
              start.b = b(t);
              start.opacity = opacity(t);
              return start + "";
          };
      }
  
      function hcl$1(hue$$1) {
          return function(start, end) {
              var h = hue$$1((start = hcl(start)).h, (end = hcl(end)).h),
                  c = nogamma(start.c, end.c),
                  l = nogamma(start.l, end.l),
                  opacity = nogamma(start.opacity, end.opacity);
              return function(t) {
                  start.h = h(t);
                  start.c = c(t);
                  start.l = l(t);
                  start.opacity = opacity(t);
                  return start + "";
              };
          }
      }
  
      var hcl$2 = hcl$1(hue);
      var hclLong = hcl$1(nogamma);
  
      function cubehelix$1(hue$$1) {
          return (function cubehelixGamma(y) {
              y = +y;
  
              function cubehelix$$1(start, end) {
                  var h = hue$$1((start = cubehelix(start)).h, (end = cubehelix(end)).h),
                      s = nogamma(start.s, end.s),
                      l = nogamma(start.l, end.l),
                      opacity = nogamma(start.opacity, end.opacity);
                  return function(t) {
                      start.h = h(t);
                      start.s = s(t);
                      start.l = l(Math.pow(t, y));
                      start.opacity = opacity(t);
                      return start + "";
                  };
              }
  
              cubehelix$$1.gamma = cubehelixGamma;
  
              return cubehelix$$1;
          })(1);
      }
  
      var cubehelix$2 = cubehelix$1(hue);
      var cubehelixLong = cubehelix$1(nogamma);
  
      var quantize = function(interpolator, n) {
          var samples = new Array(n);
          for (var i = 0; i < n; ++i) samples[i] = interpolator(i / (n - 1));
          return samples;
      };
  
      var frame = 0;
      var timeout = 0;
      var interval = 0;
      var pokeDelay = 1000;
      var taskHead;
      var taskTail;
      var clockLast = 0;
      var clockNow = 0;
      var clockSkew = 0;
      var clock = typeof performance === "object" && performance.now ? performance : Date;
      var setFrame = typeof requestAnimationFrame === "function" ? requestAnimationFrame : function(f) { setTimeout(f, 17); };
  
      function now() {
          return clockNow || (setFrame(clearNow), clockNow = clock.now() + clockSkew);
      }
  
      function clearNow() {
          clockNow = 0;
      }
  
      function Timer() {
          this._call =
              this._time =
                  this._next = null;
      }
  
      Timer.prototype = timer.prototype = {
          constructor: Timer,
          restart: function(callback, delay, time) {
              if (typeof callback !== "function") throw new TypeError("callback is not a function");
              time = (time == null ? now() : +time) + (delay == null ? 0 : +delay);
              if (!this._next && taskTail !== this) {
                  if (taskTail) taskTail._next = this;
                  else taskHead = this;
                  taskTail = this;
              }
              this._call = callback;
              this._time = time;
              sleep();
          },
          stop: function() {
              if (this._call) {
                  this._call = null;
                  this._time = Infinity;
                  sleep();
              }
          }
      };
  
      function timer(callback, delay, time) {
          var t = new Timer;
          t.restart(callback, delay, time);
          return t;
      }
  
      function timerFlush() {
          now(); // Get the current time, if not already set.
          ++frame; // Pretend we’ve set an alarm, if we haven’t already.
          var t = taskHead, e;
          while (t) {
              if ((e = clockNow - t._time) >= 0) t._call.call(null, e);
              t = t._next;
          }
          --frame;
      }
  
      function wake() {
          clockNow = (clockLast = clock.now()) + clockSkew;
          frame = timeout = 0;
          try {
              timerFlush();
          } finally {
              frame = 0;
              nap();
              clockNow = 0;
          }
      }
  
      function poke() {
          var now = clock.now(), delay = now - clockLast;
          if (delay > pokeDelay) clockSkew -= delay, clockLast = now;
      }
  
      function nap() {
          var t0, t1 = taskHead, t2, time = Infinity;
          while (t1) {
              if (t1._call) {
                  if (time > t1._time) time = t1._time;
                  t0 = t1, t1 = t1._next;
              } else {
                  t2 = t1._next, t1._next = null;
                  t1 = t0 ? t0._next = t2 : taskHead = t2;
              }
          }
          taskTail = t0;
          sleep(time);
      }
  
      function sleep(time) {
          if (frame) return; // Soonest alarm already set, or will be.
          if (timeout) timeout = clearTimeout(timeout);
          var delay = time - clockNow;
          if (delay > 24) {
              if (time < Infinity) timeout = setTimeout(wake, delay);
              if (interval) interval = clearInterval(interval);
          } else {
              if (!interval) clockLast = clockNow, interval = setInterval(poke, pokeDelay);
              frame = 1, setFrame(wake);
          }
      }
  
      var timeout$1 = function(callback, delay, time) {
          var t = new Timer;
          delay = delay == null ? 0 : +delay;
          t.restart(function(elapsed) {
              t.stop();
              callback(elapsed + delay);
          }, delay, time);
          return t;
      };
  
      var interval$1 = function(callback, delay, time) {
          var t = new Timer, total = delay;
          if (delay == null) return t.restart(callback, delay, time), t;
          delay = +delay, time = time == null ? now() : +time;
          t.restart(function tick(elapsed) {
              elapsed += total;
              t.restart(tick, total += delay, time);
              callback(elapsed);
          }, delay, time);
          return t;
      };
  
      var emptyOn = dispatch("start", "end", "interrupt");
      var emptyTween = [];
  
      var CREATED = 0;
      var SCHEDULED = 1;
      var STARTING = 2;
      var STARTED = 3;
      var RUNNING = 4;
      var ENDING = 5;
      var ENDED = 6;
  
      var schedule = function(node, name, id, index, group, timing) {
          var schedules = node.__transition;
          if (!schedules) node.__transition = {};
          else if (id in schedules) return;
          create(node, id, {
              name: name,
              index: index, // For context during callback.
              group: group, // For context during callback.
              on: emptyOn,
              tween: emptyTween,
              time: timing.time,
              delay: timing.delay,
              duration: timing.duration,
              ease: timing.ease,
              timer: null,
              state: CREATED
          });
      };
  
      function init(node, id) {
          var schedule = node.__transition;
          if (!schedule || !(schedule = schedule[id]) || schedule.state > CREATED) throw new Error("too late");
          return schedule;
      }
  
      function set$1(node, id) {
          var schedule = node.__transition;
          if (!schedule || !(schedule = schedule[id]) || schedule.state > STARTING) throw new Error("too late");
          return schedule;
      }
  
      function get$1(node, id) {
          var schedule = node.__transition;
          if (!schedule || !(schedule = schedule[id])) throw new Error("too late");
          return schedule;
      }
  
      function create(node, id, self) {
          var schedules = node.__transition,
              tween;
  
          // Initialize the self timer when the transition is created.
          // Note the actual delay is not known until the first callback!
          schedules[id] = self;
          self.timer = timer(schedule, 0, self.time);
  
          function schedule(elapsed) {
              self.state = SCHEDULED;
              self.timer.restart(start, self.delay, self.time);
  
              // If the elapsed delay is less than our first sleep, start immediately.
              if (self.delay <= elapsed) start(elapsed - self.delay);
          }
  
          function start(elapsed) {
              var i, j, n, o;
  
              // If the state is not SCHEDULED, then we previously errored on start.
              if (self.state !== SCHEDULED) return stop();
  
              for (i in schedules) {
                  o = schedules[i];
                  if (o.name !== self.name) continue;
  
                  // While this element already has a starting transition during this frame,
                  // defer starting an interrupting transition until that transition has a
                  // chance to tick (and possibly end); see d3/d3-transition#54!
                  if (o.state === STARTED) return timeout$1(start);
  
                  // Interrupt the active transition, if any.
                  // Dispatch the interrupt event.
                  if (o.state === RUNNING) {
                      o.state = ENDED;
                      o.timer.stop();
                      o.on.call("interrupt", node, node.__data__, o.index, o.group);
                      delete schedules[i];
                  }
  
                  // Cancel any pre-empted transitions. No interrupt event is dispatched
                  // because the cancelled transitions never started. Note that this also
                  // removes this transition from the pending list!
                  else if (+i < id) {
                      o.state = ENDED;
                      o.timer.stop();
                      delete schedules[i];
                  }
              }
  
              // Defer the first tick to end of the current frame; see d3/d3#1576.
              // Note the transition may be canceled after start and before the first tick!
              // Note this must be scheduled before the start event; see d3/d3-transition#16!
              // Assuming this is successful, subsequent callbacks go straight to tick.
              timeout$1(function() {
                  if (self.state === STARTED) {
                      self.state = RUNNING;
                      self.timer.restart(tick, self.delay, self.time);
                      tick(elapsed);
                  }
              });
  
              // Dispatch the start event.
              // Note this must be done before the tween are initialized.
              self.state = STARTING;
              self.on.call("start", node, node.__data__, self.index, self.group);
              if (self.state !== STARTING) return; // interrupted
              self.state = STARTED;
  
              // Initialize the tween, deleting null tween.
              tween = new Array(n = self.tween.length);
              for (i = 0, j = -1; i < n; ++i) {
                  if (o = self.tween[i].value.call(node, node.__data__, self.index, self.group)) {
                      tween[++j] = o;
                  }
              }
              tween.length = j + 1;
          }
  
          function tick(elapsed) {
              var t = elapsed < self.duration ? self.ease.call(null, elapsed / self.duration) : (self.timer.restart(stop), self.state = ENDING, 1),
                  i = -1,
                  n = tween.length;
  
              while (++i < n) {
                  tween[i].call(null, t);
              }
  
              // Dispatch the end event.
              if (self.state === ENDING) {
                  self.on.call("end", node, node.__data__, self.index, self.group);
                  stop();
              }
          }
  
          function stop() {
              self.state = ENDED;
              self.timer.stop();
              delete schedules[id];
              for (var i in schedules) return; // eslint-disable-line no-unused-vars
              delete node.__transition;
          }
      }
  
      var interrupt = function(node, name) {
          var schedules = node.__transition,
              schedule,
              active,
              empty = true,
              i;
  
          if (!schedules) return;
  
          name = name == null ? null : name + "";
  
          for (i in schedules) {
              if ((schedule = schedules[i]).name !== name) { empty = false; continue; }
              active = schedule.state > STARTING && schedule.state < ENDING;
              schedule.state = ENDED;
              schedule.timer.stop();
              if (active) schedule.on.call("interrupt", node, node.__data__, schedule.index, schedule.group);
              delete schedules[i];
          }
  
          if (empty) delete node.__transition;
      };
  
      var selection_interrupt = function(name) {
          return this.each(function() {
              interrupt(this, name);
          });
      };
  
      function tweenRemove(id, name) {
          var tween0, tween1;
          return function() {
              var schedule = set$1(this, id),
                  tween = schedule.tween;
  
              // If this node shared tween with the previous node,
              // just assign the updated shared tween and we’re done!
              // Otherwise, copy-on-write.
              if (tween !== tween0) {
                  tween1 = tween0 = tween;
                  for (var i = 0, n = tween1.length; i < n; ++i) {
                      if (tween1[i].name === name) {
                          tween1 = tween1.slice();
                          tween1.splice(i, 1);
                          break;
                      }
                  }
              }
  
              schedule.tween = tween1;
          };
      }
  
      function tweenFunction(id, name, value) {
          var tween0, tween1;
          if (typeof value !== "function") throw new Error;
          return function() {
              var schedule = set$1(this, id),
                  tween = schedule.tween;
  
              // If this node shared tween with the previous node,
              // just assign the updated shared tween and we’re done!
              // Otherwise, copy-on-write.
              if (tween !== tween0) {
                  tween1 = (tween0 = tween).slice();
                  for (var t = {name: name, value: value}, i = 0, n = tween1.length; i < n; ++i) {
                      if (tween1[i].name === name) {
                          tween1[i] = t;
                          break;
                      }
                  }
                  if (i === n) tween1.push(t);
              }
  
              schedule.tween = tween1;
          };
      }
  
      var transition_tween = function(name, value) {
          var id = this._id;
  
          name += "";
  
          if (arguments.length < 2) {
              var tween = get$1(this.node(), id).tween;
              for (var i = 0, n = tween.length, t; i < n; ++i) {
                  if ((t = tween[i]).name === name) {
                      return t.value;
                  }
              }
              return null;
          }
  
          return this.each((value == null ? tweenRemove : tweenFunction)(id, name, value));
      };
  
      function tweenValue(transition, name, value) {
          var id = transition._id;
  
          transition.each(function() {
              var schedule = set$1(this, id);
              (schedule.value || (schedule.value = {}))[name] = value.apply(this, arguments);
          });
  
          return function(node) {
              return get$1(node, id).value[name];
          };
      }
  
      var interpolate$$1 = function(a, b) {
          var c;
          return (typeof b === "number" ? reinterpolate
              : b instanceof color ? interpolateRgb
                  : (c = color(b)) ? (b = c, interpolateRgb)
                      : interpolateString)(a, b);
      };
  
      function attrRemove$1(name) {
          return function() {
              this.removeAttribute(name);
          };
      }
  
      function attrRemoveNS$1(fullname) {
          return function() {
              this.removeAttributeNS(fullname.space, fullname.local);
          };
      }
  
      function attrConstant$1(name, interpolate$$1, value1) {
          var value00,
              interpolate0;
          return function() {
              var value0 = this.getAttribute(name);
              return value0 === value1 ? null
                  : value0 === value00 ? interpolate0
                      : interpolate0 = interpolate$$1(value00 = value0, value1);
          };
      }
  
      function attrConstantNS$1(fullname, interpolate$$1, value1) {
          var value00,
              interpolate0;
          return function() {
              var value0 = this.getAttributeNS(fullname.space, fullname.local);
              return value0 === value1 ? null
                  : value0 === value00 ? interpolate0
                      : interpolate0 = interpolate$$1(value00 = value0, value1);
          };
      }
  
      function attrFunction$1(name, interpolate$$1, value) {
          var value00,
              value10,
              interpolate0;
          return function() {
              var value0, value1 = value(this);
              if (value1 == null) return void this.removeAttribute(name);
              value0 = this.getAttribute(name);
              return value0 === value1 ? null
                  : value0 === value00 && value1 === value10 ? interpolate0
                      : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
          };
      }
  
      function attrFunctionNS$1(fullname, interpolate$$1, value) {
          var value00,
              value10,
              interpolate0;
          return function() {
              var value0, value1 = value(this);
              if (value1 == null) return void this.removeAttributeNS(fullname.space, fullname.local);
              value0 = this.getAttributeNS(fullname.space, fullname.local);
              return value0 === value1 ? null
                  : value0 === value00 && value1 === value10 ? interpolate0
                      : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
          };
      }
  
      var transition_attr = function(name, value) {
          var fullname = namespace(name), i = fullname === "transform" ? interpolateTransformSvg : interpolate$$1;
          return this.attrTween(name, typeof value === "function"
              ? (fullname.local ? attrFunctionNS$1 : attrFunction$1)(fullname, i, tweenValue(this, "attr." + name, value))
              : value == null ? (fullname.local ? attrRemoveNS$1 : attrRemove$1)(fullname)
                  : (fullname.local ? attrConstantNS$1 : attrConstant$1)(fullname, i, value + ""));
      };
  
      function attrTweenNS(fullname, value) {
          function tween() {
              var node = this, i = value.apply(node, arguments);
              return i && function(t) {
                      node.setAttributeNS(fullname.space, fullname.local, i(t));
                  };
          }
          tween._value = value;
          return tween;
      }
  
      function attrTween(name, value) {
          function tween() {
              var node = this, i = value.apply(node, arguments);
              return i && function(t) {
                      node.setAttribute(name, i(t));
                  };
          }
          tween._value = value;
          return tween;
      }
  
      var transition_attrTween = function(name, value) {
          var key = "attr." + name;
          if (arguments.length < 2) return (key = this.tween(key)) && key._value;
          if (value == null) return this.tween(key, null);
          if (typeof value !== "function") throw new Error;
          var fullname = namespace(name);
          return this.tween(key, (fullname.local ? attrTweenNS : attrTween)(fullname, value));
      };
  
      function delayFunction(id, value) {
          return function() {
              init(this, id).delay = +value.apply(this, arguments);
          };
      }
  
      function delayConstant(id, value) {
          return value = +value, function() {
              init(this, id).delay = value;
          };
      }
  
      var transition_delay = function(value) {
          var id = this._id;
  
          return arguments.length
              ? this.each((typeof value === "function"
                  ? delayFunction
                  : delayConstant)(id, value))
              : get$1(this.node(), id).delay;
      };
  
      function durationFunction(id, value) {
          return function() {
              set$1(this, id).duration = +value.apply(this, arguments);
          };
      }
  
      function durationConstant(id, value) {
          return value = +value, function() {
              set$1(this, id).duration = value;
          };
      }
  
      var transition_duration = function(value) {
          var id = this._id;
  
          return arguments.length
              ? this.each((typeof value === "function"
                  ? durationFunction
                  : durationConstant)(id, value))
              : get$1(this.node(), id).duration;
      };
  
      function easeConstant(id, value) {
          if (typeof value !== "function") throw new Error;
          return function() {
              set$1(this, id).ease = value;
          };
      }
  
      var transition_ease = function(value) {
          var id = this._id;
  
          return arguments.length
              ? this.each(easeConstant(id, value))
              : get$1(this.node(), id).ease;
      };
  
      var transition_filter = function(match) {
          if (typeof match !== "function") match = matcher$1(match);
  
          for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
                  if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
                      subgroup.push(node);
                  }
              }
          }
  
          return new Transition(subgroups, this._parents, this._name, this._id);
      };
  
      var transition_merge = function(transition) {
          if (transition._id !== this._id) throw new Error;
  
          for (var groups0 = this._groups, groups1 = transition._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
              for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
                  if (node = group0[i] || group1[i]) {
                      merge[i] = node;
                  }
              }
          }
  
          for (; j < m0; ++j) {
              merges[j] = groups0[j];
          }
  
          return new Transition(merges, this._parents, this._name, this._id);
      };
  
      function start(name) {
          return (name + "").trim().split(/^|\s+/).every(function(t) {
              var i = t.indexOf(".");
              if (i >= 0) t = t.slice(0, i);
              return !t || t === "start";
          });
      }
  
      function onFunction(id, name, listener) {
          var on0, on1, sit = start(name) ? init : set$1;
          return function() {
              var schedule = sit(this, id),
                  on = schedule.on;
  
              // If this node shared a dispatch with the previous node,
              // just assign the updated shared dispatch and we’re done!
              // Otherwise, copy-on-write.
              if (on !== on0) (on1 = (on0 = on).copy()).on(name, listener);
  
              schedule.on = on1;
          };
      }
  
      var transition_on = function(name, listener) {
          var id = this._id;
  
          return arguments.length < 2
              ? get$1(this.node(), id).on.on(name)
              : this.each(onFunction(id, name, listener));
      };
  
      function removeFunction(id) {
          return function() {
              var parent = this.parentNode;
              for (var i in this.__transition) if (+i !== id) return;
              if (parent) parent.removeChild(this);
          };
      }
  
      var transition_remove = function() {
          return this.on("end.remove", removeFunction(this._id));
      };
  
      var transition_select = function(select$$1) {
          var name = this._name,
              id = this._id;
  
          if (typeof select$$1 !== "function") select$$1 = selector(select$$1);
  
          for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
                  if ((node = group[i]) && (subnode = select$$1.call(node, node.__data__, i, group))) {
                      if ("__data__" in node) subnode.__data__ = node.__data__;
                      subgroup[i] = subnode;
                      schedule(subgroup[i], name, id, i, subgroup, get$1(node, id));
                  }
              }
          }
  
          return new Transition(subgroups, this._parents, name, id);
      };
  
      var transition_selectAll = function(select$$1) {
          var name = this._name,
              id = this._id;
  
          if (typeof select$$1 !== "function") select$$1 = selectorAll(select$$1);
  
          for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                  if (node = group[i]) {
                      for (var children = select$$1.call(node, node.__data__, i, group), child, inherit = get$1(node, id), k = 0, l = children.length; k < l; ++k) {
                          if (child = children[k]) {
                              schedule(child, name, id, k, children, inherit);
                          }
                      }
                      subgroups.push(children);
                      parents.push(node);
                  }
              }
          }
  
          return new Transition(subgroups, parents, name, id);
      };
  
      var Selection$1 = selection.prototype.constructor;
  
      var transition_selection = function() {
          return new Selection$1(this._groups, this._parents);
      };
  
      function styleRemove$1(name, interpolate$$2) {
          var value00,
              value10,
              interpolate0;
          return function() {
              var style = window(this).getComputedStyle(this, null),
                  value0 = style.getPropertyValue(name),
                  value1 = (this.style.removeProperty(name), style.getPropertyValue(name));
              return value0 === value1 ? null
                  : value0 === value00 && value1 === value10 ? interpolate0
                      : interpolate0 = interpolate$$2(value00 = value0, value10 = value1);
          };
      }
  
      function styleRemoveEnd(name) {
          return function() {
              this.style.removeProperty(name);
          };
      }
  
      function styleConstant$1(name, interpolate$$2, value1) {
          var value00,
              interpolate0;
          return function() {
              var value0 = window(this).getComputedStyle(this, null).getPropertyValue(name);
              return value0 === value1 ? null
                  : value0 === value00 ? interpolate0
                      : interpolate0 = interpolate$$2(value00 = value0, value1);
          };
      }
  
      function styleFunction$1(name, interpolate$$2, value) {
          var value00,
              value10,
              interpolate0;
          return function() {
              var style = window(this).getComputedStyle(this, null),
                  value0 = style.getPropertyValue(name),
                  value1 = value(this);
              if (value1 == null) value1 = (this.style.removeProperty(name), style.getPropertyValue(name));
              return value0 === value1 ? null
                  : value0 === value00 && value1 === value10 ? interpolate0
                      : interpolate0 = interpolate$$2(value00 = value0, value10 = value1);
          };
      }
  
      var transition_style = function(name, value, priority) {
          var i = (name += "") === "transform" ? interpolateTransformCss : interpolate$$1;
          return value == null ? this
              .styleTween(name, styleRemove$1(name, i))
              .on("end.style." + name, styleRemoveEnd(name))
              : this.styleTween(name, typeof value === "function"
                  ? styleFunction$1(name, i, tweenValue(this, "style." + name, value))
                  : styleConstant$1(name, i, value + ""), priority);
      };
  
      function styleTween(name, value, priority) {
          function tween() {
              var node = this, i = value.apply(node, arguments);
              return i && function(t) {
                      node.style.setProperty(name, i(t), priority);
                  };
          }
          tween._value = value;
          return tween;
      }
  
      var transition_styleTween = function(name, value, priority) {
          var key = "style." + (name += "");
          if (arguments.length < 2) return (key = this.tween(key)) && key._value;
          if (value == null) return this.tween(key, null);
          if (typeof value !== "function") throw new Error;
          return this.tween(key, styleTween(name, value, priority == null ? "" : priority));
      };
  
      function textConstant$1(value) {
          return function() {
              this.textContent = value;
          };
      }
  
      function textFunction$1(value) {
          return function() {
              var value1 = value(this);
              this.textContent = value1 == null ? "" : value1;
          };
      }
  
      var transition_text = function(value) {
          return this.tween("text", typeof value === "function"
              ? textFunction$1(tweenValue(this, "text", value))
              : textConstant$1(value == null ? "" : value + ""));
      };
  
      var transition_transition = function() {
          var name = this._name,
              id0 = this._id,
              id1 = newId();
  
          for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                  if (node = group[i]) {
                      var inherit = get$1(node, id0);
                      schedule(node, name, id1, i, group, {
                          time: inherit.time + inherit.delay + inherit.duration,
                          delay: 0,
                          duration: inherit.duration,
                          ease: inherit.ease
                      });
                  }
              }
          }
  
          return new Transition(groups, this._parents, name, id1);
      };
  
      var id = 0;
  
      function Transition(groups, parents, name, id) {
          this._groups = groups;
          this._parents = parents;
          this._name = name;
          this._id = id;
      }
  
      function transition(name) {
          return selection().transition(name);
      }
  
      function newId() {
          return ++id;
      }
  
      var selection_prototype = selection.prototype;
  
      Transition.prototype = transition.prototype = {
          constructor: Transition,
          select: transition_select,
          selectAll: transition_selectAll,
          filter: transition_filter,
          merge: transition_merge,
          selection: transition_selection,
          transition: transition_transition,
          call: selection_prototype.call,
          nodes: selection_prototype.nodes,
          node: selection_prototype.node,
          size: selection_prototype.size,
          empty: selection_prototype.empty,
          each: selection_prototype.each,
          on: transition_on,
          attr: transition_attr,
          attrTween: transition_attrTween,
          style: transition_style,
          styleTween: transition_styleTween,
          text: transition_text,
          remove: transition_remove,
          tween: transition_tween,
          delay: transition_delay,
          duration: transition_duration,
          ease: transition_ease
      };
  
      function linear$1(t) {
          return +t;
      }
  
      function quadIn(t) {
          return t * t;
      }
  
      function quadOut(t) {
          return t * (2 - t);
      }
  
      function quadInOut(t) {
          return ((t *= 2) <= 1 ? t * t : --t * (2 - t) + 1) / 2;
      }
  
      function cubicIn(t) {
          return t * t * t;
      }
  
      function cubicOut(t) {
          return --t * t * t + 1;
      }
  
      function cubicInOut(t) {
          return ((t *= 2) <= 1 ? t * t * t : (t -= 2) * t * t + 2) / 2;
      }
  
      var exponent = 3;
  
      var polyIn = (function custom(e) {
          e = +e;
  
          function polyIn(t) {
              return Math.pow(t, e);
          }
  
          polyIn.exponent = custom;
  
          return polyIn;
      })(exponent);
  
      var polyOut = (function custom(e) {
          e = +e;
  
          function polyOut(t) {
              return 1 - Math.pow(1 - t, e);
          }
  
          polyOut.exponent = custom;
  
          return polyOut;
      })(exponent);
  
      var polyInOut = (function custom(e) {
          e = +e;
  
          function polyInOut(t) {
              return ((t *= 2) <= 1 ? Math.pow(t, e) : 2 - Math.pow(2 - t, e)) / 2;
          }
  
          polyInOut.exponent = custom;
  
          return polyInOut;
      })(exponent);
  
      var pi = Math.PI;
      var halfPi = pi / 2;
  
      function sinIn(t) {
          return 1 - Math.cos(t * halfPi);
      }
  
      function sinOut(t) {
          return Math.sin(t * halfPi);
      }
  
      function sinInOut(t) {
          return (1 - Math.cos(pi * t)) / 2;
      }
  
      function expIn(t) {
          return Math.pow(2, 10 * t - 10);
      }
  
      function expOut(t) {
          return 1 - Math.pow(2, -10 * t);
      }
  
      function expInOut(t) {
          return ((t *= 2) <= 1 ? Math.pow(2, 10 * t - 10) : 2 - Math.pow(2, 10 - 10 * t)) / 2;
      }
  
      function circleIn(t) {
          return 1 - Math.sqrt(1 - t * t);
      }
  
      function circleOut(t) {
          return Math.sqrt(1 - --t * t);
      }
  
      function circleInOut(t) {
          return ((t *= 2) <= 1 ? 1 - Math.sqrt(1 - t * t) : Math.sqrt(1 - (t -= 2) * t) + 1) / 2;
      }
  
      var b1 = 4 / 11;
      var b2 = 6 / 11;
      var b3 = 8 / 11;
      var b4 = 3 / 4;
      var b5 = 9 / 11;
      var b6 = 10 / 11;
      var b7 = 15 / 16;
      var b8 = 21 / 22;
      var b9 = 63 / 64;
      var b0 = 1 / b1 / b1;
  
      function bounceIn(t) {
          return 1 - bounceOut(1 - t);
      }
  
      function bounceOut(t) {
          return (t = +t) < b1 ? b0 * t * t : t < b3 ? b0 * (t -= b2) * t + b4 : t < b6 ? b0 * (t -= b5) * t + b7 : b0 * (t -= b8) * t + b9;
      }
  
      function bounceInOut(t) {
          return ((t *= 2) <= 1 ? 1 - bounceOut(1 - t) : bounceOut(t - 1) + 1) / 2;
      }
  
      var overshoot = 1.70158;
  
      var backIn = (function custom(s) {
          s = +s;
  
          function backIn(t) {
              return t * t * ((s + 1) * t - s);
          }
  
          backIn.overshoot = custom;
  
          return backIn;
      })(overshoot);
  
      var backOut = (function custom(s) {
          s = +s;
  
          function backOut(t) {
              return --t * t * ((s + 1) * t + s) + 1;
          }
  
          backOut.overshoot = custom;
  
          return backOut;
      })(overshoot);
  
      var backInOut = (function custom(s) {
          s = +s;
  
          function backInOut(t) {
              return ((t *= 2) < 1 ? t * t * ((s + 1) * t - s) : (t -= 2) * t * ((s + 1) * t + s) + 2) / 2;
          }
  
          backInOut.overshoot = custom;
  
          return backInOut;
      })(overshoot);
  
      var tau = 2 * Math.PI;
      var amplitude = 1;
      var period = 0.3;
  
      var elasticIn = (function custom(a, p) {
          var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);
  
          function elasticIn(t) {
              return a * Math.pow(2, 10 * --t) * Math.sin((s - t) / p);
          }
  
          elasticIn.amplitude = function(a) { return custom(a, p * tau); };
          elasticIn.period = function(p) { return custom(a, p); };
  
          return elasticIn;
      })(amplitude, period);
  
      var elasticOut = (function custom(a, p) {
          var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);
  
          function elasticOut(t) {
              return 1 - a * Math.pow(2, -10 * (t = +t)) * Math.sin((t + s) / p);
          }
  
          elasticOut.amplitude = function(a) { return custom(a, p * tau); };
          elasticOut.period = function(p) { return custom(a, p); };
  
          return elasticOut;
      })(amplitude, period);
  
      var elasticInOut = (function custom(a, p) {
          var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);
  
          function elasticInOut(t) {
              return ((t = t * 2 - 1) < 0
                      ? a * Math.pow(2, 10 * t) * Math.sin((s - t) / p)
                      : 2 - a * Math.pow(2, -10 * t) * Math.sin((s + t) / p)) / 2;
          }
  
          elasticInOut.amplitude = function(a) { return custom(a, p * tau); };
          elasticInOut.period = function(p) { return custom(a, p); };
  
          return elasticInOut;
      })(amplitude, period);
  
      var defaultTiming = {
          time: null, // Set on use.
          delay: 0,
          duration: 250,
          ease: cubicInOut
      };
  
      function inherit(node, id) {
          var timing;
          while (!(timing = node.__transition) || !(timing = timing[id])) {
              if (!(node = node.parentNode)) {
                  return defaultTiming.time = now(), defaultTiming;
              }
          }
          return timing;
      }
  
      var selection_transition = function(name) {
          var id,
              timing;
  
          if (name instanceof Transition) {
              id = name._id, name = name._name;
          } else {
              id = newId(), (timing = defaultTiming).time = now(), name = name == null ? null : name + "";
          }
  
          for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
              for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                  if (node = group[i]) {
                      schedule(node, name, id, i, group, timing || inherit(node, id));
                  }
              }
          }
  
          return new Transition(groups, this._parents, name, id);
      };
  
      selection.prototype.interrupt = selection_interrupt;
      selection.prototype.transition = selection_transition;
  
      var root$1 = [null];
  
      var active = function(node, name) {
          var schedules = node.__transition,
              schedule,
              i;
  
          if (schedules) {
              name = name == null ? null : name + "";
              for (i in schedules) {
                  if ((schedule = schedules[i]).state > SCHEDULED && schedule.name === name) {
                      return new Transition([[node]], root$1, name, +i);
                  }
              }
          }
  
          return null;
      };
  
      var constant$4 = function(x) {
          return function() {
              return x;
          };
      };
  
      var BrushEvent = function(target, type, selection) {
          this.target = target;
          this.type = type;
          this.selection = selection;
      };
  
      function nopropagation$1() {
          exports.event.stopImmediatePropagation();
      }
  
      var noevent$1 = function() {
          exports.event.preventDefault();
          exports.event.stopImmediatePropagation();
      };
  
      var MODE_DRAG = {name: "drag"};
      var MODE_SPACE = {name: "space"};
      var MODE_HANDLE = {name: "handle"};
      var MODE_CENTER = {name: "center"};
  
      var X = {
          name: "x",
          handles: ["e", "w"].map(type),
          input: function(x, e) { return x && [[x[0], e[0][1]], [x[1], e[1][1]]]; },
          output: function(xy) { return xy && [xy[0][0], xy[1][0]]; }
      };
  
      var Y = {
          name: "y",
          handles: ["n", "s"].map(type),
          input: function(y, e) { return y && [[e[0][0], y[0]], [e[1][0], y[1]]]; },
          output: function(xy) { return xy && [xy[0][1], xy[1][1]]; }
      };
  
      var XY = {
          name: "xy",
          handles: ["n", "e", "s", "w", "nw", "ne", "se", "sw"].map(type),
          input: function(xy) { return xy; },
          output: function(xy) { return xy; }
      };
  
      var cursors = {
          overlay: "crosshair",
          selection: "move",
          n: "ns-resize",
          e: "ew-resize",
          s: "ns-resize",
          w: "ew-resize",
          nw: "nwse-resize",
          ne: "nesw-resize",
          se: "nwse-resize",
          sw: "nesw-resize"
      };
  
      var flipX = {
          e: "w",
          w: "e",
          nw: "ne",
          ne: "nw",
          se: "sw",
          sw: "se"
      };
  
      var flipY = {
          n: "s",
          s: "n",
          nw: "sw",
          ne: "se",
          se: "ne",
          sw: "nw"
      };
  
      var signsX = {
          overlay: +1,
          selection: +1,
          n: null,
          e: +1,
          s: null,
          w: -1,
          nw: -1,
          ne: +1,
          se: +1,
          sw: -1
      };
  
      var signsY = {
          overlay: +1,
          selection: +1,
          n: -1,
          e: null,
          s: +1,
          w: null,
          nw: -1,
          ne: -1,
          se: +1,
          sw: +1
      };
  
      function type(t) {
          return {type: t};
      }
  
  // Ignore right-click, since that should open the context menu.
      function defaultFilter() {
          return !exports.event.button;
      }
  
      function defaultExtent() {
          var svg = this.ownerSVGElement || this;
          return [[0, 0], [svg.width.baseVal.value, svg.height.baseVal.value]];
      }
  
  // Like d3.local, but with the name “__brush” rather than auto-generated.
      function local$$1(node) {
          while (!node.__brush) if (!(node = node.parentNode)) return;
          return node.__brush;
      }
  
      function empty(extent) {
          return extent[0][0] === extent[1][0]
              || extent[0][1] === extent[1][1];
      }
  
      function brushSelection(node) {
          var state = node.__brush;
          return state ? state.dim.output(state.selection) : null;
      }
  
      function brushX() {
          return brush$1(X);
      }
  
      function brushY() {
          return brush$1(Y);
      }
  
      var brush = function() {
          return brush$1(XY);
      };
  
      function brush$1(dim) {
          var extent = defaultExtent,
              filter = defaultFilter,
              listeners = dispatch(brush, "start", "brush", "end"),
              handleSize = 6,
              touchending;
  
          function brush(group) {
              var overlay = group
                  .property("__brush", initialize)
                  .selectAll(".overlay")
                  .data([type("overlay")]);
  
              overlay.enter().append("rect")
                  .attr("class", "overlay")
                  .attr("pointer-events", "all")
                  .attr("cursor", cursors.overlay)
                  .merge(overlay)
                  .each(function() {
                      var extent = local$$1(this).extent;
                      select(this)
                          .attr("x", extent[0][0])
                          .attr("y", extent[0][1])
                          .attr("width", extent[1][0] - extent[0][0])
                          .attr("height", extent[1][1] - extent[0][1]);
                  });
  
              group.selectAll(".selection")
                  .data([type("selection")])
                  .enter().append("rect")
                  .attr("class", "selection")
                  .attr("cursor", cursors.selection)
                  .attr("fill", "#777")
                  .attr("fill-opacity", 0.3)
                  .attr("stroke", "#fff")
                  .attr("shape-rendering", "crispEdges");
  
              var handle = group.selectAll(".handle")
                  .data(dim.handles, function(d) { return d.type; });
  
              handle.exit().remove();
  
              handle.enter().append("rect")
                  .attr("class", function(d) { return "handle handle--" + d.type; })
                  .attr("cursor", function(d) { return cursors[d.type]; });
  
              group
                  .each(redraw)
                  .attr("fill", "none")
                  .attr("pointer-events", "all")
                  .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)")
                  .on("mousedown.brush touchstart.brush", started);
          }
  
          brush.move = function(group, selection$$1) {
              if (group.selection) {
                  group
                      .on("start.brush", function() { emitter(this, arguments).beforestart().start(); })
                      .on("interrupt.brush end.brush", function() { emitter(this, arguments).end(); })
                      .tween("brush", function() {
                          var that = this,
                              state = that.__brush,
                              emit = emitter(that, arguments),
                              selection0 = state.selection,
                              selection1 = dim.input(typeof selection$$1 === "function" ? selection$$1.apply(this, arguments) : selection$$1, state.extent),
                              i = interpolateValue(selection0, selection1);
  
                          function tween(t) {
                              state.selection = t === 1 && empty(selection1) ? null : i(t);
                              redraw.call(that);
                              emit.brush();
                          }
  
                          return selection0 && selection1 ? tween : tween(1);
                      });
              } else {
                  group
                      .each(function() {
                          var that = this,
                              args = arguments,
                              state = that.__brush,
                              selection1 = dim.input(typeof selection$$1 === "function" ? selection$$1.apply(that, args) : selection$$1, state.extent),
                              emit = emitter(that, args).beforestart();
  
                          interrupt(that);
                          state.selection = selection1 == null || empty(selection1) ? null : selection1;
                          redraw.call(that);
                          emit.start().brush().end();
                      });
              }
          };
  
          function redraw() {
              var group = select(this),
                  selection$$1 = local$$1(this).selection;
  
              if (selection$$1) {
                  group.selectAll(".selection")
                      .style("display", null)
                      .attr("x", selection$$1[0][0])
                      .attr("y", selection$$1[0][1])
                      .attr("width", selection$$1[1][0] - selection$$1[0][0])
                      .attr("height", selection$$1[1][1] - selection$$1[0][1]);
  
                  group.selectAll(".handle")
                      .style("display", null)
                      .attr("x", function(d) { return d.type[d.type.length - 1] === "e" ? selection$$1[1][0] - handleSize / 2 : selection$$1[0][0] - handleSize / 2; })
                      .attr("y", function(d) { return d.type[0] === "s" ? selection$$1[1][1] - handleSize / 2 : selection$$1[0][1] - handleSize / 2; })
                      .attr("width", function(d) { return d.type === "n" || d.type === "s" ? selection$$1[1][0] - selection$$1[0][0] + handleSize : handleSize; })
                      .attr("height", function(d) { return d.type === "e" || d.type === "w" ? selection$$1[1][1] - selection$$1[0][1] + handleSize : handleSize; });
              }
  
              else {
                  group.selectAll(".selection,.handle")
                      .style("display", "none")
                      .attr("x", null)
                      .attr("y", null)
                      .attr("width", null)
                      .attr("height", null);
              }
          }
  
          function emitter(that, args) {
              return that.__brush.emitter || new Emitter(that, args);
          }
  
          function Emitter(that, args) {
              this.that = that;
              this.args = args;
              this.state = that.__brush;
              this.active = 0;
          }
  
          Emitter.prototype = {
              beforestart: function() {
                  if (++this.active === 1) this.state.emitter = this, this.starting = true;
                  return this;
              },
              start: function() {
                  if (this.starting) this.starting = false, this.emit("start");
                  return this;
              },
              brush: function() {
                  this.emit("brush");
                  return this;
              },
              end: function() {
                  if (--this.active === 0) delete this.state.emitter, this.emit("end");
                  return this;
              },
              emit: function(type) {
                  customEvent(new BrushEvent(brush, type, dim.output(this.state.selection)), listeners.apply, listeners, [type, this.that, this.args]);
              }
          };
  
          function started() {
              if (exports.event.touches) { if (exports.event.changedTouches.length < exports.event.touches.length) return noevent$1(); }
              else if (touchending) return;
              if (!filter.apply(this, arguments)) return;
  
              var that = this,
                  type = exports.event.target.__data__.type,
                  mode = (exports.event.metaKey ? type = "overlay" : type) === "selection" ? MODE_DRAG : (exports.event.altKey ? MODE_CENTER : MODE_HANDLE),
                  signX = dim === Y ? null : signsX[type],
                  signY = dim === X ? null : signsY[type],
                  state = local$$1(that),
                  extent = state.extent,
                  selection$$1 = state.selection,
                  W = extent[0][0], w0, w1,
                  N = extent[0][1], n0, n1,
                  E = extent[1][0], e0, e1,
                  S = extent[1][1], s0, s1,
                  dx,
                  dy,
                  moving,
                  shifting = signX && signY && exports.event.shiftKey,
                  lockX,
                  lockY,
                  point0 = mouse(that),
                  point = point0,
                  emit = emitter(that, arguments).beforestart();
  
              if (type === "overlay") {
                  state.selection = selection$$1 = [
                      [w0 = dim === Y ? W : point0[0], n0 = dim === X ? N : point0[1]],
                      [e0 = dim === Y ? E : w0, s0 = dim === X ? S : n0]
                  ];
              } else {
                  w0 = selection$$1[0][0];
                  n0 = selection$$1[0][1];
                  e0 = selection$$1[1][0];
                  s0 = selection$$1[1][1];
              }
  
              w1 = w0;
              n1 = n0;
              e1 = e0;
              s1 = s0;
  
              var group = select(that)
                  .attr("pointer-events", "none");
  
              var overlay = group.selectAll(".overlay")
                  .attr("cursor", cursors[type]);
  
              if (exports.event.touches) {
                  group
                      .on("touchmove.brush", moved, true)
                      .on("touchend.brush touchcancel.brush", ended, true);
              } else {
                  var view = select(exports.event.view)
                      .on("keydown.brush", keydowned, true)
                      .on("keyup.brush", keyupped, true)
                      .on("mousemove.brush", moved, true)
                      .on("mouseup.brush", ended, true);
  
                  dragDisable(exports.event.view);
              }
  
              nopropagation$1();
              interrupt(that);
              redraw.call(that);
              emit.start();
  
              function moved() {
                  var point1 = mouse(that);
                  if (shifting && !lockX && !lockY) {
                      if (Math.abs(point1[0] - point[0]) > Math.abs(point1[1] - point[1])) lockY = true;
                      else lockX = true;
                  }
                  point = point1;
                  moving = true;
                  noevent$1();
                  move();
              }
  
              function move() {
                  var t;
  
                  dx = point[0] - point0[0];
                  dy = point[1] - point0[1];
  
                  switch (mode) {
                      case MODE_SPACE:
                      case MODE_DRAG: {
                          if (signX) dx = Math.max(W - w0, Math.min(E - e0, dx)), w1 = w0 + dx, e1 = e0 + dx;
                          if (signY) dy = Math.max(N - n0, Math.min(S - s0, dy)), n1 = n0 + dy, s1 = s0 + dy;
                          break;
                      }
                      case MODE_HANDLE: {
                          if (signX < 0) dx = Math.max(W - w0, Math.min(E - w0, dx)), w1 = w0 + dx, e1 = e0;
                          else if (signX > 0) dx = Math.max(W - e0, Math.min(E - e0, dx)), w1 = w0, e1 = e0 + dx;
                          if (signY < 0) dy = Math.max(N - n0, Math.min(S - n0, dy)), n1 = n0 + dy, s1 = s0;
                          else if (signY > 0) dy = Math.max(N - s0, Math.min(S - s0, dy)), n1 = n0, s1 = s0 + dy;
                          break;
                      }
                      case MODE_CENTER: {
                          if (signX) w1 = Math.max(W, Math.min(E, w0 - dx * signX)), e1 = Math.max(W, Math.min(E, e0 + dx * signX));
                          if (signY) n1 = Math.max(N, Math.min(S, n0 - dy * signY)), s1 = Math.max(N, Math.min(S, s0 + dy * signY));
                          break;
                      }
                  }
  
                  if (e1 < w1) {
                      signX *= -1;
                      t = w0, w0 = e0, e0 = t;
                      t = w1, w1 = e1, e1 = t;
                      if (type in flipX) overlay.attr("cursor", cursors[type = flipX[type]]);
                  }
  
                  if (s1 < n1) {
                      signY *= -1;
                      t = n0, n0 = s0, s0 = t;
                      t = n1, n1 = s1, s1 = t;
                      if (type in flipY) overlay.attr("cursor", cursors[type = flipY[type]]);
                  }
  
                  if (state.selection) selection$$1 = state.selection; // May be set by brush.move!
                  if (lockX) w1 = selection$$1[0][0], e1 = selection$$1[1][0];
                  if (lockY) n1 = selection$$1[0][1], s1 = selection$$1[1][1];
  
                  if (selection$$1[0][0] !== w1
                      || selection$$1[0][1] !== n1
                      || selection$$1[1][0] !== e1
                      || selection$$1[1][1] !== s1) {
                      state.selection = [[w1, n1], [e1, s1]];
                      redraw.call(that);
                      emit.brush();
                  }
              }
  
              function ended() {
                  nopropagation$1();
                  if (exports.event.touches) {
                      if (exports.event.touches.length) return;
                      if (touchending) clearTimeout(touchending);
                      touchending = setTimeout(function() { touchending = null; }, 500); // Ghost clicks are delayed!
                      group.on("touchmove.brush touchend.brush touchcancel.brush", null);
                  } else {
                      yesdrag(exports.event.view, moving);
                      view.on("keydown.brush keyup.brush mousemove.brush mouseup.brush", null);
                  }
                  group.attr("pointer-events", "all");
                  overlay.attr("cursor", cursors.overlay);
                  if (state.selection) selection$$1 = state.selection; // May be set by brush.move (on start)!
                  if (empty(selection$$1)) state.selection = null, redraw.call(that);
                  emit.end();
              }
  
              function keydowned() {
                  switch (exports.event.keyCode) {
                      case 16: { // SHIFT
                          shifting = signX && signY;
                          break;
                      }
                      case 18: { // ALT
                          if (mode === MODE_HANDLE) {
                              if (signX) e0 = e1 - dx * signX, w0 = w1 + dx * signX;
                              if (signY) s0 = s1 - dy * signY, n0 = n1 + dy * signY;
                              mode = MODE_CENTER;
                              move();
                          }
                          break;
                      }
                      case 32: { // SPACE; takes priority over ALT
                          if (mode === MODE_HANDLE || mode === MODE_CENTER) {
                              if (signX < 0) e0 = e1 - dx; else if (signX > 0) w0 = w1 - dx;
                              if (signY < 0) s0 = s1 - dy; else if (signY > 0) n0 = n1 - dy;
                              mode = MODE_SPACE;
                              overlay.attr("cursor", cursors.selection);
                              move();
                          }
                          break;
                      }
                      default: return;
                  }
                  noevent$1();
              }
  
              function keyupped() {
                  switch (exports.event.keyCode) {
                      case 16: { // SHIFT
                          if (shifting) {
                              lockX = lockY = shifting = false;
                              move();
                          }
                          break;
                      }
                      case 18: { // ALT
                          if (mode === MODE_CENTER) {
                              if (signX < 0) e0 = e1; else if (signX > 0) w0 = w1;
                              if (signY < 0) s0 = s1; else if (signY > 0) n0 = n1;
                              mode = MODE_HANDLE;
                              move();
                          }
                          break;
                      }
                      case 32: { // SPACE
                          if (mode === MODE_SPACE) {
                              if (exports.event.altKey) {
                                  if (signX) e0 = e1 - dx * signX, w0 = w1 + dx * signX;
                                  if (signY) s0 = s1 - dy * signY, n0 = n1 + dy * signY;
                                  mode = MODE_CENTER;
                              } else {
                                  if (signX < 0) e0 = e1; else if (signX > 0) w0 = w1;
                                  if (signY < 0) s0 = s1; else if (signY > 0) n0 = n1;
                                  mode = MODE_HANDLE;
                              }
                              overlay.attr("cursor", cursors[type]);
                              move();
                          }
                          break;
                      }
                      default: return;
                  }
                  noevent$1();
              }
          }
  
          function initialize() {
              var state = this.__brush || {selection: null};
              state.extent = extent.apply(this, arguments);
              state.dim = dim;
              return state;
          }
  
          brush.extent = function(_) {
              return arguments.length ? (extent = typeof _ === "function" ? _ : constant$4([[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]]), brush) : extent;
          };
  
          brush.filter = function(_) {
              return arguments.length ? (filter = typeof _ === "function" ? _ : constant$4(!!_), brush) : filter;
          };
  
          brush.handleSize = function(_) {
              return arguments.length ? (handleSize = +_, brush) : handleSize;
          };
  
          brush.on = function() {
              var value = listeners.on.apply(listeners, arguments);
              return value === listeners ? brush : value;
          };
  
          return brush;
      }
  
      var cos = Math.cos;
      var sin = Math.sin;
      var pi$1 = Math.PI;
      var halfPi$1 = pi$1 / 2;
      var tau$1 = pi$1 * 2;
      var max$1 = Math.max;
  
      function compareValue(compare) {
          return function(a, b) {
              return compare(
                  a.source.value + a.target.value,
                  b.source.value + b.target.value
              );
          };
      }
  
      var chord = function() {
          var padAngle = 0,
              sortGroups = null,
              sortSubgroups = null,
              sortChords = null;
  
          function chord(matrix) {
              var n = matrix.length,
                  groupSums = [],
                  groupIndex = sequence(n),
                  subgroupIndex = [],
                  chords = [],
                  groups = chords.groups = new Array(n),
                  subgroups = new Array(n * n),
                  k,
                  x,
                  x0,
                  dx,
                  i,
                  j;
  
              // Compute the sum.
              k = 0, i = -1; while (++i < n) {
                  x = 0, j = -1; while (++j < n) {
                      x += matrix[i][j];
                  }
                  groupSums.push(x);
                  subgroupIndex.push(sequence(n));
                  k += x;
              }
  
              // Sort groups…
              if (sortGroups) groupIndex.sort(function(a, b) {
                  return sortGroups(groupSums[a], groupSums[b]);
              });
  
              // Sort subgroups…
              if (sortSubgroups) subgroupIndex.forEach(function(d, i) {
                  d.sort(function(a, b) {
                      return sortSubgroups(matrix[i][a], matrix[i][b]);
                  });
              });
  
              // Convert the sum to scaling factor for [0, 2pi].
              // TODO Allow start and end angle to be specified?
              // TODO Allow padding to be specified as percentage?
              k = max$1(0, tau$1 - padAngle * n) / k;
              dx = k ? padAngle : tau$1 / n;
  
              // Compute the start and end angle for each group and subgroup.
              // Note: Opera has a bug reordering object literal properties!
              x = 0, i = -1; while (++i < n) {
                  x0 = x, j = -1; while (++j < n) {
                      var di = groupIndex[i],
                          dj = subgroupIndex[di][j],
                          v = matrix[di][dj],
                          a0 = x,
                          a1 = x += v * k;
                      subgroups[dj * n + di] = {
                          index: di,
                          subindex: dj,
                          startAngle: a0,
                          endAngle: a1,
                          value: v
                      };
                  }
                  groups[di] = {
                      index: di,
                      startAngle: x0,
                      endAngle: x,
                      value: groupSums[di]
                  };
                  x += dx;
              }
  
              // Generate chords for each (non-empty) subgroup-subgroup link.
              i = -1; while (++i < n) {
                  j = i - 1; while (++j < n) {
                      var source = subgroups[j * n + i],
                          target = subgroups[i * n + j];
                      if (source.value || target.value) {
                          chords.push(source.value < target.value
                              ? {source: target, target: source}
                              : {source: source, target: target});
                      }
                  }
              }
  
              return sortChords ? chords.sort(sortChords) : chords;
          }
  
          chord.padAngle = function(_) {
              return arguments.length ? (padAngle = max$1(0, _), chord) : padAngle;
          };
  
          chord.sortGroups = function(_) {
              return arguments.length ? (sortGroups = _, chord) : sortGroups;
          };
  
          chord.sortSubgroups = function(_) {
              return arguments.length ? (sortSubgroups = _, chord) : sortSubgroups;
          };
  
          chord.sortChords = function(_) {
              return arguments.length ? (_ == null ? sortChords = null : (sortChords = compareValue(_))._ = _, chord) : sortChords && sortChords._;
          };
  
          return chord;
      };
  
      var slice$2 = Array.prototype.slice;
  
      var constant$5 = function(x) {
          return function() {
              return x;
          };
      };
  
      var pi$2 = Math.PI;
      var tau$2 = 2 * pi$2;
      var epsilon$1 = 1e-6;
      var tauEpsilon = tau$2 - epsilon$1;
  
      function Path() {
          this._x0 = this._y0 = // start of current subpath
              this._x1 = this._y1 = null; // end of current subpath
          this._ = "";
      }
  
      function path() {
          return new Path;
      }
  
      Path.prototype = path.prototype = {
          constructor: Path,
          moveTo: function(x, y) {
              this._ += "M" + (this._x0 = this._x1 = +x) + "," + (this._y0 = this._y1 = +y);
          },
          closePath: function() {
              if (this._x1 !== null) {
                  this._x1 = this._x0, this._y1 = this._y0;
                  this._ += "Z";
              }
          },
          lineTo: function(x, y) {
              this._ += "L" + (this._x1 = +x) + "," + (this._y1 = +y);
          },
          quadraticCurveTo: function(x1, y1, x, y) {
              this._ += "Q" + (+x1) + "," + (+y1) + "," + (this._x1 = +x) + "," + (this._y1 = +y);
          },
          bezierCurveTo: function(x1, y1, x2, y2, x, y) {
              this._ += "C" + (+x1) + "," + (+y1) + "," + (+x2) + "," + (+y2) + "," + (this._x1 = +x) + "," + (this._y1 = +y);
          },
          arcTo: function(x1, y1, x2, y2, r) {
              x1 = +x1, y1 = +y1, x2 = +x2, y2 = +y2, r = +r;
              var x0 = this._x1,
                  y0 = this._y1,
                  x21 = x2 - x1,
                  y21 = y2 - y1,
                  x01 = x0 - x1,
                  y01 = y0 - y1,
                  l01_2 = x01 * x01 + y01 * y01;
  
              // Is the radius negative? Error.
              if (r < 0) throw new Error("negative radius: " + r);
  
              // Is this path empty? Move to (x1,y1).
              if (this._x1 === null) {
                  this._ += "M" + (this._x1 = x1) + "," + (this._y1 = y1);
              }
  
              // Or, is (x1,y1) coincident with (x0,y0)? Do nothing.
              else if (!(l01_2 > epsilon$1)) {}
  
              // Or, are (x0,y0), (x1,y1) and (x2,y2) collinear?
              // Equivalently, is (x1,y1) coincident with (x2,y2)?
              // Or, is the radius zero? Line to (x1,y1).
              else if (!(Math.abs(y01 * x21 - y21 * x01) > epsilon$1) || !r) {
                  this._ += "L" + (this._x1 = x1) + "," + (this._y1 = y1);
              }
  
              // Otherwise, draw an arc!
              else {
                  var x20 = x2 - x0,
                      y20 = y2 - y0,
                      l21_2 = x21 * x21 + y21 * y21,
                      l20_2 = x20 * x20 + y20 * y20,
                      l21 = Math.sqrt(l21_2),
                      l01 = Math.sqrt(l01_2),
                      l = r * Math.tan((pi$2 - Math.acos((l21_2 + l01_2 - l20_2) / (2 * l21 * l01))) / 2),
                      t01 = l / l01,
                      t21 = l / l21;
  
                  // If the start tangent is not coincident with (x0,y0), line to.
                  if (Math.abs(t01 - 1) > epsilon$1) {
                      this._ += "L" + (x1 + t01 * x01) + "," + (y1 + t01 * y01);
                  }
  
                  this._ += "A" + r + "," + r + ",0,0," + (+(y01 * x20 > x01 * y20)) + "," + (this._x1 = x1 + t21 * x21) + "," + (this._y1 = y1 + t21 * y21);
              }
          },
          arc: function(x, y, r, a0, a1, ccw) {
              x = +x, y = +y, r = +r;
              var dx = r * Math.cos(a0),
                  dy = r * Math.sin(a0),
                  x0 = x + dx,
                  y0 = y + dy,
                  cw = 1 ^ ccw,
                  da = ccw ? a0 - a1 : a1 - a0;
  
              // Is the radius negative? Error.
              if (r < 0) throw new Error("negative radius: " + r);
  
              // Is this path empty? Move to (x0,y0).
              if (this._x1 === null) {
                  this._ += "M" + x0 + "," + y0;
              }
  
              // Or, is (x0,y0) not coincident with the previous point? Line to (x0,y0).
              else if (Math.abs(this._x1 - x0) > epsilon$1 || Math.abs(this._y1 - y0) > epsilon$1) {
                  this._ += "L" + x0 + "," + y0;
              }
  
              // Is this arc empty? We’re done.
              if (!r) return;
  
              // Does the angle go the wrong way? Flip the direction.
              if (da < 0) da = da % tau$2 + tau$2;
  
              // Is this a complete circle? Draw two arcs to complete the circle.
              if (da > tauEpsilon) {
                  this._ += "A" + r + "," + r + ",0,1," + cw + "," + (x - dx) + "," + (y - dy) + "A" + r + "," + r + ",0,1," + cw + "," + (this._x1 = x0) + "," + (this._y1 = y0);
              }
  
              // Is this arc non-empty? Draw an arc!
              else if (da > epsilon$1) {
                  this._ += "A" + r + "," + r + ",0," + (+(da >= pi$2)) + "," + cw + "," + (this._x1 = x + r * Math.cos(a1)) + "," + (this._y1 = y + r * Math.sin(a1));
              }
          },
          rect: function(x, y, w, h) {
              this._ += "M" + (this._x0 = this._x1 = +x) + "," + (this._y0 = this._y1 = +y) + "h" + (+w) + "v" + (+h) + "h" + (-w) + "Z";
          },
          toString: function() {
              return this._;
          }
      };
  
      function defaultSource(d) {
          return d.source;
      }
  
      function defaultTarget(d) {
          return d.target;
      }
  
      function defaultRadius(d) {
          return d.radius;
      }
  
      function defaultStartAngle(d) {
          return d.startAngle;
      }
  
      function defaultEndAngle(d) {
          return d.endAngle;
      }
  
      var ribbon = function() {
          var source = defaultSource,
              target = defaultTarget,
              radius = defaultRadius,
              startAngle = defaultStartAngle,
              endAngle = defaultEndAngle,
              context = null;
  
          function ribbon() {
              var buffer,
                  argv = slice$2.call(arguments),
                  s = source.apply(this, argv),
                  t = target.apply(this, argv),
                  sr = +radius.apply(this, (argv[0] = s, argv)),
                  sa0 = startAngle.apply(this, argv) - halfPi$1,
                  sa1 = endAngle.apply(this, argv) - halfPi$1,
                  sx0 = sr * cos(sa0),
                  sy0 = sr * sin(sa0),
                  tr = +radius.apply(this, (argv[0] = t, argv)),
                  ta0 = startAngle.apply(this, argv) - halfPi$1,
                  ta1 = endAngle.apply(this, argv) - halfPi$1;
  
              if (!context) context = buffer = path();
  
              context.moveTo(sx0, sy0);
              context.arc(0, 0, sr, sa0, sa1);
              if (sa0 !== ta0 || sa1 !== ta1) { // TODO sr !== tr?
                  context.quadraticCurveTo(0, 0, tr * cos(ta0), tr * sin(ta0));
                  context.arc(0, 0, tr, ta0, ta1);
              }
              context.quadraticCurveTo(0, 0, sx0, sy0);
              context.closePath();
  
              if (buffer) return context = null, buffer + "" || null;
          }
  
          ribbon.radius = function(_) {
              return arguments.length ? (radius = typeof _ === "function" ? _ : constant$5(+_), ribbon) : radius;
          };
  
          ribbon.startAngle = function(_) {
              return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$5(+_), ribbon) : startAngle;
          };
  
          ribbon.endAngle = function(_) {
              return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$5(+_), ribbon) : endAngle;
          };
  
          ribbon.source = function(_) {
              return arguments.length ? (source = _, ribbon) : source;
          };
  
          ribbon.target = function(_) {
              return arguments.length ? (target = _, ribbon) : target;
          };
  
          ribbon.context = function(_) {
              return arguments.length ? ((context = _ == null ? null : _), ribbon) : context;
          };
  
          return ribbon;
      };
  
      var prefix = "$";
  
      function Map() {}
  
      Map.prototype = map$1.prototype = {
          constructor: Map,
          has: function(key) {
              return (prefix + key) in this;
          },
          get: function(key) {
              return this[prefix + key];
          },
          set: function(key, value) {
              this[prefix + key] = value;
              return this;
          },
          remove: function(key) {
              var property = prefix + key;
              return property in this && delete this[property];
          },
          clear: function() {
              for (var property in this) if (property[0] === prefix) delete this[property];
          },
          keys: function() {
              var keys = [];
              for (var property in this) if (property[0] === prefix) keys.push(property.slice(1));
              return keys;
          },
          values: function() {
              var values = [];
              for (var property in this) if (property[0] === prefix) values.push(this[property]);
              return values;
          },
          entries: function() {
              var entries = [];
              for (var property in this) if (property[0] === prefix) entries.push({key: property.slice(1), value: this[property]});
              return entries;
          },
          size: function() {
              var size = 0;
              for (var property in this) if (property[0] === prefix) ++size;
              return size;
          },
          empty: function() {
              for (var property in this) if (property[0] === prefix) return false;
              return true;
          },
          each: function(f) {
              for (var property in this) if (property[0] === prefix) f(this[property], property.slice(1), this);
          }
      };
  
      function map$1(object, f) {
          var map = new Map;
  
          // Copy constructor.
          if (object instanceof Map) object.each(function(value, key) { map.set(key, value); });
  
          // Index array by numeric index or specified key function.
          else if (Array.isArray(object)) {
              var i = -1,
                  n = object.length,
                  o;
  
              if (f == null) while (++i < n) map.set(i, object[i]);
              else while (++i < n) map.set(f(o = object[i], i, object), o);
          }
  
          // Convert object to map.
          else if (object) for (var key in object) map.set(key, object[key]);
  
          return map;
      }
  
      var nest = function() {
          var keys = [],
              sortKeys = [],
              sortValues,
              rollup,
              nest;
  
          function apply(array, depth, createResult, setResult) {
              if (depth >= keys.length) return rollup != null
                  ? rollup(array) : (sortValues != null
                      ? array.sort(sortValues)
                      : array);
  
              var i = -1,
                  n = array.length,
                  key = keys[depth++],
                  keyValue,
                  value,
                  valuesByKey = map$1(),
                  values,
                  result = createResult();
  
              while (++i < n) {
                  if (values = valuesByKey.get(keyValue = key(value = array[i]) + "")) {
                      values.push(value);
                  } else {
                      valuesByKey.set(keyValue, [value]);
                  }
              }
  
              valuesByKey.each(function(values, key) {
                  setResult(result, key, apply(values, depth, createResult, setResult));
              });
  
              return result;
          }
  
          function entries(map, depth) {
              if (++depth > keys.length) return map;
              var array, sortKey = sortKeys[depth - 1];
              if (rollup != null && depth >= keys.length) array = map.entries();
              else array = [], map.each(function(v, k) { array.push({key: k, values: entries(v, depth)}); });
              return sortKey != null ? array.sort(function(a, b) { return sortKey(a.key, b.key); }) : array;
          }
  
          return nest = {
              object: function(array) { return apply(array, 0, createObject, setObject); },
              map: function(array) { return apply(array, 0, createMap, setMap); },
              entries: function(array) { return entries(apply(array, 0, createMap, setMap), 0); },
              key: function(d) { keys.push(d); return nest; },
              sortKeys: function(order) { sortKeys[keys.length - 1] = order; return nest; },
              sortValues: function(order) { sortValues = order; return nest; },
              rollup: function(f) { rollup = f; return nest; }
          };
      };
  
      function createObject() {
          return {};
      }
  
      function setObject(object, key, value) {
          object[key] = value;
      }
  
      function createMap() {
          return map$1();
      }
  
      function setMap(map, key, value) {
          map.set(key, value);
      }
  
      function Set() {}
  
      var proto = map$1.prototype;
  
      Set.prototype = set$2.prototype = {
          constructor: Set,
          has: proto.has,
          add: function(value) {
              value += "";
              this[prefix + value] = value;
              return this;
          },
          remove: proto.remove,
          clear: proto.clear,
          values: proto.keys,
          size: proto.size,
          empty: proto.empty,
          each: proto.each
      };
  
      function set$2(object, f) {
          var set = new Set;
  
          // Copy constructor.
          if (object instanceof Set) object.each(function(value) { set.add(value); });
  
          // Otherwise, assume it’s an array.
          else if (object) {
              var i = -1, n = object.length;
              if (f == null) while (++i < n) set.add(object[i]);
              else while (++i < n) set.add(f(object[i], i, object));
          }
  
          return set;
      }
  
      var keys = function(map) {
          var keys = [];
          for (var key in map) keys.push(key);
          return keys;
      };
  
      var values = function(map) {
          var values = [];
          for (var key in map) values.push(map[key]);
          return values;
      };
  
      var entries = function(map) {
          var entries = [];
          for (var key in map) entries.push({key: key, value: map[key]});
          return entries;
      };
  
      function objectConverter(columns) {
          return new Function("d", "return {" + columns.map(function(name, i) {
                  return JSON.stringify(name) + ": d[" + i + "]";
              }).join(",") + "}");
      }
  
      function customConverter(columns, f) {
          var object = objectConverter(columns);
          return function(row, i) {
              return f(object(row), i, columns);
          };
      }
  
  // Compute unique columns in order of discovery.
      function inferColumns(rows) {
          var columnSet = Object.create(null),
              columns = [];
  
          rows.forEach(function(row) {
              for (var column in row) {
                  if (!(column in columnSet)) {
                      columns.push(columnSet[column] = column);
                  }
              }
          });
  
          return columns;
      }
  
      var dsv = function(delimiter) {
          var reFormat = new RegExp("[\"" + delimiter + "\n\r]"),
              delimiterCode = delimiter.charCodeAt(0);
  
          function parse(text, f) {
              var convert, columns, rows = parseRows(text, function(row, i) {
                  if (convert) return convert(row, i - 1);
                  columns = row, convert = f ? customConverter(row, f) : objectConverter(row);
              });
              rows.columns = columns;
              return rows;
          }
  
          function parseRows(text, f) {
              var EOL = {}, // sentinel value for end-of-line
                  EOF = {}, // sentinel value for end-of-file
                  rows = [], // output rows
                  N = text.length,
                  I = 0, // current character index
                  n = 0, // the current line number
                  t, // the current token
                  eol; // is the current token followed by EOL?
  
              function token() {
                  if (I >= N) return EOF; // special case: end of file
                  if (eol) return eol = false, EOL; // special case: end of line
  
                  // special case: quotes
                  var j = I, c;
                  if (text.charCodeAt(j) === 34) {
                      var i = j;
                      while (i++ < N) {
                          if (text.charCodeAt(i) === 34) {
                              if (text.charCodeAt(i + 1) !== 34) break;
                              ++i;
                          }
                      }
                      I = i + 2;
                      c = text.charCodeAt(i + 1);
                      if (c === 13) {
                          eol = true;
                          if (text.charCodeAt(i + 2) === 10) ++I;
                      } else if (c === 10) {
                          eol = true;
                      }
                      return text.slice(j + 1, i).replace(/""/g, "\"");
                  }
  
                  // common case: find next delimiter or newline
                  while (I < N) {
                      var k = 1;
                      c = text.charCodeAt(I++);
                      if (c === 10) eol = true; // \n
                      else if (c === 13) { eol = true; if (text.charCodeAt(I) === 10) ++I, ++k; } // \r|\r\n
                      else if (c !== delimiterCode) continue;
                      return text.slice(j, I - k);
                  }
  
                  // special case: last token before EOF
                  return text.slice(j);
              }
  
              while ((t = token()) !== EOF) {
                  var a = [];
                  while (t !== EOL && t !== EOF) {
                      a.push(t);
                      t = token();
                  }
                  if (f && (a = f(a, n++)) == null) continue;
                  rows.push(a);
              }
  
              return rows;
          }
  
          function format(rows, columns) {
              if (columns == null) columns = inferColumns(rows);
              return [columns.map(formatValue).join(delimiter)].concat(rows.map(function(row) {
                  return columns.map(function(column) {
                      return formatValue(row[column]);
                  }).join(delimiter);
              })).join("\n");
          }
  
          function formatRows(rows) {
              return rows.map(formatRow).join("\n");
          }
  
          function formatRow(row) {
              return row.map(formatValue).join(delimiter);
          }
  
          function formatValue(text) {
              return text == null ? ""
                  : reFormat.test(text += "") ? "\"" + text.replace(/\"/g, "\"\"") + "\""
                      : text;
          }
  
          return {
              parse: parse,
              parseRows: parseRows,
              format: format,
              formatRows: formatRows
          };
      };
  
      var csv = dsv(",");
  
      var csvParse = csv.parse;
      var csvParseRows = csv.parseRows;
      var csvFormat = csv.format;
      var csvFormatRows = csv.formatRows;
  
      var tsv = dsv("\t");
  
      var tsvParse = tsv.parse;
      var tsvParseRows = tsv.parseRows;
      var tsvFormat = tsv.format;
      var tsvFormatRows = tsv.formatRows;
  
      var center$1 = function(x, y) {
          var nodes;
  
          if (x == null) x = 0;
          if (y == null) y = 0;
  
          function force() {
              var i,
                  n = nodes.length,
                  node,
                  sx = 0,
                  sy = 0;
  
              for (i = 0; i < n; ++i) {
                  node = nodes[i], sx += node.x, sy += node.y;
              }
  
              for (sx = sx / n - x, sy = sy / n - y, i = 0; i < n; ++i) {
                  node = nodes[i], node.x -= sx, node.y -= sy;
              }
          }
  
          force.initialize = function(_) {
              nodes = _;
          };
  
          force.x = function(_) {
              return arguments.length ? (x = +_, force) : x;
          };
  
          force.y = function(_) {
              return arguments.length ? (y = +_, force) : y;
          };
  
          return force;
      };
  
      var constant$6 = function(x) {
          return function() {
              return x;
          };
      };
  
      var jiggle = function() {
          return (Math.random() - 0.5) * 1e-6;
      };
  
      var tree_add = function(d) {
          var x = +this._x.call(null, d),
              y = +this._y.call(null, d);
          return add(this.cover(x, y), x, y, d);
      };
  
      function add(tree, x, y, d) {
          if (isNaN(x) || isNaN(y)) return tree; // ignore invalid points
  
          var parent,
              node = tree._root,
              leaf = {data: d},
              x0 = tree._x0,
              y0 = tree._y0,
              x1 = tree._x1,
              y1 = tree._y1,
              xm,
              ym,
              xp,
              yp,
              right,
              bottom,
              i,
              j;
  
          // If the tree is empty, initialize the root as a leaf.
          if (!node) return tree._root = leaf, tree;
  
          // Find the existing leaf for the new point, or add it.
          while (node.length) {
              if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
              if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
              if (parent = node, !(node = node[i = bottom << 1 | right])) return parent[i] = leaf, tree;
          }
  
          // Is the new point is exactly coincident with the existing point?
          xp = +tree._x.call(null, node.data);
          yp = +tree._y.call(null, node.data);
          if (x === xp && y === yp) return leaf.next = node, parent ? parent[i] = leaf : tree._root = leaf, tree;
  
          // Otherwise, split the leaf node until the old and new point are separated.
          do {
              parent = parent ? parent[i] = new Array(4) : tree._root = new Array(4);
              if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
              if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
          } while ((i = bottom << 1 | right) === (j = (yp >= ym) << 1 | (xp >= xm)));
          return parent[j] = node, parent[i] = leaf, tree;
      }
  
      function addAll(data) {
          var d, i, n = data.length,
              x,
              y,
              xz = new Array(n),
              yz = new Array(n),
              x0 = Infinity,
              y0 = Infinity,
              x1 = -Infinity,
              y1 = -Infinity;
  
          // Compute the points and their extent.
          for (i = 0; i < n; ++i) {
              if (isNaN(x = +this._x.call(null, d = data[i])) || isNaN(y = +this._y.call(null, d))) continue;
              xz[i] = x;
              yz[i] = y;
              if (x < x0) x0 = x;
              if (x > x1) x1 = x;
              if (y < y0) y0 = y;
              if (y > y1) y1 = y;
          }
  
          // If there were no (valid) points, inherit the existing extent.
          if (x1 < x0) x0 = this._x0, x1 = this._x1;
          if (y1 < y0) y0 = this._y0, y1 = this._y1;
  
          // Expand the tree to cover the new points.
          this.cover(x0, y0).cover(x1, y1);
  
          // Add the new points.
          for (i = 0; i < n; ++i) {
              add(this, xz[i], yz[i], data[i]);
          }
  
          return this;
      }
  
      var tree_cover = function(x, y) {
          if (isNaN(x = +x) || isNaN(y = +y)) return this; // ignore invalid points
  
          var x0 = this._x0,
              y0 = this._y0,
              x1 = this._x1,
              y1 = this._y1;
  
          // If the quadtree has no extent, initialize them.
          // Integer extent are necessary so that if we later double the extent,
          // the existing quadrant boundaries don’t change due to floating point error!
          if (isNaN(x0)) {
              x1 = (x0 = Math.floor(x)) + 1;
              y1 = (y0 = Math.floor(y)) + 1;
          }
  
          // Otherwise, double repeatedly to cover.
          else if (x0 > x || x > x1 || y0 > y || y > y1) {
              var z = x1 - x0,
                  node = this._root,
                  parent,
                  i;
  
              switch (i = (y < (y0 + y1) / 2) << 1 | (x < (x0 + x1) / 2)) {
                  case 0: {
                      do parent = new Array(4), parent[i] = node, node = parent;
                      while (z *= 2, x1 = x0 + z, y1 = y0 + z, x > x1 || y > y1);
                      break;
                  }
                  case 1: {
                      do parent = new Array(4), parent[i] = node, node = parent;
                      while (z *= 2, x0 = x1 - z, y1 = y0 + z, x0 > x || y > y1);
                      break;
                  }
                  case 2: {
                      do parent = new Array(4), parent[i] = node, node = parent;
                      while (z *= 2, x1 = x0 + z, y0 = y1 - z, x > x1 || y0 > y);
                      break;
                  }
                  case 3: {
                      do parent = new Array(4), parent[i] = node, node = parent;
                      while (z *= 2, x0 = x1 - z, y0 = y1 - z, x0 > x || y0 > y);
                      break;
                  }
              }
  
              if (this._root && this._root.length) this._root = node;
          }
  
          // If the quadtree covers the point already, just return.
          else return this;
  
          this._x0 = x0;
          this._y0 = y0;
          this._x1 = x1;
          this._y1 = y1;
          return this;
      };
  
      var tree_data = function() {
          var data = [];
          this.visit(function(node) {
              if (!node.length) do data.push(node.data); while (node = node.next)
          });
          return data;
      };
  
      var tree_extent = function(_) {
          return arguments.length
              ? this.cover(+_[0][0], +_[0][1]).cover(+_[1][0], +_[1][1])
              : isNaN(this._x0) ? undefined : [[this._x0, this._y0], [this._x1, this._y1]];
      };
  
      var Quad = function(node, x0, y0, x1, y1) {
          this.node = node;
          this.x0 = x0;
          this.y0 = y0;
          this.x1 = x1;
          this.y1 = y1;
      };
  
      var tree_find = function(x, y, radius) {
          var data,
              x0 = this._x0,
              y0 = this._y0,
              x1,
              y1,
              x2,
              y2,
              x3 = this._x1,
              y3 = this._y1,
              quads = [],
              node = this._root,
              q,
              i;
  
          if (node) quads.push(new Quad(node, x0, y0, x3, y3));
          if (radius == null) radius = Infinity;
          else {
              x0 = x - radius, y0 = y - radius;
              x3 = x + radius, y3 = y + radius;
              radius *= radius;
          }
  
          while (q = quads.pop()) {
  
              // Stop searching if this quadrant can’t contain a closer node.
              if (!(node = q.node)
                  || (x1 = q.x0) > x3
                  || (y1 = q.y0) > y3
                  || (x2 = q.x1) < x0
                  || (y2 = q.y1) < y0) continue;
  
              // Bisect the current quadrant.
              if (node.length) {
                  var xm = (x1 + x2) / 2,
                      ym = (y1 + y2) / 2;
  
                  quads.push(
                      new Quad(node[3], xm, ym, x2, y2),
                      new Quad(node[2], x1, ym, xm, y2),
                      new Quad(node[1], xm, y1, x2, ym),
                      new Quad(node[0], x1, y1, xm, ym)
                  );
  
                  // Visit the closest quadrant first.
                  if (i = (y >= ym) << 1 | (x >= xm)) {
                      q = quads[quads.length - 1];
                      quads[quads.length - 1] = quads[quads.length - 1 - i];
                      quads[quads.length - 1 - i] = q;
                  }
              }
  
              // Visit this point. (Visiting coincident points isn’t necessary!)
              else {
                  var dx = x - +this._x.call(null, node.data),
                      dy = y - +this._y.call(null, node.data),
                      d2 = dx * dx + dy * dy;
                  if (d2 < radius) {
                      var d = Math.sqrt(radius = d2);
                      x0 = x - d, y0 = y - d;
                      x3 = x + d, y3 = y + d;
                      data = node.data;
                  }
              }
          }
  
          return data;
      };
  
      var tree_remove = function(d) {
          if (isNaN(x = +this._x.call(null, d)) || isNaN(y = +this._y.call(null, d))) return this; // ignore invalid points
  
          var parent,
              node = this._root,
              retainer,
              previous,
              next,
              x0 = this._x0,
              y0 = this._y0,
              x1 = this._x1,
              y1 = this._y1,
              x,
              y,
              xm,
              ym,
              right,
              bottom,
              i,
              j;
  
          // If the tree is empty, initialize the root as a leaf.
          if (!node) return this;
  
          // Find the leaf node for the point.
          // While descending, also retain the deepest parent with a non-removed sibling.
          if (node.length) while (true) {
              if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
              if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
              if (!(parent = node, node = node[i = bottom << 1 | right])) return this;
              if (!node.length) break;
              if (parent[(i + 1) & 3] || parent[(i + 2) & 3] || parent[(i + 3) & 3]) retainer = parent, j = i;
          }
  
          // Find the point to remove.
          while (node.data !== d) if (!(previous = node, node = node.next)) return this;
          if (next = node.next) delete node.next;
  
          // If there are multiple coincident points, remove just the point.
          if (previous) return (next ? previous.next = next : delete previous.next), this;
  
          // If this is the root point, remove it.
          if (!parent) return this._root = next, this;
  
          // Remove this leaf.
          next ? parent[i] = next : delete parent[i];
  
          // If the parent now contains exactly one leaf, collapse superfluous parents.
          if ((node = parent[0] || parent[1] || parent[2] || parent[3])
              && node === (parent[3] || parent[2] || parent[1] || parent[0])
              && !node.length) {
              if (retainer) retainer[j] = node;
              else this._root = node;
          }
  
          return this;
      };
  
      function removeAll(data) {
          for (var i = 0, n = data.length; i < n; ++i) this.remove(data[i]);
          return this;
      }
  
      var tree_root = function() {
          return this._root;
      };
  
      var tree_size = function() {
          var size = 0;
          this.visit(function(node) {
              if (!node.length) do ++size; while (node = node.next)
          });
          return size;
      };
  
      var tree_visit = function(callback) {
          var quads = [], q, node = this._root, child, x0, y0, x1, y1;
          if (node) quads.push(new Quad(node, this._x0, this._y0, this._x1, this._y1));
          while (q = quads.pop()) {
              if (!callback(node = q.node, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1) && node.length) {
                  var xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
                  if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
                  if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
                  if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
                  if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
              }
          }
          return this;
      };
  
      var tree_visitAfter = function(callback) {
          var quads = [], next = [], q;
          if (this._root) quads.push(new Quad(this._root, this._x0, this._y0, this._x1, this._y1));
          while (q = quads.pop()) {
              var node = q.node;
              if (node.length) {
                  var child, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1, xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
                  if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
                  if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
                  if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
                  if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
              }
              next.push(q);
          }
          while (q = next.pop()) {
              callback(q.node, q.x0, q.y0, q.x1, q.y1);
          }
          return this;
      };
  
      function defaultX(d) {
          return d[0];
      }
  
      var tree_x = function(_) {
          return arguments.length ? (this._x = _, this) : this._x;
      };
  
      function defaultY(d) {
          return d[1];
      }
  
      var tree_y = function(_) {
          return arguments.length ? (this._y = _, this) : this._y;
      };
  
      function quadtree(nodes, x, y) {
          var tree = new Quadtree(x == null ? defaultX : x, y == null ? defaultY : y, NaN, NaN, NaN, NaN);
          return nodes == null ? tree : tree.addAll(nodes);
      }
  
      function Quadtree(x, y, x0, y0, x1, y1) {
          this._x = x;
          this._y = y;
          this._x0 = x0;
          this._y0 = y0;
          this._x1 = x1;
          this._y1 = y1;
          this._root = undefined;
      }
  
      function leaf_copy(leaf) {
          var copy = {data: leaf.data}, next = copy;
          while (leaf = leaf.next) next = next.next = {data: leaf.data};
          return copy;
      }
  
      var treeProto = quadtree.prototype = Quadtree.prototype;
  
      treeProto.copy = function() {
          var copy = new Quadtree(this._x, this._y, this._x0, this._y0, this._x1, this._y1),
              node = this._root,
              nodes,
              child;
  
          if (!node) return copy;
  
          if (!node.length) return copy._root = leaf_copy(node), copy;
  
          nodes = [{source: node, target: copy._root = new Array(4)}];
          while (node = nodes.pop()) {
              for (var i = 0; i < 4; ++i) {
                  if (child = node.source[i]) {
                      if (child.length) nodes.push({source: child, target: node.target[i] = new Array(4)});
                      else node.target[i] = leaf_copy(child);
                  }
              }
          }
  
          return copy;
      };
  
      treeProto.add = tree_add;
      treeProto.addAll = addAll;
      treeProto.cover = tree_cover;
      treeProto.data = tree_data;
      treeProto.extent = tree_extent;
      treeProto.find = tree_find;
      treeProto.remove = tree_remove;
      treeProto.removeAll = removeAll;
      treeProto.root = tree_root;
      treeProto.size = tree_size;
      treeProto.visit = tree_visit;
      treeProto.visitAfter = tree_visitAfter;
      treeProto.x = tree_x;
      treeProto.y = tree_y;
  
      function x(d) {
          return d.x + d.vx;
      }
  
      function y(d) {
          return d.y + d.vy;
      }
  
      var collide = function(radius) {
          var nodes,
              radii,
              strength = 1,
              iterations = 1;
  
          if (typeof radius !== "function") radius = constant$6(radius == null ? 1 : +radius);
  
          function force() {
              var i, n = nodes.length,
                  tree,
                  node,
                  xi,
                  yi,
                  ri,
                  ri2;
  
              for (var k = 0; k < iterations; ++k) {
                  tree = quadtree(nodes, x, y).visitAfter(prepare);
                  for (i = 0; i < n; ++i) {
                      node = nodes[i];
                      ri = radii[node.index], ri2 = ri * ri;
                      xi = node.x + node.vx;
                      yi = node.y + node.vy;
                      tree.visit(apply);
                  }
              }
  
              function apply(quad, x0, y0, x1, y1) {
                  var data = quad.data, rj = quad.r, r = ri + rj;
                  if (data) {
                      if (data.index > node.index) {
                          var x = xi - data.x - data.vx,
                              y = yi - data.y - data.vy,
                              l = x * x + y * y;
                          if (l < r * r) {
                              if (x === 0) x = jiggle(), l += x * x;
                              if (y === 0) y = jiggle(), l += y * y;
                              l = (r - (l = Math.sqrt(l))) / l * strength;
                              node.vx += (x *= l) * (r = (rj *= rj) / (ri2 + rj));
                              node.vy += (y *= l) * r;
                              data.vx -= x * (r = 1 - r);
                              data.vy -= y * r;
                          }
                      }
                      return;
                  }
                  return x0 > xi + r || x1 < xi - r || y0 > yi + r || y1 < yi - r;
              }
          }
  
          function prepare(quad) {
              if (quad.data) return quad.r = radii[quad.data.index];
              for (var i = quad.r = 0; i < 4; ++i) {
                  if (quad[i] && quad[i].r > quad.r) {
                      quad.r = quad[i].r;
                  }
              }
          }
  
          function initialize() {
              if (!nodes) return;
              var i, n = nodes.length, node;
              radii = new Array(n);
              for (i = 0; i < n; ++i) node = nodes[i], radii[node.index] = +radius(node, i, nodes);
          }
  
          force.initialize = function(_) {
              nodes = _;
              initialize();
          };
  
          force.iterations = function(_) {
              return arguments.length ? (iterations = +_, force) : iterations;
          };
  
          force.strength = function(_) {
              return arguments.length ? (strength = +_, force) : strength;
          };
  
          force.radius = function(_) {
              return arguments.length ? (radius = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : radius;
          };
  
          return force;
      };
  
      function index(d) {
          return d.index;
      }
  
      function find(nodeById, nodeId) {
          var node = nodeById.get(nodeId);
          if (!node) throw new Error("missing: " + nodeId);
          return node;
      }
  
      var link = function(links) {
          var id = index,
              strength = defaultStrength,
              strengths,
              distance = constant$6(30),
              distances,
              nodes,
              count,
              bias,
              iterations = 1;
  
          if (links == null) links = [];
  
          function defaultStrength(link) {
              return 1 / Math.min(count[link.source.index], count[link.target.index]);
          }
  
          function force(alpha) {
              for (var k = 0, n = links.length; k < iterations; ++k) {
                  for (var i = 0, link, source, target, x, y, l, b; i < n; ++i) {
                      link = links[i], source = link.source, target = link.target;
                      x = target.x + target.vx - source.x - source.vx || jiggle();
                      y = target.y + target.vy - source.y - source.vy || jiggle();
                      l = Math.sqrt(x * x + y * y);
                      l = (l - distances[i]) / l * alpha * strengths[i];
                      x *= l, y *= l;
                      target.vx -= x * (b = bias[i]);
                      target.vy -= y * b;
                      source.vx += x * (b = 1 - b);
                      source.vy += y * b;
                  }
              }
          }
  
          function initialize() {
              if (!nodes) return;
  
              var i,
                  n = nodes.length,
                  m = links.length,
                  nodeById = map$1(nodes, id),
                  link;
  
              for (i = 0, count = new Array(n); i < m; ++i) {
                  link = links[i], link.index = i;
                  if (typeof link.source !== "object") link.source = find(nodeById, link.source);
                  if (typeof link.target !== "object") link.target = find(nodeById, link.target);
                  count[link.source.index] = (count[link.source.index] || 0) + 1;
                  count[link.target.index] = (count[link.target.index] || 0) + 1;
              }
  
              for (i = 0, bias = new Array(m); i < m; ++i) {
                  link = links[i], bias[i] = count[link.source.index] / (count[link.source.index] + count[link.target.index]);
              }
  
              strengths = new Array(m), initializeStrength();
              distances = new Array(m), initializeDistance();
          }
  
          function initializeStrength() {
              if (!nodes) return;
  
              for (var i = 0, n = links.length; i < n; ++i) {
                  strengths[i] = +strength(links[i], i, links);
              }
          }
  
          function initializeDistance() {
              if (!nodes) return;
  
              for (var i = 0, n = links.length; i < n; ++i) {
                  distances[i] = +distance(links[i], i, links);
              }
          }
  
          force.initialize = function(_) {
              nodes = _;
              initialize();
          };
  
          force.links = function(_) {
              return arguments.length ? (links = _, initialize(), force) : links;
          };
  
          force.id = function(_) {
              return arguments.length ? (id = _, force) : id;
          };
  
          force.iterations = function(_) {
              return arguments.length ? (iterations = +_, force) : iterations;
          };
  
          force.strength = function(_) {
              return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initializeStrength(), force) : strength;
          };
  
          force.distance = function(_) {
              return arguments.length ? (distance = typeof _ === "function" ? _ : constant$6(+_), initializeDistance(), force) : distance;
          };
  
          return force;
      };
  
      function x$1(d) {
          return d.x;
      }
  
      function y$1(d) {
          return d.y;
      }
  
      var initialRadius = 10;
      var initialAngle = Math.PI * (3 - Math.sqrt(5));
  
      var simulation = function(nodes) {
          var simulation,
              alpha = 1,
              alphaMin = 0.001,
              alphaDecay = 1 - Math.pow(alphaMin, 1 / 300),
              alphaTarget = 0,
              velocityDecay = 0.6,
              forces = map$1(),
              stepper = timer(step),
              event = dispatch("tick", "end");
  
          if (nodes == null) nodes = [];
  
          function step() {
              tick();
              event.call("tick", simulation);
              if (alpha < alphaMin) {
                  stepper.stop();
                  event.call("end", simulation);
              }
          }
  
          function tick() {
              var i, n = nodes.length, node;
  
              alpha += (alphaTarget - alpha) * alphaDecay;
  
              forces.each(function(force) {
                  force(alpha);
              });
  
              for (i = 0; i < n; ++i) {
                  node = nodes[i];
                  if (node.fx == null) node.x += node.vx *= velocityDecay;
                  else node.x = node.fx, node.vx = 0;
                  if (node.fy == null) node.y += node.vy *= velocityDecay;
                  else node.y = node.fy, node.vy = 0;
              }
          }
  
          function initializeNodes() {
              for (var i = 0, n = nodes.length, node; i < n; ++i) {
                  node = nodes[i], node.index = i;
                  if (isNaN(node.x) || isNaN(node.y)) {
                      var radius = initialRadius * Math.sqrt(i), angle = i * initialAngle;
                      node.x = radius * Math.cos(angle);
                      node.y = radius * Math.sin(angle);
                  }
                  if (isNaN(node.vx) || isNaN(node.vy)) {
                      node.vx = node.vy = 0;
                  }
              }
          }
  
          function initializeForce(force) {
              if (force.initialize) force.initialize(nodes);
              return force;
          }
  
          initializeNodes();
  
          return simulation = {
              tick: tick,
  
              restart: function() {
                  return stepper.restart(step), simulation;
              },
  
              stop: function() {
                  return stepper.stop(), simulation;
              },
  
              nodes: function(_) {
                  return arguments.length ? (nodes = _, initializeNodes(), forces.each(initializeForce), simulation) : nodes;
              },
  
              alpha: function(_) {
                  return arguments.length ? (alpha = +_, simulation) : alpha;
              },
  
              alphaMin: function(_) {
                  return arguments.length ? (alphaMin = +_, simulation) : alphaMin;
              },
  
              alphaDecay: function(_) {
                  return arguments.length ? (alphaDecay = +_, simulation) : +alphaDecay;
              },
  
              alphaTarget: function(_) {
                  return arguments.length ? (alphaTarget = +_, simulation) : alphaTarget;
              },
  
              velocityDecay: function(_) {
                  return arguments.length ? (velocityDecay = 1 - _, simulation) : 1 - velocityDecay;
              },
  
              force: function(name, _) {
                  return arguments.length > 1 ? ((_ == null ? forces.remove(name) : forces.set(name, initializeForce(_))), simulation) : forces.get(name);
              },
  
              find: function(x, y, radius) {
                  var i = 0,
                      n = nodes.length,
                      dx,
                      dy,
                      d2,
                      node,
                      closest;
  
                  if (radius == null) radius = Infinity;
                  else radius *= radius;
  
                  for (i = 0; i < n; ++i) {
                      node = nodes[i];
                      dx = x - node.x;
                      dy = y - node.y;
                      d2 = dx * dx + dy * dy;
                      if (d2 < radius) closest = node, radius = d2;
                  }
  
                  return closest;
              },
  
              on: function(name, _) {
                  return arguments.length > 1 ? (event.on(name, _), simulation) : event.on(name);
              }
          };
      };
  
      var manyBody = function() {
          var nodes,
              node,
              alpha,
              strength = constant$6(-30),
              strengths,
              distanceMin2 = 1,
              distanceMax2 = Infinity,
              theta2 = 0.81;
  
          function force(_) {
              var i, n = nodes.length, tree = quadtree(nodes, x$1, y$1).visitAfter(accumulate);
              for (alpha = _, i = 0; i < n; ++i) node = nodes[i], tree.visit(apply);
          }
  
          function initialize() {
              if (!nodes) return;
              var i, n = nodes.length, node;
              strengths = new Array(n);
              for (i = 0; i < n; ++i) node = nodes[i], strengths[node.index] = +strength(node, i, nodes);
          }
  
          function accumulate(quad) {
              var strength = 0, q, c, x$$1, y$$1, i;
  
              // For internal nodes, accumulate forces from child quadrants.
              if (quad.length) {
                  for (x$$1 = y$$1 = i = 0; i < 4; ++i) {
                      if ((q = quad[i]) && (c = q.value)) {
                          strength += c, x$$1 += c * q.x, y$$1 += c * q.y;
                      }
                  }
                  quad.x = x$$1 / strength;
                  quad.y = y$$1 / strength;
              }
  
              // For leaf nodes, accumulate forces from coincident quadrants.
              else {
                  q = quad;
                  q.x = q.data.x;
                  q.y = q.data.y;
                  do strength += strengths[q.data.index];
                  while (q = q.next);
              }
  
              quad.value = strength;
          }
  
          function apply(quad, x1, _, x2) {
              if (!quad.value) return true;
  
              var x$$1 = quad.x - node.x,
                  y$$1 = quad.y - node.y,
                  w = x2 - x1,
                  l = x$$1 * x$$1 + y$$1 * y$$1;
  
              // Apply the Barnes-Hut approximation if possible.
              // Limit forces for very close nodes; randomize direction if coincident.
              if (w * w / theta2 < l) {
                  if (l < distanceMax2) {
                      if (x$$1 === 0) x$$1 = jiggle(), l += x$$1 * x$$1;
                      if (y$$1 === 0) y$$1 = jiggle(), l += y$$1 * y$$1;
                      if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
                      node.vx += x$$1 * quad.value * alpha / l;
                      node.vy += y$$1 * quad.value * alpha / l;
                  }
                  return true;
              }
  
              // Otherwise, process points directly.
              else if (quad.length || l >= distanceMax2) return;
  
              // Limit forces for very close nodes; randomize direction if coincident.
              if (quad.data !== node || quad.next) {
                  if (x$$1 === 0) x$$1 = jiggle(), l += x$$1 * x$$1;
                  if (y$$1 === 0) y$$1 = jiggle(), l += y$$1 * y$$1;
                  if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
              }
  
              do if (quad.data !== node) {
                  w = strengths[quad.data.index] * alpha / l;
                  node.vx += x$$1 * w;
                  node.vy += y$$1 * w;
              } while (quad = quad.next);
          }
  
          force.initialize = function(_) {
              nodes = _;
              initialize();
          };
  
          force.strength = function(_) {
              return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
          };
  
          force.distanceMin = function(_) {
              return arguments.length ? (distanceMin2 = _ * _, force) : Math.sqrt(distanceMin2);
          };
  
          force.distanceMax = function(_) {
              return arguments.length ? (distanceMax2 = _ * _, force) : Math.sqrt(distanceMax2);
          };
  
          force.theta = function(_) {
              return arguments.length ? (theta2 = _ * _, force) : Math.sqrt(theta2);
          };
  
          return force;
      };
  
      var x$2 = function(x) {
          var strength = constant$6(0.1),
              nodes,
              strengths,
              xz;
  
          if (typeof x !== "function") x = constant$6(x == null ? 0 : +x);
  
          function force(alpha) {
              for (var i = 0, n = nodes.length, node; i < n; ++i) {
                  node = nodes[i], node.vx += (xz[i] - node.x) * strengths[i] * alpha;
              }
          }
  
          function initialize() {
              if (!nodes) return;
              var i, n = nodes.length;
              strengths = new Array(n);
              xz = new Array(n);
              for (i = 0; i < n; ++i) {
                  strengths[i] = isNaN(xz[i] = +x(nodes[i], i, nodes)) ? 0 : +strength(nodes[i], i, nodes);
              }
          }
  
          force.initialize = function(_) {
              nodes = _;
              initialize();
          };
  
          force.strength = function(_) {
              return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
          };
  
          force.x = function(_) {
              return arguments.length ? (x = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : x;
          };
  
          return force;
      };
  
      var y$2 = function(y) {
          var strength = constant$6(0.1),
              nodes,
              strengths,
              yz;
  
          if (typeof y !== "function") y = constant$6(y == null ? 0 : +y);
  
          function force(alpha) {
              for (var i = 0, n = nodes.length, node; i < n; ++i) {
                  node = nodes[i], node.vy += (yz[i] - node.y) * strengths[i] * alpha;
              }
          }
  
          function initialize() {
              if (!nodes) return;
              var i, n = nodes.length;
              strengths = new Array(n);
              yz = new Array(n);
              for (i = 0; i < n; ++i) {
                  strengths[i] = isNaN(yz[i] = +y(nodes[i], i, nodes)) ? 0 : +strength(nodes[i], i, nodes);
              }
          }
  
          force.initialize = function(_) {
              nodes = _;
              initialize();
          };
  
          force.strength = function(_) {
              return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
          };
  
          force.y = function(_) {
              return arguments.length ? (y = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : y;
          };
  
          return force;
      };
  
  // Computes the decimal coefficient and exponent of the specified number x with
  // significant digits p, where x is positive and p is in [1, 21] or undefined.
  // For example, formatDecimal(1.23) returns ["123", 0].
      var formatDecimal = function(x, p) {
          if ((i = (x = p ? x.toExponential(p - 1) : x.toExponential()).indexOf("e")) < 0) return null; // NaN, ±Infinity
          var i, coefficient = x.slice(0, i);
  
          // The string returned by toExponential either has the form \d\.\d+e[-+]\d+
          // (e.g., 1.2e+3) or the form \de[-+]\d+ (e.g., 1e+3).
          return [
              coefficient.length > 1 ? coefficient[0] + coefficient.slice(2) : coefficient,
              +x.slice(i + 1)
          ];
      };
  
      var exponent$1 = function(x) {
          return x = formatDecimal(Math.abs(x)), x ? x[1] : NaN;
      };
  
      var formatGroup = function(grouping, thousands) {
          return function(value, width) {
              var i = value.length,
                  t = [],
                  j = 0,
                  g = grouping[0],
                  length = 0;
  
              while (i > 0 && g > 0) {
                  if (length + g + 1 > width) g = Math.max(1, width - length);
                  t.push(value.substring(i -= g, i + g));
                  if ((length += g + 1) > width) break;
                  g = grouping[j = (j + 1) % grouping.length];
              }
  
              return t.reverse().join(thousands);
          };
      };
  
      var formatNumerals = function(numerals) {
          return function(value) {
              return value.replace(/[0-9]/g, function(i) {
                  return numerals[+i];
              });
          };
      };
  
      var formatDefault = function(x, p) {
          x = x.toPrecision(p);
  
          out: for (var n = x.length, i = 1, i0 = -1, i1; i < n; ++i) {
              switch (x[i]) {
                  case ".": i0 = i1 = i; break;
                  case "0": if (i0 === 0) i0 = i; i1 = i; break;
                  case "e": break out;
                  default: if (i0 > 0) i0 = 0; break;
              }
          }
  
          return i0 > 0 ? x.slice(0, i0) + x.slice(i1 + 1) : x;
      };
  
      var prefixExponent;
  
      var formatPrefixAuto = function(x, p) {
          var d = formatDecimal(x, p);
          if (!d) return x + "";
          var coefficient = d[0],
              exponent = d[1],
              i = exponent - (prefixExponent = Math.max(-8, Math.min(8, Math.floor(exponent / 3))) * 3) + 1,
              n = coefficient.length;
          return i === n ? coefficient
              : i > n ? coefficient + new Array(i - n + 1).join("0")
                  : i > 0 ? coefficient.slice(0, i) + "." + coefficient.slice(i)
                      : "0." + new Array(1 - i).join("0") + formatDecimal(x, Math.max(0, p + i - 1))[0]; // less than 1y!
      };
  
      var formatRounded = function(x, p) {
          var d = formatDecimal(x, p);
          if (!d) return x + "";
          var coefficient = d[0],
              exponent = d[1];
          return exponent < 0 ? "0." + new Array(-exponent).join("0") + coefficient
              : coefficient.length > exponent + 1 ? coefficient.slice(0, exponent + 1) + "." + coefficient.slice(exponent + 1)
                  : coefficient + new Array(exponent - coefficient.length + 2).join("0");
      };
  
      var formatTypes = {
          "": formatDefault,
          "%": function(x, p) { return (x * 100).toFixed(p); },
          "b": function(x) { return Math.round(x).toString(2); },
          "c": function(x) { return x + ""; },
          "d": function(x) { return Math.round(x).toString(10); },
          "e": function(x, p) { return x.toExponential(p); },
          "f": function(x, p) { return x.toFixed(p); },
          "g": function(x, p) { return x.toPrecision(p); },
          "o": function(x) { return Math.round(x).toString(8); },
          "p": function(x, p) { return formatRounded(x * 100, p); },
          "r": formatRounded,
          "s": formatPrefixAuto,
          "X": function(x) { return Math.round(x).toString(16).toUpperCase(); },
          "x": function(x) { return Math.round(x).toString(16); }
      };
  
  // [[fill]align][sign][symbol][0][width][,][.precision][type]
      var re = /^(?:(.)?([<>=^]))?([+\-\( ])?([$#])?(0)?(\d+)?(,)?(\.\d+)?([a-z%])?$/i;
  
      function formatSpecifier(specifier) {
          return new FormatSpecifier(specifier);
      }
  
      formatSpecifier.prototype = FormatSpecifier.prototype; // instanceof
  
      function FormatSpecifier(specifier) {
          if (!(match = re.exec(specifier))) throw new Error("invalid format: " + specifier);
  
          var match,
              fill = match[1] || " ",
              align = match[2] || ">",
              sign = match[3] || "-",
              symbol = match[4] || "",
              zero = !!match[5],
              width = match[6] && +match[6],
              comma = !!match[7],
              precision = match[8] && +match[8].slice(1),
              type = match[9] || "";
  
          // The "n" type is an alias for ",g".
          if (type === "n") comma = true, type = "g";
  
          // Map invalid types to the default format.
          else if (!formatTypes[type]) type = "";
  
          // If zero fill is specified, padding goes after sign and before digits.
          if (zero || (fill === "0" && align === "=")) zero = true, fill = "0", align = "=";
  
          this.fill = fill;
          this.align = align;
          this.sign = sign;
          this.symbol = symbol;
          this.zero = zero;
          this.width = width;
          this.comma = comma;
          this.precision = precision;
          this.type = type;
      }
  
      FormatSpecifier.prototype.toString = function() {
          return this.fill
              + this.align
              + this.sign
              + this.symbol
              + (this.zero ? "0" : "")
              + (this.width == null ? "" : Math.max(1, this.width | 0))
              + (this.comma ? "," : "")
              + (this.precision == null ? "" : "." + Math.max(0, this.precision | 0))
              + this.type;
      };
  
      var identity$3 = function(x) {
          return x;
      };
  
      var prefixes = ["y","z","a","f","p","n","\xB5","m","","k","M","G","T","P","E","Z","Y"];
  
      var formatLocale = function(locale) {
          var group = locale.grouping && locale.thousands ? formatGroup(locale.grouping, locale.thousands) : identity$3,
              currency = locale.currency,
              decimal = locale.decimal,
              numerals = locale.numerals ? formatNumerals(locale.numerals) : identity$3,
              percent = locale.percent || "%";
  
          function newFormat(specifier) {
              specifier = formatSpecifier(specifier);
  
              var fill = specifier.fill,
                  align = specifier.align,
                  sign = specifier.sign,
                  symbol = specifier.symbol,
                  zero = specifier.zero,
                  width = specifier.width,
                  comma = specifier.comma,
                  precision = specifier.precision,
                  type = specifier.type;
  
              // Compute the prefix and suffix.
              // For SI-prefix, the suffix is lazily computed.
              var prefix = symbol === "$" ? currency[0] : symbol === "#" && /[boxX]/.test(type) ? "0" + type.toLowerCase() : "",
                  suffix = symbol === "$" ? currency[1] : /[%p]/.test(type) ? percent : "";
  
              // What format function should we use?
              // Is this an integer type?
              // Can this type generate exponential notation?
              var formatType = formatTypes[type],
                  maybeSuffix = !type || /[defgprs%]/.test(type);
  
              // Set the default precision if not specified,
              // or clamp the specified precision to the supported range.
              // For significant precision, it must be in [1, 21].
              // For fixed precision, it must be in [0, 20].
              precision = precision == null ? (type ? 6 : 12)
                  : /[gprs]/.test(type) ? Math.max(1, Math.min(21, precision))
                      : Math.max(0, Math.min(20, precision));
  
              function format(value) {
                  var valuePrefix = prefix,
                      valueSuffix = suffix,
                      i, n, c;
  
                  if (type === "c") {
                      valueSuffix = formatType(value) + valueSuffix;
                      value = "";
                  } else {
                      value = +value;
  
                      // Perform the initial formatting.
                      var valueNegative = value < 0;
                      value = formatType(Math.abs(value), precision);
  
                      // If a negative value rounds to zero during formatting, treat as positive.
                      if (valueNegative && +value === 0) valueNegative = false;
  
                      // Compute the prefix and suffix.
                      valuePrefix = (valueNegative ? (sign === "(" ? sign : "-") : sign === "-" || sign === "(" ? "" : sign) + valuePrefix;
                      valueSuffix = valueSuffix + (type === "s" ? prefixes[8 + prefixExponent / 3] : "") + (valueNegative && sign === "(" ? ")" : "");
  
                      // Break the formatted value into the integer “value” part that can be
                      // grouped, and fractional or exponential “suffix” part that is not.
                      if (maybeSuffix) {
                          i = -1, n = value.length;
                          while (++i < n) {
                              if (c = value.charCodeAt(i), 48 > c || c > 57) {
                                  valueSuffix = (c === 46 ? decimal + value.slice(i + 1) : value.slice(i)) + valueSuffix;
                                  value = value.slice(0, i);
                                  break;
                              }
                          }
                      }
                  }
  
                  // If the fill character is not "0", grouping is applied before padding.
                  if (comma && !zero) value = group(value, Infinity);
  
                  // Compute the padding.
                  var length = valuePrefix.length + value.length + valueSuffix.length,
                      padding = length < width ? new Array(width - length + 1).join(fill) : "";
  
                  // If the fill character is "0", grouping is applied after padding.
                  if (comma && zero) value = group(padding + value, padding.length ? width - valueSuffix.length : Infinity), padding = "";
  
                  // Reconstruct the final output based on the desired alignment.
                  switch (align) {
                      case "<": value = valuePrefix + value + valueSuffix + padding; break;
                      case "=": value = valuePrefix + padding + value + valueSuffix; break;
                      case "^": value = padding.slice(0, length = padding.length >> 1) + valuePrefix + value + valueSuffix + padding.slice(length); break;
                      default: value = padding + valuePrefix + value + valueSuffix; break;
                  }
  
                  return numerals(value);
              }
  
              format.toString = function() {
                  return specifier + "";
              };
  
              return format;
          }
  
          function formatPrefix(specifier, value) {
              var f = newFormat((specifier = formatSpecifier(specifier), specifier.type = "f", specifier)),
                  e = Math.max(-8, Math.min(8, Math.floor(exponent$1(value) / 3))) * 3,
                  k = Math.pow(10, -e),
                  prefix = prefixes[8 + e / 3];
              return function(value) {
                  return f(k * value) + prefix;
              };
          }
  
          return {
              format: newFormat,
              formatPrefix: formatPrefix
          };
      };
  
      var locale$1;
  
  
  
      defaultLocale({
          decimal: ".",
          thousands: ",",
          grouping: [3],
          currency: ["$", ""]
      });
  
      function defaultLocale(definition) {
          locale$1 = formatLocale(definition);
          exports.format = locale$1.format;
          exports.formatPrefix = locale$1.formatPrefix;
          return locale$1;
      }
  
      var precisionFixed = function(step) {
          return Math.max(0, -exponent$1(Math.abs(step)));
      };
  
      var precisionPrefix = function(step, value) {
          return Math.max(0, Math.max(-8, Math.min(8, Math.floor(exponent$1(value) / 3))) * 3 - exponent$1(Math.abs(step)));
      };
  
      var precisionRound = function(step, max) {
          step = Math.abs(step), max = Math.abs(max) - step;
          return Math.max(0, exponent$1(max) - exponent$1(step)) + 1;
      };
  
  // Adds floating point numbers with twice the normal precision.
  // Reference: J. R. Shewchuk, Adaptive Precision Floating-Point Arithmetic and
  // Fast Robust Geometric Predicates, Discrete & Computational Geometry 18(3)
  // 305–363 (1997).
  // Code adapted from GeographicLib by Charles F. F. Karney,
  // http://geographiclib.sourceforge.net/
  
      var adder = function() {
          return new Adder;
      };
  
      function Adder() {
          this.reset();
      }
  
      Adder.prototype = {
          constructor: Adder,
          reset: function() {
              this.s = // rounded value
                  this.t = 0; // exact error
          },
          add: function(y) {
              add$1(temp, y, this.t);
              add$1(this, temp.s, this.s);
              if (this.s) this.t += temp.t;
              else this.s = temp.t;
          },
          valueOf: function() {
              return this.s;
          }
      };
  
      var temp = new Adder;
  
      function add$1(adder, a, b) {
          var x = adder.s = a + b,
              bv = x - a,
              av = x - bv;
          adder.t = (a - av) + (b - bv);
      }
  
      var epsilon$2 = 1e-6;
      var epsilon2$1 = 1e-12;
      var pi$3 = Math.PI;
      var halfPi$2 = pi$3 / 2;
      var quarterPi = pi$3 / 4;
      var tau$3 = pi$3 * 2;
  
      var degrees$1 = 180 / pi$3;
      var radians = pi$3 / 180;
  
      var abs = Math.abs;
      var atan = Math.atan;
      var atan2 = Math.atan2;
      var cos$1 = Math.cos;
      var ceil = Math.ceil;
      var exp = Math.exp;
  
      var log = Math.log;
      var pow = Math.pow;
      var sin$1 = Math.sin;
      var sign = Math.sign || function(x) { return x > 0 ? 1 : x < 0 ? -1 : 0; };
      var sqrt = Math.sqrt;
      var tan = Math.tan;
  
      function acos(x) {
          return x > 1 ? 0 : x < -1 ? pi$3 : Math.acos(x);
      }
  
      function asin(x) {
          return x > 1 ? halfPi$2 : x < -1 ? -halfPi$2 : Math.asin(x);
      }
  
      function haversin(x) {
          return (x = sin$1(x / 2)) * x;
      }
  
      function noop$1() {}
  
      function streamGeometry(geometry, stream) {
          if (geometry && streamGeometryType.hasOwnProperty(geometry.type)) {
              streamGeometryType[geometry.type](geometry, stream);
          }
      }
  
      var streamObjectType = {
          Feature: function(object, stream) {
              streamGeometry(object.geometry, stream);
          },
          FeatureCollection: function(object, stream) {
              var features = object.features, i = -1, n = features.length;
              while (++i < n) streamGeometry(features[i].geometry, stream);
          }
      };
  
      var streamGeometryType = {
          Sphere: function(object, stream) {
              stream.sphere();
          },
          Point: function(object, stream) {
              object = object.coordinates;
              stream.point(object[0], object[1], object[2]);
          },
          MultiPoint: function(object, stream) {
              var coordinates = object.coordinates, i = -1, n = coordinates.length;
              while (++i < n) object = coordinates[i], stream.point(object[0], object[1], object[2]);
          },
          LineString: function(object, stream) {
              streamLine(object.coordinates, stream, 0);
          },
          MultiLineString: function(object, stream) {
              var coordinates = object.coordinates, i = -1, n = coordinates.length;
              while (++i < n) streamLine(coordinates[i], stream, 0);
          },
          Polygon: function(object, stream) {
              streamPolygon(object.coordinates, stream);
          },
          MultiPolygon: function(object, stream) {
              var coordinates = object.coordinates, i = -1, n = coordinates.length;
              while (++i < n) streamPolygon(coordinates[i], stream);
          },
          GeometryCollection: function(object, stream) {
              var geometries = object.geometries, i = -1, n = geometries.length;
              while (++i < n) streamGeometry(geometries[i], stream);
          }
      };
  
      function streamLine(coordinates, stream, closed) {
          var i = -1, n = coordinates.length - closed, coordinate;
          stream.lineStart();
          while (++i < n) coordinate = coordinates[i], stream.point(coordinate[0], coordinate[1], coordinate[2]);
          stream.lineEnd();
      }
  
      function streamPolygon(coordinates, stream) {
          var i = -1, n = coordinates.length;
          stream.polygonStart();
          while (++i < n) streamLine(coordinates[i], stream, 1);
          stream.polygonEnd();
      }
  
      var geoStream = function(object, stream) {
          if (object && streamObjectType.hasOwnProperty(object.type)) {
              streamObjectType[object.type](object, stream);
          } else {
              streamGeometry(object, stream);
          }
      };
  
      var areaRingSum = adder();
  
      var areaSum = adder();
      var lambda00;
      var phi00;
      var lambda0;
      var cosPhi0;
      var sinPhi0;
  
      var areaStream = {
          point: noop$1,
          lineStart: noop$1,
          lineEnd: noop$1,
          polygonStart: function() {
              areaRingSum.reset();
              areaStream.lineStart = areaRingStart;
              areaStream.lineEnd = areaRingEnd;
          },
          polygonEnd: function() {
              var areaRing = +areaRingSum;
              areaSum.add(areaRing < 0 ? tau$3 + areaRing : areaRing);
              this.lineStart = this.lineEnd = this.point = noop$1;
          },
          sphere: function() {
              areaSum.add(tau$3);
          }
      };
  
      function areaRingStart() {
          areaStream.point = areaPointFirst;
      }
  
      function areaRingEnd() {
          areaPoint(lambda00, phi00);
      }
  
      function areaPointFirst(lambda, phi) {
          areaStream.point = areaPoint;
          lambda00 = lambda, phi00 = phi;
          lambda *= radians, phi *= radians;
          lambda0 = lambda, cosPhi0 = cos$1(phi = phi / 2 + quarterPi), sinPhi0 = sin$1(phi);
      }
  
      function areaPoint(lambda, phi) {
          lambda *= radians, phi *= radians;
          phi = phi / 2 + quarterPi; // half the angular distance from south pole
  
          // Spherical excess E for a spherical triangle with vertices: south pole,
          // previous point, current point.  Uses a formula derived from Cagnoli’s
          // theorem.  See Todhunter, Spherical Trig. (1871), Sec. 103, Eq. (2).
          var dLambda = lambda - lambda0,
              sdLambda = dLambda >= 0 ? 1 : -1,
              adLambda = sdLambda * dLambda,
              cosPhi = cos$1(phi),
              sinPhi = sin$1(phi),
              k = sinPhi0 * sinPhi,
              u = cosPhi0 * cosPhi + k * cos$1(adLambda),
              v = k * sdLambda * sin$1(adLambda);
          areaRingSum.add(atan2(v, u));
  
          // Advance the previous points.
          lambda0 = lambda, cosPhi0 = cosPhi, sinPhi0 = sinPhi;
      }
  
      var area = function(object) {
          areaSum.reset();
          geoStream(object, areaStream);
          return areaSum * 2;
      };
  
      function spherical(cartesian) {
          return [atan2(cartesian[1], cartesian[0]), asin(cartesian[2])];
      }
  
      function cartesian(spherical) {
          var lambda = spherical[0], phi = spherical[1], cosPhi = cos$1(phi);
          return [cosPhi * cos$1(lambda), cosPhi * sin$1(lambda), sin$1(phi)];
      }
  
      function cartesianDot(a, b) {
          return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
      }
  
      function cartesianCross(a, b) {
          return [a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]];
      }
  
  // TODO return a
      function cartesianAddInPlace(a, b) {
          a[0] += b[0], a[1] += b[1], a[2] += b[2];
      }
  
      function cartesianScale(vector, k) {
          return [vector[0] * k, vector[1] * k, vector[2] * k];
      }
  
  // TODO return d
      function cartesianNormalizeInPlace(d) {
          var l = sqrt(d[0] * d[0] + d[1] * d[1] + d[2] * d[2]);
          d[0] /= l, d[1] /= l, d[2] /= l;
      }
  
      var lambda0$1;
      var phi0;
      var lambda1;
      var phi1;
      var lambda2;
      var lambda00$1;
      var phi00$1;
      var p0;
      var deltaSum = adder();
      var ranges;
      var range;
  
      var boundsStream = {
          point: boundsPoint,
          lineStart: boundsLineStart,
          lineEnd: boundsLineEnd,
          polygonStart: function() {
              boundsStream.point = boundsRingPoint;
              boundsStream.lineStart = boundsRingStart;
              boundsStream.lineEnd = boundsRingEnd;
              deltaSum.reset();
              areaStream.polygonStart();
          },
          polygonEnd: function() {
              areaStream.polygonEnd();
              boundsStream.point = boundsPoint;
              boundsStream.lineStart = boundsLineStart;
              boundsStream.lineEnd = boundsLineEnd;
              if (areaRingSum < 0) lambda0$1 = -(lambda1 = 180), phi0 = -(phi1 = 90);
              else if (deltaSum > epsilon$2) phi1 = 90;
              else if (deltaSum < -epsilon$2) phi0 = -90;
              range[0] = lambda0$1, range[1] = lambda1;
          }
      };
  
      function boundsPoint(lambda, phi) {
          ranges.push(range = [lambda0$1 = lambda, lambda1 = lambda]);
          if (phi < phi0) phi0 = phi;
          if (phi > phi1) phi1 = phi;
      }
  
      function linePoint(lambda, phi) {
          var p = cartesian([lambda * radians, phi * radians]);
          if (p0) {
              var normal = cartesianCross(p0, p),
                  equatorial = [normal[1], -normal[0], 0],
                  inflection = cartesianCross(equatorial, normal);
              cartesianNormalizeInPlace(inflection);
              inflection = spherical(inflection);
              var delta = lambda - lambda2,
                  sign$$1 = delta > 0 ? 1 : -1,
                  lambdai = inflection[0] * degrees$1 * sign$$1,
                  phii,
                  antimeridian = abs(delta) > 180;
              if (antimeridian ^ (sign$$1 * lambda2 < lambdai && lambdai < sign$$1 * lambda)) {
                  phii = inflection[1] * degrees$1;
                  if (phii > phi1) phi1 = phii;
              } else if (lambdai = (lambdai + 360) % 360 - 180, antimeridian ^ (sign$$1 * lambda2 < lambdai && lambdai < sign$$1 * lambda)) {
                  phii = -inflection[1] * degrees$1;
                  if (phii < phi0) phi0 = phii;
              } else {
                  if (phi < phi0) phi0 = phi;
                  if (phi > phi1) phi1 = phi;
              }
              if (antimeridian) {
                  if (lambda < lambda2) {
                      if (angle(lambda0$1, lambda) > angle(lambda0$1, lambda1)) lambda1 = lambda;
                  } else {
                      if (angle(lambda, lambda1) > angle(lambda0$1, lambda1)) lambda0$1 = lambda;
                  }
              } else {
                  if (lambda1 >= lambda0$1) {
                      if (lambda < lambda0$1) lambda0$1 = lambda;
                      if (lambda > lambda1) lambda1 = lambda;
                  } else {
                      if (lambda > lambda2) {
                          if (angle(lambda0$1, lambda) > angle(lambda0$1, lambda1)) lambda1 = lambda;
                      } else {
                          if (angle(lambda, lambda1) > angle(lambda0$1, lambda1)) lambda0$1 = lambda;
                      }
                  }
              }
          } else {
              ranges.push(range = [lambda0$1 = lambda, lambda1 = lambda]);
          }
          if (phi < phi0) phi0 = phi;
          if (phi > phi1) phi1 = phi;
          p0 = p, lambda2 = lambda;
      }
  
      function boundsLineStart() {
          boundsStream.point = linePoint;
      }
  
      function boundsLineEnd() {
          range[0] = lambda0$1, range[1] = lambda1;
          boundsStream.point = boundsPoint;
          p0 = null;
      }
  
      function boundsRingPoint(lambda, phi) {
          if (p0) {
              var delta = lambda - lambda2;
              deltaSum.add(abs(delta) > 180 ? delta + (delta > 0 ? 360 : -360) : delta);
          } else {
              lambda00$1 = lambda, phi00$1 = phi;
          }
          areaStream.point(lambda, phi);
          linePoint(lambda, phi);
      }
  
      function boundsRingStart() {
          areaStream.lineStart();
      }
  
      function boundsRingEnd() {
          boundsRingPoint(lambda00$1, phi00$1);
          areaStream.lineEnd();
          if (abs(deltaSum) > epsilon$2) lambda0$1 = -(lambda1 = 180);
          range[0] = lambda0$1, range[1] = lambda1;
          p0 = null;
      }
  
  // Finds the left-right distance between two longitudes.
  // This is almost the same as (lambda1 - lambda0 + 360°) % 360°, except that we want
  // the distance between ±180° to be 360°.
      function angle(lambda0, lambda1) {
          return (lambda1 -= lambda0) < 0 ? lambda1 + 360 : lambda1;
      }
  
      function rangeCompare(a, b) {
          return a[0] - b[0];
      }
  
      function rangeContains(range, x) {
          return range[0] <= range[1] ? range[0] <= x && x <= range[1] : x < range[0] || range[1] < x;
      }
  
      var bounds = function(feature) {
          var i, n, a, b, merged, deltaMax, delta;
  
          phi1 = lambda1 = -(lambda0$1 = phi0 = Infinity);
          ranges = [];
          geoStream(feature, boundsStream);
  
          // First, sort ranges by their minimum longitudes.
          if (n = ranges.length) {
              ranges.sort(rangeCompare);
  
              // Then, merge any ranges that overlap.
              for (i = 1, a = ranges[0], merged = [a]; i < n; ++i) {
                  b = ranges[i];
                  if (rangeContains(a, b[0]) || rangeContains(a, b[1])) {
                      if (angle(a[0], b[1]) > angle(a[0], a[1])) a[1] = b[1];
                      if (angle(b[0], a[1]) > angle(a[0], a[1])) a[0] = b[0];
                  } else {
                      merged.push(a = b);
                  }
              }
  
              // Finally, find the largest gap between the merged ranges.
              // The final bounding box will be the inverse of this gap.
              for (deltaMax = -Infinity, n = merged.length - 1, i = 0, a = merged[n]; i <= n; a = b, ++i) {
                  b = merged[i];
                  if ((delta = angle(a[1], b[0])) > deltaMax) deltaMax = delta, lambda0$1 = b[0], lambda1 = a[1];
              }
          }
  
          ranges = range = null;
  
          return lambda0$1 === Infinity || phi0 === Infinity
              ? [[NaN, NaN], [NaN, NaN]]
              : [[lambda0$1, phi0], [lambda1, phi1]];
      };
  
      var W0;
      var W1;
      var X0;
      var Y0;
      var Z0;
      var X1;
      var Y1;
      var Z1;
      var X2;
      var Y2;
      var Z2;
      var lambda00$2;
      var phi00$2;
      var x0;
      var y0;
      var z0; // previous point
  
      var centroidStream = {
          sphere: noop$1,
          point: centroidPoint,
          lineStart: centroidLineStart,
          lineEnd: centroidLineEnd,
          polygonStart: function() {
              centroidStream.lineStart = centroidRingStart;
              centroidStream.lineEnd = centroidRingEnd;
          },
          polygonEnd: function() {
              centroidStream.lineStart = centroidLineStart;
              centroidStream.lineEnd = centroidLineEnd;
          }
      };
  
  // Arithmetic mean of Cartesian vectors.
      function centroidPoint(lambda, phi) {
          lambda *= radians, phi *= radians;
          var cosPhi = cos$1(phi);
          centroidPointCartesian(cosPhi * cos$1(lambda), cosPhi * sin$1(lambda), sin$1(phi));
      }
  
      function centroidPointCartesian(x, y, z) {
          ++W0;
          X0 += (x - X0) / W0;
          Y0 += (y - Y0) / W0;
          Z0 += (z - Z0) / W0;
      }
  
      function centroidLineStart() {
          centroidStream.point = centroidLinePointFirst;
      }
  
      function centroidLinePointFirst(lambda, phi) {
          lambda *= radians, phi *= radians;
          var cosPhi = cos$1(phi);
          x0 = cosPhi * cos$1(lambda);
          y0 = cosPhi * sin$1(lambda);
          z0 = sin$1(phi);
          centroidStream.point = centroidLinePoint;
          centroidPointCartesian(x0, y0, z0);
      }
  
      function centroidLinePoint(lambda, phi) {
          lambda *= radians, phi *= radians;
          var cosPhi = cos$1(phi),
              x = cosPhi * cos$1(lambda),
              y = cosPhi * sin$1(lambda),
              z = sin$1(phi),
              w = atan2(sqrt((w = y0 * z - z0 * y) * w + (w = z0 * x - x0 * z) * w + (w = x0 * y - y0 * x) * w), x0 * x + y0 * y + z0 * z);
          W1 += w;
          X1 += w * (x0 + (x0 = x));
          Y1 += w * (y0 + (y0 = y));
          Z1 += w * (z0 + (z0 = z));
          centroidPointCartesian(x0, y0, z0);
      }
  
      function centroidLineEnd() {
          centroidStream.point = centroidPoint;
      }
  
  // See J. E. Brock, The Inertia Tensor for a Spherical Triangle,
  // J. Applied Mechanics 42, 239 (1975).
      function centroidRingStart() {
          centroidStream.point = centroidRingPointFirst;
      }
  
      function centroidRingEnd() {
          centroidRingPoint(lambda00$2, phi00$2);
          centroidStream.point = centroidPoint;
      }
  
      function centroidRingPointFirst(lambda, phi) {
          lambda00$2 = lambda, phi00$2 = phi;
          lambda *= radians, phi *= radians;
          centroidStream.point = centroidRingPoint;
          var cosPhi = cos$1(phi);
          x0 = cosPhi * cos$1(lambda);
          y0 = cosPhi * sin$1(lambda);
          z0 = sin$1(phi);
          centroidPointCartesian(x0, y0, z0);
      }
  
      function centroidRingPoint(lambda, phi) {
          lambda *= radians, phi *= radians;
          var cosPhi = cos$1(phi),
              x = cosPhi * cos$1(lambda),
              y = cosPhi * sin$1(lambda),
              z = sin$1(phi),
              cx = y0 * z - z0 * y,
              cy = z0 * x - x0 * z,
              cz = x0 * y - y0 * x,
              m = sqrt(cx * cx + cy * cy + cz * cz),
              w = asin(m), // line weight = angle
              v = m && -w / m; // area weight multiplier
          X2 += v * cx;
          Y2 += v * cy;
          Z2 += v * cz;
          W1 += w;
          X1 += w * (x0 + (x0 = x));
          Y1 += w * (y0 + (y0 = y));
          Z1 += w * (z0 + (z0 = z));
          centroidPointCartesian(x0, y0, z0);
      }
  
      var centroid = function(object) {
          W0 = W1 =
              X0 = Y0 = Z0 =
                  X1 = Y1 = Z1 =
                      X2 = Y2 = Z2 = 0;
          geoStream(object, centroidStream);
  
          var x = X2,
              y = Y2,
              z = Z2,
              m = x * x + y * y + z * z;
  
          // If the area-weighted ccentroid is undefined, fall back to length-weighted ccentroid.
          if (m < epsilon2$1) {
              x = X1, y = Y1, z = Z1;
              // If the feature has zero length, fall back to arithmetic mean of point vectors.
              if (W1 < epsilon$2) x = X0, y = Y0, z = Z0;
              m = x * x + y * y + z * z;
              // If the feature still has an undefined ccentroid, then return.
              if (m < epsilon2$1) return [NaN, NaN];
          }
  
          return [atan2(y, x) * degrees$1, asin(z / sqrt(m)) * degrees$1];
      };
  
      var constant$7 = function(x) {
          return function() {
              return x;
          };
      };
  
      var compose = function(a, b) {
  
          function compose(x, y) {
              return x = a(x, y), b(x[0], x[1]);
          }
  
          if (a.invert && b.invert) compose.invert = function(x, y) {
              return x = b.invert(x, y), x && a.invert(x[0], x[1]);
          };
  
          return compose;
      };
  
      function rotationIdentity(lambda, phi) {
          return [lambda > pi$3 ? lambda - tau$3 : lambda < -pi$3 ? lambda + tau$3 : lambda, phi];
      }
  
      rotationIdentity.invert = rotationIdentity;
  
      function rotateRadians(deltaLambda, deltaPhi, deltaGamma) {
          return (deltaLambda %= tau$3) ? (deltaPhi || deltaGamma ? compose(rotationLambda(deltaLambda), rotationPhiGamma(deltaPhi, deltaGamma))
              : rotationLambda(deltaLambda))
              : (deltaPhi || deltaGamma ? rotationPhiGamma(deltaPhi, deltaGamma)
                  : rotationIdentity);
      }
  
      function forwardRotationLambda(deltaLambda) {
          return function(lambda, phi) {
              return lambda += deltaLambda, [lambda > pi$3 ? lambda - tau$3 : lambda < -pi$3 ? lambda + tau$3 : lambda, phi];
          };
      }
  
      function rotationLambda(deltaLambda) {
          var rotation = forwardRotationLambda(deltaLambda);
          rotation.invert = forwardRotationLambda(-deltaLambda);
          return rotation;
      }
  
      function rotationPhiGamma(deltaPhi, deltaGamma) {
          var cosDeltaPhi = cos$1(deltaPhi),
              sinDeltaPhi = sin$1(deltaPhi),
              cosDeltaGamma = cos$1(deltaGamma),
              sinDeltaGamma = sin$1(deltaGamma);
  
          function rotation(lambda, phi) {
              var cosPhi = cos$1(phi),
                  x = cos$1(lambda) * cosPhi,
                  y = sin$1(lambda) * cosPhi,
                  z = sin$1(phi),
                  k = z * cosDeltaPhi + x * sinDeltaPhi;
              return [
                  atan2(y * cosDeltaGamma - k * sinDeltaGamma, x * cosDeltaPhi - z * sinDeltaPhi),
                  asin(k * cosDeltaGamma + y * sinDeltaGamma)
              ];
          }
  
          rotation.invert = function(lambda, phi) {
              var cosPhi = cos$1(phi),
                  x = cos$1(lambda) * cosPhi,
                  y = sin$1(lambda) * cosPhi,
                  z = sin$1(phi),
                  k = z * cosDeltaGamma - y * sinDeltaGamma;
              return [
                  atan2(y * cosDeltaGamma + z * sinDeltaGamma, x * cosDeltaPhi + k * sinDeltaPhi),
                  asin(k * cosDeltaPhi - x * sinDeltaPhi)
              ];
          };
  
          return rotation;
      }
  
      var rotation = function(rotate) {
          rotate = rotateRadians(rotate[0] * radians, rotate[1] * radians, rotate.length > 2 ? rotate[2] * radians : 0);
  
          function forward(coordinates) {
              coordinates = rotate(coordinates[0] * radians, coordinates[1] * radians);
              return coordinates[0] *= degrees$1, coordinates[1] *= degrees$1, coordinates;
          }
  
          forward.invert = function(coordinates) {
              coordinates = rotate.invert(coordinates[0] * radians, coordinates[1] * radians);
              return coordinates[0] *= degrees$1, coordinates[1] *= degrees$1, coordinates;
          };
  
          return forward;
      };
  
  // Generates a circle centered at [0°, 0°], with a given radius and precision.
      function circleStream(stream, radius, delta, direction, t0, t1) {
          if (!delta) return;
          var cosRadius = cos$1(radius),
              sinRadius = sin$1(radius),
              step = direction * delta;
          if (t0 == null) {
              t0 = radius + direction * tau$3;
              t1 = radius - step / 2;
          } else {
              t0 = circleRadius(cosRadius, t0);
              t1 = circleRadius(cosRadius, t1);
              if (direction > 0 ? t0 < t1 : t0 > t1) t0 += direction * tau$3;
          }
          for (var point, t = t0; direction > 0 ? t > t1 : t < t1; t -= step) {
              point = spherical([cosRadius, -sinRadius * cos$1(t), -sinRadius * sin$1(t)]);
              stream.point(point[0], point[1]);
          }
      }
  
  // Returns the signed angle of a cartesian point relative to [cosRadius, 0, 0].
      function circleRadius(cosRadius, point) {
          point = cartesian(point), point[0] -= cosRadius;
          cartesianNormalizeInPlace(point);
          var radius = acos(-point[1]);
          return ((-point[2] < 0 ? -radius : radius) + tau$3 - epsilon$2) % tau$3;
      }
  
      var circle = function() {
          var center = constant$7([0, 0]),
              radius = constant$7(90),
              precision = constant$7(6),
              ring,
              rotate,
              stream = {point: point};
  
          function point(x, y) {
              ring.push(x = rotate(x, y));
              x[0] *= degrees$1, x[1] *= degrees$1;
          }
  
          function circle() {
              var c = center.apply(this, arguments),
                  r = radius.apply(this, arguments) * radians,
                  p = precision.apply(this, arguments) * radians;
              ring = [];
              rotate = rotateRadians(-c[0] * radians, -c[1] * radians, 0).invert;
              circleStream(stream, r, p, 1);
              c = {type: "Polygon", coordinates: [ring]};
              ring = rotate = null;
              return c;
          }
  
          circle.center = function(_) {
              return arguments.length ? (center = typeof _ === "function" ? _ : constant$7([+_[0], +_[1]]), circle) : center;
          };
  
          circle.radius = function(_) {
              return arguments.length ? (radius = typeof _ === "function" ? _ : constant$7(+_), circle) : radius;
          };
  
          circle.precision = function(_) {
              return arguments.length ? (precision = typeof _ === "function" ? _ : constant$7(+_), circle) : precision;
          };
  
          return circle;
      };
  
      var clipBuffer = function() {
          var lines = [],
              line;
          return {
              point: function(x, y) {
                  line.push([x, y]);
              },
              lineStart: function() {
                  lines.push(line = []);
              },
              lineEnd: noop$1,
              rejoin: function() {
                  if (lines.length > 1) lines.push(lines.pop().concat(lines.shift()));
              },
              result: function() {
                  var result = lines;
                  lines = [];
                  line = null;
                  return result;
              }
          };
      };
  
      var clipLine = function(a, b, x0, y0, x1, y1) {
          var ax = a[0],
              ay = a[1],
              bx = b[0],
              by = b[1],
              t0 = 0,
              t1 = 1,
              dx = bx - ax,
              dy = by - ay,
              r;
  
          r = x0 - ax;
          if (!dx && r > 0) return;
          r /= dx;
          if (dx < 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          } else if (dx > 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          }
  
          r = x1 - ax;
          if (!dx && r < 0) return;
          r /= dx;
          if (dx < 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          } else if (dx > 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          }
  
          r = y0 - ay;
          if (!dy && r > 0) return;
          r /= dy;
          if (dy < 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          } else if (dy > 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          }
  
          r = y1 - ay;
          if (!dy && r < 0) return;
          r /= dy;
          if (dy < 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          } else if (dy > 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          }
  
          if (t0 > 0) a[0] = ax + t0 * dx, a[1] = ay + t0 * dy;
          if (t1 < 1) b[0] = ax + t1 * dx, b[1] = ay + t1 * dy;
          return true;
      };
  
      var pointEqual = function(a, b) {
          return abs(a[0] - b[0]) < epsilon$2 && abs(a[1] - b[1]) < epsilon$2;
      };
  
      function Intersection(point, points, other, entry) {
          this.x = point;
          this.z = points;
          this.o = other; // another intersection
          this.e = entry; // is an entry?
          this.v = false; // visited
          this.n = this.p = null; // next & previous
      }
  
  // A generalized polygon clipping algorithm: given a polygon that has been cut
  // into its visible line segments, and rejoins the segments by interpolating
  // along the clip edge.
      var clipPolygon = function(segments, compareIntersection, startInside, interpolate, stream) {
          var subject = [],
              clip = [],
              i,
              n;
  
          segments.forEach(function(segment) {
              if ((n = segment.length - 1) <= 0) return;
              var n, p0 = segment[0], p1 = segment[n], x;
  
              // If the first and last points of a segment are coincident, then treat as a
              // closed ring. TODO if all rings are closed, then the winding order of the
              // exterior ring should be checked.
              if (pointEqual(p0, p1)) {
                  stream.lineStart();
                  for (i = 0; i < n; ++i) stream.point((p0 = segment[i])[0], p0[1]);
                  stream.lineEnd();
                  return;
              }
  
              subject.push(x = new Intersection(p0, segment, null, true));
              clip.push(x.o = new Intersection(p0, null, x, false));
              subject.push(x = new Intersection(p1, segment, null, false));
              clip.push(x.o = new Intersection(p1, null, x, true));
          });
  
          if (!subject.length) return;
  
          clip.sort(compareIntersection);
          link$1(subject);
          link$1(clip);
  
          for (i = 0, n = clip.length; i < n; ++i) {
              clip[i].e = startInside = !startInside;
          }
  
          var start = subject[0],
              points,
              point;
  
          while (1) {
              // Find first unvisited intersection.
              var current = start,
                  isSubject = true;
              while (current.v) if ((current = current.n) === start) return;
              points = current.z;
              stream.lineStart();
              do {
                  current.v = current.o.v = true;
                  if (current.e) {
                      if (isSubject) {
                          for (i = 0, n = points.length; i < n; ++i) stream.point((point = points[i])[0], point[1]);
                      } else {
                          interpolate(current.x, current.n.x, 1, stream);
                      }
                      current = current.n;
                  } else {
                      if (isSubject) {
                          points = current.p.z;
                          for (i = points.length - 1; i >= 0; --i) stream.point((point = points[i])[0], point[1]);
                      } else {
                          interpolate(current.x, current.p.x, -1, stream);
                      }
                      current = current.p;
                  }
                  current = current.o;
                  points = current.z;
                  isSubject = !isSubject;
              } while (!current.v);
              stream.lineEnd();
          }
      };
  
      function link$1(array) {
          if (!(n = array.length)) return;
          var n,
              i = 0,
              a = array[0],
              b;
          while (++i < n) {
              a.n = b = array[i];
              b.p = a;
              a = b;
          }
          a.n = b = array[0];
          b.p = a;
      }
  
      var clipMax = 1e9;
      var clipMin = -clipMax;
  
  // TODO Use d3-polygon’s polygonContains here for the ring check?
  // TODO Eliminate duplicate buffering in clipBuffer and polygon.push?
  
      function clipExtent(x0, y0, x1, y1) {
  
          function visible(x, y) {
              return x0 <= x && x <= x1 && y0 <= y && y <= y1;
          }
  
          function interpolate(from, to, direction, stream) {
              var a = 0, a1 = 0;
              if (from == null
                  || (a = corner(from, direction)) !== (a1 = corner(to, direction))
                  || comparePoint(from, to) < 0 ^ direction > 0) {
                  do stream.point(a === 0 || a === 3 ? x0 : x1, a > 1 ? y1 : y0);
                  while ((a = (a + direction + 4) % 4) !== a1);
              } else {
                  stream.point(to[0], to[1]);
              }
          }
  
          function corner(p, direction) {
              return abs(p[0] - x0) < epsilon$2 ? direction > 0 ? 0 : 3
                  : abs(p[0] - x1) < epsilon$2 ? direction > 0 ? 2 : 1
                      : abs(p[1] - y0) < epsilon$2 ? direction > 0 ? 1 : 0
                          : direction > 0 ? 3 : 2; // abs(p[1] - y1) < epsilon
          }
  
          function compareIntersection(a, b) {
              return comparePoint(a.x, b.x);
          }
  
          function comparePoint(a, b) {
              var ca = corner(a, 1),
                  cb = corner(b, 1);
              return ca !== cb ? ca - cb
                  : ca === 0 ? b[1] - a[1]
                      : ca === 1 ? a[0] - b[0]
                          : ca === 2 ? a[1] - b[1]
                              : b[0] - a[0];
          }
  
          return function(stream) {
              var activeStream = stream,
                  bufferStream = clipBuffer(),
                  segments,
                  polygon,
                  ring,
                  x__, y__, v__, // first point
                  x_, y_, v_, // previous point
                  first,
                  clean;
  
              var clipStream = {
                  point: point,
                  lineStart: lineStart,
                  lineEnd: lineEnd,
                  polygonStart: polygonStart,
                  polygonEnd: polygonEnd
              };
  
              function point(x, y) {
                  if (visible(x, y)) activeStream.point(x, y);
              }
  
              function polygonInside() {
                  var winding = 0;
  
                  for (var i = 0, n = polygon.length; i < n; ++i) {
                      for (var ring = polygon[i], j = 1, m = ring.length, point = ring[0], a0, a1, b0 = point[0], b1 = point[1]; j < m; ++j) {
                          a0 = b0, a1 = b1, point = ring[j], b0 = point[0], b1 = point[1];
                          if (a1 <= y1) { if (b1 > y1 && (b0 - a0) * (y1 - a1) > (b1 - a1) * (x0 - a0)) ++winding; }
                          else { if (b1 <= y1 && (b0 - a0) * (y1 - a1) < (b1 - a1) * (x0 - a0)) --winding; }
                      }
                  }
  
                  return winding;
              }
  
              // Buffer geometry within a polygon and then clip it en masse.
              function polygonStart() {
                  activeStream = bufferStream, segments = [], polygon = [], clean = true;
              }
  
              function polygonEnd() {
                  var startInside = polygonInside(),
                      cleanInside = clean && startInside,
                      visible = (segments = merge(segments)).length;
                  if (cleanInside || visible) {
                      stream.polygonStart();
                      if (cleanInside) {
                          stream.lineStart();
                          interpolate(null, null, 1, stream);
                          stream.lineEnd();
                      }
                      if (visible) {
                          clipPolygon(segments, compareIntersection, startInside, interpolate, stream);
                      }
                      stream.polygonEnd();
                  }
                  activeStream = stream, segments = polygon = ring = null;
              }
  
              function lineStart() {
                  clipStream.point = linePoint;
                  if (polygon) polygon.push(ring = []);
                  first = true;
                  v_ = false;
                  x_ = y_ = NaN;
              }
  
              // TODO rather than special-case polygons, simply handle them separately.
              // Ideally, coincident intersection points should be jittered to avoid
              // clipping issues.
              function lineEnd() {
                  if (segments) {
                      linePoint(x__, y__);
                      if (v__ && v_) bufferStream.rejoin();
                      segments.push(bufferStream.result());
                  }
                  clipStream.point = point;
                  if (v_) activeStream.lineEnd();
              }
  
              function linePoint(x, y) {
                  var v = visible(x, y);
                  if (polygon) ring.push([x, y]);
                  if (first) {
                      x__ = x, y__ = y, v__ = v;
                      first = false;
                      if (v) {
                          activeStream.lineStart();
                          activeStream.point(x, y);
                      }
                  } else {
                      if (v && v_) activeStream.point(x, y);
                      else {
                          var a = [x_ = Math.max(clipMin, Math.min(clipMax, x_)), y_ = Math.max(clipMin, Math.min(clipMax, y_))],
                              b = [x = Math.max(clipMin, Math.min(clipMax, x)), y = Math.max(clipMin, Math.min(clipMax, y))];
                          if (clipLine(a, b, x0, y0, x1, y1)) {
                              if (!v_) {
                                  activeStream.lineStart();
                                  activeStream.point(a[0], a[1]);
                              }
                              activeStream.point(b[0], b[1]);
                              if (!v) activeStream.lineEnd();
                              clean = false;
                          } else if (v) {
                              activeStream.lineStart();
                              activeStream.point(x, y);
                              clean = false;
                          }
                      }
                  }
                  x_ = x, y_ = y, v_ = v;
              }
  
              return clipStream;
          };
      }
  
      var extent$1 = function() {
          var x0 = 0,
              y0 = 0,
              x1 = 960,
              y1 = 500,
              cache,
              cacheStream,
              clip;
  
          return clip = {
              stream: function(stream) {
                  return cache && cacheStream === stream ? cache : cache = clipExtent(x0, y0, x1, y1)(cacheStream = stream);
              },
              extent: function(_) {
                  return arguments.length ? (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1], cache = cacheStream = null, clip) : [[x0, y0], [x1, y1]];
              }
          };
      };
  
      var sum$1 = adder();
  
      var polygonContains = function(polygon, point) {
          var lambda = point[0],
              phi = point[1],
              normal = [sin$1(lambda), -cos$1(lambda), 0],
              angle = 0,
              winding = 0;
  
          sum$1.reset();
  
          for (var i = 0, n = polygon.length; i < n; ++i) {
              if (!(m = (ring = polygon[i]).length)) continue;
              var ring,
                  m,
                  point0 = ring[m - 1],
                  lambda0 = point0[0],
                  phi0 = point0[1] / 2 + quarterPi,
                  sinPhi0 = sin$1(phi0),
                  cosPhi0 = cos$1(phi0);
  
              for (var j = 0; j < m; ++j, lambda0 = lambda1, sinPhi0 = sinPhi1, cosPhi0 = cosPhi1, point0 = point1) {
                  var point1 = ring[j],
                      lambda1 = point1[0],
                      phi1 = point1[1] / 2 + quarterPi,
                      sinPhi1 = sin$1(phi1),
                      cosPhi1 = cos$1(phi1),
                      delta = lambda1 - lambda0,
                      sign$$1 = delta >= 0 ? 1 : -1,
                      absDelta = sign$$1 * delta,
                      antimeridian = absDelta > pi$3,
                      k = sinPhi0 * sinPhi1;
  
                  sum$1.add(atan2(k * sign$$1 * sin$1(absDelta), cosPhi0 * cosPhi1 + k * cos$1(absDelta)));
                  angle += antimeridian ? delta + sign$$1 * tau$3 : delta;
  
                  // Are the longitudes either side of the point’s meridian (lambda),
                  // and are the latitudes smaller than the parallel (phi)?
                  if (antimeridian ^ lambda0 >= lambda ^ lambda1 >= lambda) {
                      var arc = cartesianCross(cartesian(point0), cartesian(point1));
                      cartesianNormalizeInPlace(arc);
                      var intersection = cartesianCross(normal, arc);
                      cartesianNormalizeInPlace(intersection);
                      var phiArc = (antimeridian ^ delta >= 0 ? -1 : 1) * asin(intersection[2]);
                      if (phi > phiArc || phi === phiArc && (arc[0] || arc[1])) {
                          winding += antimeridian ^ delta >= 0 ? 1 : -1;
                      }
                  }
              }
          }
  
          // First, determine whether the South pole is inside or outside:
          //
          // It is inside if:
          // * the polygon winds around it in a clockwise direction.
          // * the polygon does not (cumulatively) wind around it, but has a negative
          //   (counter-clockwise) area.
          //
          // Second, count the (signed) number of times a segment crosses a lambda
          // from the point to the South pole.  If it is zero, then the point is the
          // same side as the South pole.
  
          return (angle < -epsilon$2 || angle < epsilon$2 && sum$1 < -epsilon$2) ^ (winding & 1);
      };
  
      var lengthSum = adder();
      var lambda0$2;
      var sinPhi0$1;
      var cosPhi0$1;
  
      var lengthStream = {
          sphere: noop$1,
          point: noop$1,
          lineStart: lengthLineStart,
          lineEnd: noop$1,
          polygonStart: noop$1,
          polygonEnd: noop$1
      };
  
      function lengthLineStart() {
          lengthStream.point = lengthPointFirst;
          lengthStream.lineEnd = lengthLineEnd;
      }
  
      function lengthLineEnd() {
          lengthStream.point = lengthStream.lineEnd = noop$1;
      }
  
      function lengthPointFirst(lambda, phi) {
          lambda *= radians, phi *= radians;
          lambda0$2 = lambda, sinPhi0$1 = sin$1(phi), cosPhi0$1 = cos$1(phi);
          lengthStream.point = lengthPoint;
      }
  
      function lengthPoint(lambda, phi) {
          lambda *= radians, phi *= radians;
          var sinPhi = sin$1(phi),
              cosPhi = cos$1(phi),
              delta = abs(lambda - lambda0$2),
              cosDelta = cos$1(delta),
              sinDelta = sin$1(delta),
              x = cosPhi * sinDelta,
              y = cosPhi0$1 * sinPhi - sinPhi0$1 * cosPhi * cosDelta,
              z = sinPhi0$1 * sinPhi + cosPhi0$1 * cosPhi * cosDelta;
          lengthSum.add(atan2(sqrt(x * x + y * y), z));
          lambda0$2 = lambda, sinPhi0$1 = sinPhi, cosPhi0$1 = cosPhi;
      }
  
      var length$1 = function(object) {
          lengthSum.reset();
          geoStream(object, lengthStream);
          return +lengthSum;
      };
  
      var coordinates = [null, null];
      var object$1 = {type: "LineString", coordinates: coordinates};
  
      var distance = function(a, b) {
          coordinates[0] = a;
          coordinates[1] = b;
          return length$1(object$1);
      };
  
      var containsObjectType = {
          Feature: function(object, point) {
              return containsGeometry(object.geometry, point);
          },
          FeatureCollection: function(object, point) {
              var features = object.features, i = -1, n = features.length;
              while (++i < n) if (containsGeometry(features[i].geometry, point)) return true;
              return false;
          }
      };
  
      var containsGeometryType = {
          Sphere: function() {
              return true;
          },
          Point: function(object, point) {
              return containsPoint(object.coordinates, point);
          },
          MultiPoint: function(object, point) {
              var coordinates = object.coordinates, i = -1, n = coordinates.length;
              while (++i < n) if (containsPoint(coordinates[i], point)) return true;
              return false;
          },
          LineString: function(object, point) {
              return containsLine(object.coordinates, point);
          },
          MultiLineString: function(object, point) {
              var coordinates = object.coordinates, i = -1, n = coordinates.length;
              while (++i < n) if (containsLine(coordinates[i], point)) return true;
              return false;
          },
          Polygon: function(object, point) {
              return containsPolygon(object.coordinates, point);
          },
          MultiPolygon: function(object, point) {
              var coordinates = object.coordinates, i = -1, n = coordinates.length;
              while (++i < n) if (containsPolygon(coordinates[i], point)) return true;
              return false;
          },
          GeometryCollection: function(object, point) {
              var geometries = object.geometries, i = -1, n = geometries.length;
              while (++i < n) if (containsGeometry(geometries[i], point)) return true;
              return false;
          }
      };
  
      function containsGeometry(geometry, point) {
          return geometry && containsGeometryType.hasOwnProperty(geometry.type)
              ? containsGeometryType[geometry.type](geometry, point)
              : false;
      }
  
      function containsPoint(coordinates, point) {
          return distance(coordinates, point) === 0;
      }
  
      function containsLine(coordinates, point) {
          var ab = distance(coordinates[0], coordinates[1]),
              ao = distance(coordinates[0], point),
              ob = distance(point, coordinates[1]);
          return ao + ob <= ab + epsilon$2;
      }
  
      function containsPolygon(coordinates, point) {
          return !!polygonContains(coordinates.map(ringRadians), pointRadians(point));
      }
  
      function ringRadians(ring) {
          return ring = ring.map(pointRadians), ring.pop(), ring;
      }
  
      function pointRadians(point) {
          return [point[0] * radians, point[1] * radians];
      }
  
      var contains = function(object, point) {
          return (object && containsObjectType.hasOwnProperty(object.type)
              ? containsObjectType[object.type]
              : containsGeometry)(object, point);
      };
  
      function graticuleX(y0, y1, dy) {
          var y = sequence(y0, y1 - epsilon$2, dy).concat(y1);
          return function(x) { return y.map(function(y) { return [x, y]; }); };
      }
  
      function graticuleY(x0, x1, dx) {
          var x = sequence(x0, x1 - epsilon$2, dx).concat(x1);
          return function(y) { return x.map(function(x) { return [x, y]; }); };
      }
  
      function graticule() {
          var x1, x0, X1, X0,
              y1, y0, Y1, Y0,
              dx = 10, dy = dx, DX = 90, DY = 360,
              x, y, X, Y,
              precision = 2.5;
  
          function graticule() {
              return {type: "MultiLineString", coordinates: lines()};
          }
  
          function lines() {
              return sequence(ceil(X0 / DX) * DX, X1, DX).map(X)
                  .concat(sequence(ceil(Y0 / DY) * DY, Y1, DY).map(Y))
                  .concat(sequence(ceil(x0 / dx) * dx, x1, dx).filter(function(x) { return abs(x % DX) > epsilon$2; }).map(x))
                  .concat(sequence(ceil(y0 / dy) * dy, y1, dy).filter(function(y) { return abs(y % DY) > epsilon$2; }).map(y));
          }
  
          graticule.lines = function() {
              return lines().map(function(coordinates) { return {type: "LineString", coordinates: coordinates}; });
          };
  
          graticule.outline = function() {
              return {
                  type: "Polygon",
                  coordinates: [
                      X(X0).concat(
                          Y(Y1).slice(1),
                          X(X1).reverse().slice(1),
                          Y(Y0).reverse().slice(1))
                  ]
              };
          };
  
          graticule.extent = function(_) {
              if (!arguments.length) return graticule.extentMinor();
              return graticule.extentMajor(_).extentMinor(_);
          };
  
          graticule.extentMajor = function(_) {
              if (!arguments.length) return [[X0, Y0], [X1, Y1]];
              X0 = +_[0][0], X1 = +_[1][0];
              Y0 = +_[0][1], Y1 = +_[1][1];
              if (X0 > X1) _ = X0, X0 = X1, X1 = _;
              if (Y0 > Y1) _ = Y0, Y0 = Y1, Y1 = _;
              return graticule.precision(precision);
          };
  
          graticule.extentMinor = function(_) {
              if (!arguments.length) return [[x0, y0], [x1, y1]];
              x0 = +_[0][0], x1 = +_[1][0];
              y0 = +_[0][1], y1 = +_[1][1];
              if (x0 > x1) _ = x0, x0 = x1, x1 = _;
              if (y0 > y1) _ = y0, y0 = y1, y1 = _;
              return graticule.precision(precision);
          };
  
          graticule.step = function(_) {
              if (!arguments.length) return graticule.stepMinor();
              return graticule.stepMajor(_).stepMinor(_);
          };
  
          graticule.stepMajor = function(_) {
              if (!arguments.length) return [DX, DY];
              DX = +_[0], DY = +_[1];
              return graticule;
          };
  
          graticule.stepMinor = function(_) {
              if (!arguments.length) return [dx, dy];
              dx = +_[0], dy = +_[1];
              return graticule;
          };
  
          graticule.precision = function(_) {
              if (!arguments.length) return precision;
              precision = +_;
              x = graticuleX(y0, y1, 90);
              y = graticuleY(x0, x1, precision);
              X = graticuleX(Y0, Y1, 90);
              Y = graticuleY(X0, X1, precision);
              return graticule;
          };
  
          return graticule
              .extentMajor([[-180, -90 + epsilon$2], [180, 90 - epsilon$2]])
              .extentMinor([[-180, -80 - epsilon$2], [180, 80 + epsilon$2]]);
      }
  
      function graticule10() {
          return graticule()();
      }
  
      var interpolate$1 = function(a, b) {
          var x0 = a[0] * radians,
              y0 = a[1] * radians,
              x1 = b[0] * radians,
              y1 = b[1] * radians,
              cy0 = cos$1(y0),
              sy0 = sin$1(y0),
              cy1 = cos$1(y1),
              sy1 = sin$1(y1),
              kx0 = cy0 * cos$1(x0),
              ky0 = cy0 * sin$1(x0),
              kx1 = cy1 * cos$1(x1),
              ky1 = cy1 * sin$1(x1),
              d = 2 * asin(sqrt(haversin(y1 - y0) + cy0 * cy1 * haversin(x1 - x0))),
              k = sin$1(d);
  
          var interpolate = d ? function(t) {
              var B = sin$1(t *= d) / k,
                  A = sin$1(d - t) / k,
                  x = A * kx0 + B * kx1,
                  y = A * ky0 + B * ky1,
                  z = A * sy0 + B * sy1;
              return [
                  atan2(y, x) * degrees$1,
                  atan2(z, sqrt(x * x + y * y)) * degrees$1
              ];
          } : function() {
              return [x0 * degrees$1, y0 * degrees$1];
          };
  
          interpolate.distance = d;
  
          return interpolate;
      };
  
      var identity$4 = function(x) {
          return x;
      };
  
      var areaSum$1 = adder();
      var areaRingSum$1 = adder();
      var x00;
      var y00;
      var x0$1;
      var y0$1;
  
      var areaStream$1 = {
          point: noop$1,
          lineStart: noop$1,
          lineEnd: noop$1,
          polygonStart: function() {
              areaStream$1.lineStart = areaRingStart$1;
              areaStream$1.lineEnd = areaRingEnd$1;
          },
          polygonEnd: function() {
              areaStream$1.lineStart = areaStream$1.lineEnd = areaStream$1.point = noop$1;
              areaSum$1.add(abs(areaRingSum$1));
              areaRingSum$1.reset();
          },
          result: function() {
              var area = areaSum$1 / 2;
              areaSum$1.reset();
              return area;
          }
      };
  
      function areaRingStart$1() {
          areaStream$1.point = areaPointFirst$1;
      }
  
      function areaPointFirst$1(x, y) {
          areaStream$1.point = areaPoint$1;
          x00 = x0$1 = x, y00 = y0$1 = y;
      }
  
      function areaPoint$1(x, y) {
          areaRingSum$1.add(y0$1 * x - x0$1 * y);
          x0$1 = x, y0$1 = y;
      }
  
      function areaRingEnd$1() {
          areaPoint$1(x00, y00);
      }
  
      var x0$2 = Infinity;
      var y0$2 = x0$2;
      var x1 = -x0$2;
      var y1 = x1;
  
      var boundsStream$1 = {
          point: boundsPoint$1,
          lineStart: noop$1,
          lineEnd: noop$1,
          polygonStart: noop$1,
          polygonEnd: noop$1,
          result: function() {
              var bounds = [[x0$2, y0$2], [x1, y1]];
              x1 = y1 = -(y0$2 = x0$2 = Infinity);
              return bounds;
          }
      };
  
      function boundsPoint$1(x, y) {
          if (x < x0$2) x0$2 = x;
          if (x > x1) x1 = x;
          if (y < y0$2) y0$2 = y;
          if (y > y1) y1 = y;
      }
  
  // TODO Enforce positive area for exterior, negative area for interior?
  
      var X0$1 = 0;
      var Y0$1 = 0;
      var Z0$1 = 0;
      var X1$1 = 0;
      var Y1$1 = 0;
      var Z1$1 = 0;
      var X2$1 = 0;
      var Y2$1 = 0;
      var Z2$1 = 0;
      var x00$1;
      var y00$1;
      var x0$3;
      var y0$3;
  
      var centroidStream$1 = {
          point: centroidPoint$1,
          lineStart: centroidLineStart$1,
          lineEnd: centroidLineEnd$1,
          polygonStart: function() {
              centroidStream$1.lineStart = centroidRingStart$1;
              centroidStream$1.lineEnd = centroidRingEnd$1;
          },
          polygonEnd: function() {
              centroidStream$1.point = centroidPoint$1;
              centroidStream$1.lineStart = centroidLineStart$1;
              centroidStream$1.lineEnd = centroidLineEnd$1;
          },
          result: function() {
              var centroid = Z2$1 ? [X2$1 / Z2$1, Y2$1 / Z2$1]
                  : Z1$1 ? [X1$1 / Z1$1, Y1$1 / Z1$1]
                      : Z0$1 ? [X0$1 / Z0$1, Y0$1 / Z0$1]
                          : [NaN, NaN];
              X0$1 = Y0$1 = Z0$1 =
                  X1$1 = Y1$1 = Z1$1 =
                      X2$1 = Y2$1 = Z2$1 = 0;
              return centroid;
          }
      };
  
      function centroidPoint$1(x, y) {
          X0$1 += x;
          Y0$1 += y;
          ++Z0$1;
      }
  
      function centroidLineStart$1() {
          centroidStream$1.point = centroidPointFirstLine;
      }
  
      function centroidPointFirstLine(x, y) {
          centroidStream$1.point = centroidPointLine;
          centroidPoint$1(x0$3 = x, y0$3 = y);
      }
  
      function centroidPointLine(x, y) {
          var dx = x - x0$3, dy = y - y0$3, z = sqrt(dx * dx + dy * dy);
          X1$1 += z * (x0$3 + x) / 2;
          Y1$1 += z * (y0$3 + y) / 2;
          Z1$1 += z;
          centroidPoint$1(x0$3 = x, y0$3 = y);
      }
  
      function centroidLineEnd$1() {
          centroidStream$1.point = centroidPoint$1;
      }
  
      function centroidRingStart$1() {
          centroidStream$1.point = centroidPointFirstRing;
      }
  
      function centroidRingEnd$1() {
          centroidPointRing(x00$1, y00$1);
      }
  
      function centroidPointFirstRing(x, y) {
          centroidStream$1.point = centroidPointRing;
          centroidPoint$1(x00$1 = x0$3 = x, y00$1 = y0$3 = y);
      }
  
      function centroidPointRing(x, y) {
          var dx = x - x0$3,
              dy = y - y0$3,
              z = sqrt(dx * dx + dy * dy);
  
          X1$1 += z * (x0$3 + x) / 2;
          Y1$1 += z * (y0$3 + y) / 2;
          Z1$1 += z;
  
          z = y0$3 * x - x0$3 * y;
          X2$1 += z * (x0$3 + x);
          Y2$1 += z * (y0$3 + y);
          Z2$1 += z * 3;
          centroidPoint$1(x0$3 = x, y0$3 = y);
      }
  
      function PathContext(context) {
          this._context = context;
      }
  
      PathContext.prototype = {
          _radius: 4.5,
          pointRadius: function(_) {
              return this._radius = _, this;
          },
          polygonStart: function() {
              this._line = 0;
          },
          polygonEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._point = 0;
          },
          lineEnd: function() {
              if (this._line === 0) this._context.closePath();
              this._point = NaN;
          },
          point: function(x, y) {
              switch (this._point) {
                  case 0: {
                      this._context.moveTo(x, y);
                      this._point = 1;
                      break;
                  }
                  case 1: {
                      this._context.lineTo(x, y);
                      break;
                  }
                  default: {
                      this._context.moveTo(x + this._radius, y);
                      this._context.arc(x, y, this._radius, 0, tau$3);
                      break;
                  }
              }
          },
          result: noop$1
      };
  
      var lengthSum$1 = adder();
      var lengthRing;
      var x00$2;
      var y00$2;
      var x0$4;
      var y0$4;
  
      var lengthStream$1 = {
          point: noop$1,
          lineStart: function() {
              lengthStream$1.point = lengthPointFirst$1;
          },
          lineEnd: function() {
              if (lengthRing) lengthPoint$1(x00$2, y00$2);
              lengthStream$1.point = noop$1;
          },
          polygonStart: function() {
              lengthRing = true;
          },
          polygonEnd: function() {
              lengthRing = null;
          },
          result: function() {
              var length = +lengthSum$1;
              lengthSum$1.reset();
              return length;
          }
      };
  
      function lengthPointFirst$1(x, y) {
          lengthStream$1.point = lengthPoint$1;
          x00$2 = x0$4 = x, y00$2 = y0$4 = y;
      }
  
      function lengthPoint$1(x, y) {
          x0$4 -= x, y0$4 -= y;
          lengthSum$1.add(sqrt(x0$4 * x0$4 + y0$4 * y0$4));
          x0$4 = x, y0$4 = y;
      }
  
      function PathString() {
          this._string = [];
      }
  
      PathString.prototype = {
          _circle: circle$1(4.5),
          pointRadius: function(_) {
              return this._circle = circle$1(_), this;
          },
          polygonStart: function() {
              this._line = 0;
          },
          polygonEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._point = 0;
          },
          lineEnd: function() {
              if (this._line === 0) this._string.push("Z");
              this._point = NaN;
          },
          point: function(x, y) {
              switch (this._point) {
                  case 0: {
                      this._string.push("M", x, ",", y);
                      this._point = 1;
                      break;
                  }
                  case 1: {
                      this._string.push("L", x, ",", y);
                      break;
                  }
                  default: {
                      this._string.push("M", x, ",", y, this._circle);
                      break;
                  }
              }
          },
          result: function() {
              if (this._string.length) {
                  var result = this._string.join("");
                  this._string = [];
                  return result;
              }
          }
      };
  
      function circle$1(radius) {
          return "m0," + radius
              + "a" + radius + "," + radius + " 0 1,1 0," + -2 * radius
              + "a" + radius + "," + radius + " 0 1,1 0," + 2 * radius
              + "z";
      }
  
      var index$1 = function(projection, context) {
          var pointRadius = 4.5,
              projectionStream,
              contextStream;
  
          function path(object) {
              if (object) {
                  if (typeof pointRadius === "function") contextStream.pointRadius(+pointRadius.apply(this, arguments));
                  geoStream(object, projectionStream(contextStream));
              }
              return contextStream.result();
          }
  
          path.area = function(object) {
              geoStream(object, projectionStream(areaStream$1));
              return areaStream$1.result();
          };
  
          path.measure = function(object) {
              geoStream(object, projectionStream(lengthStream$1));
              return lengthStream$1.result();
          };
  
          path.bounds = function(object) {
              geoStream(object, projectionStream(boundsStream$1));
              return boundsStream$1.result();
          };
  
          path.centroid = function(object) {
              geoStream(object, projectionStream(centroidStream$1));
              return centroidStream$1.result();
          };
  
          path.projection = function(_) {
              return arguments.length ? (projectionStream = _ == null ? (projection = null, identity$4) : (projection = _).stream, path) : projection;
          };
  
          path.context = function(_) {
              if (!arguments.length) return context;
              contextStream = _ == null ? (context = null, new PathString) : new PathContext(context = _);
              if (typeof pointRadius !== "function") contextStream.pointRadius(pointRadius);
              return path;
          };
  
          path.pointRadius = function(_) {
              if (!arguments.length) return pointRadius;
              pointRadius = typeof _ === "function" ? _ : (contextStream.pointRadius(+_), +_);
              return path;
          };
  
          return path.projection(projection).context(context);
      };
  
      var clip = function(pointVisible, clipLine, interpolate, start) {
          return function(rotate, sink) {
              var line = clipLine(sink),
                  rotatedStart = rotate.invert(start[0], start[1]),
                  ringBuffer = clipBuffer(),
                  ringSink = clipLine(ringBuffer),
                  polygonStarted = false,
                  polygon,
                  segments,
                  ring;
  
              var clip = {
                  point: point,
                  lineStart: lineStart,
                  lineEnd: lineEnd,
                  polygonStart: function() {
                      clip.point = pointRing;
                      clip.lineStart = ringStart;
                      clip.lineEnd = ringEnd;
                      segments = [];
                      polygon = [];
                  },
                  polygonEnd: function() {
                      clip.point = point;
                      clip.lineStart = lineStart;
                      clip.lineEnd = lineEnd;
                      segments = merge(segments);
                      var startInside = polygonContains(polygon, rotatedStart);
                      if (segments.length) {
                          if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
                          clipPolygon(segments, compareIntersection, startInside, interpolate, sink);
                      } else if (startInside) {
                          if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
                          sink.lineStart();
                          interpolate(null, null, 1, sink);
                          sink.lineEnd();
                      }
                      if (polygonStarted) sink.polygonEnd(), polygonStarted = false;
                      segments = polygon = null;
                  },
                  sphere: function() {
                      sink.polygonStart();
                      sink.lineStart();
                      interpolate(null, null, 1, sink);
                      sink.lineEnd();
                      sink.polygonEnd();
                  }
              };
  
              function point(lambda, phi) {
                  var point = rotate(lambda, phi);
                  if (pointVisible(lambda = point[0], phi = point[1])) sink.point(lambda, phi);
              }
  
              function pointLine(lambda, phi) {
                  var point = rotate(lambda, phi);
                  line.point(point[0], point[1]);
              }
  
              function lineStart() {
                  clip.point = pointLine;
                  line.lineStart();
              }
  
              function lineEnd() {
                  clip.point = point;
                  line.lineEnd();
              }
  
              function pointRing(lambda, phi) {
                  ring.push([lambda, phi]);
                  var point = rotate(lambda, phi);
                  ringSink.point(point[0], point[1]);
              }
  
              function ringStart() {
                  ringSink.lineStart();
                  ring = [];
              }
  
              function ringEnd() {
                  pointRing(ring[0][0], ring[0][1]);
                  ringSink.lineEnd();
  
                  var clean = ringSink.clean(),
                      ringSegments = ringBuffer.result(),
                      i, n = ringSegments.length, m,
                      segment,
                      point;
  
                  ring.pop();
                  polygon.push(ring);
                  ring = null;
  
                  if (!n) return;
  
                  // No intersections.
                  if (clean & 1) {
                      segment = ringSegments[0];
                      if ((m = segment.length - 1) > 0) {
                          if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
                          sink.lineStart();
                          for (i = 0; i < m; ++i) sink.point((point = segment[i])[0], point[1]);
                          sink.lineEnd();
                      }
                      return;
                  }
  
                  // Rejoin connected segments.
                  // TODO reuse ringBuffer.rejoin()?
                  if (n > 1 && clean & 2) ringSegments.push(ringSegments.pop().concat(ringSegments.shift()));
  
                  segments.push(ringSegments.filter(validSegment));
              }
  
              return clip;
          };
      };
  
      function validSegment(segment) {
          return segment.length > 1;
      }
  
  // Intersections are sorted along the clip edge. For both antimeridian cutting
  // and circle clipping, the same comparison is used.
      function compareIntersection(a, b) {
          return ((a = a.x)[0] < 0 ? a[1] - halfPi$2 - epsilon$2 : halfPi$2 - a[1])
              - ((b = b.x)[0] < 0 ? b[1] - halfPi$2 - epsilon$2 : halfPi$2 - b[1]);
      }
  
      var clipAntimeridian = clip(
          function() { return true; },
          clipAntimeridianLine,
          clipAntimeridianInterpolate,
          [-pi$3, -halfPi$2]
      );
  
  // Takes a line and cuts into visible segments. Return values: 0 - there were
  // intersections or the line was empty; 1 - no intersections; 2 - there were
  // intersections, and the first and last segments should be rejoined.
      function clipAntimeridianLine(stream) {
          var lambda0 = NaN,
              phi0 = NaN,
              sign0 = NaN,
              clean; // no intersections
  
          return {
              lineStart: function() {
                  stream.lineStart();
                  clean = 1;
              },
              point: function(lambda1, phi1) {
                  var sign1 = lambda1 > 0 ? pi$3 : -pi$3,
                      delta = abs(lambda1 - lambda0);
                  if (abs(delta - pi$3) < epsilon$2) { // line crosses a pole
                      stream.point(lambda0, phi0 = (phi0 + phi1) / 2 > 0 ? halfPi$2 : -halfPi$2);
                      stream.point(sign0, phi0);
                      stream.lineEnd();
                      stream.lineStart();
                      stream.point(sign1, phi0);
                      stream.point(lambda1, phi0);
                      clean = 0;
                  } else if (sign0 !== sign1 && delta >= pi$3) { // line crosses antimeridian
                      if (abs(lambda0 - sign0) < epsilon$2) lambda0 -= sign0 * epsilon$2; // handle degeneracies
                      if (abs(lambda1 - sign1) < epsilon$2) lambda1 -= sign1 * epsilon$2;
                      phi0 = clipAntimeridianIntersect(lambda0, phi0, lambda1, phi1);
                      stream.point(sign0, phi0);
                      stream.lineEnd();
                      stream.lineStart();
                      stream.point(sign1, phi0);
                      clean = 0;
                  }
                  stream.point(lambda0 = lambda1, phi0 = phi1);
                  sign0 = sign1;
              },
              lineEnd: function() {
                  stream.lineEnd();
                  lambda0 = phi0 = NaN;
              },
              clean: function() {
                  return 2 - clean; // if intersections, rejoin first and last segments
              }
          };
      }
  
      function clipAntimeridianIntersect(lambda0, phi0, lambda1, phi1) {
          var cosPhi0,
              cosPhi1,
              sinLambda0Lambda1 = sin$1(lambda0 - lambda1);
          return abs(sinLambda0Lambda1) > epsilon$2
              ? atan((sin$1(phi0) * (cosPhi1 = cos$1(phi1)) * sin$1(lambda1)
                  - sin$1(phi1) * (cosPhi0 = cos$1(phi0)) * sin$1(lambda0))
                  / (cosPhi0 * cosPhi1 * sinLambda0Lambda1))
              : (phi0 + phi1) / 2;
      }
  
      function clipAntimeridianInterpolate(from, to, direction, stream) {
          var phi;
          if (from == null) {
              phi = direction * halfPi$2;
              stream.point(-pi$3, phi);
              stream.point(0, phi);
              stream.point(pi$3, phi);
              stream.point(pi$3, 0);
              stream.point(pi$3, -phi);
              stream.point(0, -phi);
              stream.point(-pi$3, -phi);
              stream.point(-pi$3, 0);
              stream.point(-pi$3, phi);
          } else if (abs(from[0] - to[0]) > epsilon$2) {
              var lambda = from[0] < to[0] ? pi$3 : -pi$3;
              phi = direction * lambda / 2;
              stream.point(-lambda, phi);
              stream.point(0, phi);
              stream.point(lambda, phi);
          } else {
              stream.point(to[0], to[1]);
          }
      }
  
      var clipCircle = function(radius, delta) {
          var cr = cos$1(radius),
              smallRadius = cr > 0,
              notHemisphere = abs(cr) > epsilon$2; // TODO optimise for this common case
  
          function interpolate(from, to, direction, stream) {
              circleStream(stream, radius, delta, direction, from, to);
          }
  
          function visible(lambda, phi) {
              return cos$1(lambda) * cos$1(phi) > cr;
          }
  
          // Takes a line and cuts into visible segments. Return values used for polygon
          // clipping: 0 - there were intersections or the line was empty; 1 - no
          // intersections 2 - there were intersections, and the first and last segments
          // should be rejoined.
          function clipLine(stream) {
              var point0, // previous point
                  c0, // code for previous point
                  v0, // visibility of previous point
                  v00, // visibility of first point
                  clean; // no intersections
              return {
                  lineStart: function() {
                      v00 = v0 = false;
                      clean = 1;
                  },
                  point: function(lambda, phi) {
                      var point1 = [lambda, phi],
                          point2,
                          v = visible(lambda, phi),
                          c = smallRadius
                              ? v ? 0 : code(lambda, phi)
                              : v ? code(lambda + (lambda < 0 ? pi$3 : -pi$3), phi) : 0;
                      if (!point0 && (v00 = v0 = v)) stream.lineStart();
                      // Handle degeneracies.
                      // TODO ignore if not clipping polygons.
                      if (v !== v0) {
                          point2 = intersect(point0, point1);
                          if (pointEqual(point0, point2) || pointEqual(point1, point2)) {
                              point1[0] += epsilon$2;
                              point1[1] += epsilon$2;
                              v = visible(point1[0], point1[1]);
                          }
                      }
                      if (v !== v0) {
                          clean = 0;
                          if (v) {
                              // outside going in
                              stream.lineStart();
                              point2 = intersect(point1, point0);
                              stream.point(point2[0], point2[1]);
                          } else {
                              // inside going out
                              point2 = intersect(point0, point1);
                              stream.point(point2[0], point2[1]);
                              stream.lineEnd();
                          }
                          point0 = point2;
                      } else if (notHemisphere && point0 && smallRadius ^ v) {
                          var t;
                          // If the codes for two points are different, or are both zero,
                          // and there this segment intersects with the small circle.
                          if (!(c & c0) && (t = intersect(point1, point0, true))) {
                              clean = 0;
                              if (smallRadius) {
                                  stream.lineStart();
                                  stream.point(t[0][0], t[0][1]);
                                  stream.point(t[1][0], t[1][1]);
                                  stream.lineEnd();
                              } else {
                                  stream.point(t[1][0], t[1][1]);
                                  stream.lineEnd();
                                  stream.lineStart();
                                  stream.point(t[0][0], t[0][1]);
                              }
                          }
                      }
                      if (v && (!point0 || !pointEqual(point0, point1))) {
                          stream.point(point1[0], point1[1]);
                      }
                      point0 = point1, v0 = v, c0 = c;
                  },
                  lineEnd: function() {
                      if (v0) stream.lineEnd();
                      point0 = null;
                  },
                  // Rejoin first and last segments if there were intersections and the first
                  // and last points were visible.
                  clean: function() {
                      return clean | ((v00 && v0) << 1);
                  }
              };
          }
  
          // Intersects the great circle between a and b with the clip circle.
          function intersect(a, b, two) {
              var pa = cartesian(a),
                  pb = cartesian(b);
  
              // We have two planes, n1.p = d1 and n2.p = d2.
              // Find intersection line p(t) = c1 n1 + c2 n2 + t (n1 ⨯ n2).
              var n1 = [1, 0, 0], // normal
                  n2 = cartesianCross(pa, pb),
                  n2n2 = cartesianDot(n2, n2),
                  n1n2 = n2[0], // cartesianDot(n1, n2),
                  determinant = n2n2 - n1n2 * n1n2;
  
              // Two polar points.
              if (!determinant) return !two && a;
  
              var c1 =  cr * n2n2 / determinant,
                  c2 = -cr * n1n2 / determinant,
                  n1xn2 = cartesianCross(n1, n2),
                  A = cartesianScale(n1, c1),
                  B = cartesianScale(n2, c2);
              cartesianAddInPlace(A, B);
  
              // Solve |p(t)|^2 = 1.
              var u = n1xn2,
                  w = cartesianDot(A, u),
                  uu = cartesianDot(u, u),
                  t2 = w * w - uu * (cartesianDot(A, A) - 1);
  
              if (t2 < 0) return;
  
              var t = sqrt(t2),
                  q = cartesianScale(u, (-w - t) / uu);
              cartesianAddInPlace(q, A);
              q = spherical(q);
  
              if (!two) return q;
  
              // Two intersection points.
              var lambda0 = a[0],
                  lambda1 = b[0],
                  phi0 = a[1],
                  phi1 = b[1],
                  z;
  
              if (lambda1 < lambda0) z = lambda0, lambda0 = lambda1, lambda1 = z;
  
              var delta = lambda1 - lambda0,
                  polar = abs(delta - pi$3) < epsilon$2,
                  meridian = polar || delta < epsilon$2;
  
              if (!polar && phi1 < phi0) z = phi0, phi0 = phi1, phi1 = z;
  
              // Check that the first point is between a and b.
              if (meridian
                      ? polar
                          ? phi0 + phi1 > 0 ^ q[1] < (abs(q[0] - lambda0) < epsilon$2 ? phi0 : phi1)
                          : phi0 <= q[1] && q[1] <= phi1
                      : delta > pi$3 ^ (lambda0 <= q[0] && q[0] <= lambda1)) {
                  var q1 = cartesianScale(u, (-w + t) / uu);
                  cartesianAddInPlace(q1, A);
                  return [q, spherical(q1)];
              }
          }
  
          // Generates a 4-bit vector representing the location of a point relative to
          // the small circle's bounding box.
          function code(lambda, phi) {
              var r = smallRadius ? radius : pi$3 - radius,
                  code = 0;
              if (lambda < -r) code |= 1; // left
              else if (lambda > r) code |= 2; // right
              if (phi < -r) code |= 4; // below
              else if (phi > r) code |= 8; // above
              return code;
          }
  
          return clip(visible, clipLine, interpolate, smallRadius ? [0, -radius] : [-pi$3, radius - pi$3]);
      };
  
      var transform = function(methods) {
          return {
              stream: transformer(methods)
          };
      };
  
      function transformer(methods) {
          return function(stream) {
              var s = new TransformStream;
              for (var key in methods) s[key] = methods[key];
              s.stream = stream;
              return s;
          };
      }
  
      function TransformStream() {}
  
      TransformStream.prototype = {
          constructor: TransformStream,
          point: function(x, y) { this.stream.point(x, y); },
          sphere: function() { this.stream.sphere(); },
          lineStart: function() { this.stream.lineStart(); },
          lineEnd: function() { this.stream.lineEnd(); },
          polygonStart: function() { this.stream.polygonStart(); },
          polygonEnd: function() { this.stream.polygonEnd(); }
      };
  
      function fitExtent(projection, extent, object) {
          var w = extent[1][0] - extent[0][0],
              h = extent[1][1] - extent[0][1],
              clip = projection.clipExtent && projection.clipExtent();
  
          projection
              .scale(150)
              .translate([0, 0]);
  
          if (clip != null) projection.clipExtent(null);
  
          geoStream(object, projection.stream(boundsStream$1));
  
          var b = boundsStream$1.result(),
              k = Math.min(w / (b[1][0] - b[0][0]), h / (b[1][1] - b[0][1])),
              x = +extent[0][0] + (w - k * (b[1][0] + b[0][0])) / 2,
              y = +extent[0][1] + (h - k * (b[1][1] + b[0][1])) / 2;
  
          if (clip != null) projection.clipExtent(clip);
  
          return projection
              .scale(k * 150)
              .translate([x, y]);
      }
  
      function fitSize(projection, size, object) {
          return fitExtent(projection, [[0, 0], size], object);
      }
  
      var maxDepth = 16;
      var cosMinDistance = cos$1(30 * radians); // cos(minimum angular distance)
  
      var resample = function(project, delta2) {
          return +delta2 ? resample$1(project, delta2) : resampleNone(project);
      };
  
      function resampleNone(project) {
          return transformer({
              point: function(x, y) {
                  x = project(x, y);
                  this.stream.point(x[0], x[1]);
              }
          });
      }
  
      function resample$1(project, delta2) {
  
          function resampleLineTo(x0, y0, lambda0, a0, b0, c0, x1, y1, lambda1, a1, b1, c1, depth, stream) {
              var dx = x1 - x0,
                  dy = y1 - y0,
                  d2 = dx * dx + dy * dy;
              if (d2 > 4 * delta2 && depth--) {
                  var a = a0 + a1,
                      b = b0 + b1,
                      c = c0 + c1,
                      m = sqrt(a * a + b * b + c * c),
                      phi2 = asin(c /= m),
                      lambda2 = abs(abs(c) - 1) < epsilon$2 || abs(lambda0 - lambda1) < epsilon$2 ? (lambda0 + lambda1) / 2 : atan2(b, a),
                      p = project(lambda2, phi2),
                      x2 = p[0],
                      y2 = p[1],
                      dx2 = x2 - x0,
                      dy2 = y2 - y0,
                      dz = dy * dx2 - dx * dy2;
                  if (dz * dz / d2 > delta2 // perpendicular projected distance
                      || abs((dx * dx2 + dy * dy2) / d2 - 0.5) > 0.3 // midpoint close to an end
                      || a0 * a1 + b0 * b1 + c0 * c1 < cosMinDistance) { // angular distance
                      resampleLineTo(x0, y0, lambda0, a0, b0, c0, x2, y2, lambda2, a /= m, b /= m, c, depth, stream);
                      stream.point(x2, y2);
                      resampleLineTo(x2, y2, lambda2, a, b, c, x1, y1, lambda1, a1, b1, c1, depth, stream);
                  }
              }
          }
          return function(stream) {
              var lambda00, x00, y00, a00, b00, c00, // first point
                  lambda0, x0, y0, a0, b0, c0; // previous point
  
              var resampleStream = {
                  point: point,
                  lineStart: lineStart,
                  lineEnd: lineEnd,
                  polygonStart: function() { stream.polygonStart(); resampleStream.lineStart = ringStart; },
                  polygonEnd: function() { stream.polygonEnd(); resampleStream.lineStart = lineStart; }
              };
  
              function point(x, y) {
                  x = project(x, y);
                  stream.point(x[0], x[1]);
              }
  
              function lineStart() {
                  x0 = NaN;
                  resampleStream.point = linePoint;
                  stream.lineStart();
              }
  
              function linePoint(lambda, phi) {
                  var c = cartesian([lambda, phi]), p = project(lambda, phi);
                  resampleLineTo(x0, y0, lambda0, a0, b0, c0, x0 = p[0], y0 = p[1], lambda0 = lambda, a0 = c[0], b0 = c[1], c0 = c[2], maxDepth, stream);
                  stream.point(x0, y0);
              }
  
              function lineEnd() {
                  resampleStream.point = point;
                  stream.lineEnd();
              }
  
              function ringStart() {
                  lineStart();
                  resampleStream.point = ringPoint;
                  resampleStream.lineEnd = ringEnd;
              }
  
              function ringPoint(lambda, phi) {
                  linePoint(lambda00 = lambda, phi), x00 = x0, y00 = y0, a00 = a0, b00 = b0, c00 = c0;
                  resampleStream.point = linePoint;
              }
  
              function ringEnd() {
                  resampleLineTo(x0, y0, lambda0, a0, b0, c0, x00, y00, lambda00, a00, b00, c00, maxDepth, stream);
                  resampleStream.lineEnd = lineEnd;
                  lineEnd();
              }
  
              return resampleStream;
          };
      }
  
      var transformRadians = transformer({
          point: function(x, y) {
              this.stream.point(x * radians, y * radians);
          }
      });
  
      function projection(project) {
          return projectionMutator(function() { return project; })();
      }
  
      function projectionMutator(projectAt) {
          var project,
              k = 150, // scale
              x = 480, y = 250, // translate
              dx, dy, lambda = 0, phi = 0, // center
              deltaLambda = 0, deltaPhi = 0, deltaGamma = 0, rotate, projectRotate, // rotate
              theta = null, preclip = clipAntimeridian, // clip angle
              x0 = null, y0, x1, y1, postclip = identity$4, // clip extent
              delta2 = 0.5, projectResample = resample(projectTransform, delta2), // precision
              cache,
              cacheStream;
  
          function projection(point) {
              point = projectRotate(point[0] * radians, point[1] * radians);
              return [point[0] * k + dx, dy - point[1] * k];
          }
  
          function invert(point) {
              point = projectRotate.invert((point[0] - dx) / k, (dy - point[1]) / k);
              return point && [point[0] * degrees$1, point[1] * degrees$1];
          }
  
          function projectTransform(x, y) {
              return x = project(x, y), [x[0] * k + dx, dy - x[1] * k];
          }
  
          projection.stream = function(stream) {
              return cache && cacheStream === stream ? cache : cache = transformRadians(preclip(rotate, projectResample(postclip(cacheStream = stream))));
          };
  
          projection.clipAngle = function(_) {
              return arguments.length ? (preclip = +_ ? clipCircle(theta = _ * radians, 6 * radians) : (theta = null, clipAntimeridian), reset()) : theta * degrees$1;
          };
  
          projection.clipExtent = function(_) {
              return arguments.length ? (postclip = _ == null ? (x0 = y0 = x1 = y1 = null, identity$4) : clipExtent(x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]), reset()) : x0 == null ? null : [[x0, y0], [x1, y1]];
          };
  
          projection.scale = function(_) {
              return arguments.length ? (k = +_, recenter()) : k;
          };
  
          projection.translate = function(_) {
              return arguments.length ? (x = +_[0], y = +_[1], recenter()) : [x, y];
          };
  
          projection.center = function(_) {
              return arguments.length ? (lambda = _[0] % 360 * radians, phi = _[1] % 360 * radians, recenter()) : [lambda * degrees$1, phi * degrees$1];
          };
  
          projection.rotate = function(_) {
              return arguments.length ? (deltaLambda = _[0] % 360 * radians, deltaPhi = _[1] % 360 * radians, deltaGamma = _.length > 2 ? _[2] % 360 * radians : 0, recenter()) : [deltaLambda * degrees$1, deltaPhi * degrees$1, deltaGamma * degrees$1];
          };
  
          projection.precision = function(_) {
              return arguments.length ? (projectResample = resample(projectTransform, delta2 = _ * _), reset()) : sqrt(delta2);
          };
  
          projection.fitExtent = function(extent, object) {
              return fitExtent(projection, extent, object);
          };
  
          projection.fitSize = function(size, object) {
              return fitSize(projection, size, object);
          };
  
          function recenter() {
              projectRotate = compose(rotate = rotateRadians(deltaLambda, deltaPhi, deltaGamma), project);
              var center = project(lambda, phi);
              dx = x - center[0] * k;
              dy = y + center[1] * k;
              return reset();
          }
  
          function reset() {
              cache = cacheStream = null;
              return projection;
          }
  
          return function() {
              project = projectAt.apply(this, arguments);
              projection.invert = project.invert && invert;
              return recenter();
          };
      }
  
      function conicProjection(projectAt) {
          var phi0 = 0,
              phi1 = pi$3 / 3,
              m = projectionMutator(projectAt),
              p = m(phi0, phi1);
  
          p.parallels = function(_) {
              return arguments.length ? m(phi0 = _[0] * radians, phi1 = _[1] * radians) : [phi0 * degrees$1, phi1 * degrees$1];
          };
  
          return p;
      }
  
      function cylindricalEqualAreaRaw(phi0) {
          var cosPhi0 = cos$1(phi0);
  
          function forward(lambda, phi) {
              return [lambda * cosPhi0, sin$1(phi) / cosPhi0];
          }
  
          forward.invert = function(x, y) {
              return [x / cosPhi0, asin(y * cosPhi0)];
          };
  
          return forward;
      }
  
      function conicEqualAreaRaw(y0, y1) {
          var sy0 = sin$1(y0), n = (sy0 + sin$1(y1)) / 2;
  
          // Are the parallels symmetrical around the Equator?
          if (abs(n) < epsilon$2) return cylindricalEqualAreaRaw(y0);
  
          var c = 1 + sy0 * (2 * n - sy0), r0 = sqrt(c) / n;
  
          function project(x, y) {
              var r = sqrt(c - 2 * n * sin$1(y)) / n;
              return [r * sin$1(x *= n), r0 - r * cos$1(x)];
          }
  
          project.invert = function(x, y) {
              var r0y = r0 - y;
              return [atan2(x, abs(r0y)) / n * sign(r0y), asin((c - (x * x + r0y * r0y) * n * n) / (2 * n))];
          };
  
          return project;
      }
  
      var conicEqualArea = function() {
          return conicProjection(conicEqualAreaRaw)
              .scale(155.424)
              .center([0, 33.6442]);
      };
  
      var albers = function() {
          return conicEqualArea()
              .parallels([29.5, 45.5])
              .scale(1070)
              .translate([480, 250])
              .rotate([96, 0])
              .center([-0.6, 38.7]);
      };
  
  // The projections must have mutually exclusive clip regions on the sphere,
  // as this will avoid emitting interleaving lines and polygons.
      function multiplex(streams) {
          var n = streams.length;
          return {
              point: function(x, y) { var i = -1; while (++i < n) streams[i].point(x, y); },
              sphere: function() { var i = -1; while (++i < n) streams[i].sphere(); },
              lineStart: function() { var i = -1; while (++i < n) streams[i].lineStart(); },
              lineEnd: function() { var i = -1; while (++i < n) streams[i].lineEnd(); },
              polygonStart: function() { var i = -1; while (++i < n) streams[i].polygonStart(); },
              polygonEnd: function() { var i = -1; while (++i < n) streams[i].polygonEnd(); }
          };
      }
  
  // A composite projection for the United States, configured by default for
  // 960×500. The projection also works quite well at 960×600 if you change the
  // scale to 1285 and adjust the translate accordingly. The set of standard
  // parallels for each region comes from USGS, which is published here:
  // http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html#albers
      var albersUsa = function() {
          var cache,
              cacheStream,
              lower48 = albers(), lower48Point,
              alaska = conicEqualArea().rotate([154, 0]).center([-2, 58.5]).parallels([55, 65]), alaskaPoint, // EPSG:3338
              hawaii = conicEqualArea().rotate([157, 0]).center([-3, 19.9]).parallels([8, 18]), hawaiiPoint, // ESRI:102007
              point, pointStream = {point: function(x, y) { point = [x, y]; }};
  
          function albersUsa(coordinates) {
              var x = coordinates[0], y = coordinates[1];
              return point = null,
              (lower48Point.point(x, y), point)
              || (alaskaPoint.point(x, y), point)
              || (hawaiiPoint.point(x, y), point);
          }
  
          albersUsa.invert = function(coordinates) {
              var k = lower48.scale(),
                  t = lower48.translate(),
                  x = (coordinates[0] - t[0]) / k,
                  y = (coordinates[1] - t[1]) / k;
              return (y >= 0.120 && y < 0.234 && x >= -0.425 && x < -0.214 ? alaska
                  : y >= 0.166 && y < 0.234 && x >= -0.214 && x < -0.115 ? hawaii
                      : lower48).invert(coordinates);
          };
  
          albersUsa.stream = function(stream) {
              return cache && cacheStream === stream ? cache : cache = multiplex([lower48.stream(cacheStream = stream), alaska.stream(stream), hawaii.stream(stream)]);
          };
  
          albersUsa.precision = function(_) {
              if (!arguments.length) return lower48.precision();
              lower48.precision(_), alaska.precision(_), hawaii.precision(_);
              return reset();
          };
  
          albersUsa.scale = function(_) {
              if (!arguments.length) return lower48.scale();
              lower48.scale(_), alaska.scale(_ * 0.35), hawaii.scale(_);
              return albersUsa.translate(lower48.translate());
          };
  
          albersUsa.translate = function(_) {
              if (!arguments.length) return lower48.translate();
              var k = lower48.scale(), x = +_[0], y = +_[1];
  
              lower48Point = lower48
                  .translate(_)
                  .clipExtent([[x - 0.455 * k, y - 0.238 * k], [x + 0.455 * k, y + 0.238 * k]])
                  .stream(pointStream);
  
              alaskaPoint = alaska
                  .translate([x - 0.307 * k, y + 0.201 * k])
                  .clipExtent([[x - 0.425 * k + epsilon$2, y + 0.120 * k + epsilon$2], [x - 0.214 * k - epsilon$2, y + 0.234 * k - epsilon$2]])
                  .stream(pointStream);
  
              hawaiiPoint = hawaii
                  .translate([x - 0.205 * k, y + 0.212 * k])
                  .clipExtent([[x - 0.214 * k + epsilon$2, y + 0.166 * k + epsilon$2], [x - 0.115 * k - epsilon$2, y + 0.234 * k - epsilon$2]])
                  .stream(pointStream);
  
              return reset();
          };
  
          albersUsa.fitExtent = function(extent, object) {
              return fitExtent(albersUsa, extent, object);
          };
  
          albersUsa.fitSize = function(size, object) {
              return fitSize(albersUsa, size, object);
          };
  
          function reset() {
              cache = cacheStream = null;
              return albersUsa;
          }
  
          return albersUsa.scale(1070);
      };
  
      function azimuthalRaw(scale) {
          return function(x, y) {
              var cx = cos$1(x),
                  cy = cos$1(y),
                  k = scale(cx * cy);
              return [
                  k * cy * sin$1(x),
                  k * sin$1(y)
              ];
          }
      }
  
      function azimuthalInvert(angle) {
          return function(x, y) {
              var z = sqrt(x * x + y * y),
                  c = angle(z),
                  sc = sin$1(c),
                  cc = cos$1(c);
              return [
                  atan2(x * sc, z * cc),
                  asin(z && y * sc / z)
              ];
          }
      }
  
      var azimuthalEqualAreaRaw = azimuthalRaw(function(cxcy) {
          return sqrt(2 / (1 + cxcy));
      });
  
      azimuthalEqualAreaRaw.invert = azimuthalInvert(function(z) {
          return 2 * asin(z / 2);
      });
  
      var azimuthalEqualArea = function() {
          return projection(azimuthalEqualAreaRaw)
              .scale(124.75)
              .clipAngle(180 - 1e-3);
      };
  
      var azimuthalEquidistantRaw = azimuthalRaw(function(c) {
          return (c = acos(c)) && c / sin$1(c);
      });
  
      azimuthalEquidistantRaw.invert = azimuthalInvert(function(z) {
          return z;
      });
  
      var azimuthalEquidistant = function() {
          return projection(azimuthalEquidistantRaw)
              .scale(79.4188)
              .clipAngle(180 - 1e-3);
      };
  
      function mercatorRaw(lambda, phi) {
          return [lambda, log(tan((halfPi$2 + phi) / 2))];
      }
  
      mercatorRaw.invert = function(x, y) {
          return [x, 2 * atan(exp(y)) - halfPi$2];
      };
  
      var mercator = function() {
          return mercatorProjection(mercatorRaw)
              .scale(961 / tau$3);
      };
  
      function mercatorProjection(project) {
          var m = projection(project),
              center = m.center,
              scale = m.scale,
              translate = m.translate,
              clipExtent = m.clipExtent,
              x0 = null, y0, x1, y1; // clip extent
  
          m.scale = function(_) {
              return arguments.length ? (scale(_), reclip()) : scale();
          };
  
          m.translate = function(_) {
              return arguments.length ? (translate(_), reclip()) : translate();
          };
  
          m.center = function(_) {
              return arguments.length ? (center(_), reclip()) : center();
          };
  
          m.clipExtent = function(_) {
              return arguments.length ? ((_ == null ? x0 = y0 = x1 = y1 = null : (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1])), reclip()) : x0 == null ? null : [[x0, y0], [x1, y1]];
          };
  
          function reclip() {
              var k = pi$3 * scale(),
                  t = m(rotation(m.rotate()).invert([0, 0]));
              return clipExtent(x0 == null
                  ? [[t[0] - k, t[1] - k], [t[0] + k, t[1] + k]] : project === mercatorRaw
                      ? [[Math.max(t[0] - k, x0), y0], [Math.min(t[0] + k, x1), y1]]
                      : [[x0, Math.max(t[1] - k, y0)], [x1, Math.min(t[1] + k, y1)]]);
          }
  
          return reclip();
      }
  
      function tany(y) {
          return tan((halfPi$2 + y) / 2);
      }
  
      function conicConformalRaw(y0, y1) {
          var cy0 = cos$1(y0),
              n = y0 === y1 ? sin$1(y0) : log(cy0 / cos$1(y1)) / log(tany(y1) / tany(y0)),
              f = cy0 * pow(tany(y0), n) / n;
  
          if (!n) return mercatorRaw;
  
          function project(x, y) {
              if (f > 0) { if (y < -halfPi$2 + epsilon$2) y = -halfPi$2 + epsilon$2; }
              else { if (y > halfPi$2 - epsilon$2) y = halfPi$2 - epsilon$2; }
              var r = f / pow(tany(y), n);
              return [r * sin$1(n * x), f - r * cos$1(n * x)];
          }
  
          project.invert = function(x, y) {
              var fy = f - y, r = sign(n) * sqrt(x * x + fy * fy);
              return [atan2(x, abs(fy)) / n * sign(fy), 2 * atan(pow(f / r, 1 / n)) - halfPi$2];
          };
  
          return project;
      }
  
      var conicConformal = function() {
          return conicProjection(conicConformalRaw)
              .scale(109.5)
              .parallels([30, 30]);
      };
  
      function equirectangularRaw(lambda, phi) {
          return [lambda, phi];
      }
  
      equirectangularRaw.invert = equirectangularRaw;
  
      var equirectangular = function() {
          return projection(equirectangularRaw)
              .scale(152.63);
      };
  
      function conicEquidistantRaw(y0, y1) {
          var cy0 = cos$1(y0),
              n = y0 === y1 ? sin$1(y0) : (cy0 - cos$1(y1)) / (y1 - y0),
              g = cy0 / n + y0;
  
          if (abs(n) < epsilon$2) return equirectangularRaw;
  
          function project(x, y) {
              var gy = g - y, nx = n * x;
              return [gy * sin$1(nx), g - gy * cos$1(nx)];
          }
  
          project.invert = function(x, y) {
              var gy = g - y;
              return [atan2(x, abs(gy)) / n * sign(gy), g - sign(n) * sqrt(x * x + gy * gy)];
          };
  
          return project;
      }
  
      var conicEquidistant = function() {
          return conicProjection(conicEquidistantRaw)
              .scale(131.154)
              .center([0, 13.9389]);
      };
  
      function gnomonicRaw(x, y) {
          var cy = cos$1(y), k = cos$1(x) * cy;
          return [cy * sin$1(x) / k, sin$1(y) / k];
      }
  
      gnomonicRaw.invert = azimuthalInvert(atan);
  
      var gnomonic = function() {
          return projection(gnomonicRaw)
              .scale(144.049)
              .clipAngle(60);
      };
  
      function scaleTranslate(kx, ky, tx, ty) {
          return kx === 1 && ky === 1 && tx === 0 && ty === 0 ? identity$4 : transformer({
              point: function(x, y) {
                  this.stream.point(x * kx + tx, y * ky + ty);
              }
          });
      }
  
      var identity$5 = function() {
          var k = 1, tx = 0, ty = 0, sx = 1, sy = 1, transform = identity$4, // scale, translate and reflect
              x0 = null, y0, x1, y1, clip = identity$4, // clip extent
              cache,
              cacheStream,
              projection;
  
          function reset() {
              cache = cacheStream = null;
              return projection;
          }
  
          return projection = {
              stream: function(stream) {
                  return cache && cacheStream === stream ? cache : cache = transform(clip(cacheStream = stream));
              },
              clipExtent: function(_) {
                  return arguments.length ? (clip = _ == null ? (x0 = y0 = x1 = y1 = null, identity$4) : clipExtent(x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]), reset()) : x0 == null ? null : [[x0, y0], [x1, y1]];
              },
              scale: function(_) {
                  return arguments.length ? (transform = scaleTranslate((k = +_) * sx, k * sy, tx, ty), reset()) : k;
              },
              translate: function(_) {
                  return arguments.length ? (transform = scaleTranslate(k * sx, k * sy, tx = +_[0], ty = +_[1]), reset()) : [tx, ty];
              },
              reflectX: function(_) {
                  return arguments.length ? (transform = scaleTranslate(k * (sx = _ ? -1 : 1), k * sy, tx, ty), reset()) : sx < 0;
              },
              reflectY: function(_) {
                  return arguments.length ? (transform = scaleTranslate(k * sx, k * (sy = _ ? -1 : 1), tx, ty), reset()) : sy < 0;
              },
              fitExtent: function(extent, object) {
                  return fitExtent(projection, extent, object);
              },
              fitSize: function(size, object) {
                  return fitSize(projection, size, object);
              }
          };
      };
  
      function orthographicRaw(x, y) {
          return [cos$1(y) * sin$1(x), sin$1(y)];
      }
  
      orthographicRaw.invert = azimuthalInvert(asin);
  
      var orthographic = function() {
          return projection(orthographicRaw)
              .scale(249.5)
              .clipAngle(90 + epsilon$2);
      };
  
      function stereographicRaw(x, y) {
          var cy = cos$1(y), k = 1 + cos$1(x) * cy;
          return [cy * sin$1(x) / k, sin$1(y) / k];
      }
  
      stereographicRaw.invert = azimuthalInvert(function(z) {
          return 2 * atan(z);
      });
  
      var stereographic = function() {
          return projection(stereographicRaw)
              .scale(250)
              .clipAngle(142);
      };
  
      function transverseMercatorRaw(lambda, phi) {
          return [log(tan((halfPi$2 + phi) / 2)), -lambda];
      }
  
      transverseMercatorRaw.invert = function(x, y) {
          return [-y, 2 * atan(exp(x)) - halfPi$2];
      };
  
      var transverseMercator = function() {
          var m = mercatorProjection(transverseMercatorRaw),
              center = m.center,
              rotate = m.rotate;
  
          m.center = function(_) {
              return arguments.length ? center([-_[1], _[0]]) : (_ = center(), [_[1], -_[0]]);
          };
  
          m.rotate = function(_) {
              return arguments.length ? rotate([_[0], _[1], _.length > 2 ? _[2] + 90 : 90]) : (_ = rotate(), [_[0], _[1], _[2] - 90]);
          };
  
          return rotate([0, 0, 90])
              .scale(159.155);
      };
  
      function defaultSeparation(a, b) {
          return a.parent === b.parent ? 1 : 2;
      }
  
      function meanX(children) {
          return children.reduce(meanXReduce, 0) / children.length;
      }
  
      function meanXReduce(x, c) {
          return x + c.x;
      }
  
      function maxY(children) {
          return 1 + children.reduce(maxYReduce, 0);
      }
  
      function maxYReduce(y, c) {
          return Math.max(y, c.y);
      }
  
      function leafLeft(node) {
          var children;
          while (children = node.children) node = children[0];
          return node;
      }
  
      function leafRight(node) {
          var children;
          while (children = node.children) node = children[children.length - 1];
          return node;
      }
  
      var cluster = function() {
          var separation = defaultSeparation,
              dx = 1,
              dy = 1,
              nodeSize = false;
  
          function cluster(root) {
              var previousNode,
                  x = 0;
  
              // First walk, computing the initial x & y values.
              root.eachAfter(function(node) {
                  var children = node.children;
                  if (children) {
                      node.x = meanX(children);
                      node.y = maxY(children);
                  } else {
                      node.x = previousNode ? x += separation(node, previousNode) : 0;
                      node.y = 0;
                      previousNode = node;
                  }
              });
  
              var left = leafLeft(root),
                  right = leafRight(root),
                  x0 = left.x - separation(left, right) / 2,
                  x1 = right.x + separation(right, left) / 2;
  
              // Second walk, normalizing x & y to the desired size.
              return root.eachAfter(nodeSize ? function(node) {
                  node.x = (node.x - root.x) * dx;
                  node.y = (root.y - node.y) * dy;
              } : function(node) {
                  node.x = (node.x - x0) / (x1 - x0) * dx;
                  node.y = (1 - (root.y ? node.y / root.y : 1)) * dy;
              });
          }
  
          cluster.separation = function(x) {
              return arguments.length ? (separation = x, cluster) : separation;
          };
  
          cluster.size = function(x) {
              return arguments.length ? (nodeSize = false, dx = +x[0], dy = +x[1], cluster) : (nodeSize ? null : [dx, dy]);
          };
  
          cluster.nodeSize = function(x) {
              return arguments.length ? (nodeSize = true, dx = +x[0], dy = +x[1], cluster) : (nodeSize ? [dx, dy] : null);
          };
  
          return cluster;
      };
  
      function count(node) {
          var sum = 0,
              children = node.children,
              i = children && children.length;
          if (!i) sum = 1;
          else while (--i >= 0) sum += children[i].value;
          node.value = sum;
      }
  
      var node_count = function() {
          return this.eachAfter(count);
      };
  
      var node_each = function(callback) {
          var node = this, current, next = [node], children, i, n;
          do {
              current = next.reverse(), next = [];
              while (node = current.pop()) {
                  callback(node), children = node.children;
                  if (children) for (i = 0, n = children.length; i < n; ++i) {
                      next.push(children[i]);
                  }
              }
          } while (next.length);
          return this;
      };
  
      var node_eachBefore = function(callback) {
          var node = this, nodes = [node], children, i;
          while (node = nodes.pop()) {
              callback(node), children = node.children;
              if (children) for (i = children.length - 1; i >= 0; --i) {
                  nodes.push(children[i]);
              }
          }
          return this;
      };
  
      var node_eachAfter = function(callback) {
          var node = this, nodes = [node], next = [], children, i, n;
          while (node = nodes.pop()) {
              next.push(node), children = node.children;
              if (children) for (i = 0, n = children.length; i < n; ++i) {
                  nodes.push(children[i]);
              }
          }
          while (node = next.pop()) {
              callback(node);
          }
          return this;
      };
  
      var node_sum = function(value) {
          return this.eachAfter(function(node) {
              var sum = +value(node.data) || 0,
                  children = node.children,
                  i = children && children.length;
              while (--i >= 0) sum += children[i].value;
              node.value = sum;
          });
      };
  
      var node_sort = function(compare) {
          return this.eachBefore(function(node) {
              if (node.children) {
                  node.children.sort(compare);
              }
          });
      };
  
      var node_path = function(end) {
          var start = this,
              ancestor = leastCommonAncestor(start, end),
              nodes = [start];
          while (start !== ancestor) {
              start = start.parent;
              nodes.push(start);
          }
          var k = nodes.length;
          while (end !== ancestor) {
              nodes.splice(k, 0, end);
              end = end.parent;
          }
          return nodes;
      };
  
      function leastCommonAncestor(a, b) {
          if (a === b) return a;
          var aNodes = a.ancestors(),
              bNodes = b.ancestors(),
              c = null;
          a = aNodes.pop();
          b = bNodes.pop();
          while (a === b) {
              c = a;
              a = aNodes.pop();
              b = bNodes.pop();
          }
          return c;
      }
  
      var node_ancestors = function() {
          var node = this, nodes = [node];
          while (node = node.parent) {
              nodes.push(node);
          }
          return nodes;
      };
  
      var node_descendants = function() {
          var nodes = [];
          this.each(function(node) {
              nodes.push(node);
          });
          return nodes;
      };
  
      var node_leaves = function() {
          var leaves = [];
          this.eachBefore(function(node) {
              if (!node.children) {
                  leaves.push(node);
              }
          });
          return leaves;
      };
  
      var node_links = function() {
          var root = this, links = [];
          root.each(function(node) {
              if (node !== root) { // Don’t include the root’s parent, if any.
                  links.push({source: node.parent, target: node});
              }
          });
          return links;
      };
  
      function hierarchy(data, children) {
          var root = new Node(data),
              valued = +data.value && (root.value = data.value),
              node,
              nodes = [root],
              child,
              childs,
              i,
              n;
  
          if (children == null) children = defaultChildren;
  
          while (node = nodes.pop()) {
              if (valued) node.value = +node.data.value;
              if ((childs = children(node.data)) && (n = childs.length)) {
                  node.children = new Array(n);
                  for (i = n - 1; i >= 0; --i) {
                      nodes.push(child = node.children[i] = new Node(childs[i]));
                      child.parent = node;
                      child.depth = node.depth + 1;
                  }
              }
          }
  
          return root.eachBefore(computeHeight);
      }
  
      function node_copy() {
          return hierarchy(this).eachBefore(copyData);
      }
  
      function defaultChildren(d) {
          return d.children;
      }
  
      function copyData(node) {
          node.data = node.data.data;
      }
  
      function computeHeight(node) {
          var height = 0;
          do node.height = height;
          while ((node = node.parent) && (node.height < ++height));
      }
  
      function Node(data) {
          this.data = data;
          this.depth =
              this.height = 0;
          this.parent = null;
      }
  
      Node.prototype = hierarchy.prototype = {
          constructor: Node,
          count: node_count,
          each: node_each,
          eachAfter: node_eachAfter,
          eachBefore: node_eachBefore,
          sum: node_sum,
          sort: node_sort,
          path: node_path,
          ancestors: node_ancestors,
          descendants: node_descendants,
          leaves: node_leaves,
          links: node_links,
          copy: node_copy
      };
  
      function Node$2(value) {
          this._ = value;
          this.next = null;
      }
  
      var shuffle$1 = function(array) {
          var i,
              n = (array = array.slice()).length,
              head = null,
              node = head;
  
          while (n) {
              var next = new Node$2(array[n - 1]);
              if (node) node = node.next = next;
              else node = head = next;
              array[i] = array[--n];
          }
  
          return {
              head: head,
              tail: node
          };
      };
  
      var enclose = function(circles) {
          return encloseN(shuffle$1(circles), []);
      };
  
      function encloses(a, b) {
          var dx = b.x - a.x,
              dy = b.y - a.y,
              dr = a.r - b.r;
          return dr * dr + 1e-6 > dx * dx + dy * dy;
      }
  
  // Returns the smallest circle that contains circles L and intersects circles B.
      function encloseN(L, B) {
          var circle,
              l0 = null,
              l1 = L.head,
              l2,
              p1;
  
          switch (B.length) {
              case 1: circle = enclose1(B[0]); break;
              case 2: circle = enclose2(B[0], B[1]); break;
              case 3: circle = enclose3(B[0], B[1], B[2]); break;
          }
  
          while (l1) {
              p1 = l1._, l2 = l1.next;
              if (!circle || !encloses(circle, p1)) {
  
                  // Temporarily truncate L before l1.
                  if (l0) L.tail = l0, l0.next = null;
                  else L.head = L.tail = null;
  
                  B.push(p1);
                  circle = encloseN(L, B); // Note: reorders L!
                  B.pop();
  
                  // Move l1 to the front of L and reconnect the truncated list L.
                  if (L.head) l1.next = L.head, L.head = l1;
                  else l1.next = null, L.head = L.tail = l1;
                  l0 = L.tail, l0.next = l2;
  
              } else {
                  l0 = l1;
              }
              l1 = l2;
          }
  
          L.tail = l0;
          return circle;
      }
  
      function enclose1(a) {
          return {
              x: a.x,
              y: a.y,
              r: a.r
          };
      }
  
      function enclose2(a, b) {
          var x1 = a.x, y1 = a.y, r1 = a.r,
              x2 = b.x, y2 = b.y, r2 = b.r,
              x21 = x2 - x1, y21 = y2 - y1, r21 = r2 - r1,
              l = Math.sqrt(x21 * x21 + y21 * y21);
          return {
              x: (x1 + x2 + x21 / l * r21) / 2,
              y: (y1 + y2 + y21 / l * r21) / 2,
              r: (l + r1 + r2) / 2
          };
      }
  
      function enclose3(a, b, c) {
          var x1 = a.x, y1 = a.y, r1 = a.r,
              x2 = b.x, y2 = b.y, r2 = b.r,
              x3 = c.x, y3 = c.y, r3 = c.r,
              a2 = 2 * (x1 - x2),
              b2 = 2 * (y1 - y2),
              c2 = 2 * (r2 - r1),
              d2 = x1 * x1 + y1 * y1 - r1 * r1 - x2 * x2 - y2 * y2 + r2 * r2,
              a3 = 2 * (x1 - x3),
              b3 = 2 * (y1 - y3),
              c3 = 2 * (r3 - r1),
              d3 = x1 * x1 + y1 * y1 - r1 * r1 - x3 * x3 - y3 * y3 + r3 * r3,
              ab = a3 * b2 - a2 * b3,
              xa = (b2 * d3 - b3 * d2) / ab - x1,
              xb = (b3 * c2 - b2 * c3) / ab,
              ya = (a3 * d2 - a2 * d3) / ab - y1,
              yb = (a2 * c3 - a3 * c2) / ab,
              A = xb * xb + yb * yb - 1,
              B = 2 * (xa * xb + ya * yb + r1),
              C = xa * xa + ya * ya - r1 * r1,
              r = (-B - Math.sqrt(B * B - 4 * A * C)) / (2 * A);
          return {
              x: xa + xb * r + x1,
              y: ya + yb * r + y1,
              r: r
          };
      }
  
      function place(a, b, c) {
          var ax = a.x,
              ay = a.y,
              da = b.r + c.r,
              db = a.r + c.r,
              dx = b.x - ax,
              dy = b.y - ay,
              dc = dx * dx + dy * dy;
          if (dc) {
              var x = 0.5 + ((db *= db) - (da *= da)) / (2 * dc),
                  y = Math.sqrt(Math.max(0, 2 * da * (db + dc) - (db -= dc) * db - da * da)) / (2 * dc);
              c.x = ax + x * dx + y * dy;
              c.y = ay + x * dy - y * dx;
          } else {
              c.x = ax + db;
              c.y = ay;
          }
      }
  
      function intersects(a, b) {
          var dx = b.x - a.x,
              dy = b.y - a.y,
              dr = a.r + b.r;
          return dr * dr - 1e-6 > dx * dx + dy * dy;
      }
  
      function distance2(node, x, y) {
          var a = node._,
              b = node.next._,
              ab = a.r + b.r,
              dx = (a.x * b.r + b.x * a.r) / ab - x,
              dy = (a.y * b.r + b.y * a.r) / ab - y;
          return dx * dx + dy * dy;
      }
  
      function Node$1(circle) {
          this._ = circle;
          this.next = null;
          this.previous = null;
      }
  
      function packEnclose(circles) {
          if (!(n = circles.length)) return 0;
  
          var a, b, c, n;
  
          // Place the first circle.
          a = circles[0], a.x = 0, a.y = 0;
          if (!(n > 1)) return a.r;
  
          // Place the second circle.
          b = circles[1], a.x = -b.r, b.x = a.r, b.y = 0;
          if (!(n > 2)) return a.r + b.r;
  
          // Place the third circle.
          place(b, a, c = circles[2]);
  
          // Initialize the weighted centroid.
          var aa = a.r * a.r,
              ba = b.r * b.r,
              ca = c.r * c.r,
              oa = aa + ba + ca,
              ox = aa * a.x + ba * b.x + ca * c.x,
              oy = aa * a.y + ba * b.y + ca * c.y,
              cx, cy, i, j, k, sj, sk;
  
          // Initialize the front-chain using the first three circles a, b and c.
          a = new Node$1(a), b = new Node$1(b), c = new Node$1(c);
          a.next = c.previous = b;
          b.next = a.previous = c;
          c.next = b.previous = a;
  
          // Attempt to place each remaining circle…
          pack: for (i = 3; i < n; ++i) {
              place(a._, b._, c = circles[i]), c = new Node$1(c);
  
              // Find the closest intersecting circle on the front-chain, if any.
              // “Closeness” is determined by linear distance along the front-chain.
              // “Ahead” or “behind” is likewise determined by linear distance.
              j = b.next, k = a.previous, sj = b._.r, sk = a._.r;
              do {
                  if (sj <= sk) {
                      if (intersects(j._, c._)) {
                          b = j, a.next = b, b.previous = a, --i;
                          continue pack;
                      }
                      sj += j._.r, j = j.next;
                  } else {
                      if (intersects(k._, c._)) {
                          a = k, a.next = b, b.previous = a, --i;
                          continue pack;
                      }
                      sk += k._.r, k = k.previous;
                  }
              } while (j !== k.next);
  
              // Success! Insert the new circle c between a and b.
              c.previous = a, c.next = b, a.next = b.previous = b = c;
  
              // Update the weighted centroid.
              oa += ca = c._.r * c._.r;
              ox += ca * c._.x;
              oy += ca * c._.y;
  
              // Compute the new closest circle pair to the centroid.
              aa = distance2(a, cx = ox / oa, cy = oy / oa);
              while ((c = c.next) !== b) {
                  if ((ca = distance2(c, cx, cy)) < aa) {
                      a = c, aa = ca;
                  }
              }
              b = a.next;
          }
  
          // Compute the enclosing circle of the front chain.
          a = [b._], c = b; while ((c = c.next) !== b) a.push(c._); c = enclose(a);
  
          // Translate the circles to put the enclosing circle around the origin.
          for (i = 0; i < n; ++i) a = circles[i], a.x -= c.x, a.y -= c.y;
  
          return c.r;
      }
  
      var siblings = function(circles) {
          packEnclose(circles);
          return circles;
      };
  
      function optional(f) {
          return f == null ? null : required(f);
      }
  
      function required(f) {
          if (typeof f !== "function") throw new Error;
          return f;
      }
  
      function constantZero() {
          return 0;
      }
  
      var constant$8 = function(x) {
          return function() {
              return x;
          };
      };
  
      function defaultRadius$1(d) {
          return Math.sqrt(d.value);
      }
  
      var index$2 = function() {
          var radius = null,
              dx = 1,
              dy = 1,
              padding = constantZero;
  
          function pack(root) {
              root.x = dx / 2, root.y = dy / 2;
              if (radius) {
                  root.eachBefore(radiusLeaf(radius))
                      .eachAfter(packChildren(padding, 0.5))
                      .eachBefore(translateChild(1));
              } else {
                  root.eachBefore(radiusLeaf(defaultRadius$1))
                      .eachAfter(packChildren(constantZero, 1))
                      .eachAfter(packChildren(padding, root.r / Math.min(dx, dy)))
                      .eachBefore(translateChild(Math.min(dx, dy) / (2 * root.r)));
              }
              return root;
          }
  
          pack.radius = function(x) {
              return arguments.length ? (radius = optional(x), pack) : radius;
          };
  
          pack.size = function(x) {
              return arguments.length ? (dx = +x[0], dy = +x[1], pack) : [dx, dy];
          };
  
          pack.padding = function(x) {
              return arguments.length ? (padding = typeof x === "function" ? x : constant$8(+x), pack) : padding;
          };
  
          return pack;
      };
  
      function radiusLeaf(radius) {
          return function(node) {
              if (!node.children) {
                  node.r = Math.max(0, +radius(node) || 0);
              }
          };
      }
  
      function packChildren(padding, k) {
          return function(node) {
              if (children = node.children) {
                  var children,
                      i,
                      n = children.length,
                      r = padding(node) * k || 0,
                      e;
  
                  if (r) for (i = 0; i < n; ++i) children[i].r += r;
                  e = packEnclose(children);
                  if (r) for (i = 0; i < n; ++i) children[i].r -= r;
                  node.r = e + r;
              }
          };
      }
  
      function translateChild(k) {
          return function(node) {
              var parent = node.parent;
              node.r *= k;
              if (parent) {
                  node.x = parent.x + k * node.x;
                  node.y = parent.y + k * node.y;
              }
          };
      }
  
      var roundNode = function(node) {
          node.x0 = Math.round(node.x0);
          node.y0 = Math.round(node.y0);
          node.x1 = Math.round(node.x1);
          node.y1 = Math.round(node.y1);
      };
  
      var treemapDice = function(parent, x0, y0, x1, y1) {
          var nodes = parent.children,
              node,
              i = -1,
              n = nodes.length,
              k = parent.value && (x1 - x0) / parent.value;
  
          while (++i < n) {
              node = nodes[i], node.y0 = y0, node.y1 = y1;
              node.x0 = x0, node.x1 = x0 += node.value * k;
          }
      };
  
      var partition = function() {
          var dx = 1,
              dy = 1,
              padding = 0,
              round = false;
  
          function partition(root) {
              var n = root.height + 1;
              root.x0 =
                  root.y0 = padding;
              root.x1 = dx;
              root.y1 = dy / n;
              root.eachBefore(positionNode(dy, n));
              if (round) root.eachBefore(roundNode);
              return root;
          }
  
          function positionNode(dy, n) {
              return function(node) {
                  if (node.children) {
                      treemapDice(node, node.x0, dy * (node.depth + 1) / n, node.x1, dy * (node.depth + 2) / n);
                  }
                  var x0 = node.x0,
                      y0 = node.y0,
                      x1 = node.x1 - padding,
                      y1 = node.y1 - padding;
                  if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
                  if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
                  node.x0 = x0;
                  node.y0 = y0;
                  node.x1 = x1;
                  node.y1 = y1;
              };
          }
  
          partition.round = function(x) {
              return arguments.length ? (round = !!x, partition) : round;
          };
  
          partition.size = function(x) {
              return arguments.length ? (dx = +x[0], dy = +x[1], partition) : [dx, dy];
          };
  
          partition.padding = function(x) {
              return arguments.length ? (padding = +x, partition) : padding;
          };
  
          return partition;
      };
  
      var keyPrefix$1 = "$";
      var preroot = {depth: -1};
      var ambiguous = {};
  
      function defaultId(d) {
          return d.id;
      }
  
      function defaultParentId(d) {
          return d.parentId;
      }
  
      var stratify = function() {
          var id = defaultId,
              parentId = defaultParentId;
  
          function stratify(data) {
              var d,
                  i,
                  n = data.length,
                  root,
                  parent,
                  node,
                  nodes = new Array(n),
                  nodeId,
                  nodeKey,
                  nodeByKey = {};
  
              for (i = 0; i < n; ++i) {
                  d = data[i], node = nodes[i] = new Node(d);
                  if ((nodeId = id(d, i, data)) != null && (nodeId += "")) {
                      nodeKey = keyPrefix$1 + (node.id = nodeId);
                      nodeByKey[nodeKey] = nodeKey in nodeByKey ? ambiguous : node;
                  }
              }
  
              for (i = 0; i < n; ++i) {
                  node = nodes[i], nodeId = parentId(data[i], i, data);
                  if (nodeId == null || !(nodeId += "")) {
                      if (root) throw new Error("multiple roots");
                      root = node;
                  } else {
                      parent = nodeByKey[keyPrefix$1 + nodeId];
                      if (!parent) throw new Error("missing: " + nodeId);
                      if (parent === ambiguous) throw new Error("ambiguous: " + nodeId);
                      if (parent.children) parent.children.push(node);
                      else parent.children = [node];
                      node.parent = parent;
                  }
              }
  
              if (!root) throw new Error("no root");
              root.parent = preroot;
              root.eachBefore(function(node) { node.depth = node.parent.depth + 1; --n; }).eachBefore(computeHeight);
              root.parent = null;
              if (n > 0) throw new Error("cycle");
  
              return root;
          }
  
          stratify.id = function(x) {
              return arguments.length ? (id = required(x), stratify) : id;
          };
  
          stratify.parentId = function(x) {
              return arguments.length ? (parentId = required(x), stratify) : parentId;
          };
  
          return stratify;
      };
  
      function defaultSeparation$1(a, b) {
          return a.parent === b.parent ? 1 : 2;
      }
  
  // function radialSeparation(a, b) {
  //   return (a.parent === b.parent ? 1 : 2) / a.depth;
  // }
  
  // This function is used to traverse the left contour of a subtree (or
  // subforest). It returns the successor of v on this contour. This successor is
  // either given by the leftmost child of v or by the thread of v. The function
  // returns null if and only if v is on the highest level of its subtree.
      function nextLeft(v) {
          var children = v.children;
          return children ? children[0] : v.t;
      }
  
  // This function works analogously to nextLeft.
      function nextRight(v) {
          var children = v.children;
          return children ? children[children.length - 1] : v.t;
      }
  
  // Shifts the current subtree rooted at w+. This is done by increasing
  // prelim(w+) and mod(w+) by shift.
      function moveSubtree(wm, wp, shift) {
          var change = shift / (wp.i - wm.i);
          wp.c -= change;
          wp.s += shift;
          wm.c += change;
          wp.z += shift;
          wp.m += shift;
      }
  
  // All other shifts, applied to the smaller subtrees between w- and w+, are
  // performed by this function. To prepare the shifts, we have to adjust
  // change(w+), shift(w+), and change(w-).
      function executeShifts(v) {
          var shift = 0,
              change = 0,
              children = v.children,
              i = children.length,
              w;
          while (--i >= 0) {
              w = children[i];
              w.z += shift;
              w.m += shift;
              shift += w.s + (change += w.c);
          }
      }
  
  // If vi-’s ancestor is a sibling of v, returns vi-’s ancestor. Otherwise,
  // returns the specified (default) ancestor.
      function nextAncestor(vim, v, ancestor) {
          return vim.a.parent === v.parent ? vim.a : ancestor;
      }
  
      function TreeNode(node, i) {
          this._ = node;
          this.parent = null;
          this.children = null;
          this.A = null; // default ancestor
          this.a = this; // ancestor
          this.z = 0; // prelim
          this.m = 0; // mod
          this.c = 0; // change
          this.s = 0; // shift
          this.t = null; // thread
          this.i = i; // number
      }
  
      TreeNode.prototype = Object.create(Node.prototype);
  
      function treeRoot(root) {
          var tree = new TreeNode(root, 0),
              node,
              nodes = [tree],
              child,
              children,
              i,
              n;
  
          while (node = nodes.pop()) {
              if (children = node._.children) {
                  node.children = new Array(n = children.length);
                  for (i = n - 1; i >= 0; --i) {
                      nodes.push(child = node.children[i] = new TreeNode(children[i], i));
                      child.parent = node;
                  }
              }
          }
  
          (tree.parent = new TreeNode(null, 0)).children = [tree];
          return tree;
      }
  
  // Node-link tree diagram using the Reingold-Tilford "tidy" algorithm
      var tree = function() {
          var separation = defaultSeparation$1,
              dx = 1,
              dy = 1,
              nodeSize = null;
  
          function tree(root) {
              var t = treeRoot(root);
  
              // Compute the layout using Buchheim et al.’s algorithm.
              t.eachAfter(firstWalk), t.parent.m = -t.z;
              t.eachBefore(secondWalk);
  
              // If a fixed node size is specified, scale x and y.
              if (nodeSize) root.eachBefore(sizeNode);
  
              // If a fixed tree size is specified, scale x and y based on the extent.
              // Compute the left-most, right-most, and depth-most nodes for extents.
              else {
                  var left = root,
                      right = root,
                      bottom = root;
                  root.eachBefore(function(node) {
                      if (node.x < left.x) left = node;
                      if (node.x > right.x) right = node;
                      if (node.depth > bottom.depth) bottom = node;
                  });
                  var s = left === right ? 1 : separation(left, right) / 2,
                      tx = s - left.x,
                      kx = dx / (right.x + s + tx),
                      ky = dy / (bottom.depth || 1);
                  root.eachBefore(function(node) {
                      node.x = (node.x + tx) * kx;
                      node.y = node.depth * ky;
                  });
              }
  
              return root;
          }
  
          // Computes a preliminary x-coordinate for v. Before that, FIRST WALK is
          // applied recursively to the children of v, as well as the function
          // APPORTION. After spacing out the children by calling EXECUTE SHIFTS, the
          // node v is placed to the midpoint of its outermost children.
          function firstWalk(v) {
              var children = v.children,
                  siblings = v.parent.children,
                  w = v.i ? siblings[v.i - 1] : null;
              if (children) {
                  executeShifts(v);
                  var midpoint = (children[0].z + children[children.length - 1].z) / 2;
                  if (w) {
                      v.z = w.z + separation(v._, w._);
                      v.m = v.z - midpoint;
                  } else {
                      v.z = midpoint;
                  }
              } else if (w) {
                  v.z = w.z + separation(v._, w._);
              }
              v.parent.A = apportion(v, w, v.parent.A || siblings[0]);
          }
  
          // Computes all real x-coordinates by summing up the modifiers recursively.
          function secondWalk(v) {
              v._.x = v.z + v.parent.m;
              v.m += v.parent.m;
          }
  
          // The core of the algorithm. Here, a new subtree is combined with the
          // previous subtrees. Threads are used to traverse the inside and outside
          // contours of the left and right subtree up to the highest common level. The
          // vertices used for the traversals are vi+, vi-, vo-, and vo+, where the
          // superscript o means outside and i means inside, the subscript - means left
          // subtree and + means right subtree. For summing up the modifiers along the
          // contour, we use respective variables si+, si-, so-, and so+. Whenever two
          // nodes of the inside contours conflict, we compute the left one of the
          // greatest uncommon ancestors using the function ANCESTOR and call MOVE
          // SUBTREE to shift the subtree and prepare the shifts of smaller subtrees.
          // Finally, we add a new thread (if necessary).
          function apportion(v, w, ancestor) {
              if (w) {
                  var vip = v,
                      vop = v,
                      vim = w,
                      vom = vip.parent.children[0],
                      sip = vip.m,
                      sop = vop.m,
                      sim = vim.m,
                      som = vom.m,
                      shift;
                  while (vim = nextRight(vim), vip = nextLeft(vip), vim && vip) {
                      vom = nextLeft(vom);
                      vop = nextRight(vop);
                      vop.a = v;
                      shift = vim.z + sim - vip.z - sip + separation(vim._, vip._);
                      if (shift > 0) {
                          moveSubtree(nextAncestor(vim, v, ancestor), v, shift);
                          sip += shift;
                          sop += shift;
                      }
                      sim += vim.m;
                      sip += vip.m;
                      som += vom.m;
                      sop += vop.m;
                  }
                  if (vim && !nextRight(vop)) {
                      vop.t = vim;
                      vop.m += sim - sop;
                  }
                  if (vip && !nextLeft(vom)) {
                      vom.t = vip;
                      vom.m += sip - som;
                      ancestor = v;
                  }
              }
              return ancestor;
          }
  
          function sizeNode(node) {
              node.x *= dx;
              node.y = node.depth * dy;
          }
  
          tree.separation = function(x) {
              return arguments.length ? (separation = x, tree) : separation;
          };
  
          tree.size = function(x) {
              return arguments.length ? (nodeSize = false, dx = +x[0], dy = +x[1], tree) : (nodeSize ? null : [dx, dy]);
          };
  
          tree.nodeSize = function(x) {
              return arguments.length ? (nodeSize = true, dx = +x[0], dy = +x[1], tree) : (nodeSize ? [dx, dy] : null);
          };
  
          return tree;
      };
  
      var treemapSlice = function(parent, x0, y0, x1, y1) {
          var nodes = parent.children,
              node,
              i = -1,
              n = nodes.length,
              k = parent.value && (y1 - y0) / parent.value;
  
          while (++i < n) {
              node = nodes[i], node.x0 = x0, node.x1 = x1;
              node.y0 = y0, node.y1 = y0 += node.value * k;
          }
      };
  
      var phi = (1 + Math.sqrt(5)) / 2;
  
      function squarifyRatio(ratio, parent, x0, y0, x1, y1) {
          var rows = [],
              nodes = parent.children,
              row,
              nodeValue,
              i0 = 0,
              i1 = 0,
              n = nodes.length,
              dx, dy,
              value = parent.value,
              sumValue,
              minValue,
              maxValue,
              newRatio,
              minRatio,
              alpha,
              beta;
  
          while (i0 < n) {
              dx = x1 - x0, dy = y1 - y0;
  
              // Find the next non-empty node.
              do sumValue = nodes[i1++].value; while (!sumValue && i1 < n);
              minValue = maxValue = sumValue;
              alpha = Math.max(dy / dx, dx / dy) / (value * ratio);
              beta = sumValue * sumValue * alpha;
              minRatio = Math.max(maxValue / beta, beta / minValue);
  
              // Keep adding nodes while the aspect ratio maintains or improves.
              for (; i1 < n; ++i1) {
                  sumValue += nodeValue = nodes[i1].value;
                  if (nodeValue < minValue) minValue = nodeValue;
                  if (nodeValue > maxValue) maxValue = nodeValue;
                  beta = sumValue * sumValue * alpha;
                  newRatio = Math.max(maxValue / beta, beta / minValue);
                  if (newRatio > minRatio) { sumValue -= nodeValue; break; }
                  minRatio = newRatio;
              }
  
              // Position and record the row orientation.
              rows.push(row = {value: sumValue, dice: dx < dy, children: nodes.slice(i0, i1)});
              if (row.dice) treemapDice(row, x0, y0, x1, value ? y0 += dy * sumValue / value : y1);
              else treemapSlice(row, x0, y0, value ? x0 += dx * sumValue / value : x1, y1);
              value -= sumValue, i0 = i1;
          }
  
          return rows;
      }
  
      var squarify = ((function custom(ratio) {
  
          function squarify(parent, x0, y0, x1, y1) {
              squarifyRatio(ratio, parent, x0, y0, x1, y1);
          }
  
          squarify.ratio = function(x) {
              return custom((x = +x) > 1 ? x : 1);
          };
  
          return squarify;
      }))(phi);
  
      var index$3 = function() {
          var tile = squarify,
              round = false,
              dx = 1,
              dy = 1,
              paddingStack = [0],
              paddingInner = constantZero,
              paddingTop = constantZero,
              paddingRight = constantZero,
              paddingBottom = constantZero,
              paddingLeft = constantZero;
  
          function treemap(root) {
              root.x0 =
                  root.y0 = 0;
              root.x1 = dx;
              root.y1 = dy;
              root.eachBefore(positionNode);
              paddingStack = [0];
              if (round) root.eachBefore(roundNode);
              return root;
          }
  
          function positionNode(node) {
              var p = paddingStack[node.depth],
                  x0 = node.x0 + p,
                  y0 = node.y0 + p,
                  x1 = node.x1 - p,
                  y1 = node.y1 - p;
              if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
              if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
              node.x0 = x0;
              node.y0 = y0;
              node.x1 = x1;
              node.y1 = y1;
              if (node.children) {
                  p = paddingStack[node.depth + 1] = paddingInner(node) / 2;
                  x0 += paddingLeft(node) - p;
                  y0 += paddingTop(node) - p;
                  x1 -= paddingRight(node) - p;
                  y1 -= paddingBottom(node) - p;
                  if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
                  if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
                  tile(node, x0, y0, x1, y1);
              }
          }
  
          treemap.round = function(x) {
              return arguments.length ? (round = !!x, treemap) : round;
          };
  
          treemap.size = function(x) {
              return arguments.length ? (dx = +x[0], dy = +x[1], treemap) : [dx, dy];
          };
  
          treemap.tile = function(x) {
              return arguments.length ? (tile = required(x), treemap) : tile;
          };
  
          treemap.padding = function(x) {
              return arguments.length ? treemap.paddingInner(x).paddingOuter(x) : treemap.paddingInner();
          };
  
          treemap.paddingInner = function(x) {
              return arguments.length ? (paddingInner = typeof x === "function" ? x : constant$8(+x), treemap) : paddingInner;
          };
  
          treemap.paddingOuter = function(x) {
              return arguments.length ? treemap.paddingTop(x).paddingRight(x).paddingBottom(x).paddingLeft(x) : treemap.paddingTop();
          };
  
          treemap.paddingTop = function(x) {
              return arguments.length ? (paddingTop = typeof x === "function" ? x : constant$8(+x), treemap) : paddingTop;
          };
  
          treemap.paddingRight = function(x) {
              return arguments.length ? (paddingRight = typeof x === "function" ? x : constant$8(+x), treemap) : paddingRight;
          };
  
          treemap.paddingBottom = function(x) {
              return arguments.length ? (paddingBottom = typeof x === "function" ? x : constant$8(+x), treemap) : paddingBottom;
          };
  
          treemap.paddingLeft = function(x) {
              return arguments.length ? (paddingLeft = typeof x === "function" ? x : constant$8(+x), treemap) : paddingLeft;
          };
  
          return treemap;
      };
  
      var binary = function(parent, x0, y0, x1, y1) {
          var nodes = parent.children,
              i, n = nodes.length,
              sum, sums = new Array(n + 1);
  
          for (sums[0] = sum = i = 0; i < n; ++i) {
              sums[i + 1] = sum += nodes[i].value;
          }
  
          partition(0, n, parent.value, x0, y0, x1, y1);
  
          function partition(i, j, value, x0, y0, x1, y1) {
              if (i >= j - 1) {
                  var node = nodes[i];
                  node.x0 = x0, node.y0 = y0;
                  node.x1 = x1, node.y1 = y1;
                  return;
              }
  
              var valueOffset = sums[i],
                  valueTarget = (value / 2) + valueOffset,
                  k = i + 1,
                  hi = j - 1;
  
              while (k < hi) {
                  var mid = k + hi >>> 1;
                  if (sums[mid] < valueTarget) k = mid + 1;
                  else hi = mid;
              }
  
              if ((valueTarget - sums[k - 1]) < (sums[k] - valueTarget) && i + 1 < k) --k;
  
              var valueLeft = sums[k] - valueOffset,
                  valueRight = value - valueLeft;
  
              if ((x1 - x0) > (y1 - y0)) {
                  var xk = (x0 * valueRight + x1 * valueLeft) / value;
                  partition(i, k, valueLeft, x0, y0, xk, y1);
                  partition(k, j, valueRight, xk, y0, x1, y1);
              } else {
                  var yk = (y0 * valueRight + y1 * valueLeft) / value;
                  partition(i, k, valueLeft, x0, y0, x1, yk);
                  partition(k, j, valueRight, x0, yk, x1, y1);
              }
          }
      };
  
      var sliceDice = function(parent, x0, y0, x1, y1) {
          (parent.depth & 1 ? treemapSlice : treemapDice)(parent, x0, y0, x1, y1);
      };
  
      var resquarify = ((function custom(ratio) {
  
          function resquarify(parent, x0, y0, x1, y1) {
              if ((rows = parent._squarify) && (rows.ratio === ratio)) {
                  var rows,
                      row,
                      nodes,
                      i,
                      j = -1,
                      n,
                      m = rows.length,
                      value = parent.value;
  
                  while (++j < m) {
                      row = rows[j], nodes = row.children;
                      for (i = row.value = 0, n = nodes.length; i < n; ++i) row.value += nodes[i].value;
                      if (row.dice) treemapDice(row, x0, y0, x1, y0 += (y1 - y0) * row.value / value);
                      else treemapSlice(row, x0, y0, x0 += (x1 - x0) * row.value / value, y1);
                      value -= row.value;
                  }
              } else {
                  parent._squarify = rows = squarifyRatio(ratio, parent, x0, y0, x1, y1);
                  rows.ratio = ratio;
              }
          }
  
          resquarify.ratio = function(x) {
              return custom((x = +x) > 1 ? x : 1);
          };
  
          return resquarify;
      }))(phi);
  
      var area$1 = function(polygon) {
          var i = -1,
              n = polygon.length,
              a,
              b = polygon[n - 1],
              area = 0;
  
          while (++i < n) {
              a = b;
              b = polygon[i];
              area += a[1] * b[0] - a[0] * b[1];
          }
  
          return area / 2;
      };
  
      var centroid$1 = function(polygon) {
          var i = -1,
              n = polygon.length,
              x = 0,
              y = 0,
              a,
              b = polygon[n - 1],
              c,
              k = 0;
  
          while (++i < n) {
              a = b;
              b = polygon[i];
              k += c = a[0] * b[1] - b[0] * a[1];
              x += (a[0] + b[0]) * c;
              y += (a[1] + b[1]) * c;
          }
  
          return k *= 3, [x / k, y / k];
      };
  
  // Returns the 2D cross product of AB and AC vectors, i.e., the z-component of
  // the 3D cross product in a quadrant I Cartesian coordinate system (+x is
  // right, +y is up). Returns a positive value if ABC is counter-clockwise,
  // negative if clockwise, and zero if the points are collinear.
      var cross$1 = function(a, b, c) {
          return (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
      };
  
      function lexicographicOrder(a, b) {
          return a[0] - b[0] || a[1] - b[1];
      }
  
  // Computes the upper convex hull per the monotone chain algorithm.
  // Assumes points.length >= 3, is sorted by x, unique in y.
  // Returns an array of indices into points in left-to-right order.
      function computeUpperHullIndexes(points) {
          var n = points.length,
              indexes = [0, 1],
              size = 2;
  
          for (var i = 2; i < n; ++i) {
              while (size > 1 && cross$1(points[indexes[size - 2]], points[indexes[size - 1]], points[i]) <= 0) --size;
              indexes[size++] = i;
          }
  
          return indexes.slice(0, size); // remove popped points
      }
  
      var hull = function(points) {
          if ((n = points.length) < 3) return null;
  
          var i,
              n,
              sortedPoints = new Array(n),
              flippedPoints = new Array(n);
  
          for (i = 0; i < n; ++i) sortedPoints[i] = [+points[i][0], +points[i][1], i];
          sortedPoints.sort(lexicographicOrder);
          for (i = 0; i < n; ++i) flippedPoints[i] = [sortedPoints[i][0], -sortedPoints[i][1]];
  
          var upperIndexes = computeUpperHullIndexes(sortedPoints),
              lowerIndexes = computeUpperHullIndexes(flippedPoints);
  
          // Construct the hull polygon, removing possible duplicate endpoints.
          var skipLeft = lowerIndexes[0] === upperIndexes[0],
              skipRight = lowerIndexes[lowerIndexes.length - 1] === upperIndexes[upperIndexes.length - 1],
              hull = [];
  
          // Add upper hull in right-to-l order.
          // Then add lower hull in left-to-right order.
          for (i = upperIndexes.length - 1; i >= 0; --i) hull.push(points[sortedPoints[upperIndexes[i]][2]]);
          for (i = +skipLeft; i < lowerIndexes.length - skipRight; ++i) hull.push(points[sortedPoints[lowerIndexes[i]][2]]);
  
          return hull;
      };
  
      var contains$1 = function(polygon, point) {
          var n = polygon.length,
              p = polygon[n - 1],
              x = point[0], y = point[1],
              x0 = p[0], y0 = p[1],
              x1, y1,
              inside = false;
  
          for (var i = 0; i < n; ++i) {
              p = polygon[i], x1 = p[0], y1 = p[1];
              if (((y1 > y) !== (y0 > y)) && (x < (x0 - x1) * (y - y1) / (y0 - y1) + x1)) inside = !inside;
              x0 = x1, y0 = y1;
          }
  
          return inside;
      };
  
      var length$2 = function(polygon) {
          var i = -1,
              n = polygon.length,
              b = polygon[n - 1],
              xa,
              ya,
              xb = b[0],
              yb = b[1],
              perimeter = 0;
  
          while (++i < n) {
              xa = xb;
              ya = yb;
              b = polygon[i];
              xb = b[0];
              yb = b[1];
              xa -= xb;
              ya -= yb;
              perimeter += Math.sqrt(xa * xa + ya * ya);
          }
  
          return perimeter;
      };
  
      var slice$3 = [].slice;
  
      var noabort = {};
  
      function Queue(size) {
          if (!(size >= 1)) throw new Error;
          this._size = size;
          this._call =
              this._error = null;
          this._tasks = [];
          this._data = [];
          this._waiting =
              this._active =
                  this._ended =
                      this._start = 0; // inside a synchronous task callback?
      }
  
      Queue.prototype = queue.prototype = {
          constructor: Queue,
          defer: function(callback) {
              if (typeof callback !== "function" || this._call) throw new Error;
              if (this._error != null) return this;
              var t = slice$3.call(arguments, 1);
              t.push(callback);
              ++this._waiting, this._tasks.push(t);
              poke$1(this);
              return this;
          },
          abort: function() {
              if (this._error == null) abort(this, new Error("abort"));
              return this;
          },
          await: function(callback) {
              if (typeof callback !== "function" || this._call) throw new Error;
              this._call = function(error, results) { callback.apply(null, [error].concat(results)); };
              maybeNotify(this);
              return this;
          },
          awaitAll: function(callback) {
              if (typeof callback !== "function" || this._call) throw new Error;
              this._call = callback;
              maybeNotify(this);
              return this;
          }
      };
  
      function poke$1(q) {
          if (!q._start) {
              try { start$1(q); } // let the current task complete
              catch (e) {
                  if (q._tasks[q._ended + q._active - 1]) abort(q, e); // task errored synchronously
                  else if (!q._data) throw e; // await callback errored synchronously
              }
          }
      }
  
      function start$1(q) {
          while (q._start = q._waiting && q._active < q._size) {
              var i = q._ended + q._active,
                  t = q._tasks[i],
                  j = t.length - 1,
                  c = t[j];
              t[j] = end(q, i);
              --q._waiting, ++q._active;
              t = c.apply(null, t);
              if (!q._tasks[i]) continue; // task finished synchronously
              q._tasks[i] = t || noabort;
          }
      }
  
      function end(q, i) {
          return function(e, r) {
              if (!q._tasks[i]) return; // ignore multiple callbacks
              --q._active, ++q._ended;
              q._tasks[i] = null;
              if (q._error != null) return; // ignore secondary errors
              if (e != null) {
                  abort(q, e);
              } else {
                  q._data[i] = r;
                  if (q._waiting) poke$1(q);
                  else maybeNotify(q);
              }
          };
      }
  
      function abort(q, e) {
          var i = q._tasks.length, t;
          q._error = e; // ignore active callbacks
          q._data = undefined; // allow gc
          q._waiting = NaN; // prevent starting
  
          while (--i >= 0) {
              if (t = q._tasks[i]) {
                  q._tasks[i] = null;
                  if (t.abort) {
                      try { t.abort(); }
                      catch (e) { /* ignore */ }
                  }
              }
          }
  
          q._active = NaN; // allow notification
          maybeNotify(q);
      }
  
      function maybeNotify(q) {
          if (!q._active && q._call) {
              var d = q._data;
              q._data = undefined; // allow gc
              q._call(q._error, d);
          }
      }
  
      function queue(concurrency) {
          return new Queue(arguments.length ? +concurrency : Infinity);
      }
  
      var uniform = function(min, max) {
          min = min == null ? 0 : +min;
          max = max == null ? 1 : +max;
          if (arguments.length === 1) max = min, min = 0;
          else max -= min;
          return function() {
              return Math.random() * max + min;
          };
      };
  
      var normal = function(mu, sigma) {
          var x, r;
          mu = mu == null ? 0 : +mu;
          sigma = sigma == null ? 1 : +sigma;
          return function() {
              var y;
  
              // If available, use the second previously-generated uniform random.
              if (x != null) y = x, x = null;
  
              // Otherwise, generate a new x and y.
              else do {
                  x = Math.random() * 2 - 1;
                  y = Math.random() * 2 - 1;
                  r = x * x + y * y;
              } while (!r || r > 1);
  
              return mu + sigma * y * Math.sqrt(-2 * Math.log(r) / r);
          };
      };
  
      var logNormal = function() {
          var randomNormal = normal.apply(this, arguments);
          return function() {
              return Math.exp(randomNormal());
          };
      };
  
      var irwinHall = function(n) {
          return function() {
              for (var sum = 0, i = 0; i < n; ++i) sum += Math.random();
              return sum;
          };
      };
  
      var bates = function(n) {
          var randomIrwinHall = irwinHall(n);
          return function() {
              return randomIrwinHall() / n;
          };
      };
  
      var exponential$1 = function(lambda) {
          return function() {
              return -Math.log(1 - Math.random()) / lambda;
          };
      };
  
      var request = function(url, callback) {
          var request,
              event = dispatch("beforesend", "progress", "load", "error"),
              mimeType,
              headers = map$1(),
              xhr = new XMLHttpRequest,
              user = null,
              password = null,
              response,
              responseType,
              timeout = 0;
  
          // If IE does not support CORS, use XDomainRequest.
          if (typeof XDomainRequest !== "undefined"
              && !("withCredentials" in xhr)
              && /^(http(s)?:)?\/\//.test(url)) xhr = new XDomainRequest;
  
          "onload" in xhr
              ? xhr.onload = xhr.onerror = xhr.ontimeout = respond
              : xhr.onreadystatechange = function(o) { xhr.readyState > 3 && respond(o); };
  
          function respond(o) {
              var status = xhr.status, result;
              if (!status && hasResponse(xhr)
                  || status >= 200 && status < 300
                  || status === 304) {
                  if (response) {
                      try {
                          result = response.call(request, xhr);
                      } catch (e) {
                          event.call("error", request, e);
                          return;
                      }
                  } else {
                      result = xhr;
                  }
                  event.call("load", request, result);
              } else {
                  event.call("error", request, o);
              }
          }
  
          xhr.onprogress = function(e) {
              event.call("progress", request, e);
          };
  
          request = {
              header: function(name, value) {
                  name = (name + "").toLowerCase();
                  if (arguments.length < 2) return headers.get(name);
                  if (value == null) headers.remove(name);
                  else headers.set(name, value + "");
                  return request;
              },
  
              // If mimeType is non-null and no Accept header is set, a default is used.
              mimeType: function(value) {
                  if (!arguments.length) return mimeType;
                  mimeType = value == null ? null : value + "";
                  return request;
              },
  
              // Specifies what type the response value should take;
              // for instance, arraybuffer, blob, document, or text.
              responseType: function(value) {
                  if (!arguments.length) return responseType;
                  responseType = value;
                  return request;
              },
  
              timeout: function(value) {
                  if (!arguments.length) return timeout;
                  timeout = +value;
                  return request;
              },
  
              user: function(value) {
                  return arguments.length < 1 ? user : (user = value == null ? null : value + "", request);
              },
  
              password: function(value) {
                  return arguments.length < 1 ? password : (password = value == null ? null : value + "", request);
              },
  
              // Specify how to convert the response content to a specific type;
              // changes the callback value on "load" events.
              response: function(value) {
                  response = value;
                  return request;
              },
  
              // Alias for send("GET", …).
              get: function(data, callback) {
                  return request.send("GET", data, callback);
              },
  
              // Alias for send("POST", …).
              post: function(data, callback) {
                  return request.send("POST", data, callback);
              },
  
              // If callback is non-null, it will be used for error and load events.
              send: function(method, data, callback) {
                  xhr.open(method, url, true, user, password);
                  if (mimeType != null && !headers.has("accept")) headers.set("accept", mimeType + ",*/*");
                  if (xhr.setRequestHeader) headers.each(function(value, name) { xhr.setRequestHeader(name, value); });
                  if (mimeType != null && xhr.overrideMimeType) xhr.overrideMimeType(mimeType);
                  if (responseType != null) xhr.responseType = responseType;
                  if (timeout > 0) xhr.timeout = timeout;
                  if (callback == null && typeof data === "function") callback = data, data = null;
                  if (callback != null && callback.length === 1) callback = fixCallback(callback);
                  if (callback != null) request.on("error", callback).on("load", function(xhr) { callback(null, xhr); });
                  event.call("beforesend", request, xhr);
                  xhr.send(data == null ? null : data);
                  return request;
              },
  
              abort: function() {
                  xhr.abort();
                  return request;
              },
  
              on: function() {
                  var value = event.on.apply(event, arguments);
                  return value === event ? request : value;
              }
          };
  
          if (callback != null) {
              if (typeof callback !== "function") throw new Error("invalid callback: " + callback);
              return request.get(callback);
          }
  
          return request;
      };
  
      function fixCallback(callback) {
          return function(error, xhr) {
              callback(error == null ? xhr : null);
          };
      }
  
      function hasResponse(xhr) {
          var type = xhr.responseType;
          return type && type !== "text"
              ? xhr.response // null on error
              : xhr.responseText; // "" on error
      }
  
      var type$1 = function(defaultMimeType, response) {
          return function(url, callback) {
              var r = request(url).mimeType(defaultMimeType).response(response);
              if (callback != null) {
                  if (typeof callback !== "function") throw new Error("invalid callback: " + callback);
                  return r.get(callback);
              }
              return r;
          };
      };
  
      var html = type$1("text/html", function(xhr) {
          return document.createRange().createContextualFragment(xhr.responseText);
      });
  
      var json = type$1("application/json", function(xhr) {
          return JSON.parse(xhr.responseText);
      });
  
      var text = type$1("text/plain", function(xhr) {
          return xhr.responseText;
      });
  
      var xml = type$1("application/xml", function(xhr) {
          var xml = xhr.responseXML;
          if (!xml) throw new Error("parse error");
          return xml;
      });
  
      var dsv$1 = function(defaultMimeType, parse) {
          return function(url, row, callback) {
              if (arguments.length < 3) callback = row, row = null;
              var r = request(url).mimeType(defaultMimeType);
              r.row = function(_) { return arguments.length ? r.response(responseOf(parse, row = _)) : row; };
              r.row(row);
              return callback ? r.get(callback) : r;
          };
      };
  
      function responseOf(parse, row) {
          return function(request$$1) {
              return parse(request$$1.responseText, row);
          };
      }
  
      var csv$1 = dsv$1("text/csv", csvParse);
  
      var tsv$1 = dsv$1("text/tab-separated-values", tsvParse);
  
      var array$2 = Array.prototype;
  
      var map$3 = array$2.map;
      var slice$4 = array$2.slice;
  
      var implicit = {name: "implicit"};
  
      function ordinal(range) {
          var index = map$1(),
              domain = [],
              unknown = implicit;
  
          range = range == null ? [] : slice$4.call(range);
  
          function scale(d) {
              var key = d + "", i = index.get(key);
              if (!i) {
                  if (unknown !== implicit) return unknown;
                  index.set(key, i = domain.push(d));
              }
              return range[(i - 1) % range.length];
          }
  
          scale.domain = function(_) {
              if (!arguments.length) return domain.slice();
              domain = [], index = map$1();
              var i = -1, n = _.length, d, key;
              while (++i < n) if (!index.has(key = (d = _[i]) + "")) index.set(key, domain.push(d));
              return scale;
          };
  
          scale.range = function(_) {
              return arguments.length ? (range = slice$4.call(_), scale) : range.slice();
          };
  
          scale.unknown = function(_) {
              return arguments.length ? (unknown = _, scale) : unknown;
          };
  
          scale.copy = function() {
              return ordinal()
                  .domain(domain)
                  .range(range)
                  .unknown(unknown);
          };
  
          return scale;
      }
  
      function band() {
          var scale = ordinal().unknown(undefined),
              domain = scale.domain,
              ordinalRange = scale.range,
              range$$1 = [0, 1],
              step,
              bandwidth,
              round = false,
              paddingInner = 0,
              paddingOuter = 0,
              align = 0.5;
  
          delete scale.unknown;
  
          function rescale() {
              var n = domain().length,
                  reverse = range$$1[1] < range$$1[0],
                  start = range$$1[reverse - 0],
                  stop = range$$1[1 - reverse];
              step = (stop - start) / Math.max(1, n - paddingInner + paddingOuter * 2);
              if (round) step = Math.floor(step);
              start += (stop - start - step * (n - paddingInner)) * align;
              bandwidth = step * (1 - paddingInner);
              if (round) start = Math.round(start), bandwidth = Math.round(bandwidth);
              var values = sequence(n).map(function(i) { return start + step * i; });
              return ordinalRange(reverse ? values.reverse() : values);
          }
  
          scale.domain = function(_) {
              return arguments.length ? (domain(_), rescale()) : domain();
          };
  
          scale.range = function(_) {
              return arguments.length ? (range$$1 = [+_[0], +_[1]], rescale()) : range$$1.slice();
          };
  
          scale.rangeRound = function(_) {
              return range$$1 = [+_[0], +_[1]], round = true, rescale();
          };
  
          scale.bandwidth = function() {
              return bandwidth;
          };
  
          scale.step = function() {
              return step;
          };
  
          scale.round = function(_) {
              return arguments.length ? (round = !!_, rescale()) : round;
          };
  
          scale.padding = function(_) {
              return arguments.length ? (paddingInner = paddingOuter = Math.max(0, Math.min(1, _)), rescale()) : paddingInner;
          };
  
          scale.paddingInner = function(_) {
              return arguments.length ? (paddingInner = Math.max(0, Math.min(1, _)), rescale()) : paddingInner;
          };
  
          scale.paddingOuter = function(_) {
              return arguments.length ? (paddingOuter = Math.max(0, Math.min(1, _)), rescale()) : paddingOuter;
          };
  
          scale.align = function(_) {
              return arguments.length ? (align = Math.max(0, Math.min(1, _)), rescale()) : align;
          };
  
          scale.copy = function() {
              return band()
                  .domain(domain())
                  .range(range$$1)
                  .round(round)
                  .paddingInner(paddingInner)
                  .paddingOuter(paddingOuter)
                  .align(align);
          };
  
          return rescale();
      }
  
      function pointish(scale) {
          var copy = scale.copy;
  
          scale.padding = scale.paddingOuter;
          delete scale.paddingInner;
          delete scale.paddingOuter;
  
          scale.copy = function() {
              return pointish(copy());
          };
  
          return scale;
      }
  
      function point$1() {
          return pointish(band().paddingInner(1));
      }
  
      var constant$9 = function(x) {
          return function() {
              return x;
          };
      };
  
      var number$1 = function(x) {
          return +x;
      };
  
      var unit = [0, 1];
  
      function deinterpolateLinear(a, b) {
          return (b -= (a = +a))
              ? function(x) { return (x - a) / b; }
              : constant$9(b);
      }
  
      function deinterpolateClamp(deinterpolate) {
          return function(a, b) {
              var d = deinterpolate(a = +a, b = +b);
              return function(x) { return x <= a ? 0 : x >= b ? 1 : d(x); };
          };
      }
  
      function reinterpolateClamp(reinterpolate) {
          return function(a, b) {
              var r = reinterpolate(a = +a, b = +b);
              return function(t) { return t <= 0 ? a : t >= 1 ? b : r(t); };
          };
      }
  
      function bimap(domain, range$$1, deinterpolate, reinterpolate) {
          var d0 = domain[0], d1 = domain[1], r0 = range$$1[0], r1 = range$$1[1];
          if (d1 < d0) d0 = deinterpolate(d1, d0), r0 = reinterpolate(r1, r0);
          else d0 = deinterpolate(d0, d1), r0 = reinterpolate(r0, r1);
          return function(x) { return r0(d0(x)); };
      }
  
      function polymap(domain, range$$1, deinterpolate, reinterpolate) {
          var j = Math.min(domain.length, range$$1.length) - 1,
              d = new Array(j),
              r = new Array(j),
              i = -1;
  
          // Reverse descending domains.
          if (domain[j] < domain[0]) {
              domain = domain.slice().reverse();
              range$$1 = range$$1.slice().reverse();
          }
  
          while (++i < j) {
              d[i] = deinterpolate(domain[i], domain[i + 1]);
              r[i] = reinterpolate(range$$1[i], range$$1[i + 1]);
          }
  
          return function(x) {
              var i = bisectRight(domain, x, 1, j) - 1;
              return r[i](d[i](x));
          };
      }
  
      function copy(source, target) {
          return target
              .domain(source.domain())
              .range(source.range())
              .interpolate(source.interpolate())
              .clamp(source.clamp());
      }
  
  // deinterpolate(a, b)(x) takes a domain value x in [a,b] and returns the corresponding parameter t in [0,1].
  // reinterpolate(a, b)(t) takes a parameter t in [0,1] and returns the corresponding domain value x in [a,b].
      function continuous(deinterpolate, reinterpolate) {
          var domain = unit,
              range$$1 = unit,
              interpolate$$1 = interpolateValue,
              clamp = false,
              piecewise,
              output,
              input;
  
          function rescale() {
              piecewise = Math.min(domain.length, range$$1.length) > 2 ? polymap : bimap;
              output = input = null;
              return scale;
          }
  
          function scale(x) {
              return (output || (output = piecewise(domain, range$$1, clamp ? deinterpolateClamp(deinterpolate) : deinterpolate, interpolate$$1)))(+x);
          }
  
          scale.invert = function(y) {
              return (input || (input = piecewise(range$$1, domain, deinterpolateLinear, clamp ? reinterpolateClamp(reinterpolate) : reinterpolate)))(+y);
          };
  
          scale.domain = function(_) {
              return arguments.length ? (domain = map$3.call(_, number$1), rescale()) : domain.slice();
          };
  
          scale.range = function(_) {
              return arguments.length ? (range$$1 = slice$4.call(_), rescale()) : range$$1.slice();
          };
  
          scale.rangeRound = function(_) {
              return range$$1 = slice$4.call(_), interpolate$$1 = interpolateRound, rescale();
          };
  
          scale.clamp = function(_) {
              return arguments.length ? (clamp = !!_, rescale()) : clamp;
          };
  
          scale.interpolate = function(_) {
              return arguments.length ? (interpolate$$1 = _, rescale()) : interpolate$$1;
          };
  
          return rescale();
      }
  
      var tickFormat = function(domain, count, specifier) {
          var start = domain[0],
              stop = domain[domain.length - 1],
              step = tickStep(start, stop, count == null ? 10 : count),
              precision;
          specifier = formatSpecifier(specifier == null ? ",f" : specifier);
          switch (specifier.type) {
              case "s": {
                  var value = Math.max(Math.abs(start), Math.abs(stop));
                  if (specifier.precision == null && !isNaN(precision = precisionPrefix(step, value))) specifier.precision = precision;
                  return exports.formatPrefix(specifier, value);
              }
              case "":
              case "e":
              case "g":
              case "p":
              case "r": {
                  if (specifier.precision == null && !isNaN(precision = precisionRound(step, Math.max(Math.abs(start), Math.abs(stop))))) specifier.precision = precision - (specifier.type === "e");
                  break;
              }
              case "f":
              case "%": {
                  if (specifier.precision == null && !isNaN(precision = precisionFixed(step))) specifier.precision = precision - (specifier.type === "%") * 2;
                  break;
              }
          }
          return exports.format(specifier);
      };
  
      function linearish(scale) {
          var domain = scale.domain;
  
          scale.ticks = function(count) {
              var d = domain();
              return ticks(d[0], d[d.length - 1], count == null ? 10 : count);
          };
  
          scale.tickFormat = function(count, specifier) {
              return tickFormat(domain(), count, specifier);
          };
  
          scale.nice = function(count) {
              var d = domain(),
                  i = d.length - 1,
                  n = count == null ? 10 : count,
                  start = d[0],
                  stop = d[i],
                  step = tickStep(start, stop, n);
  
              if (step) {
                  step = tickStep(Math.floor(start / step) * step, Math.ceil(stop / step) * step, n);
                  d[0] = Math.floor(start / step) * step;
                  d[i] = Math.ceil(stop / step) * step;
                  domain(d);
              }
  
              return scale;
          };
  
          return scale;
      }
  
      function linear$2() {
          var scale = continuous(deinterpolateLinear, reinterpolate);
  
          scale.copy = function() {
              return copy(scale, linear$2());
          };
  
          return linearish(scale);
      }
  
      function identity$6() {
          var domain = [0, 1];
  
          function scale(x) {
              return +x;
          }
  
          scale.invert = scale;
  
          scale.domain = scale.range = function(_) {
              return arguments.length ? (domain = map$3.call(_, number$1), scale) : domain.slice();
          };
  
          scale.copy = function() {
              return identity$6().domain(domain);
          };
  
          return linearish(scale);
      }
  
      var nice = function(domain, interval) {
          domain = domain.slice();
  
          var i0 = 0,
              i1 = domain.length - 1,
              x0 = domain[i0],
              x1 = domain[i1],
              t;
  
          if (x1 < x0) {
              t = i0, i0 = i1, i1 = t;
              t = x0, x0 = x1, x1 = t;
          }
  
          domain[i0] = interval.floor(x0);
          domain[i1] = interval.ceil(x1);
          return domain;
      };
  
      function deinterpolate(a, b) {
          return (b = Math.log(b / a))
              ? function(x) { return Math.log(x / a) / b; }
              : constant$9(b);
      }
  
      function reinterpolate$1(a, b) {
          return a < 0
              ? function(t) { return -Math.pow(-b, t) * Math.pow(-a, 1 - t); }
              : function(t) { return Math.pow(b, t) * Math.pow(a, 1 - t); };
      }
  
      function pow10(x) {
          return isFinite(x) ? +("1e" + x) : x < 0 ? 0 : x;
      }
  
      function powp(base) {
          return base === 10 ? pow10
              : base === Math.E ? Math.exp
                  : function(x) { return Math.pow(base, x); };
      }
  
      function logp(base) {
          return base === Math.E ? Math.log
              : base === 10 && Math.log10
              || base === 2 && Math.log2
              || (base = Math.log(base), function(x) { return Math.log(x) / base; });
      }
  
      function reflect(f) {
          return function(x) {
              return -f(-x);
          };
      }
  
      function log$1() {
          var scale = continuous(deinterpolate, reinterpolate$1).domain([1, 10]),
              domain = scale.domain,
              base = 10,
              logs = logp(10),
              pows = powp(10);
  
          function rescale() {
              logs = logp(base), pows = powp(base);
              if (domain()[0] < 0) logs = reflect(logs), pows = reflect(pows);
              return scale;
          }
  
          scale.base = function(_) {
              return arguments.length ? (base = +_, rescale()) : base;
          };
  
          scale.domain = function(_) {
              return arguments.length ? (domain(_), rescale()) : domain();
          };
  
          scale.ticks = function(count) {
              var d = domain(),
                  u = d[0],
                  v = d[d.length - 1],
                  r;
  
              if (r = v < u) i = u, u = v, v = i;
  
              var i = logs(u),
                  j = logs(v),
                  p,
                  k,
                  t,
                  n = count == null ? 10 : +count,
                  z = [];
  
              if (!(base % 1) && j - i < n) {
                  i = Math.round(i) - 1, j = Math.round(j) + 1;
                  if (u > 0) for (; i < j; ++i) {
                      for (k = 1, p = pows(i); k < base; ++k) {
                          t = p * k;
                          if (t < u) continue;
                          if (t > v) break;
                          z.push(t);
                      }
                  } else for (; i < j; ++i) {
                      for (k = base - 1, p = pows(i); k >= 1; --k) {
                          t = p * k;
                          if (t < u) continue;
                          if (t > v) break;
                          z.push(t);
                      }
                  }
              } else {
                  z = ticks(i, j, Math.min(j - i, n)).map(pows);
              }
  
              return r ? z.reverse() : z;
          };
  
          scale.tickFormat = function(count, specifier) {
              if (specifier == null) specifier = base === 10 ? ".0e" : ",";
              if (typeof specifier !== "function") specifier = exports.format(specifier);
              if (count === Infinity) return specifier;
              if (count == null) count = 10;
              var k = Math.max(1, base * count / scale.ticks().length); // TODO fast estimate?
              return function(d) {
                  var i = d / pows(Math.round(logs(d)));
                  if (i * base < base - 0.5) i *= base;
                  return i <= k ? specifier(d) : "";
              };
          };
  
          scale.nice = function() {
              return domain(nice(domain(), {
                  floor: function(x) { return pows(Math.floor(logs(x))); },
                  ceil: function(x) { return pows(Math.ceil(logs(x))); }
              }));
          };
  
          scale.copy = function() {
              return copy(scale, log$1().base(base));
          };
  
          return scale;
      }
  
      function raise$1(x, exponent) {
          return x < 0 ? -Math.pow(-x, exponent) : Math.pow(x, exponent);
      }
  
      function pow$1() {
          var exponent = 1,
              scale = continuous(deinterpolate, reinterpolate),
              domain = scale.domain;
  
          function deinterpolate(a, b) {
              return (b = raise$1(b, exponent) - (a = raise$1(a, exponent)))
                  ? function(x) { return (raise$1(x, exponent) - a) / b; }
                  : constant$9(b);
          }
  
          function reinterpolate(a, b) {
              b = raise$1(b, exponent) - (a = raise$1(a, exponent));
              return function(t) { return raise$1(a + b * t, 1 / exponent); };
          }
  
          scale.exponent = function(_) {
              return arguments.length ? (exponent = +_, domain(domain())) : exponent;
          };
  
          scale.copy = function() {
              return copy(scale, pow$1().exponent(exponent));
          };
  
          return linearish(scale);
      }
  
      function sqrt$1() {
          return pow$1().exponent(0.5);
      }
  
      function quantile$$1() {
          var domain = [],
              range$$1 = [],
              thresholds = [];
  
          function rescale() {
              var i = 0, n = Math.max(1, range$$1.length);
              thresholds = new Array(n - 1);
              while (++i < n) thresholds[i - 1] = threshold(domain, i / n);
              return scale;
          }
  
          function scale(x) {
              if (!isNaN(x = +x)) return range$$1[bisectRight(thresholds, x)];
          }
  
          scale.invertExtent = function(y) {
              var i = range$$1.indexOf(y);
              return i < 0 ? [NaN, NaN] : [
                  i > 0 ? thresholds[i - 1] : domain[0],
                  i < thresholds.length ? thresholds[i] : domain[domain.length - 1]
              ];
          };
  
          scale.domain = function(_) {
              if (!arguments.length) return domain.slice();
              domain = [];
              for (var i = 0, n = _.length, d; i < n; ++i) if (d = _[i], d != null && !isNaN(d = +d)) domain.push(d);
              domain.sort(ascending);
              return rescale();
          };
  
          scale.range = function(_) {
              return arguments.length ? (range$$1 = slice$4.call(_), rescale()) : range$$1.slice();
          };
  
          scale.quantiles = function() {
              return thresholds.slice();
          };
  
          scale.copy = function() {
              return quantile$$1()
                  .domain(domain)
                  .range(range$$1);
          };
  
          return scale;
      }
  
      function quantize$1() {
          var x0 = 0,
              x1 = 1,
              n = 1,
              domain = [0.5],
              range$$1 = [0, 1];
  
          function scale(x) {
              if (x <= x) return range$$1[bisectRight(domain, x, 0, n)];
          }
  
          function rescale() {
              var i = -1;
              domain = new Array(n);
              while (++i < n) domain[i] = ((i + 1) * x1 - (i - n) * x0) / (n + 1);
              return scale;
          }
  
          scale.domain = function(_) {
              return arguments.length ? (x0 = +_[0], x1 = +_[1], rescale()) : [x0, x1];
          };
  
          scale.range = function(_) {
              return arguments.length ? (n = (range$$1 = slice$4.call(_)).length - 1, rescale()) : range$$1.slice();
          };
  
          scale.invertExtent = function(y) {
              var i = range$$1.indexOf(y);
              return i < 0 ? [NaN, NaN]
                  : i < 1 ? [x0, domain[0]]
                      : i >= n ? [domain[n - 1], x1]
                          : [domain[i - 1], domain[i]];
          };
  
          scale.copy = function() {
              return quantize$1()
                  .domain([x0, x1])
                  .range(range$$1);
          };
  
          return linearish(scale);
      }
  
      function threshold$1() {
          var domain = [0.5],
              range$$1 = [0, 1],
              n = 1;
  
          function scale(x) {
              if (x <= x) return range$$1[bisectRight(domain, x, 0, n)];
          }
  
          scale.domain = function(_) {
              return arguments.length ? (domain = slice$4.call(_), n = Math.min(domain.length, range$$1.length - 1), scale) : domain.slice();
          };
  
          scale.range = function(_) {
              return arguments.length ? (range$$1 = slice$4.call(_), n = Math.min(domain.length, range$$1.length - 1), scale) : range$$1.slice();
          };
  
          scale.invertExtent = function(y) {
              var i = range$$1.indexOf(y);
              return [domain[i - 1], domain[i]];
          };
  
          scale.copy = function() {
              return threshold$1()
                  .domain(domain)
                  .range(range$$1);
          };
  
          return scale;
      }
  
      var t0$1 = new Date;
      var t1$1 = new Date;
  
      function newInterval(floori, offseti, count, field) {
  
          function interval(date) {
              return floori(date = new Date(+date)), date;
          }
  
          interval.floor = interval;
  
          interval.ceil = function(date) {
              return floori(date = new Date(date - 1)), offseti(date, 1), floori(date), date;
          };
  
          interval.round = function(date) {
              var d0 = interval(date),
                  d1 = interval.ceil(date);
              return date - d0 < d1 - date ? d0 : d1;
          };
  
          interval.offset = function(date, step) {
              return offseti(date = new Date(+date), step == null ? 1 : Math.floor(step)), date;
          };
  
          interval.range = function(start, stop, step) {
              var range = [];
              start = interval.ceil(start);
              step = step == null ? 1 : Math.floor(step);
              if (!(start < stop) || !(step > 0)) return range; // also handles Invalid Date
              do range.push(new Date(+start)); while (offseti(start, step), floori(start), start < stop)
              return range;
          };
  
          interval.filter = function(test) {
              return newInterval(function(date) {
                  if (date >= date) while (floori(date), !test(date)) date.setTime(date - 1);
              }, function(date, step) {
                  if (date >= date) while (--step >= 0) while (offseti(date, 1), !test(date)) {} // eslint-disable-line no-empty
              });
          };
  
          if (count) {
              interval.count = function(start, end) {
                  t0$1.setTime(+start), t1$1.setTime(+end);
                  floori(t0$1), floori(t1$1);
                  return Math.floor(count(t0$1, t1$1));
              };
  
              interval.every = function(step) {
                  step = Math.floor(step);
                  return !isFinite(step) || !(step > 0) ? null
                      : !(step > 1) ? interval
                          : interval.filter(field
                              ? function(d) { return field(d) % step === 0; }
                              : function(d) { return interval.count(0, d) % step === 0; });
              };
          }
  
          return interval;
      }
  
      var millisecond = newInterval(function() {
          // noop
      }, function(date, step) {
          date.setTime(+date + step);
      }, function(start, end) {
          return end - start;
      });
  
  // An optimized implementation for this simple case.
      millisecond.every = function(k) {
          k = Math.floor(k);
          if (!isFinite(k) || !(k > 0)) return null;
          if (!(k > 1)) return millisecond;
          return newInterval(function(date) {
              date.setTime(Math.floor(date / k) * k);
          }, function(date, step) {
              date.setTime(+date + step * k);
          }, function(start, end) {
              return (end - start) / k;
          });
      };
  
      var milliseconds = millisecond.range;
  
      var durationSecond$1 = 1e3;
      var durationMinute$1 = 6e4;
      var durationHour$1 = 36e5;
      var durationDay$1 = 864e5;
      var durationWeek$1 = 6048e5;
  
      var second = newInterval(function(date) {
          date.setTime(Math.floor(date / durationSecond$1) * durationSecond$1);
      }, function(date, step) {
          date.setTime(+date + step * durationSecond$1);
      }, function(start, end) {
          return (end - start) / durationSecond$1;
      }, function(date) {
          return date.getUTCSeconds();
      });
  
      var seconds = second.range;
  
      var minute = newInterval(function(date) {
          date.setTime(Math.floor(date / durationMinute$1) * durationMinute$1);
      }, function(date, step) {
          date.setTime(+date + step * durationMinute$1);
      }, function(start, end) {
          return (end - start) / durationMinute$1;
      }, function(date) {
          return date.getMinutes();
      });
  
      var minutes = minute.range;
  
      var hour = newInterval(function(date) {
          var offset = date.getTimezoneOffset() * durationMinute$1 % durationHour$1;
          if (offset < 0) offset += durationHour$1;
          date.setTime(Math.floor((+date - offset) / durationHour$1) * durationHour$1 + offset);
      }, function(date, step) {
          date.setTime(+date + step * durationHour$1);
      }, function(start, end) {
          return (end - start) / durationHour$1;
      }, function(date) {
          return date.getHours();
      });
  
      var hours = hour.range;
  
      var day = newInterval(function(date) {
          date.setHours(0, 0, 0, 0);
      }, function(date, step) {
          date.setDate(date.getDate() + step);
      }, function(start, end) {
          return (end - start - (end.getTimezoneOffset() - start.getTimezoneOffset()) * durationMinute$1) / durationDay$1;
      }, function(date) {
          return date.getDate() - 1;
      });
  
      var days = day.range;
  
      function weekday(i) {
          return newInterval(function(date) {
              date.setDate(date.getDate() - (date.getDay() + 7 - i) % 7);
              date.setHours(0, 0, 0, 0);
          }, function(date, step) {
              date.setDate(date.getDate() + step * 7);
          }, function(start, end) {
              return (end - start - (end.getTimezoneOffset() - start.getTimezoneOffset()) * durationMinute$1) / durationWeek$1;
          });
      }
  
      var sunday = weekday(0);
      var monday = weekday(1);
      var tuesday = weekday(2);
      var wednesday = weekday(3);
      var thursday = weekday(4);
      var friday = weekday(5);
      var saturday = weekday(6);
  
      var sundays = sunday.range;
      var mondays = monday.range;
      var tuesdays = tuesday.range;
      var wednesdays = wednesday.range;
      var thursdays = thursday.range;
      var fridays = friday.range;
      var saturdays = saturday.range;
  
      var month = newInterval(function(date) {
          date.setDate(1);
          date.setHours(0, 0, 0, 0);
      }, function(date, step) {
          date.setMonth(date.getMonth() + step);
      }, function(start, end) {
          return end.getMonth() - start.getMonth() + (end.getFullYear() - start.getFullYear()) * 12;
      }, function(date) {
          return date.getMonth();
      });
  
      var months = month.range;
  
      var year = newInterval(function(date) {
          date.setMonth(0, 1);
          date.setHours(0, 0, 0, 0);
      }, function(date, step) {
          date.setFullYear(date.getFullYear() + step);
      }, function(start, end) {
          return end.getFullYear() - start.getFullYear();
      }, function(date) {
          return date.getFullYear();
      });
  
  // An optimized implementation for this simple case.
      year.every = function(k) {
          return !isFinite(k = Math.floor(k)) || !(k > 0) ? null : newInterval(function(date) {
              date.setFullYear(Math.floor(date.getFullYear() / k) * k);
              date.setMonth(0, 1);
              date.setHours(0, 0, 0, 0);
          }, function(date, step) {
              date.setFullYear(date.getFullYear() + step * k);
          });
      };
  
      var years = year.range;
  
      var utcMinute = newInterval(function(date) {
          date.setUTCSeconds(0, 0);
      }, function(date, step) {
          date.setTime(+date + step * durationMinute$1);
      }, function(start, end) {
          return (end - start) / durationMinute$1;
      }, function(date) {
          return date.getUTCMinutes();
      });
  
      var utcMinutes = utcMinute.range;
  
      var utcHour = newInterval(function(date) {
          date.setUTCMinutes(0, 0, 0);
      }, function(date, step) {
          date.setTime(+date + step * durationHour$1);
      }, function(start, end) {
          return (end - start) / durationHour$1;
      }, function(date) {
          return date.getUTCHours();
      });
  
      var utcHours = utcHour.range;
  
      var utcDay = newInterval(function(date) {
          date.setUTCHours(0, 0, 0, 0);
      }, function(date, step) {
          date.setUTCDate(date.getUTCDate() + step);
      }, function(start, end) {
          return (end - start) / durationDay$1;
      }, function(date) {
          return date.getUTCDate() - 1;
      });
  
      var utcDays = utcDay.range;
  
      function utcWeekday(i) {
          return newInterval(function(date) {
              date.setUTCDate(date.getUTCDate() - (date.getUTCDay() + 7 - i) % 7);
              date.setUTCHours(0, 0, 0, 0);
          }, function(date, step) {
              date.setUTCDate(date.getUTCDate() + step * 7);
          }, function(start, end) {
              return (end - start) / durationWeek$1;
          });
      }
  
      var utcSunday = utcWeekday(0);
      var utcMonday = utcWeekday(1);
      var utcTuesday = utcWeekday(2);
      var utcWednesday = utcWeekday(3);
      var utcThursday = utcWeekday(4);
      var utcFriday = utcWeekday(5);
      var utcSaturday = utcWeekday(6);
  
      var utcSundays = utcSunday.range;
      var utcMondays = utcMonday.range;
      var utcTuesdays = utcTuesday.range;
      var utcWednesdays = utcWednesday.range;
      var utcThursdays = utcThursday.range;
      var utcFridays = utcFriday.range;
      var utcSaturdays = utcSaturday.range;
  
      var utcMonth = newInterval(function(date) {
          date.setUTCDate(1);
          date.setUTCHours(0, 0, 0, 0);
      }, function(date, step) {
          date.setUTCMonth(date.getUTCMonth() + step);
      }, function(start, end) {
          return end.getUTCMonth() - start.getUTCMonth() + (end.getUTCFullYear() - start.getUTCFullYear()) * 12;
      }, function(date) {
          return date.getUTCMonth();
      });
  
      var utcMonths = utcMonth.range;
  
      var utcYear = newInterval(function(date) {
          date.setUTCMonth(0, 1);
          date.setUTCHours(0, 0, 0, 0);
      }, function(date, step) {
          date.setUTCFullYear(date.getUTCFullYear() + step);
      }, function(start, end) {
          return end.getUTCFullYear() - start.getUTCFullYear();
      }, function(date) {
          return date.getUTCFullYear();
      });
  
  // An optimized implementation for this simple case.
      utcYear.every = function(k) {
          return !isFinite(k = Math.floor(k)) || !(k > 0) ? null : newInterval(function(date) {
              date.setUTCFullYear(Math.floor(date.getUTCFullYear() / k) * k);
              date.setUTCMonth(0, 1);
              date.setUTCHours(0, 0, 0, 0);
          }, function(date, step) {
              date.setUTCFullYear(date.getUTCFullYear() + step * k);
          });
      };
  
      var utcYears = utcYear.range;
  
      function localDate(d) {
          if (0 <= d.y && d.y < 100) {
              var date = new Date(-1, d.m, d.d, d.H, d.M, d.S, d.L);
              date.setFullYear(d.y);
              return date;
          }
          return new Date(d.y, d.m, d.d, d.H, d.M, d.S, d.L);
      }
  
      function utcDate(d) {
          if (0 <= d.y && d.y < 100) {
              var date = new Date(Date.UTC(-1, d.m, d.d, d.H, d.M, d.S, d.L));
              date.setUTCFullYear(d.y);
              return date;
          }
          return new Date(Date.UTC(d.y, d.m, d.d, d.H, d.M, d.S, d.L));
      }
  
      function newYear(y) {
          return {y: y, m: 0, d: 1, H: 0, M: 0, S: 0, L: 0};
      }
  
      function formatLocale$1(locale) {
          var locale_dateTime = locale.dateTime,
              locale_date = locale.date,
              locale_time = locale.time,
              locale_periods = locale.periods,
              locale_weekdays = locale.days,
              locale_shortWeekdays = locale.shortDays,
              locale_months = locale.months,
              locale_shortMonths = locale.shortMonths;
  
          var periodRe = formatRe(locale_periods),
              periodLookup = formatLookup(locale_periods),
              weekdayRe = formatRe(locale_weekdays),
              weekdayLookup = formatLookup(locale_weekdays),
              shortWeekdayRe = formatRe(locale_shortWeekdays),
              shortWeekdayLookup = formatLookup(locale_shortWeekdays),
              monthRe = formatRe(locale_months),
              monthLookup = formatLookup(locale_months),
              shortMonthRe = formatRe(locale_shortMonths),
              shortMonthLookup = formatLookup(locale_shortMonths);
  
          var formats = {
              "a": formatShortWeekday,
              "A": formatWeekday,
              "b": formatShortMonth,
              "B": formatMonth,
              "c": null,
              "d": formatDayOfMonth,
              "e": formatDayOfMonth,
              "H": formatHour24,
              "I": formatHour12,
              "j": formatDayOfYear,
              "L": formatMilliseconds,
              "m": formatMonthNumber,
              "M": formatMinutes,
              "p": formatPeriod,
              "S": formatSeconds,
              "U": formatWeekNumberSunday,
              "w": formatWeekdayNumber,
              "W": formatWeekNumberMonday,
              "x": null,
              "X": null,
              "y": formatYear,
              "Y": formatFullYear,
              "Z": formatZone,
              "%": formatLiteralPercent
          };
  
          var utcFormats = {
              "a": formatUTCShortWeekday,
              "A": formatUTCWeekday,
              "b": formatUTCShortMonth,
              "B": formatUTCMonth,
              "c": null,
              "d": formatUTCDayOfMonth,
              "e": formatUTCDayOfMonth,
              "H": formatUTCHour24,
              "I": formatUTCHour12,
              "j": formatUTCDayOfYear,
              "L": formatUTCMilliseconds,
              "m": formatUTCMonthNumber,
              "M": formatUTCMinutes,
              "p": formatUTCPeriod,
              "S": formatUTCSeconds,
              "U": formatUTCWeekNumberSunday,
              "w": formatUTCWeekdayNumber,
              "W": formatUTCWeekNumberMonday,
              "x": null,
              "X": null,
              "y": formatUTCYear,
              "Y": formatUTCFullYear,
              "Z": formatUTCZone,
              "%": formatLiteralPercent
          };
  
          var parses = {
              "a": parseShortWeekday,
              "A": parseWeekday,
              "b": parseShortMonth,
              "B": parseMonth,
              "c": parseLocaleDateTime,
              "d": parseDayOfMonth,
              "e": parseDayOfMonth,
              "H": parseHour24,
              "I": parseHour24,
              "j": parseDayOfYear,
              "L": parseMilliseconds,
              "m": parseMonthNumber,
              "M": parseMinutes,
              "p": parsePeriod,
              "S": parseSeconds,
              "U": parseWeekNumberSunday,
              "w": parseWeekdayNumber,
              "W": parseWeekNumberMonday,
              "x": parseLocaleDate,
              "X": parseLocaleTime,
              "y": parseYear,
              "Y": parseFullYear,
              "Z": parseZone,
              "%": parseLiteralPercent
          };
  
          // These recursive directive definitions must be deferred.
          formats.x = newFormat(locale_date, formats);
          formats.X = newFormat(locale_time, formats);
          formats.c = newFormat(locale_dateTime, formats);
          utcFormats.x = newFormat(locale_date, utcFormats);
          utcFormats.X = newFormat(locale_time, utcFormats);
          utcFormats.c = newFormat(locale_dateTime, utcFormats);
  
          function newFormat(specifier, formats) {
              return function(date) {
                  var string = [],
                      i = -1,
                      j = 0,
                      n = specifier.length,
                      c,
                      pad,
                      format;
  
                  if (!(date instanceof Date)) date = new Date(+date);
  
                  while (++i < n) {
                      if (specifier.charCodeAt(i) === 37) {
                          string.push(specifier.slice(j, i));
                          if ((pad = pads[c = specifier.charAt(++i)]) != null) c = specifier.charAt(++i);
                          else pad = c === "e" ? " " : "0";
                          if (format = formats[c]) c = format(date, pad);
                          string.push(c);
                          j = i + 1;
                      }
                  }
  
                  string.push(specifier.slice(j, i));
                  return string.join("");
              };
          }
  
          function newParse(specifier, newDate) {
              return function(string) {
                  var d = newYear(1900),
                      i = parseSpecifier(d, specifier, string += "", 0);
                  if (i != string.length) return null;
  
                  // The am-pm flag is 0 for AM, and 1 for PM.
                  if ("p" in d) d.H = d.H % 12 + d.p * 12;
  
                  // Convert day-of-week and week-of-year to day-of-year.
                  if ("W" in d || "U" in d) {
                      if (!("w" in d)) d.w = "W" in d ? 1 : 0;
                      var day$$1 = "Z" in d ? utcDate(newYear(d.y)).getUTCDay() : newDate(newYear(d.y)).getDay();
                      d.m = 0;
                      d.d = "W" in d ? (d.w + 6) % 7 + d.W * 7 - (day$$1 + 5) % 7 : d.w + d.U * 7 - (day$$1 + 6) % 7;
                  }
  
                  // If a time zone is specified, all fields are interpreted as UTC and then
                  // offset according to the specified time zone.
                  if ("Z" in d) {
                      d.H += d.Z / 100 | 0;
                      d.M += d.Z % 100;
                      return utcDate(d);
                  }
  
                  // Otherwise, all fields are in local time.
                  return newDate(d);
              };
          }
  
          function parseSpecifier(d, specifier, string, j) {
              var i = 0,
                  n = specifier.length,
                  m = string.length,
                  c,
                  parse;
  
              while (i < n) {
                  if (j >= m) return -1;
                  c = specifier.charCodeAt(i++);
                  if (c === 37) {
                      c = specifier.charAt(i++);
                      parse = parses[c in pads ? specifier.charAt(i++) : c];
                      if (!parse || ((j = parse(d, string, j)) < 0)) return -1;
                  } else if (c != string.charCodeAt(j++)) {
                      return -1;
                  }
              }
  
              return j;
          }
  
          function parsePeriod(d, string, i) {
              var n = periodRe.exec(string.slice(i));
              return n ? (d.p = periodLookup[n[0].toLowerCase()], i + n[0].length) : -1;
          }
  
          function parseShortWeekday(d, string, i) {
              var n = shortWeekdayRe.exec(string.slice(i));
              return n ? (d.w = shortWeekdayLookup[n[0].toLowerCase()], i + n[0].length) : -1;
          }
  
          function parseWeekday(d, string, i) {
              var n = weekdayRe.exec(string.slice(i));
              return n ? (d.w = weekdayLookup[n[0].toLowerCase()], i + n[0].length) : -1;
          }
  
          function parseShortMonth(d, string, i) {
              var n = shortMonthRe.exec(string.slice(i));
              return n ? (d.m = shortMonthLookup[n[0].toLowerCase()], i + n[0].length) : -1;
          }
  
          function parseMonth(d, string, i) {
              var n = monthRe.exec(string.slice(i));
              return n ? (d.m = monthLookup[n[0].toLowerCase()], i + n[0].length) : -1;
          }
  
          function parseLocaleDateTime(d, string, i) {
              return parseSpecifier(d, locale_dateTime, string, i);
          }
  
          function parseLocaleDate(d, string, i) {
              return parseSpecifier(d, locale_date, string, i);
          }
  
          function parseLocaleTime(d, string, i) {
              return parseSpecifier(d, locale_time, string, i);
          }
  
          function formatShortWeekday(d) {
              return locale_shortWeekdays[d.getDay()];
          }
  
          function formatWeekday(d) {
              return locale_weekdays[d.getDay()];
          }
  
          function formatShortMonth(d) {
              return locale_shortMonths[d.getMonth()];
          }
  
          function formatMonth(d) {
              return locale_months[d.getMonth()];
          }
  
          function formatPeriod(d) {
              return locale_periods[+(d.getHours() >= 12)];
          }
  
          function formatUTCShortWeekday(d) {
              return locale_shortWeekdays[d.getUTCDay()];
          }
  
          function formatUTCWeekday(d) {
              return locale_weekdays[d.getUTCDay()];
          }
  
          function formatUTCShortMonth(d) {
              return locale_shortMonths[d.getUTCMonth()];
          }
  
          function formatUTCMonth(d) {
              return locale_months[d.getUTCMonth()];
          }
  
          function formatUTCPeriod(d) {
              return locale_periods[+(d.getUTCHours() >= 12)];
          }
  
          return {
              format: function(specifier) {
                  var f = newFormat(specifier += "", formats);
                  f.toString = function() { return specifier; };
                  return f;
              },
              parse: function(specifier) {
                  var p = newParse(specifier += "", localDate);
                  p.toString = function() { return specifier; };
                  return p;
              },
              utcFormat: function(specifier) {
                  var f = newFormat(specifier += "", utcFormats);
                  f.toString = function() { return specifier; };
                  return f;
              },
              utcParse: function(specifier) {
                  var p = newParse(specifier, utcDate);
                  p.toString = function() { return specifier; };
                  return p;
              }
          };
      }
  
      var pads = {"-": "", "_": " ", "0": "0"};
      var numberRe = /^\s*\d+/;
      var percentRe = /^%/;
      var requoteRe = /[\\\^\$\*\+\?\|\[\]\(\)\.\{\}]/g;
  
      function pad(value, fill, width) {
          var sign = value < 0 ? "-" : "",
              string = (sign ? -value : value) + "",
              length = string.length;
          return sign + (length < width ? new Array(width - length + 1).join(fill) + string : string);
      }
  
      function requote(s) {
          return s.replace(requoteRe, "\\$&");
      }
  
      function formatRe(names) {
          return new RegExp("^(?:" + names.map(requote).join("|") + ")", "i");
      }
  
      function formatLookup(names) {
          var map = {}, i = -1, n = names.length;
          while (++i < n) map[names[i].toLowerCase()] = i;
          return map;
      }
  
      function parseWeekdayNumber(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 1));
          return n ? (d.w = +n[0], i + n[0].length) : -1;
      }
  
      function parseWeekNumberSunday(d, string, i) {
          var n = numberRe.exec(string.slice(i));
          return n ? (d.U = +n[0], i + n[0].length) : -1;
      }
  
      function parseWeekNumberMonday(d, string, i) {
          var n = numberRe.exec(string.slice(i));
          return n ? (d.W = +n[0], i + n[0].length) : -1;
      }
  
      function parseFullYear(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 4));
          return n ? (d.y = +n[0], i + n[0].length) : -1;
      }
  
      function parseYear(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 2));
          return n ? (d.y = +n[0] + (+n[0] > 68 ? 1900 : 2000), i + n[0].length) : -1;
      }
  
      function parseZone(d, string, i) {
          var n = /^(Z)|([+-]\d\d)(?:\:?(\d\d))?/.exec(string.slice(i, i + 6));
          return n ? (d.Z = n[1] ? 0 : -(n[2] + (n[3] || "00")), i + n[0].length) : -1;
      }
  
      function parseMonthNumber(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 2));
          return n ? (d.m = n[0] - 1, i + n[0].length) : -1;
      }
  
      function parseDayOfMonth(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 2));
          return n ? (d.d = +n[0], i + n[0].length) : -1;
      }
  
      function parseDayOfYear(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 3));
          return n ? (d.m = 0, d.d = +n[0], i + n[0].length) : -1;
      }
  
      function parseHour24(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 2));
          return n ? (d.H = +n[0], i + n[0].length) : -1;
      }
  
      function parseMinutes(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 2));
          return n ? (d.M = +n[0], i + n[0].length) : -1;
      }
  
      function parseSeconds(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 2));
          return n ? (d.S = +n[0], i + n[0].length) : -1;
      }
  
      function parseMilliseconds(d, string, i) {
          var n = numberRe.exec(string.slice(i, i + 3));
          return n ? (d.L = +n[0], i + n[0].length) : -1;
      }
  
      function parseLiteralPercent(d, string, i) {
          var n = percentRe.exec(string.slice(i, i + 1));
          return n ? i + n[0].length : -1;
      }
  
      function formatDayOfMonth(d, p) {
          return pad(d.getDate(), p, 2);
      }
  
      function formatHour24(d, p) {
          return pad(d.getHours(), p, 2);
      }
  
      function formatHour12(d, p) {
          return pad(d.getHours() % 12 || 12, p, 2);
      }
  
      function formatDayOfYear(d, p) {
          return pad(1 + day.count(year(d), d), p, 3);
      }
  
      function formatMilliseconds(d, p) {
          return pad(d.getMilliseconds(), p, 3);
      }
  
      function formatMonthNumber(d, p) {
          return pad(d.getMonth() + 1, p, 2);
      }
  
      function formatMinutes(d, p) {
          return pad(d.getMinutes(), p, 2);
      }
  
      function formatSeconds(d, p) {
          return pad(d.getSeconds(), p, 2);
      }
  
      function formatWeekNumberSunday(d, p) {
          return pad(sunday.count(year(d), d), p, 2);
      }
  
      function formatWeekdayNumber(d) {
          return d.getDay();
      }
  
      function formatWeekNumberMonday(d, p) {
          return pad(monday.count(year(d), d), p, 2);
      }
  
      function formatYear(d, p) {
          return pad(d.getFullYear() % 100, p, 2);
      }
  
      function formatFullYear(d, p) {
          return pad(d.getFullYear() % 10000, p, 4);
      }
  
      function formatZone(d) {
          var z = d.getTimezoneOffset();
          return (z > 0 ? "-" : (z *= -1, "+"))
              + pad(z / 60 | 0, "0", 2)
              + pad(z % 60, "0", 2);
      }
  
      function formatUTCDayOfMonth(d, p) {
          return pad(d.getUTCDate(), p, 2);
      }
  
      function formatUTCHour24(d, p) {
          return pad(d.getUTCHours(), p, 2);
      }
  
      function formatUTCHour12(d, p) {
          return pad(d.getUTCHours() % 12 || 12, p, 2);
      }
  
      function formatUTCDayOfYear(d, p) {
          return pad(1 + utcDay.count(utcYear(d), d), p, 3);
      }
  
      function formatUTCMilliseconds(d, p) {
          return pad(d.getUTCMilliseconds(), p, 3);
      }
  
      function formatUTCMonthNumber(d, p) {
          return pad(d.getUTCMonth() + 1, p, 2);
      }
  
      function formatUTCMinutes(d, p) {
          return pad(d.getUTCMinutes(), p, 2);
      }
  
      function formatUTCSeconds(d, p) {
          return pad(d.getUTCSeconds(), p, 2);
      }
  
      function formatUTCWeekNumberSunday(d, p) {
          return pad(utcSunday.count(utcYear(d), d), p, 2);
      }
  
      function formatUTCWeekdayNumber(d) {
          return d.getUTCDay();
      }
  
      function formatUTCWeekNumberMonday(d, p) {
          return pad(utcMonday.count(utcYear(d), d), p, 2);
      }
  
      function formatUTCYear(d, p) {
          return pad(d.getUTCFullYear() % 100, p, 2);
      }
  
      function formatUTCFullYear(d, p) {
          return pad(d.getUTCFullYear() % 10000, p, 4);
      }
  
      function formatUTCZone() {
          return "+0000";
      }
  
      function formatLiteralPercent() {
          return "%";
      }
  
      var locale$2;
  
  
  
  
  
      defaultLocale$1({
          dateTime: "%x, %X",
          date: "%-m/%-d/%Y",
          time: "%-I:%M:%S %p",
          periods: ["AM", "PM"],
          days: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"],
          shortDays: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"],
          months: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
          shortMonths: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
      });
  
      function defaultLocale$1(definition) {
          locale$2 = formatLocale$1(definition);
          exports.timeFormat = locale$2.format;
          exports.timeParse = locale$2.parse;
          exports.utcFormat = locale$2.utcFormat;
          exports.utcParse = locale$2.utcParse;
          return locale$2;
      }
  
      var isoSpecifier = "%Y-%m-%dT%H:%M:%S.%LZ";
  
      function formatIsoNative(date) {
          return date.toISOString();
      }
  
      var formatIso = Date.prototype.toISOString
          ? formatIsoNative
          : exports.utcFormat(isoSpecifier);
  
      function parseIsoNative(string) {
          var date = new Date(string);
          return isNaN(date) ? null : date;
      }
  
      var parseIso = +new Date("2000-01-01T00:00:00.000Z")
          ? parseIsoNative
          : exports.utcParse(isoSpecifier);
  
      var durationSecond = 1000;
      var durationMinute = durationSecond * 60;
      var durationHour = durationMinute * 60;
      var durationDay = durationHour * 24;
      var durationWeek = durationDay * 7;
      var durationMonth = durationDay * 30;
      var durationYear = durationDay * 365;
  
      function date$1(t) {
          return new Date(t);
      }
  
      function number$2(t) {
          return t instanceof Date ? +t : +new Date(+t);
      }
  
      function calendar(year$$1, month$$1, week, day$$1, hour$$1, minute$$1, second$$1, millisecond$$1, format) {
          var scale = continuous(deinterpolateLinear, reinterpolate),
              invert = scale.invert,
              domain = scale.domain;
  
          var formatMillisecond = format(".%L"),
              formatSecond = format(":%S"),
              formatMinute = format("%I:%M"),
              formatHour = format("%I %p"),
              formatDay = format("%a %d"),
              formatWeek = format("%b %d"),
              formatMonth = format("%B"),
              formatYear = format("%Y");
  
          var tickIntervals = [
              [second$$1,  1,      durationSecond],
              [second$$1,  5,  5 * durationSecond],
              [second$$1, 15, 15 * durationSecond],
              [second$$1, 30, 30 * durationSecond],
              [minute$$1,  1,      durationMinute],
              [minute$$1,  5,  5 * durationMinute],
              [minute$$1, 15, 15 * durationMinute],
              [minute$$1, 30, 30 * durationMinute],
              [  hour$$1,  1,      durationHour  ],
              [  hour$$1,  3,  3 * durationHour  ],
              [  hour$$1,  6,  6 * durationHour  ],
              [  hour$$1, 12, 12 * durationHour  ],
              [   day$$1,  1,      durationDay   ],
              [   day$$1,  2,  2 * durationDay   ],
              [  week,  1,      durationWeek  ],
              [ month$$1,  1,      durationMonth ],
              [ month$$1,  3,  3 * durationMonth ],
              [  year$$1,  1,      durationYear  ]
          ];
  
          function tickFormat(date) {
              return (second$$1(date) < date ? formatMillisecond
                  : minute$$1(date) < date ? formatSecond
                      : hour$$1(date) < date ? formatMinute
                          : day$$1(date) < date ? formatHour
                              : month$$1(date) < date ? (week(date) < date ? formatDay : formatWeek)
                                  : year$$1(date) < date ? formatMonth
                                      : formatYear)(date);
          }
  
          function tickInterval(interval, start, stop, step) {
              if (interval == null) interval = 10;
  
              // If a desired tick count is specified, pick a reasonable tick interval
              // based on the extent of the domain and a rough estimate of tick size.
              // Otherwise, assume interval is already a time interval and use it.
              if (typeof interval === "number") {
                  var target = Math.abs(stop - start) / interval,
                      i = bisector(function(i) { return i[2]; }).right(tickIntervals, target);
                  if (i === tickIntervals.length) {
                      step = tickStep(start / durationYear, stop / durationYear, interval);
                      interval = year$$1;
                  } else if (i) {
                      i = tickIntervals[target / tickIntervals[i - 1][2] < tickIntervals[i][2] / target ? i - 1 : i];
                      step = i[1];
                      interval = i[0];
                  } else {
                      step = tickStep(start, stop, interval);
                      interval = millisecond$$1;
                  }
              }
  
              return step == null ? interval : interval.every(step);
          }
  
          scale.invert = function(y) {
              return new Date(invert(y));
          };
  
          scale.domain = function(_) {
              return arguments.length ? domain(map$3.call(_, number$2)) : domain().map(date$1);
          };
  
          scale.ticks = function(interval, step) {
              var d = domain(),
                  t0 = d[0],
                  t1 = d[d.length - 1],
                  r = t1 < t0,
                  t;
              if (r) t = t0, t0 = t1, t1 = t;
              t = tickInterval(interval, t0, t1, step);
              t = t ? t.range(t0, t1 + 1) : []; // inclusive stop
              return r ? t.reverse() : t;
          };
  
          scale.tickFormat = function(count, specifier) {
              return specifier == null ? tickFormat : format(specifier);
          };
  
          scale.nice = function(interval, step) {
              var d = domain();
              return (interval = tickInterval(interval, d[0], d[d.length - 1], step))
                  ? domain(nice(d, interval))
                  : scale;
          };
  
          scale.copy = function() {
              return copy(scale, calendar(year$$1, month$$1, week, day$$1, hour$$1, minute$$1, second$$1, millisecond$$1, format));
          };
  
          return scale;
      }
  
      var time = function() {
          return calendar(year, month, sunday, day, hour, minute, second, millisecond, exports.timeFormat).domain([new Date(2000, 0, 1), new Date(2000, 0, 2)]);
      };
  
      var utcTime = function() {
          return calendar(utcYear, utcMonth, utcSunday, utcDay, utcHour, utcMinute, second, millisecond, exports.utcFormat).domain([Date.UTC(2000, 0, 1), Date.UTC(2000, 0, 2)]);
      };
  
      var colors = function(s) {
          return s.match(/.{6}/g).map(function(x) {
              return "#" + x;
          });
      };
  
      var category10 = colors("1f77b4ff7f0e2ca02cd627289467bd8c564be377c27f7f7fbcbd2217becf");
  
      var category20b = colors("393b795254a36b6ecf9c9ede6379398ca252b5cf6bcedb9c8c6d31bd9e39e7ba52e7cb94843c39ad494ad6616be7969c7b4173a55194ce6dbdde9ed6");
  
      var category20c = colors("3182bd6baed69ecae1c6dbefe6550dfd8d3cfdae6bfdd0a231a35474c476a1d99bc7e9c0756bb19e9ac8bcbddcdadaeb636363969696bdbdbdd9d9d9");
  
      var category20 = colors("1f77b4aec7e8ff7f0effbb782ca02c98df8ad62728ff98969467bdc5b0d58c564bc49c94e377c2f7b6d27f7f7fc7c7c7bcbd22dbdb8d17becf9edae5");
  
      var cubehelix$3 = cubehelixLong(cubehelix(300, 0.5, 0.0), cubehelix(-240, 0.5, 1.0));
  
      var warm = cubehelixLong(cubehelix(-100, 0.75, 0.35), cubehelix(80, 1.50, 0.8));
  
      var cool = cubehelixLong(cubehelix(260, 0.75, 0.35), cubehelix(80, 1.50, 0.8));
  
      var rainbow = cubehelix();
  
      var rainbow$1 = function(t) {
          if (t < 0 || t > 1) t -= Math.floor(t);
          var ts = Math.abs(t - 0.5);
          rainbow.h = 360 * t - 100;
          rainbow.s = 1.5 - 1.5 * ts;
          rainbow.l = 0.8 - 0.9 * ts;
          return rainbow + "";
      };
  
      function ramp(range) {
          var n = range.length;
          return function(t) {
              return range[Math.max(0, Math.min(n - 1, Math.floor(t * n)))];
          };
      }
  
      var viridis = ramp(colors("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"));
  
      var magma = ramp(colors("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"));
  
      var inferno = ramp(colors("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"));
  
      var plasma = ramp(colors("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"));
  
      function sequential(interpolator) {
          var x0 = 0,
              x1 = 1,
              clamp = false;
  
          function scale(x) {
              var t = (x - x0) / (x1 - x0);
              return interpolator(clamp ? Math.max(0, Math.min(1, t)) : t);
          }
  
          scale.domain = function(_) {
              return arguments.length ? (x0 = +_[0], x1 = +_[1], scale) : [x0, x1];
          };
  
          scale.clamp = function(_) {
              return arguments.length ? (clamp = !!_, scale) : clamp;
          };
  
          scale.interpolator = function(_) {
              return arguments.length ? (interpolator = _, scale) : interpolator;
          };
  
          scale.copy = function() {
              return sequential(interpolator).domain([x0, x1]).clamp(clamp);
          };
  
          return linearish(scale);
      }
  
      var constant$10 = function(x) {
          return function constant() {
              return x;
          };
      };
  
      var abs$1 = Math.abs;
      var atan2$1 = Math.atan2;
      var cos$2 = Math.cos;
      var max$2 = Math.max;
      var min$1 = Math.min;
      var sin$2 = Math.sin;
      var sqrt$2 = Math.sqrt;
  
      var epsilon$3 = 1e-12;
      var pi$4 = Math.PI;
      var halfPi$3 = pi$4 / 2;
      var tau$4 = 2 * pi$4;
  
      function acos$1(x) {
          return x > 1 ? 0 : x < -1 ? pi$4 : Math.acos(x);
      }
  
      function asin$1(x) {
          return x >= 1 ? halfPi$3 : x <= -1 ? -halfPi$3 : Math.asin(x);
      }
  
      function arcInnerRadius(d) {
          return d.innerRadius;
      }
  
      function arcOuterRadius(d) {
          return d.outerRadius;
      }
  
      function arcStartAngle(d) {
          return d.startAngle;
      }
  
      function arcEndAngle(d) {
          return d.endAngle;
      }
  
      function arcPadAngle(d) {
          return d && d.padAngle; // Note: optional!
      }
  
      function intersect(x0, y0, x1, y1, x2, y2, x3, y3) {
          var x10 = x1 - x0, y10 = y1 - y0,
              x32 = x3 - x2, y32 = y3 - y2,
              t = (x32 * (y0 - y2) - y32 * (x0 - x2)) / (y32 * x10 - x32 * y10);
          return [x0 + t * x10, y0 + t * y10];
      }
  
  // Compute perpendicular offset line of length rc.
  // http://mathworld.wolfram.com/Circle-LineIntersection.html
      function cornerTangents(x0, y0, x1, y1, r1, rc, cw) {
          var x01 = x0 - x1,
              y01 = y0 - y1,
              lo = (cw ? rc : -rc) / sqrt$2(x01 * x01 + y01 * y01),
              ox = lo * y01,
              oy = -lo * x01,
              x11 = x0 + ox,
              y11 = y0 + oy,
              x10 = x1 + ox,
              y10 = y1 + oy,
              x00 = (x11 + x10) / 2,
              y00 = (y11 + y10) / 2,
              dx = x10 - x11,
              dy = y10 - y11,
              d2 = dx * dx + dy * dy,
              r = r1 - rc,
              D = x11 * y10 - x10 * y11,
              d = (dy < 0 ? -1 : 1) * sqrt$2(max$2(0, r * r * d2 - D * D)),
              cx0 = (D * dy - dx * d) / d2,
              cy0 = (-D * dx - dy * d) / d2,
              cx1 = (D * dy + dx * d) / d2,
              cy1 = (-D * dx + dy * d) / d2,
              dx0 = cx0 - x00,
              dy0 = cy0 - y00,
              dx1 = cx1 - x00,
              dy1 = cy1 - y00;
  
          // Pick the closer of the two intersection points.
          // TODO Is there a faster way to determine which intersection to use?
          if (dx0 * dx0 + dy0 * dy0 > dx1 * dx1 + dy1 * dy1) cx0 = cx1, cy0 = cy1;
  
          return {
              cx: cx0,
              cy: cy0,
              x01: -ox,
              y01: -oy,
              x11: cx0 * (r1 / r - 1),
              y11: cy0 * (r1 / r - 1)
          };
      }
  
      var arc = function() {
          var innerRadius = arcInnerRadius,
              outerRadius = arcOuterRadius,
              cornerRadius = constant$10(0),
              padRadius = null,
              startAngle = arcStartAngle,
              endAngle = arcEndAngle,
              padAngle = arcPadAngle,
              context = null;
  
          function arc() {
              var buffer,
                  r,
                  r0 = +innerRadius.apply(this, arguments),
                  r1 = +outerRadius.apply(this, arguments),
                  a0 = startAngle.apply(this, arguments) - halfPi$3,
                  a1 = endAngle.apply(this, arguments) - halfPi$3,
                  da = abs$1(a1 - a0),
                  cw = a1 > a0;
  
              if (!context) context = buffer = path();
  
              // Ensure that the outer radius is always larger than the inner radius.
              if (r1 < r0) r = r1, r1 = r0, r0 = r;
  
              // Is it a point?
              if (!(r1 > epsilon$3)) context.moveTo(0, 0);
  
              // Or is it a circle or annulus?
              else if (da > tau$4 - epsilon$3) {
                  context.moveTo(r1 * cos$2(a0), r1 * sin$2(a0));
                  context.arc(0, 0, r1, a0, a1, !cw);
                  if (r0 > epsilon$3) {
                      context.moveTo(r0 * cos$2(a1), r0 * sin$2(a1));
                      context.arc(0, 0, r0, a1, a0, cw);
                  }
              }
  
              // Or is it a circular or annular sector?
              else {
                  var a01 = a0,
                      a11 = a1,
                      a00 = a0,
                      a10 = a1,
                      da0 = da,
                      da1 = da,
                      ap = padAngle.apply(this, arguments) / 2,
                      rp = (ap > epsilon$3) && (padRadius ? +padRadius.apply(this, arguments) : sqrt$2(r0 * r0 + r1 * r1)),
                      rc = min$1(abs$1(r1 - r0) / 2, +cornerRadius.apply(this, arguments)),
                      rc0 = rc,
                      rc1 = rc,
                      t0,
                      t1;
  
                  // Apply padding? Note that since r1 ≥ r0, da1 ≥ da0.
                  if (rp > epsilon$3) {
                      var p0 = asin$1(rp / r0 * sin$2(ap)),
                          p1 = asin$1(rp / r1 * sin$2(ap));
                      if ((da0 -= p0 * 2) > epsilon$3) p0 *= (cw ? 1 : -1), a00 += p0, a10 -= p0;
                      else da0 = 0, a00 = a10 = (a0 + a1) / 2;
                      if ((da1 -= p1 * 2) > epsilon$3) p1 *= (cw ? 1 : -1), a01 += p1, a11 -= p1;
                      else da1 = 0, a01 = a11 = (a0 + a1) / 2;
                  }
  
                  var x01 = r1 * cos$2(a01),
                      y01 = r1 * sin$2(a01),
                      x10 = r0 * cos$2(a10),
                      y10 = r0 * sin$2(a10);
  
                  // Apply rounded corners?
                  if (rc > epsilon$3) {
                      var x11 = r1 * cos$2(a11),
                          y11 = r1 * sin$2(a11),
                          x00 = r0 * cos$2(a00),
                          y00 = r0 * sin$2(a00);
  
                      // Restrict the corner radius according to the sector angle.
                      if (da < pi$4) {
                          var oc = da0 > epsilon$3 ? intersect(x01, y01, x00, y00, x11, y11, x10, y10) : [x10, y10],
                              ax = x01 - oc[0],
                              ay = y01 - oc[1],
                              bx = x11 - oc[0],
                              by = y11 - oc[1],
                              kc = 1 / sin$2(acos$1((ax * bx + ay * by) / (sqrt$2(ax * ax + ay * ay) * sqrt$2(bx * bx + by * by))) / 2),
                              lc = sqrt$2(oc[0] * oc[0] + oc[1] * oc[1]);
                          rc0 = min$1(rc, (r0 - lc) / (kc - 1));
                          rc1 = min$1(rc, (r1 - lc) / (kc + 1));
                      }
                  }
  
                  // Is the sector collapsed to a line?
                  if (!(da1 > epsilon$3)) context.moveTo(x01, y01);
  
                  // Does the sector’s outer ring have rounded corners?
                  else if (rc1 > epsilon$3) {
                      t0 = cornerTangents(x00, y00, x01, y01, r1, rc1, cw);
                      t1 = cornerTangents(x11, y11, x10, y10, r1, rc1, cw);
  
                      context.moveTo(t0.cx + t0.x01, t0.cy + t0.y01);
  
                      // Have the corners merged?
                      if (rc1 < rc) context.arc(t0.cx, t0.cy, rc1, atan2$1(t0.y01, t0.x01), atan2$1(t1.y01, t1.x01), !cw);
  
                      // Otherwise, draw the two corners and the ring.
                      else {
                          context.arc(t0.cx, t0.cy, rc1, atan2$1(t0.y01, t0.x01), atan2$1(t0.y11, t0.x11), !cw);
                          context.arc(0, 0, r1, atan2$1(t0.cy + t0.y11, t0.cx + t0.x11), atan2$1(t1.cy + t1.y11, t1.cx + t1.x11), !cw);
                          context.arc(t1.cx, t1.cy, rc1, atan2$1(t1.y11, t1.x11), atan2$1(t1.y01, t1.x01), !cw);
                      }
                  }
  
                  // Or is the outer ring just a circular arc?
                  else context.moveTo(x01, y01), context.arc(0, 0, r1, a01, a11, !cw);
  
                  // Is there no inner ring, and it’s a circular sector?
                  // Or perhaps it’s an annular sector collapsed due to padding?
                  if (!(r0 > epsilon$3) || !(da0 > epsilon$3)) context.lineTo(x10, y10);
  
                  // Does the sector’s inner ring (or point) have rounded corners?
                  else if (rc0 > epsilon$3) {
                      t0 = cornerTangents(x10, y10, x11, y11, r0, -rc0, cw);
                      t1 = cornerTangents(x01, y01, x00, y00, r0, -rc0, cw);
  
                      context.lineTo(t0.cx + t0.x01, t0.cy + t0.y01);
  
                      // Have the corners merged?
                      if (rc0 < rc) context.arc(t0.cx, t0.cy, rc0, atan2$1(t0.y01, t0.x01), atan2$1(t1.y01, t1.x01), !cw);
  
                      // Otherwise, draw the two corners and the ring.
                      else {
                          context.arc(t0.cx, t0.cy, rc0, atan2$1(t0.y01, t0.x01), atan2$1(t0.y11, t0.x11), !cw);
                          context.arc(0, 0, r0, atan2$1(t0.cy + t0.y11, t0.cx + t0.x11), atan2$1(t1.cy + t1.y11, t1.cx + t1.x11), cw);
                          context.arc(t1.cx, t1.cy, rc0, atan2$1(t1.y11, t1.x11), atan2$1(t1.y01, t1.x01), !cw);
                      }
                  }
  
                  // Or is the inner ring just a circular arc?
                  else context.arc(0, 0, r0, a10, a00, cw);
              }
  
              context.closePath();
  
              if (buffer) return context = null, buffer + "" || null;
          }
  
          arc.centroid = function() {
              var r = (+innerRadius.apply(this, arguments) + +outerRadius.apply(this, arguments)) / 2,
                  a = (+startAngle.apply(this, arguments) + +endAngle.apply(this, arguments)) / 2 - pi$4 / 2;
              return [cos$2(a) * r, sin$2(a) * r];
          };
  
          arc.innerRadius = function(_) {
              return arguments.length ? (innerRadius = typeof _ === "function" ? _ : constant$10(+_), arc) : innerRadius;
          };
  
          arc.outerRadius = function(_) {
              return arguments.length ? (outerRadius = typeof _ === "function" ? _ : constant$10(+_), arc) : outerRadius;
          };
  
          arc.cornerRadius = function(_) {
              return arguments.length ? (cornerRadius = typeof _ === "function" ? _ : constant$10(+_), arc) : cornerRadius;
          };
  
          arc.padRadius = function(_) {
              return arguments.length ? (padRadius = _ == null ? null : typeof _ === "function" ? _ : constant$10(+_), arc) : padRadius;
          };
  
          arc.startAngle = function(_) {
              return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$10(+_), arc) : startAngle;
          };
  
          arc.endAngle = function(_) {
              return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$10(+_), arc) : endAngle;
          };
  
          arc.padAngle = function(_) {
              return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant$10(+_), arc) : padAngle;
          };
  
          arc.context = function(_) {
              return arguments.length ? ((context = _ == null ? null : _), arc) : context;
          };
  
          return arc;
      };
  
      function Linear(context) {
          this._context = context;
      }
  
      Linear.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._point = 0;
          },
          lineEnd: function() {
              if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                  case 1: this._point = 2; // proceed
                  default: this._context.lineTo(x, y); break;
              }
          }
      };
  
      var curveLinear = function(context) {
          return new Linear(context);
      };
  
      function x$3(p) {
          return p[0];
      }
  
      function y$3(p) {
          return p[1];
      }
  
      var line = function() {
          var x$$1 = x$3,
              y$$1 = y$3,
              defined = constant$10(true),
              context = null,
              curve = curveLinear,
              output = null;
  
          function line(data) {
              var i,
                  n = data.length,
                  d,
                  defined0 = false,
                  buffer;
  
              if (context == null) output = curve(buffer = path());
  
              for (i = 0; i <= n; ++i) {
                  if (!(i < n && defined(d = data[i], i, data)) === defined0) {
                      if (defined0 = !defined0) output.lineStart();
                      else output.lineEnd();
                  }
                  if (defined0) output.point(+x$$1(d, i, data), +y$$1(d, i, data));
              }
  
              if (buffer) return output = null, buffer + "" || null;
          }
  
          line.x = function(_) {
              return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant$10(+_), line) : x$$1;
          };
  
          line.y = function(_) {
              return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$10(+_), line) : y$$1;
          };
  
          line.defined = function(_) {
              return arguments.length ? (defined = typeof _ === "function" ? _ : constant$10(!!_), line) : defined;
          };
  
          line.curve = function(_) {
              return arguments.length ? (curve = _, context != null && (output = curve(context)), line) : curve;
          };
  
          line.context = function(_) {
              return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), line) : context;
          };
  
          return line;
      };
  
      var area$2 = function() {
          var x0 = x$3,
              x1 = null,
              y0 = constant$10(0),
              y1 = y$3,
              defined = constant$10(true),
              context = null,
              curve = curveLinear,
              output = null;
  
          function area(data) {
              var i,
                  j,
                  k,
                  n = data.length,
                  d,
                  defined0 = false,
                  buffer,
                  x0z = new Array(n),
                  y0z = new Array(n);
  
              if (context == null) output = curve(buffer = path());
  
              for (i = 0; i <= n; ++i) {
                  if (!(i < n && defined(d = data[i], i, data)) === defined0) {
                      if (defined0 = !defined0) {
                          j = i;
                          output.areaStart();
                          output.lineStart();
                      } else {
                          output.lineEnd();
                          output.lineStart();
                          for (k = i - 1; k >= j; --k) {
                              output.point(x0z[k], y0z[k]);
                          }
                          output.lineEnd();
                          output.areaEnd();
                      }
                  }
                  if (defined0) {
                      x0z[i] = +x0(d, i, data), y0z[i] = +y0(d, i, data);
                      output.point(x1 ? +x1(d, i, data) : x0z[i], y1 ? +y1(d, i, data) : y0z[i]);
                  }
              }
  
              if (buffer) return output = null, buffer + "" || null;
          }
  
          function arealine() {
              return line().defined(defined).curve(curve).context(context);
          }
  
          area.x = function(_) {
              return arguments.length ? (x0 = typeof _ === "function" ? _ : constant$10(+_), x1 = null, area) : x0;
          };
  
          area.x0 = function(_) {
              return arguments.length ? (x0 = typeof _ === "function" ? _ : constant$10(+_), area) : x0;
          };
  
          area.x1 = function(_) {
              return arguments.length ? (x1 = _ == null ? null : typeof _ === "function" ? _ : constant$10(+_), area) : x1;
          };
  
          area.y = function(_) {
              return arguments.length ? (y0 = typeof _ === "function" ? _ : constant$10(+_), y1 = null, area) : y0;
          };
  
          area.y0 = function(_) {
              return arguments.length ? (y0 = typeof _ === "function" ? _ : constant$10(+_), area) : y0;
          };
  
          area.y1 = function(_) {
              return arguments.length ? (y1 = _ == null ? null : typeof _ === "function" ? _ : constant$10(+_), area) : y1;
          };
  
          area.lineX0 =
              area.lineY0 = function() {
                  return arealine().x(x0).y(y0);
              };
  
          area.lineY1 = function() {
              return arealine().x(x0).y(y1);
          };
  
          area.lineX1 = function() {
              return arealine().x(x1).y(y0);
          };
  
          area.defined = function(_) {
              return arguments.length ? (defined = typeof _ === "function" ? _ : constant$10(!!_), area) : defined;
          };
  
          area.curve = function(_) {
              return arguments.length ? (curve = _, context != null && (output = curve(context)), area) : curve;
          };
  
          area.context = function(_) {
              return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), area) : context;
          };
  
          return area;
      };
  
      var descending$1 = function(a, b) {
          return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
      };
  
      var identity$7 = function(d) {
          return d;
      };
  
      var pie = function() {
          var value = identity$7,
              sortValues = descending$1,
              sort = null,
              startAngle = constant$10(0),
              endAngle = constant$10(tau$4),
              padAngle = constant$10(0);
  
          function pie(data) {
              var i,
                  n = data.length,
                  j,
                  k,
                  sum = 0,
                  index = new Array(n),
                  arcs = new Array(n),
                  a0 = +startAngle.apply(this, arguments),
                  da = Math.min(tau$4, Math.max(-tau$4, endAngle.apply(this, arguments) - a0)),
                  a1,
                  p = Math.min(Math.abs(da) / n, padAngle.apply(this, arguments)),
                  pa = p * (da < 0 ? -1 : 1),
                  v;
  
              for (i = 0; i < n; ++i) {
                  if ((v = arcs[index[i] = i] = +value(data[i], i, data)) > 0) {
                      sum += v;
                  }
              }
  
              // Optionally sort the arcs by previously-computed values or by data.
              if (sortValues != null) index.sort(function(i, j) { return sortValues(arcs[i], arcs[j]); });
              else if (sort != null) index.sort(function(i, j) { return sort(data[i], data[j]); });
  
              // Compute the arcs! They are stored in the original data's order.
              for (i = 0, k = sum ? (da - n * pa) / sum : 0; i < n; ++i, a0 = a1) {
                  j = index[i], v = arcs[j], a1 = a0 + (v > 0 ? v * k : 0) + pa, arcs[j] = {
                      data: data[j],
                      index: i,
                      value: v,
                      startAngle: a0,
                      endAngle: a1,
                      padAngle: p
                  };
              }
  
              return arcs;
          }
  
          pie.value = function(_) {
              return arguments.length ? (value = typeof _ === "function" ? _ : constant$10(+_), pie) : value;
          };
  
          pie.sortValues = function(_) {
              return arguments.length ? (sortValues = _, sort = null, pie) : sortValues;
          };
  
          pie.sort = function(_) {
              return arguments.length ? (sort = _, sortValues = null, pie) : sort;
          };
  
          pie.startAngle = function(_) {
              return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$10(+_), pie) : startAngle;
          };
  
          pie.endAngle = function(_) {
              return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$10(+_), pie) : endAngle;
          };
  
          pie.padAngle = function(_) {
              return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant$10(+_), pie) : padAngle;
          };
  
          return pie;
      };
  
      var curveRadialLinear = curveRadial(curveLinear);
  
      function Radial(curve) {
          this._curve = curve;
      }
  
      Radial.prototype = {
          areaStart: function() {
              this._curve.areaStart();
          },
          areaEnd: function() {
              this._curve.areaEnd();
          },
          lineStart: function() {
              this._curve.lineStart();
          },
          lineEnd: function() {
              this._curve.lineEnd();
          },
          point: function(a, r) {
              this._curve.point(r * Math.sin(a), r * -Math.cos(a));
          }
      };
  
      function curveRadial(curve) {
  
          function radial(context) {
              return new Radial(curve(context));
          }
  
          radial._curve = curve;
  
          return radial;
      }
  
      function radialLine(l) {
          var c = l.curve;
  
          l.angle = l.x, delete l.x;
          l.radius = l.y, delete l.y;
  
          l.curve = function(_) {
              return arguments.length ? c(curveRadial(_)) : c()._curve;
          };
  
          return l;
      }
  
      var radialLine$1 = function() {
          return radialLine(line().curve(curveRadialLinear));
      };
  
      var radialArea = function() {
          var a = area$2().curve(curveRadialLinear),
              c = a.curve,
              x0 = a.lineX0,
              x1 = a.lineX1,
              y0 = a.lineY0,
              y1 = a.lineY1;
  
          a.angle = a.x, delete a.x;
          a.startAngle = a.x0, delete a.x0;
          a.endAngle = a.x1, delete a.x1;
          a.radius = a.y, delete a.y;
          a.innerRadius = a.y0, delete a.y0;
          a.outerRadius = a.y1, delete a.y1;
          a.lineStartAngle = function() { return radialLine(x0()); }, delete a.lineX0;
          a.lineEndAngle = function() { return radialLine(x1()); }, delete a.lineX1;
          a.lineInnerRadius = function() { return radialLine(y0()); }, delete a.lineY0;
          a.lineOuterRadius = function() { return radialLine(y1()); }, delete a.lineY1;
  
          a.curve = function(_) {
              return arguments.length ? c(curveRadial(_)) : c()._curve;
          };
  
          return a;
      };
  
      var circle$2 = {
          draw: function(context, size) {
              var r = Math.sqrt(size / pi$4);
              context.moveTo(r, 0);
              context.arc(0, 0, r, 0, tau$4);
          }
      };
  
      var cross$2 = {
          draw: function(context, size) {
              var r = Math.sqrt(size / 5) / 2;
              context.moveTo(-3 * r, -r);
              context.lineTo(-r, -r);
              context.lineTo(-r, -3 * r);
              context.lineTo(r, -3 * r);
              context.lineTo(r, -r);
              context.lineTo(3 * r, -r);
              context.lineTo(3 * r, r);
              context.lineTo(r, r);
              context.lineTo(r, 3 * r);
              context.lineTo(-r, 3 * r);
              context.lineTo(-r, r);
              context.lineTo(-3 * r, r);
              context.closePath();
          }
      };
  
      var tan30 = Math.sqrt(1 / 3);
      var tan30_2 = tan30 * 2;
  
      var diamond = {
          draw: function(context, size) {
              var y = Math.sqrt(size / tan30_2),
                  x = y * tan30;
              context.moveTo(0, -y);
              context.lineTo(x, 0);
              context.lineTo(0, y);
              context.lineTo(-x, 0);
              context.closePath();
          }
      };
  
      var ka = 0.89081309152928522810;
      var kr = Math.sin(pi$4 / 10) / Math.sin(7 * pi$4 / 10);
      var kx = Math.sin(tau$4 / 10) * kr;
      var ky = -Math.cos(tau$4 / 10) * kr;
  
      var star = {
          draw: function(context, size) {
              var r = Math.sqrt(size * ka),
                  x = kx * r,
                  y = ky * r;
              context.moveTo(0, -r);
              context.lineTo(x, y);
              for (var i = 1; i < 5; ++i) {
                  var a = tau$4 * i / 5,
                      c = Math.cos(a),
                      s = Math.sin(a);
                  context.lineTo(s * r, -c * r);
                  context.lineTo(c * x - s * y, s * x + c * y);
              }
              context.closePath();
          }
      };
  
      var square = {
          draw: function(context, size) {
              var w = Math.sqrt(size),
                  x = -w / 2;
              context.rect(x, x, w, w);
          }
      };
  
      var sqrt3 = Math.sqrt(3);
  
      var triangle = {
          draw: function(context, size) {
              var y = -Math.sqrt(size / (sqrt3 * 3));
              context.moveTo(0, y * 2);
              context.lineTo(-sqrt3 * y, -y);
              context.lineTo(sqrt3 * y, -y);
              context.closePath();
          }
      };
  
      var c = -0.5;
      var s = Math.sqrt(3) / 2;
      var k = 1 / Math.sqrt(12);
      var a = (k / 2 + 1) * 3;
  
      var wye = {
          draw: function(context, size) {
              var r = Math.sqrt(size / a),
                  x0 = r / 2,
                  y0 = r * k,
                  x1 = x0,
                  y1 = r * k + r,
                  x2 = -x1,
                  y2 = y1;
              context.moveTo(x0, y0);
              context.lineTo(x1, y1);
              context.lineTo(x2, y2);
              context.lineTo(c * x0 - s * y0, s * x0 + c * y0);
              context.lineTo(c * x1 - s * y1, s * x1 + c * y1);
              context.lineTo(c * x2 - s * y2, s * x2 + c * y2);
              context.lineTo(c * x0 + s * y0, c * y0 - s * x0);
              context.lineTo(c * x1 + s * y1, c * y1 - s * x1);
              context.lineTo(c * x2 + s * y2, c * y2 - s * x2);
              context.closePath();
          }
      };
  
      var symbols = [
          circle$2,
          cross$2,
          diamond,
          square,
          star,
          triangle,
          wye
      ];
  
      var symbol = function() {
          var type = constant$10(circle$2),
              size = constant$10(64),
              context = null;
  
          function symbol() {
              var buffer;
              if (!context) context = buffer = path();
              type.apply(this, arguments).draw(context, +size.apply(this, arguments));
              if (buffer) return context = null, buffer + "" || null;
          }
  
          symbol.type = function(_) {
              return arguments.length ? (type = typeof _ === "function" ? _ : constant$10(_), symbol) : type;
          };
  
          symbol.size = function(_) {
              return arguments.length ? (size = typeof _ === "function" ? _ : constant$10(+_), symbol) : size;
          };
  
          symbol.context = function(_) {
              return arguments.length ? (context = _ == null ? null : _, symbol) : context;
          };
  
          return symbol;
      };
  
      var noop$2 = function() {};
  
      function point$2(that, x, y) {
          that._context.bezierCurveTo(
              (2 * that._x0 + that._x1) / 3,
              (2 * that._y0 + that._y1) / 3,
              (that._x0 + 2 * that._x1) / 3,
              (that._y0 + 2 * that._y1) / 3,
              (that._x0 + 4 * that._x1 + x) / 6,
              (that._y0 + 4 * that._y1 + y) / 6
          );
      }
  
      function Basis(context) {
          this._context = context;
      }
  
      Basis.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 =
                  this._y0 = this._y1 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 3: point$2(this, this._x1, this._y1); // proceed
                  case 2: this._context.lineTo(this._x1, this._y1); break;
              }
              if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                  case 1: this._point = 2; break;
                  case 2: this._point = 3; this._context.lineTo((5 * this._x0 + this._x1) / 6, (5 * this._y0 + this._y1) / 6); // proceed
                  default: point$2(this, x, y); break;
              }
              this._x0 = this._x1, this._x1 = x;
              this._y0 = this._y1, this._y1 = y;
          }
      };
  
      var basis$2 = function(context) {
          return new Basis(context);
      };
  
      function BasisClosed(context) {
          this._context = context;
      }
  
      BasisClosed.prototype = {
          areaStart: noop$2,
          areaEnd: noop$2,
          lineStart: function() {
              this._x0 = this._x1 = this._x2 = this._x3 = this._x4 =
                  this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 1: {
                      this._context.moveTo(this._x2, this._y2);
                      this._context.closePath();
                      break;
                  }
                  case 2: {
                      this._context.moveTo((this._x2 + 2 * this._x3) / 3, (this._y2 + 2 * this._y3) / 3);
                      this._context.lineTo((this._x3 + 2 * this._x2) / 3, (this._y3 + 2 * this._y2) / 3);
                      this._context.closePath();
                      break;
                  }
                  case 3: {
                      this.point(this._x2, this._y2);
                      this.point(this._x3, this._y3);
                      this.point(this._x4, this._y4);
                      break;
                  }
              }
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; this._x2 = x, this._y2 = y; break;
                  case 1: this._point = 2; this._x3 = x, this._y3 = y; break;
                  case 2: this._point = 3; this._x4 = x, this._y4 = y; this._context.moveTo((this._x0 + 4 * this._x1 + x) / 6, (this._y0 + 4 * this._y1 + y) / 6); break;
                  default: point$2(this, x, y); break;
              }
              this._x0 = this._x1, this._x1 = x;
              this._y0 = this._y1, this._y1 = y;
          }
      };
  
      var basisClosed$1 = function(context) {
          return new BasisClosed(context);
      };
  
      function BasisOpen(context) {
          this._context = context;
      }
  
      BasisOpen.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 =
                  this._y0 = this._y1 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; break;
                  case 1: this._point = 2; break;
                  case 2: this._point = 3; var x0 = (this._x0 + 4 * this._x1 + x) / 6, y0 = (this._y0 + 4 * this._y1 + y) / 6; this._line ? this._context.lineTo(x0, y0) : this._context.moveTo(x0, y0); break;
                  case 3: this._point = 4; // proceed
                  default: point$2(this, x, y); break;
              }
              this._x0 = this._x1, this._x1 = x;
              this._y0 = this._y1, this._y1 = y;
          }
      };
  
      var basisOpen = function(context) {
          return new BasisOpen(context);
      };
  
      function Bundle(context, beta) {
          this._basis = new Basis(context);
          this._beta = beta;
      }
  
      Bundle.prototype = {
          lineStart: function() {
              this._x = [];
              this._y = [];
              this._basis.lineStart();
          },
          lineEnd: function() {
              var x = this._x,
                  y = this._y,
                  j = x.length - 1;
  
              if (j > 0) {
                  var x0 = x[0],
                      y0 = y[0],
                      dx = x[j] - x0,
                      dy = y[j] - y0,
                      i = -1,
                      t;
  
                  while (++i <= j) {
                      t = i / j;
                      this._basis.point(
                          this._beta * x[i] + (1 - this._beta) * (x0 + t * dx),
                          this._beta * y[i] + (1 - this._beta) * (y0 + t * dy)
                      );
                  }
              }
  
              this._x = this._y = null;
              this._basis.lineEnd();
          },
          point: function(x, y) {
              this._x.push(+x);
              this._y.push(+y);
          }
      };
  
      var bundle = ((function custom(beta) {
  
          function bundle(context) {
              return beta === 1 ? new Basis(context) : new Bundle(context, beta);
          }
  
          bundle.beta = function(beta) {
              return custom(+beta);
          };
  
          return bundle;
      }))(0.85);
  
      function point$3(that, x, y) {
          that._context.bezierCurveTo(
              that._x1 + that._k * (that._x2 - that._x0),
              that._y1 + that._k * (that._y2 - that._y0),
              that._x2 + that._k * (that._x1 - x),
              that._y2 + that._k * (that._y1 - y),
              that._x2,
              that._y2
          );
      }
  
      function Cardinal(context, tension) {
          this._context = context;
          this._k = (1 - tension) / 6;
      }
  
      Cardinal.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 = this._x2 =
                  this._y0 = this._y1 = this._y2 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 2: this._context.lineTo(this._x2, this._y2); break;
                  case 3: point$3(this, this._x1, this._y1); break;
              }
              if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                  case 1: this._point = 2; this._x1 = x, this._y1 = y; break;
                  case 2: this._point = 3; // proceed
                  default: point$3(this, x, y); break;
              }
              this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
              this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
          }
      };
  
      var cardinal = ((function custom(tension) {
  
          function cardinal(context) {
              return new Cardinal(context, tension);
          }
  
          cardinal.tension = function(tension) {
              return custom(+tension);
          };
  
          return cardinal;
      }))(0);
  
      function CardinalClosed(context, tension) {
          this._context = context;
          this._k = (1 - tension) / 6;
      }
  
      CardinalClosed.prototype = {
          areaStart: noop$2,
          areaEnd: noop$2,
          lineStart: function() {
              this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
                  this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 1: {
                      this._context.moveTo(this._x3, this._y3);
                      this._context.closePath();
                      break;
                  }
                  case 2: {
                      this._context.lineTo(this._x3, this._y3);
                      this._context.closePath();
                      break;
                  }
                  case 3: {
                      this.point(this._x3, this._y3);
                      this.point(this._x4, this._y4);
                      this.point(this._x5, this._y5);
                      break;
                  }
              }
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
                  case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
                  case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
                  default: point$3(this, x, y); break;
              }
              this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
              this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
          }
      };
  
      var cardinalClosed = ((function custom(tension) {
  
          function cardinal(context) {
              return new CardinalClosed(context, tension);
          }
  
          cardinal.tension = function(tension) {
              return custom(+tension);
          };
  
          return cardinal;
      }))(0);
  
      function CardinalOpen(context, tension) {
          this._context = context;
          this._k = (1 - tension) / 6;
      }
  
      CardinalOpen.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 = this._x2 =
                  this._y0 = this._y1 = this._y2 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; break;
                  case 1: this._point = 2; break;
                  case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
                  case 3: this._point = 4; // proceed
                  default: point$3(this, x, y); break;
              }
              this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
              this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
          }
      };
  
      var cardinalOpen = ((function custom(tension) {
  
          function cardinal(context) {
              return new CardinalOpen(context, tension);
          }
  
          cardinal.tension = function(tension) {
              return custom(+tension);
          };
  
          return cardinal;
      }))(0);
  
      function point$4(that, x, y) {
          var x1 = that._x1,
              y1 = that._y1,
              x2 = that._x2,
              y2 = that._y2;
  
          if (that._l01_a > epsilon$3) {
              var a = 2 * that._l01_2a + 3 * that._l01_a * that._l12_a + that._l12_2a,
                  n = 3 * that._l01_a * (that._l01_a + that._l12_a);
              x1 = (x1 * a - that._x0 * that._l12_2a + that._x2 * that._l01_2a) / n;
              y1 = (y1 * a - that._y0 * that._l12_2a + that._y2 * that._l01_2a) / n;
          }
  
          if (that._l23_a > epsilon$3) {
              var b = 2 * that._l23_2a + 3 * that._l23_a * that._l12_a + that._l12_2a,
                  m = 3 * that._l23_a * (that._l23_a + that._l12_a);
              x2 = (x2 * b + that._x1 * that._l23_2a - x * that._l12_2a) / m;
              y2 = (y2 * b + that._y1 * that._l23_2a - y * that._l12_2a) / m;
          }
  
          that._context.bezierCurveTo(x1, y1, x2, y2, that._x2, that._y2);
      }
  
      function CatmullRom(context, alpha) {
          this._context = context;
          this._alpha = alpha;
      }
  
      CatmullRom.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 = this._x2 =
                  this._y0 = this._y1 = this._y2 = NaN;
              this._l01_a = this._l12_a = this._l23_a =
                  this._l01_2a = this._l12_2a = this._l23_2a =
                      this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 2: this._context.lineTo(this._x2, this._y2); break;
                  case 3: this.point(this._x2, this._y2); break;
              }
              if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
  
              if (this._point) {
                  var x23 = this._x2 - x,
                      y23 = this._y2 - y;
                  this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
              }
  
              switch (this._point) {
                  case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                  case 1: this._point = 2; break;
                  case 2: this._point = 3; // proceed
                  default: point$4(this, x, y); break;
              }
  
              this._l01_a = this._l12_a, this._l12_a = this._l23_a;
              this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
              this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
              this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
          }
      };
  
      var catmullRom = ((function custom(alpha) {
  
          function catmullRom(context) {
              return alpha ? new CatmullRom(context, alpha) : new Cardinal(context, 0);
          }
  
          catmullRom.alpha = function(alpha) {
              return custom(+alpha);
          };
  
          return catmullRom;
      }))(0.5);
  
      function CatmullRomClosed(context, alpha) {
          this._context = context;
          this._alpha = alpha;
      }
  
      CatmullRomClosed.prototype = {
          areaStart: noop$2,
          areaEnd: noop$2,
          lineStart: function() {
              this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
                  this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
              this._l01_a = this._l12_a = this._l23_a =
                  this._l01_2a = this._l12_2a = this._l23_2a =
                      this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 1: {
                      this._context.moveTo(this._x3, this._y3);
                      this._context.closePath();
                      break;
                  }
                  case 2: {
                      this._context.lineTo(this._x3, this._y3);
                      this._context.closePath();
                      break;
                  }
                  case 3: {
                      this.point(this._x3, this._y3);
                      this.point(this._x4, this._y4);
                      this.point(this._x5, this._y5);
                      break;
                  }
              }
          },
          point: function(x, y) {
              x = +x, y = +y;
  
              if (this._point) {
                  var x23 = this._x2 - x,
                      y23 = this._y2 - y;
                  this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
              }
  
              switch (this._point) {
                  case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
                  case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
                  case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
                  default: point$4(this, x, y); break;
              }
  
              this._l01_a = this._l12_a, this._l12_a = this._l23_a;
              this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
              this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
              this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
          }
      };
  
      var catmullRomClosed = ((function custom(alpha) {
  
          function catmullRom(context) {
              return alpha ? new CatmullRomClosed(context, alpha) : new CardinalClosed(context, 0);
          }
  
          catmullRom.alpha = function(alpha) {
              return custom(+alpha);
          };
  
          return catmullRom;
      }))(0.5);
  
      function CatmullRomOpen(context, alpha) {
          this._context = context;
          this._alpha = alpha;
      }
  
      CatmullRomOpen.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 = this._x2 =
                  this._y0 = this._y1 = this._y2 = NaN;
              this._l01_a = this._l12_a = this._l23_a =
                  this._l01_2a = this._l12_2a = this._l23_2a =
                      this._point = 0;
          },
          lineEnd: function() {
              if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
  
              if (this._point) {
                  var x23 = this._x2 - x,
                      y23 = this._y2 - y;
                  this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
              }
  
              switch (this._point) {
                  case 0: this._point = 1; break;
                  case 1: this._point = 2; break;
                  case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
                  case 3: this._point = 4; // proceed
                  default: point$4(this, x, y); break;
              }
  
              this._l01_a = this._l12_a, this._l12_a = this._l23_a;
              this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
              this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
              this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
          }
      };
  
      var catmullRomOpen = ((function custom(alpha) {
  
          function catmullRom(context) {
              return alpha ? new CatmullRomOpen(context, alpha) : new CardinalOpen(context, 0);
          }
  
          catmullRom.alpha = function(alpha) {
              return custom(+alpha);
          };
  
          return catmullRom;
      }))(0.5);
  
      function LinearClosed(context) {
          this._context = context;
      }
  
      LinearClosed.prototype = {
          areaStart: noop$2,
          areaEnd: noop$2,
          lineStart: function() {
              this._point = 0;
          },
          lineEnd: function() {
              if (this._point) this._context.closePath();
          },
          point: function(x, y) {
              x = +x, y = +y;
              if (this._point) this._context.lineTo(x, y);
              else this._point = 1, this._context.moveTo(x, y);
          }
      };
  
      var linearClosed = function(context) {
          return new LinearClosed(context);
      };
  
      function sign$1(x) {
          return x < 0 ? -1 : 1;
      }
  
  // Calculate the slopes of the tangents (Hermite-type interpolation) based on
  // the following paper: Steffen, M. 1990. A Simple Method for Monotonic
  // Interpolation in One Dimension. Astronomy and Astrophysics, Vol. 239, NO.
  // NOV(II), P. 443, 1990.
      function slope3(that, x2, y2) {
          var h0 = that._x1 - that._x0,
              h1 = x2 - that._x1,
              s0 = (that._y1 - that._y0) / (h0 || h1 < 0 && -0),
              s1 = (y2 - that._y1) / (h1 || h0 < 0 && -0),
              p = (s0 * h1 + s1 * h0) / (h0 + h1);
          return (sign$1(s0) + sign$1(s1)) * Math.min(Math.abs(s0), Math.abs(s1), 0.5 * Math.abs(p)) || 0;
      }
  
  // Calculate a one-sided slope.
      function slope2(that, t) {
          var h = that._x1 - that._x0;
          return h ? (3 * (that._y1 - that._y0) / h - t) / 2 : t;
      }
  
  // According to https://en.wikipedia.org/wiki/Cubic_Hermite_spline#Representations
  // "you can express cubic Hermite interpolation in terms of cubic Bézier curves
  // with respect to the four values p0, p0 + m0 / 3, p1 - m1 / 3, p1".
      function point$5(that, t0, t1) {
          var x0 = that._x0,
              y0 = that._y0,
              x1 = that._x1,
              y1 = that._y1,
              dx = (x1 - x0) / 3;
          that._context.bezierCurveTo(x0 + dx, y0 + dx * t0, x1 - dx, y1 - dx * t1, x1, y1);
      }
  
      function MonotoneX(context) {
          this._context = context;
      }
  
      MonotoneX.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x0 = this._x1 =
                  this._y0 = this._y1 =
                      this._t0 = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              switch (this._point) {
                  case 2: this._context.lineTo(this._x1, this._y1); break;
                  case 3: point$5(this, this._t0, slope2(this, this._t0)); break;
              }
              if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
              this._line = 1 - this._line;
          },
          point: function(x, y) {
              var t1 = NaN;
  
              x = +x, y = +y;
              if (x === this._x1 && y === this._y1) return; // Ignore coincident points.
              switch (this._point) {
                  case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                  case 1: this._point = 2; break;
                  case 2: this._point = 3; point$5(this, slope2(this, t1 = slope3(this, x, y)), t1); break;
                  default: point$5(this, this._t0, t1 = slope3(this, x, y)); break;
              }
  
              this._x0 = this._x1, this._x1 = x;
              this._y0 = this._y1, this._y1 = y;
              this._t0 = t1;
          }
      };
  
      function MonotoneY(context) {
          this._context = new ReflectContext(context);
      }
  
      (MonotoneY.prototype = Object.create(MonotoneX.prototype)).point = function(x, y) {
          MonotoneX.prototype.point.call(this, y, x);
      };
  
      function ReflectContext(context) {
          this._context = context;
      }
  
      ReflectContext.prototype = {
          moveTo: function(x, y) { this._context.moveTo(y, x); },
          closePath: function() { this._context.closePath(); },
          lineTo: function(x, y) { this._context.lineTo(y, x); },
          bezierCurveTo: function(x1, y1, x2, y2, x, y) { this._context.bezierCurveTo(y1, x1, y2, x2, y, x); }
      };
  
      function monotoneX(context) {
          return new MonotoneX(context);
      }
  
      function monotoneY(context) {
          return new MonotoneY(context);
      }
  
      function Natural(context) {
          this._context = context;
      }
  
      Natural.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x = [];
              this._y = [];
          },
          lineEnd: function() {
              var x = this._x,
                  y = this._y,
                  n = x.length;
  
              if (n) {
                  this._line ? this._context.lineTo(x[0], y[0]) : this._context.moveTo(x[0], y[0]);
                  if (n === 2) {
                      this._context.lineTo(x[1], y[1]);
                  } else {
                      var px = controlPoints(x),
                          py = controlPoints(y);
                      for (var i0 = 0, i1 = 1; i1 < n; ++i0, ++i1) {
                          this._context.bezierCurveTo(px[0][i0], py[0][i0], px[1][i0], py[1][i0], x[i1], y[i1]);
                      }
                  }
              }
  
              if (this._line || (this._line !== 0 && n === 1)) this._context.closePath();
              this._line = 1 - this._line;
              this._x = this._y = null;
          },
          point: function(x, y) {
              this._x.push(+x);
              this._y.push(+y);
          }
      };
  
  // See https://www.particleincell.com/2012/bezier-splines/ for derivation.
      function controlPoints(x) {
          var i,
              n = x.length - 1,
              m,
              a = new Array(n),
              b = new Array(n),
              r = new Array(n);
          a[0] = 0, b[0] = 2, r[0] = x[0] + 2 * x[1];
          for (i = 1; i < n - 1; ++i) a[i] = 1, b[i] = 4, r[i] = 4 * x[i] + 2 * x[i + 1];
          a[n - 1] = 2, b[n - 1] = 7, r[n - 1] = 8 * x[n - 1] + x[n];
          for (i = 1; i < n; ++i) m = a[i] / b[i - 1], b[i] -= m, r[i] -= m * r[i - 1];
          a[n - 1] = r[n - 1] / b[n - 1];
          for (i = n - 2; i >= 0; --i) a[i] = (r[i] - a[i + 1]) / b[i];
          b[n - 1] = (x[n] + a[n - 1]) / 2;
          for (i = 0; i < n - 1; ++i) b[i] = 2 * x[i + 1] - a[i + 1];
          return [a, b];
      }
  
      var natural = function(context) {
          return new Natural(context);
      };
  
      function Step(context, t) {
          this._context = context;
          this._t = t;
      }
  
      Step.prototype = {
          areaStart: function() {
              this._line = 0;
          },
          areaEnd: function() {
              this._line = NaN;
          },
          lineStart: function() {
              this._x = this._y = NaN;
              this._point = 0;
          },
          lineEnd: function() {
              if (0 < this._t && this._t < 1 && this._point === 2) this._context.lineTo(this._x, this._y);
              if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
              if (this._line >= 0) this._t = 1 - this._t, this._line = 1 - this._line;
          },
          point: function(x, y) {
              x = +x, y = +y;
              switch (this._point) {
                  case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                  case 1: this._point = 2; // proceed
                  default: {
                      if (this._t <= 0) {
                          this._context.lineTo(this._x, y);
                          this._context.lineTo(x, y);
                      } else {
                          var x1 = this._x * (1 - this._t) + x * this._t;
                          this._context.lineTo(x1, this._y);
                          this._context.lineTo(x1, y);
                      }
                      break;
                  }
              }
              this._x = x, this._y = y;
          }
      };
  
      var step = function(context) {
          return new Step(context, 0.5);
      };
  
      function stepBefore(context) {
          return new Step(context, 0);
      }
  
      function stepAfter(context) {
          return new Step(context, 1);
      }
  
      var slice$5 = Array.prototype.slice;
  
      var none$1 = function(series, order) {
          if (!((n = series.length) > 1)) return;
          for (var i = 1, s0, s1 = series[order[0]], n, m = s1.length; i < n; ++i) {
              s0 = s1, s1 = series[order[i]];
              for (var j = 0; j < m; ++j) {
                  s1[j][1] += s1[j][0] = isNaN(s0[j][1]) ? s0[j][0] : s0[j][1];
              }
          }
      };
  
      var none$2 = function(series) {
          var n = series.length, o = new Array(n);
          while (--n >= 0) o[n] = n;
          return o;
      };
  
      function stackValue(d, key) {
          return d[key];
      }
  
      var stack = function() {
          var keys = constant$10([]),
              order = none$2,
              offset = none$1,
              value = stackValue;
  
          function stack(data) {
              var kz = keys.apply(this, arguments),
                  i,
                  m = data.length,
                  n = kz.length,
                  sz = new Array(n),
                  oz;
  
              for (i = 0; i < n; ++i) {
                  for (var ki = kz[i], si = sz[i] = new Array(m), j = 0, sij; j < m; ++j) {
                      si[j] = sij = [0, +value(data[j], ki, j, data)];
                      sij.data = data[j];
                  }
                  si.key = ki;
              }
  
              for (i = 0, oz = order(sz); i < n; ++i) {
                  sz[oz[i]].index = i;
              }
  
              offset(sz, oz);
              return sz;
          }
  
          stack.keys = function(_) {
              return arguments.length ? (keys = typeof _ === "function" ? _ : constant$10(slice$5.call(_)), stack) : keys;
          };
  
          stack.value = function(_) {
              return arguments.length ? (value = typeof _ === "function" ? _ : constant$10(+_), stack) : value;
          };
  
          stack.order = function(_) {
              return arguments.length ? (order = _ == null ? none$2 : typeof _ === "function" ? _ : constant$10(slice$5.call(_)), stack) : order;
          };
  
          stack.offset = function(_) {
              return arguments.length ? (offset = _ == null ? none$1 : _, stack) : offset;
          };
  
          return stack;
      };
  
      var expand = function(series, order) {
          if (!((n = series.length) > 0)) return;
          for (var i, n, j = 0, m = series[0].length, y; j < m; ++j) {
              for (y = i = 0; i < n; ++i) y += series[i][j][1] || 0;
              if (y) for (i = 0; i < n; ++i) series[i][j][1] /= y;
          }
          none$1(series, order);
      };
  
      var silhouette = function(series, order) {
          if (!((n = series.length) > 0)) return;
          for (var j = 0, s0 = series[order[0]], n, m = s0.length; j < m; ++j) {
              for (var i = 0, y = 0; i < n; ++i) y += series[i][j][1] || 0;
              s0[j][1] += s0[j][0] = -y / 2;
          }
          none$1(series, order);
      };
  
      var wiggle = function(series, order) {
          if (!((n = series.length) > 0) || !((m = (s0 = series[order[0]]).length) > 0)) return;
          for (var y = 0, j = 1, s0, m, n; j < m; ++j) {
              for (var i = 0, s1 = 0, s2 = 0; i < n; ++i) {
                  var si = series[order[i]],
                      sij0 = si[j][1] || 0,
                      sij1 = si[j - 1][1] || 0,
                      s3 = (sij0 - sij1) / 2;
                  for (var k = 0; k < i; ++k) {
                      var sk = series[order[k]],
                          skj0 = sk[j][1] || 0,
                          skj1 = sk[j - 1][1] || 0;
                      s3 += skj0 - skj1;
                  }
                  s1 += sij0, s2 += s3 * sij0;
              }
              s0[j - 1][1] += s0[j - 1][0] = y;
              if (s1) y -= s2 / s1;
          }
          s0[j - 1][1] += s0[j - 1][0] = y;
          none$1(series, order);
      };
  
      var ascending$2 = function(series) {
          var sums = series.map(sum$2);
          return none$2(series).sort(function(a, b) { return sums[a] - sums[b]; });
      };
  
      function sum$2(series) {
          var s = 0, i = -1, n = series.length, v;
          while (++i < n) if (v = +series[i][1]) s += v;
          return s;
      }
  
      var descending$2 = function(series) {
          return ascending$2(series).reverse();
      };
  
      var insideOut = function(series) {
          var n = series.length,
              i,
              j,
              sums = series.map(sum$2),
              order = none$2(series).sort(function(a, b) { return sums[b] - sums[a]; }),
              top = 0,
              bottom = 0,
              tops = [],
              bottoms = [];
  
          for (i = 0; i < n; ++i) {
              j = order[i];
              if (top < bottom) {
                  top += sums[j];
                  tops.push(j);
              } else {
                  bottom += sums[j];
                  bottoms.push(j);
              }
          }
  
          return bottoms.reverse().concat(tops);
      };
  
      var reverse = function(series) {
          return none$2(series).reverse();
      };
  
      var constant$11 = function(x) {
          return function() {
              return x;
          };
      };
  
      function x$4(d) {
          return d[0];
      }
  
      function y$4(d) {
          return d[1];
      }
  
      function RedBlackTree() {
          this._ = null; // root node
      }
  
      function RedBlackNode(node) {
          node.U = // parent node
              node.C = // color - true for red, false for black
                  node.L = // left node
                      node.R = // right node
                          node.P = // previous node
                              node.N = null; // next node
      }
  
      RedBlackTree.prototype = {
          constructor: RedBlackTree,
  
          insert: function(after, node) {
              var parent, grandpa, uncle;
  
              if (after) {
                  node.P = after;
                  node.N = after.N;
                  if (after.N) after.N.P = node;
                  after.N = node;
                  if (after.R) {
                      after = after.R;
                      while (after.L) after = after.L;
                      after.L = node;
                  } else {
                      after.R = node;
                  }
                  parent = after;
              } else if (this._) {
                  after = RedBlackFirst(this._);
                  node.P = null;
                  node.N = after;
                  after.P = after.L = node;
                  parent = after;
              } else {
                  node.P = node.N = null;
                  this._ = node;
                  parent = null;
              }
              node.L = node.R = null;
              node.U = parent;
              node.C = true;
  
              after = node;
              while (parent && parent.C) {
                  grandpa = parent.U;
                  if (parent === grandpa.L) {
                      uncle = grandpa.R;
                      if (uncle && uncle.C) {
                          parent.C = uncle.C = false;
                          grandpa.C = true;
                          after = grandpa;
                      } else {
                          if (after === parent.R) {
                              RedBlackRotateLeft(this, parent);
                              after = parent;
                              parent = after.U;
                          }
                          parent.C = false;
                          grandpa.C = true;
                          RedBlackRotateRight(this, grandpa);
                      }
                  } else {
                      uncle = grandpa.L;
                      if (uncle && uncle.C) {
                          parent.C = uncle.C = false;
                          grandpa.C = true;
                          after = grandpa;
                      } else {
                          if (after === parent.L) {
                              RedBlackRotateRight(this, parent);
                              after = parent;
                              parent = after.U;
                          }
                          parent.C = false;
                          grandpa.C = true;
                          RedBlackRotateLeft(this, grandpa);
                      }
                  }
                  parent = after.U;
              }
              this._.C = false;
          },
  
          remove: function(node) {
              if (node.N) node.N.P = node.P;
              if (node.P) node.P.N = node.N;
              node.N = node.P = null;
  
              var parent = node.U,
                  sibling,
                  left = node.L,
                  right = node.R,
                  next,
                  red;
  
              if (!left) next = right;
              else if (!right) next = left;
              else next = RedBlackFirst(right);
  
              if (parent) {
                  if (parent.L === node) parent.L = next;
                  else parent.R = next;
              } else {
                  this._ = next;
              }
  
              if (left && right) {
                  red = next.C;
                  next.C = node.C;
                  next.L = left;
                  left.U = next;
                  if (next !== right) {
                      parent = next.U;
                      next.U = node.U;
                      node = next.R;
                      parent.L = node;
                      next.R = right;
                      right.U = next;
                  } else {
                      next.U = parent;
                      parent = next;
                      node = next.R;
                  }
              } else {
                  red = node.C;
                  node = next;
              }
  
              if (node) node.U = parent;
              if (red) return;
              if (node && node.C) { node.C = false; return; }
  
              do {
                  if (node === this._) break;
                  if (node === parent.L) {
                      sibling = parent.R;
                      if (sibling.C) {
                          sibling.C = false;
                          parent.C = true;
                          RedBlackRotateLeft(this, parent);
                          sibling = parent.R;
                      }
                      if ((sibling.L && sibling.L.C)
                          || (sibling.R && sibling.R.C)) {
                          if (!sibling.R || !sibling.R.C) {
                              sibling.L.C = false;
                              sibling.C = true;
                              RedBlackRotateRight(this, sibling);
                              sibling = parent.R;
                          }
                          sibling.C = parent.C;
                          parent.C = sibling.R.C = false;
                          RedBlackRotateLeft(this, parent);
                          node = this._;
                          break;
                      }
                  } else {
                      sibling = parent.L;
                      if (sibling.C) {
                          sibling.C = false;
                          parent.C = true;
                          RedBlackRotateRight(this, parent);
                          sibling = parent.L;
                      }
                      if ((sibling.L && sibling.L.C)
                          || (sibling.R && sibling.R.C)) {
                          if (!sibling.L || !sibling.L.C) {
                              sibling.R.C = false;
                              sibling.C = true;
                              RedBlackRotateLeft(this, sibling);
                              sibling = parent.L;
                          }
                          sibling.C = parent.C;
                          parent.C = sibling.L.C = false;
                          RedBlackRotateRight(this, parent);
                          node = this._;
                          break;
                      }
                  }
                  sibling.C = true;
                  node = parent;
                  parent = parent.U;
              } while (!node.C);
  
              if (node) node.C = false;
          }
      };
  
      function RedBlackRotateLeft(tree, node) {
          var p = node,
              q = node.R,
              parent = p.U;
  
          if (parent) {
              if (parent.L === p) parent.L = q;
              else parent.R = q;
          } else {
              tree._ = q;
          }
  
          q.U = parent;
          p.U = q;
          p.R = q.L;
          if (p.R) p.R.U = p;
          q.L = p;
      }
  
      function RedBlackRotateRight(tree, node) {
          var p = node,
              q = node.L,
              parent = p.U;
  
          if (parent) {
              if (parent.L === p) parent.L = q;
              else parent.R = q;
          } else {
              tree._ = q;
          }
  
          q.U = parent;
          p.U = q;
          p.L = q.R;
          if (p.L) p.L.U = p;
          q.R = p;
      }
  
      function RedBlackFirst(node) {
          while (node.L) node = node.L;
          return node;
      }
  
      function createEdge(left, right, v0, v1) {
          var edge = [null, null],
              index = edges.push(edge) - 1;
          edge.left = left;
          edge.right = right;
          if (v0) setEdgeEnd(edge, left, right, v0);
          if (v1) setEdgeEnd(edge, right, left, v1);
          cells[left.index].halfedges.push(index);
          cells[right.index].halfedges.push(index);
          return edge;
      }
  
      function createBorderEdge(left, v0, v1) {
          var edge = [v0, v1];
          edge.left = left;
          return edge;
      }
  
      function setEdgeEnd(edge, left, right, vertex) {
          if (!edge[0] && !edge[1]) {
              edge[0] = vertex;
              edge.left = left;
              edge.right = right;
          } else if (edge.left === right) {
              edge[1] = vertex;
          } else {
              edge[0] = vertex;
          }
      }
  
  // Liang–Barsky line clipping.
      function clipEdge(edge, x0, y0, x1, y1) {
          var a = edge[0],
              b = edge[1],
              ax = a[0],
              ay = a[1],
              bx = b[0],
              by = b[1],
              t0 = 0,
              t1 = 1,
              dx = bx - ax,
              dy = by - ay,
              r;
  
          r = x0 - ax;
          if (!dx && r > 0) return;
          r /= dx;
          if (dx < 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          } else if (dx > 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          }
  
          r = x1 - ax;
          if (!dx && r < 0) return;
          r /= dx;
          if (dx < 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          } else if (dx > 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          }
  
          r = y0 - ay;
          if (!dy && r > 0) return;
          r /= dy;
          if (dy < 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          } else if (dy > 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          }
  
          r = y1 - ay;
          if (!dy && r < 0) return;
          r /= dy;
          if (dy < 0) {
              if (r > t1) return;
              if (r > t0) t0 = r;
          } else if (dy > 0) {
              if (r < t0) return;
              if (r < t1) t1 = r;
          }
  
          if (!(t0 > 0) && !(t1 < 1)) return true; // TODO Better check?
  
          if (t0 > 0) edge[0] = [ax + t0 * dx, ay + t0 * dy];
          if (t1 < 1) edge[1] = [ax + t1 * dx, ay + t1 * dy];
          return true;
      }
  
      function connectEdge(edge, x0, y0, x1, y1) {
          var v1 = edge[1];
          if (v1) return true;
  
          var v0 = edge[0],
              left = edge.left,
              right = edge.right,
              lx = left[0],
              ly = left[1],
              rx = right[0],
              ry = right[1],
              fx = (lx + rx) / 2,
              fy = (ly + ry) / 2,
              fm,
              fb;
  
          if (ry === ly) {
              if (fx < x0 || fx >= x1) return;
              if (lx > rx) {
                  if (!v0) v0 = [fx, y0];
                  else if (v0[1] >= y1) return;
                  v1 = [fx, y1];
              } else {
                  if (!v0) v0 = [fx, y1];
                  else if (v0[1] < y0) return;
                  v1 = [fx, y0];
              }
          } else {
              fm = (lx - rx) / (ry - ly);
              fb = fy - fm * fx;
              if (fm < -1 || fm > 1) {
                  if (lx > rx) {
                      if (!v0) v0 = [(y0 - fb) / fm, y0];
                      else if (v0[1] >= y1) return;
                      v1 = [(y1 - fb) / fm, y1];
                  } else {
                      if (!v0) v0 = [(y1 - fb) / fm, y1];
                      else if (v0[1] < y0) return;
                      v1 = [(y0 - fb) / fm, y0];
                  }
              } else {
                  if (ly < ry) {
                      if (!v0) v0 = [x0, fm * x0 + fb];
                      else if (v0[0] >= x1) return;
                      v1 = [x1, fm * x1 + fb];
                  } else {
                      if (!v0) v0 = [x1, fm * x1 + fb];
                      else if (v0[0] < x0) return;
                      v1 = [x0, fm * x0 + fb];
                  }
              }
          }
  
          edge[0] = v0;
          edge[1] = v1;
          return true;
      }
  
      function clipEdges(x0, y0, x1, y1) {
          var i = edges.length,
              edge;
  
          while (i--) {
              if (!connectEdge(edge = edges[i], x0, y0, x1, y1)
                  || !clipEdge(edge, x0, y0, x1, y1)
                  || !(Math.abs(edge[0][0] - edge[1][0]) > epsilon$4
                  || Math.abs(edge[0][1] - edge[1][1]) > epsilon$4)) {
                  delete edges[i];
              }
          }
      }
  
      function createCell(site) {
          return cells[site.index] = {
              site: site,
              halfedges: []
          };
      }
  
      function cellHalfedgeAngle(cell, edge) {
          var site = cell.site,
              va = edge.left,
              vb = edge.right;
          if (site === vb) vb = va, va = site;
          if (vb) return Math.atan2(vb[1] - va[1], vb[0] - va[0]);
          if (site === va) va = edge[1], vb = edge[0];
          else va = edge[0], vb = edge[1];
          return Math.atan2(va[0] - vb[0], vb[1] - va[1]);
      }
  
      function cellHalfedgeStart(cell, edge) {
          return edge[+(edge.left !== cell.site)];
      }
  
      function cellHalfedgeEnd(cell, edge) {
          return edge[+(edge.left === cell.site)];
      }
  
      function sortCellHalfedges() {
          for (var i = 0, n = cells.length, cell, halfedges, j, m; i < n; ++i) {
              if ((cell = cells[i]) && (m = (halfedges = cell.halfedges).length)) {
                  var index = new Array(m),
                      array = new Array(m);
                  for (j = 0; j < m; ++j) index[j] = j, array[j] = cellHalfedgeAngle(cell, edges[halfedges[j]]);
                  index.sort(function(i, j) { return array[j] - array[i]; });
                  for (j = 0; j < m; ++j) array[j] = halfedges[index[j]];
                  for (j = 0; j < m; ++j) halfedges[j] = array[j];
              }
          }
      }
  
      function clipCells(x0, y0, x1, y1) {
          var nCells = cells.length,
              iCell,
              cell,
              site,
              iHalfedge,
              halfedges,
              nHalfedges,
              start,
              startX,
              startY,
              end,
              endX,
              endY,
              cover = true;
  
          for (iCell = 0; iCell < nCells; ++iCell) {
              if (cell = cells[iCell]) {
                  site = cell.site;
                  halfedges = cell.halfedges;
                  iHalfedge = halfedges.length;
  
                  // Remove any dangling clipped edges.
                  while (iHalfedge--) {
                      if (!edges[halfedges[iHalfedge]]) {
                          halfedges.splice(iHalfedge, 1);
                      }
                  }
  
                  // Insert any border edges as necessary.
                  iHalfedge = 0, nHalfedges = halfedges.length;
                  while (iHalfedge < nHalfedges) {
                      end = cellHalfedgeEnd(cell, edges[halfedges[iHalfedge]]), endX = end[0], endY = end[1];
                      start = cellHalfedgeStart(cell, edges[halfedges[++iHalfedge % nHalfedges]]), startX = start[0], startY = start[1];
                      if (Math.abs(endX - startX) > epsilon$4 || Math.abs(endY - startY) > epsilon$4) {
                          halfedges.splice(iHalfedge, 0, edges.push(createBorderEdge(site, end,
                                  Math.abs(endX - x0) < epsilon$4 && y1 - endY > epsilon$4 ? [x0, Math.abs(startX - x0) < epsilon$4 ? startY : y1]
                                      : Math.abs(endY - y1) < epsilon$4 && x1 - endX > epsilon$4 ? [Math.abs(startY - y1) < epsilon$4 ? startX : x1, y1]
                                      : Math.abs(endX - x1) < epsilon$4 && endY - y0 > epsilon$4 ? [x1, Math.abs(startX - x1) < epsilon$4 ? startY : y0]
                                          : Math.abs(endY - y0) < epsilon$4 && endX - x0 > epsilon$4 ? [Math.abs(startY - y0) < epsilon$4 ? startX : x0, y0]
                                              : null)) - 1);
                          ++nHalfedges;
                      }
                  }
  
                  if (nHalfedges) cover = false;
              }
          }
  
          // If there weren’t any edges, have the closest site cover the extent.
          // It doesn’t matter which corner of the extent we measure!
          if (cover) {
              var dx, dy, d2, dc = Infinity;
  
              for (iCell = 0, cover = null; iCell < nCells; ++iCell) {
                  if (cell = cells[iCell]) {
                      site = cell.site;
                      dx = site[0] - x0;
                      dy = site[1] - y0;
                      d2 = dx * dx + dy * dy;
                      if (d2 < dc) dc = d2, cover = cell;
                  }
              }
  
              if (cover) {
                  var v00 = [x0, y0], v01 = [x0, y1], v11 = [x1, y1], v10 = [x1, y0];
                  cover.halfedges.push(
                      edges.push(createBorderEdge(site = cover.site, v00, v01)) - 1,
                      edges.push(createBorderEdge(site, v01, v11)) - 1,
                      edges.push(createBorderEdge(site, v11, v10)) - 1,
                      edges.push(createBorderEdge(site, v10, v00)) - 1
                  );
              }
          }
  
          // Lastly delete any cells with no edges; these were entirely clipped.
          for (iCell = 0; iCell < nCells; ++iCell) {
              if (cell = cells[iCell]) {
                  if (!cell.halfedges.length) {
                      delete cells[iCell];
                  }
              }
          }
      }
  
      var circlePool = [];
  
      var firstCircle;
  
      function Circle() {
          RedBlackNode(this);
          this.x =
              this.y =
                  this.arc =
                      this.site =
                          this.cy = null;
      }
  
      function attachCircle(arc) {
          var lArc = arc.P,
              rArc = arc.N;
  
          if (!lArc || !rArc) return;
  
          var lSite = lArc.site,
              cSite = arc.site,
              rSite = rArc.site;
  
          if (lSite === rSite) return;
  
          var bx = cSite[0],
              by = cSite[1],
              ax = lSite[0] - bx,
              ay = lSite[1] - by,
              cx = rSite[0] - bx,
              cy = rSite[1] - by;
  
          var d = 2 * (ax * cy - ay * cx);
          if (d >= -epsilon2$2) return;
  
          var ha = ax * ax + ay * ay,
              hc = cx * cx + cy * cy,
              x = (cy * ha - ay * hc) / d,
              y = (ax * hc - cx * ha) / d;
  
          var circle = circlePool.pop() || new Circle;
          circle.arc = arc;
          circle.site = cSite;
          circle.x = x + bx;
          circle.y = (circle.cy = y + by) + Math.sqrt(x * x + y * y); // y bottom
  
          arc.circle = circle;
  
          var before = null,
              node = circles._;
  
          while (node) {
              if (circle.y < node.y || (circle.y === node.y && circle.x <= node.x)) {
                  if (node.L) node = node.L;
                  else { before = node.P; break; }
              } else {
                  if (node.R) node = node.R;
                  else { before = node; break; }
              }
          }
  
          circles.insert(before, circle);
          if (!before) firstCircle = circle;
      }
  
      function detachCircle(arc) {
          var circle = arc.circle;
          if (circle) {
              if (!circle.P) firstCircle = circle.N;
              circles.remove(circle);
              circlePool.push(circle);
              RedBlackNode(circle);
              arc.circle = null;
          }
      }
  
      var beachPool = [];
  
      function Beach() {
          RedBlackNode(this);
          this.edge =
              this.site =
                  this.circle = null;
      }
  
      function createBeach(site) {
          var beach = beachPool.pop() || new Beach;
          beach.site = site;
          return beach;
      }
  
      function detachBeach(beach) {
          detachCircle(beach);
          beaches.remove(beach);
          beachPool.push(beach);
          RedBlackNode(beach);
      }
  
      function removeBeach(beach) {
          var circle = beach.circle,
              x = circle.x,
              y = circle.cy,
              vertex = [x, y],
              previous = beach.P,
              next = beach.N,
              disappearing = [beach];
  
          detachBeach(beach);
  
          var lArc = previous;
          while (lArc.circle
          && Math.abs(x - lArc.circle.x) < epsilon$4
          && Math.abs(y - lArc.circle.cy) < epsilon$4) {
              previous = lArc.P;
              disappearing.unshift(lArc);
              detachBeach(lArc);
              lArc = previous;
          }
  
          disappearing.unshift(lArc);
          detachCircle(lArc);
  
          var rArc = next;
          while (rArc.circle
          && Math.abs(x - rArc.circle.x) < epsilon$4
          && Math.abs(y - rArc.circle.cy) < epsilon$4) {
              next = rArc.N;
              disappearing.push(rArc);
              detachBeach(rArc);
              rArc = next;
          }
  
          disappearing.push(rArc);
          detachCircle(rArc);
  
          var nArcs = disappearing.length,
              iArc;
          for (iArc = 1; iArc < nArcs; ++iArc) {
              rArc = disappearing[iArc];
              lArc = disappearing[iArc - 1];
              setEdgeEnd(rArc.edge, lArc.site, rArc.site, vertex);
          }
  
          lArc = disappearing[0];
          rArc = disappearing[nArcs - 1];
          rArc.edge = createEdge(lArc.site, rArc.site, null, vertex);
  
          attachCircle(lArc);
          attachCircle(rArc);
      }
  
      function addBeach(site) {
          var x = site[0],
              directrix = site[1],
              lArc,
              rArc,
              dxl,
              dxr,
              node = beaches._;
  
          while (node) {
              dxl = leftBreakPoint(node, directrix) - x;
              if (dxl > epsilon$4) node = node.L; else {
                  dxr = x - rightBreakPoint(node, directrix);
                  if (dxr > epsilon$4) {
                      if (!node.R) {
                          lArc = node;
                          break;
                      }
                      node = node.R;
                  } else {
                      if (dxl > -epsilon$4) {
                          lArc = node.P;
                          rArc = node;
                      } else if (dxr > -epsilon$4) {
                          lArc = node;
                          rArc = node.N;
                      } else {
                          lArc = rArc = node;
                      }
                      break;
                  }
              }
          }
  
          createCell(site);
          var newArc = createBeach(site);
          beaches.insert(lArc, newArc);
  
          if (!lArc && !rArc) return;
  
          if (lArc === rArc) {
              detachCircle(lArc);
              rArc = createBeach(lArc.site);
              beaches.insert(newArc, rArc);
              newArc.edge = rArc.edge = createEdge(lArc.site, newArc.site);
              attachCircle(lArc);
              attachCircle(rArc);
              return;
          }
  
          if (!rArc) { // && lArc
              newArc.edge = createEdge(lArc.site, newArc.site);
              return;
          }
  
          // else lArc !== rArc
          detachCircle(lArc);
          detachCircle(rArc);
  
          var lSite = lArc.site,
              ax = lSite[0],
              ay = lSite[1],
              bx = site[0] - ax,
              by = site[1] - ay,
              rSite = rArc.site,
              cx = rSite[0] - ax,
              cy = rSite[1] - ay,
              d = 2 * (bx * cy - by * cx),
              hb = bx * bx + by * by,
              hc = cx * cx + cy * cy,
              vertex = [(cy * hb - by * hc) / d + ax, (bx * hc - cx * hb) / d + ay];
  
          setEdgeEnd(rArc.edge, lSite, rSite, vertex);
          newArc.edge = createEdge(lSite, site, null, vertex);
          rArc.edge = createEdge(site, rSite, null, vertex);
          attachCircle(lArc);
          attachCircle(rArc);
      }
  
      function leftBreakPoint(arc, directrix) {
          var site = arc.site,
              rfocx = site[0],
              rfocy = site[1],
              pby2 = rfocy - directrix;
  
          if (!pby2) return rfocx;
  
          var lArc = arc.P;
          if (!lArc) return -Infinity;
  
          site = lArc.site;
          var lfocx = site[0],
              lfocy = site[1],
              plby2 = lfocy - directrix;
  
          if (!plby2) return lfocx;
  
          var hl = lfocx - rfocx,
              aby2 = 1 / pby2 - 1 / plby2,
              b = hl / plby2;
  
          if (aby2) return (-b + Math.sqrt(b * b - 2 * aby2 * (hl * hl / (-2 * plby2) - lfocy + plby2 / 2 + rfocy - pby2 / 2))) / aby2 + rfocx;
  
          return (rfocx + lfocx) / 2;
      }
  
      function rightBreakPoint(arc, directrix) {
          var rArc = arc.N;
          if (rArc) return leftBreakPoint(rArc, directrix);
          var site = arc.site;
          return site[1] === directrix ? site[0] : Infinity;
      }
  
      var epsilon$4 = 1e-6;
      var epsilon2$2 = 1e-12;
      var beaches;
      var cells;
      var circles;
      var edges;
  
      function triangleArea(a, b, c) {
          return (a[0] - c[0]) * (b[1] - a[1]) - (a[0] - b[0]) * (c[1] - a[1]);
      }
  
      function lexicographic(a, b) {
          return b[1] - a[1]
              || b[0] - a[0];
      }
  
      function Diagram(sites, extent) {
          var site = sites.sort(lexicographic).pop(),
              x,
              y,
              circle;
  
          edges = [];
          cells = new Array(sites.length);
          beaches = new RedBlackTree;
          circles = new RedBlackTree;
  
          while (true) {
              circle = firstCircle;
              if (site && (!circle || site[1] < circle.y || (site[1] === circle.y && site[0] < circle.x))) {
                  if (site[0] !== x || site[1] !== y) {
                      addBeach(site);
                      x = site[0], y = site[1];
                  }
                  site = sites.pop();
              } else if (circle) {
                  removeBeach(circle.arc);
              } else {
                  break;
              }
          }
  
          sortCellHalfedges();
  
          if (extent) {
              var x0 = +extent[0][0],
                  y0 = +extent[0][1],
                  x1 = +extent[1][0],
                  y1 = +extent[1][1];
              clipEdges(x0, y0, x1, y1);
              clipCells(x0, y0, x1, y1);
          }
  
          this.edges = edges;
          this.cells = cells;
  
          beaches =
              circles =
                  edges =
                      cells = null;
      }
  
      Diagram.prototype = {
          constructor: Diagram,
  
          polygons: function() {
              var edges = this.edges;
  
              return this.cells.map(function(cell) {
                  var polygon = cell.halfedges.map(function(i) { return cellHalfedgeStart(cell, edges[i]); });
                  polygon.data = cell.site.data;
                  return polygon;
              });
          },
  
          triangles: function() {
              var triangles = [],
                  edges = this.edges;
  
              this.cells.forEach(function(cell, i) {
                  if (!(m = (halfedges = cell.halfedges).length)) return;
                  var site = cell.site,
                      halfedges,
                      j = -1,
                      m,
                      s0,
                      e1 = edges[halfedges[m - 1]],
                      s1 = e1.left === site ? e1.right : e1.left;
  
                  while (++j < m) {
                      s0 = s1;
                      e1 = edges[halfedges[j]];
                      s1 = e1.left === site ? e1.right : e1.left;
                      if (s0 && s1 && i < s0.index && i < s1.index && triangleArea(site, s0, s1) < 0) {
                          triangles.push([site.data, s0.data, s1.data]);
                      }
                  }
              });
  
              return triangles;
          },
  
          links: function() {
              return this.edges.filter(function(edge) {
                  return edge.right;
              }).map(function(edge) {
                  return {
                      source: edge.left.data,
                      target: edge.right.data
                  };
              });
          },
  
          find: function(x, y, radius) {
              var that = this, i0, i1 = that._found || 0, n = that.cells.length, cell;
  
              // Use the previously-found cell, or start with an arbitrary one.
              while (!(cell = that.cells[i1])) if (++i1 >= n) return null;
              var dx = x - cell.site[0], dy = y - cell.site[1], d2 = dx * dx + dy * dy;
  
              // Traverse the half-edges to find a closer cell, if any.
              do {
                  cell = that.cells[i0 = i1], i1 = null;
                  cell.halfedges.forEach(function(e) {
                      var edge = that.edges[e], v = edge.left;
                      if ((v === cell.site || !v) && !(v = edge.right)) return;
                      var vx = x - v[0], vy = y - v[1], v2 = vx * vx + vy * vy;
                      if (v2 < d2) d2 = v2, i1 = v.index;
                  });
              } while (i1 !== null);
  
              that._found = i0;
  
              return radius == null || d2 <= radius * radius ? cell.site : null;
          }
      };
  
      var voronoi = function() {
          var x$$1 = x$4,
              y$$1 = y$4,
              extent = null;
  
          function voronoi(data) {
              return new Diagram(data.map(function(d, i) {
                  var s = [Math.round(x$$1(d, i, data) / epsilon$4) * epsilon$4, Math.round(y$$1(d, i, data) / epsilon$4) * epsilon$4];
                  s.index = i;
                  s.data = d;
                  return s;
              }), extent);
          }
  
          voronoi.polygons = function(data) {
              return voronoi(data).polygons();
          };
  
          voronoi.links = function(data) {
              return voronoi(data).links();
          };
  
          voronoi.triangles = function(data) {
              return voronoi(data).triangles();
          };
  
          voronoi.x = function(_) {
              return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant$11(+_), voronoi) : x$$1;
          };
  
          voronoi.y = function(_) {
              return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$11(+_), voronoi) : y$$1;
          };
  
          voronoi.extent = function(_) {
              return arguments.length ? (extent = _ == null ? null : [[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]], voronoi) : extent && [[extent[0][0], extent[0][1]], [extent[1][0], extent[1][1]]];
          };
  
          voronoi.size = function(_) {
              return arguments.length ? (extent = _ == null ? null : [[0, 0], [+_[0], +_[1]]], voronoi) : extent && [extent[1][0] - extent[0][0], extent[1][1] - extent[0][1]];
          };
  
          return voronoi;
      };
  
      var constant$12 = function(x) {
          return function() {
              return x;
          };
      };
  
      function ZoomEvent(target, type, transform) {
          this.target = target;
          this.type = type;
          this.transform = transform;
      }
  
      function Transform(k, x, y) {
          this.k = k;
          this.x = x;
          this.y = y;
      }
  
      Transform.prototype = {
          constructor: Transform,
          scale: function(k) {
              return k === 1 ? this : new Transform(this.k * k, this.x, this.y);
          },
          translate: function(x, y) {
              return x === 0 & y === 0 ? this : new Transform(this.k, this.x + this.k * x, this.y + this.k * y);
          },
          apply: function(point) {
              return [point[0] * this.k + this.x, point[1] * this.k + this.y];
          },
          applyX: function(x) {
              return x * this.k + this.x;
          },
          applyY: function(y) {
              return y * this.k + this.y;
          },
          invert: function(location) {
              return [(location[0] - this.x) / this.k, (location[1] - this.y) / this.k];
          },
          invertX: function(x) {
              return (x - this.x) / this.k;
          },
          invertY: function(y) {
              return (y - this.y) / this.k;
          },
          rescaleX: function(x) {
              return x.copy().domain(x.range().map(this.invertX, this).map(x.invert, x));
          },
          rescaleY: function(y) {
              return y.copy().domain(y.range().map(this.invertY, this).map(y.invert, y));
          },
          toString: function() {
              return "translate(" + this.x + "," + this.y + ") scale(" + this.k + ")";
          }
      };
  
      var identity$8 = new Transform(1, 0, 0);
  
      transform$1.prototype = Transform.prototype;
  
      function transform$1(node) {
          return node.__zoom || identity$8;
      }
  
      function nopropagation$2() {
          exports.event.stopImmediatePropagation();
      }
  
      var noevent$2 = function() {
          exports.event.preventDefault();
          exports.event.stopImmediatePropagation();
      };
  
  // Ignore right-click, since that should open the context menu.
      function defaultFilter$2() {
          return !exports.event.button;
      }
  
      function defaultExtent$1() {
          var e = this, w, h;
          if (e instanceof SVGElement) {
              e = e.ownerSVGElement || e;
              w = e.width.baseVal.value;
              h = e.height.baseVal.value;
          } else {
              w = e.clientWidth;
              h = e.clientHeight;
          }
          return [[0, 0], [w, h]];
      }
  
      function defaultTransform() {
          return this.__zoom || identity$8;
      }
  
      var zoom = function() {
          var filter = defaultFilter$2,
              extent = defaultExtent$1,
              k0 = 0,
              k1 = Infinity,
              x0 = -k1,
              x1 = k1,
              y0 = x0,
              y1 = x1,
              duration = 250,
              interpolate$$1 = interpolateZoom,
              gestures = [],
              listeners = dispatch("start", "zoom", "end"),
              touchstarting,
              touchending,
              touchDelay = 500,
              wheelDelay = 150;
  
          function zoom(selection$$1) {
              selection$$1
                  .on("wheel.zoom", wheeled)
                  .on("mousedown.zoom", mousedowned)
                  .on("dblclick.zoom", dblclicked)
                  .on("touchstart.zoom", touchstarted)
                  .on("touchmove.zoom", touchmoved)
                  .on("touchend.zoom touchcancel.zoom", touchended)
                  .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)")
                  .property("__zoom", defaultTransform);
          }
  
          zoom.transform = function(collection, transform) {
              var selection$$1 = collection.selection ? collection.selection() : collection;
              selection$$1.property("__zoom", defaultTransform);
              if (collection !== selection$$1) {
                  schedule(collection, transform);
              } else {
                  selection$$1.interrupt().each(function() {
                      gesture(this, arguments)
                          .start()
                          .zoom(null, typeof transform === "function" ? transform.apply(this, arguments) : transform)
                          .end();
                  });
              }
          };
  
          zoom.scaleBy = function(selection$$1, k) {
              zoom.scaleTo(selection$$1, function() {
                  var k0 = this.__zoom.k,
                      k1 = typeof k === "function" ? k.apply(this, arguments) : k;
                  return k0 * k1;
              });
          };
  
          zoom.scaleTo = function(selection$$1, k) {
              zoom.transform(selection$$1, function() {
                  var e = extent.apply(this, arguments),
                      t0 = this.__zoom,
                      p0 = centroid(e),
                      p1 = t0.invert(p0),
                      k1 = typeof k === "function" ? k.apply(this, arguments) : k;
                  return constrain(translate(scale(t0, k1), p0, p1), e);
              });
          };
  
          zoom.translateBy = function(selection$$1, x, y) {
              zoom.transform(selection$$1, function() {
                  return constrain(this.__zoom.translate(
                      typeof x === "function" ? x.apply(this, arguments) : x,
                      typeof y === "function" ? y.apply(this, arguments) : y
                  ), extent.apply(this, arguments));
              });
          };
  
          function scale(transform, k) {
              k = Math.max(k0, Math.min(k1, k));
              return k === transform.k ? transform : new Transform(k, transform.x, transform.y);
          }
  
          function translate(transform, p0, p1) {
              var x = p0[0] - p1[0] * transform.k, y = p0[1] - p1[1] * transform.k;
              return x === transform.x && y === transform.y ? transform : new Transform(transform.k, x, y);
          }
  
          function constrain(transform, extent) {
              var dx0 = transform.invertX(extent[0][0]) - x0,
                  dx1 = transform.invertX(extent[1][0]) - x1,
                  dy0 = transform.invertY(extent[0][1]) - y0,
                  dy1 = transform.invertY(extent[1][1]) - y1;
              return transform.translate(
                  dx1 > dx0 ? (dx0 + dx1) / 2 : Math.min(0, dx0) || Math.max(0, dx1),
                  dy1 > dy0 ? (dy0 + dy1) / 2 : Math.min(0, dy0) || Math.max(0, dy1)
              );
          }
  
          function centroid(extent) {
              return [(+extent[0][0] + +extent[1][0]) / 2, (+extent[0][1] + +extent[1][1]) / 2];
          }
  
          function schedule(transition$$1, transform, center) {
              transition$$1
                  .on("start.zoom", function() { gesture(this, arguments).start(); })
                  .on("interrupt.zoom end.zoom", function() { gesture(this, arguments).end(); })
                  .tween("zoom", function() {
                      var that = this,
                          args = arguments,
                          g = gesture(that, args),
                          e = extent.apply(that, args),
                          p = center || centroid(e),
                          w = Math.max(e[1][0] - e[0][0], e[1][1] - e[0][1]),
                          a = that.__zoom,
                          b = typeof transform === "function" ? transform.apply(that, args) : transform,
                          i = interpolate$$1(a.invert(p).concat(w / a.k), b.invert(p).concat(w / b.k));
                      return function(t) {
                          if (t === 1) t = b; // Avoid rounding error on end.
                          else { var l = i(t), k = w / l[2]; t = new Transform(k, p[0] - l[0] * k, p[1] - l[1] * k); }
                          g.zoom(null, t);
                      };
                  });
          }
  
          function gesture(that, args) {
              for (var i = 0, n = gestures.length, g; i < n; ++i) {
                  if ((g = gestures[i]).that === that) {
                      return g;
                  }
              }
              return new Gesture(that, args);
          }
  
          function Gesture(that, args) {
              this.that = that;
              this.args = args;
              this.index = -1;
              this.active = 0;
              this.extent = extent.apply(that, args);
          }
  
          Gesture.prototype = {
              start: function() {
                  if (++this.active === 1) {
                      this.index = gestures.push(this) - 1;
                      this.emit("start");
                  }
                  return this;
              },
              zoom: function(key, transform) {
                  if (this.mouse && key !== "mouse") this.mouse[1] = transform.invert(this.mouse[0]);
                  if (this.touch0 && key !== "touch") this.touch0[1] = transform.invert(this.touch0[0]);
                  if (this.touch1 && key !== "touch") this.touch1[1] = transform.invert(this.touch1[0]);
                  this.that.__zoom = transform;
                  this.emit("zoom");
                  return this;
              },
              end: function() {
                  if (--this.active === 0) {
                      gestures.splice(this.index, 1);
                      this.index = -1;
                      this.emit("end");
                  }
                  return this;
              },
              emit: function(type) {
                  customEvent(new ZoomEvent(zoom, type, this.that.__zoom), listeners.apply, listeners, [type, this.that, this.args]);
              }
          };
  
          function wheeled() {
              if (!filter.apply(this, arguments)) return;
              var g = gesture(this, arguments),
                  t = this.__zoom,
                  k = Math.max(k0, Math.min(k1, t.k * Math.pow(2, -exports.event.deltaY * (exports.event.deltaMode ? 120 : 1) / 500))),
                  p = mouse(this);
  
              // If the mouse is in the same location as before, reuse it.
              // If there were recent wheel events, reset the wheel idle timeout.
              if (g.wheel) {
                  if (g.mouse[0][0] !== p[0] || g.mouse[0][1] !== p[1]) {
                      g.mouse[1] = t.invert(g.mouse[0] = p);
                  }
                  clearTimeout(g.wheel);
              }
  
              // If this wheel event won’t trigger a transform change, ignore it.
              else if (t.k === k) return;
  
              // Otherwise, capture the mouse point and location at the start.
              else {
                  g.mouse = [p, t.invert(p)];
                  interrupt(this);
                  g.start();
              }
  
              noevent$2();
              g.wheel = setTimeout(wheelidled, wheelDelay);
              g.zoom("mouse", constrain(translate(scale(t, k), g.mouse[0], g.mouse[1]), g.extent));
  
              function wheelidled() {
                  g.wheel = null;
                  g.end();
              }
          }
  
          function mousedowned() {
              if (touchending || !filter.apply(this, arguments)) return;
              var g = gesture(this, arguments),
                  v = select(exports.event.view).on("mousemove.zoom", mousemoved, true).on("mouseup.zoom", mouseupped, true),
                  p = mouse(this);
  
              dragDisable(exports.event.view);
              nopropagation$2();
              g.mouse = [p, this.__zoom.invert(p)];
              interrupt(this);
              g.start();
  
              function mousemoved() {
                  noevent$2();
                  g.moved = true;
                  g.zoom("mouse", constrain(translate(g.that.__zoom, g.mouse[0] = mouse(g.that), g.mouse[1]), g.extent));
              }
  
              function mouseupped() {
                  v.on("mousemove.zoom mouseup.zoom", null);
                  yesdrag(exports.event.view, g.moved);
                  noevent$2();
                  g.end();
              }
          }
  
          function dblclicked() {
              if (!filter.apply(this, arguments)) return;
              var t0 = this.__zoom,
                  p0 = mouse(this),
                  p1 = t0.invert(p0),
                  k1 = t0.k * (exports.event.shiftKey ? 0.5 : 2),
                  t1 = constrain(translate(scale(t0, k1), p0, p1), extent.apply(this, arguments));
  
              noevent$2();
              if (duration > 0) select(this).transition().duration(duration).call(schedule, t1, p0);
              else select(this).call(zoom.transform, t1);
          }
  
          function touchstarted() {
              if (!filter.apply(this, arguments)) return;
              var g = gesture(this, arguments),
                  touches$$1 = exports.event.changedTouches,
                  started,
                  n = touches$$1.length, i, t, p;
  
              nopropagation$2();
              for (i = 0; i < n; ++i) {
                  t = touches$$1[i], p = touch(this, touches$$1, t.identifier);
                  p = [p, this.__zoom.invert(p), t.identifier];
                  if (!g.touch0) g.touch0 = p, started = true;
                  else if (!g.touch1) g.touch1 = p;
              }
  
              // If this is a dbltap, reroute to the (optional) dblclick.zoom handler.
              if (touchstarting) {
                  touchstarting = clearTimeout(touchstarting);
                  if (!g.touch1) {
                      g.end();
                      p = select(this).on("dblclick.zoom");
                      if (p) p.apply(this, arguments);
                      return;
                  }
              }
  
              if (started) {
                  touchstarting = setTimeout(function() { touchstarting = null; }, touchDelay);
                  interrupt(this);
                  g.start();
              }
          }
  
          function touchmoved() {
              var g = gesture(this, arguments),
                  touches$$1 = exports.event.changedTouches,
                  n = touches$$1.length, i, t, p, l;
  
              noevent$2();
              if (touchstarting) touchstarting = clearTimeout(touchstarting);
              for (i = 0; i < n; ++i) {
                  t = touches$$1[i], p = touch(this, touches$$1, t.identifier);
                  if (g.touch0 && g.touch0[2] === t.identifier) g.touch0[0] = p;
                  else if (g.touch1 && g.touch1[2] === t.identifier) g.touch1[0] = p;
              }
              t = g.that.__zoom;
              if (g.touch1) {
                  var p0 = g.touch0[0], l0 = g.touch0[1],
                      p1 = g.touch1[0], l1 = g.touch1[1],
                      dp = (dp = p1[0] - p0[0]) * dp + (dp = p1[1] - p0[1]) * dp,
                      dl = (dl = l1[0] - l0[0]) * dl + (dl = l1[1] - l0[1]) * dl;
                  t = scale(t, Math.sqrt(dp / dl));
                  p = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
                  l = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2];
              }
              else if (g.touch0) p = g.touch0[0], l = g.touch0[1];
              else return;
              g.zoom("touch", constrain(translate(t, p, l), g.extent));
          }
  
          function touchended() {
              var g = gesture(this, arguments),
                  touches$$1 = exports.event.changedTouches,
                  n = touches$$1.length, i, t;
  
              nopropagation$2();
              if (touchending) clearTimeout(touchending);
              touchending = setTimeout(function() { touchending = null; }, touchDelay);
              for (i = 0; i < n; ++i) {
                  t = touches$$1[i];
                  if (g.touch0 && g.touch0[2] === t.identifier) delete g.touch0;
                  else if (g.touch1 && g.touch1[2] === t.identifier) delete g.touch1;
              }
              if (g.touch1 && !g.touch0) g.touch0 = g.touch1, delete g.touch1;
              if (g.touch0) g.touch0[1] = this.__zoom.invert(g.touch0[0]);
              else g.end();
          }
  
          zoom.filter = function(_) {
              return arguments.length ? (filter = typeof _ === "function" ? _ : constant$12(!!_), zoom) : filter;
          };
  
          zoom.extent = function(_) {
              return arguments.length ? (extent = typeof _ === "function" ? _ : constant$12([[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]]), zoom) : extent;
          };
  
          zoom.scaleExtent = function(_) {
              return arguments.length ? (k0 = +_[0], k1 = +_[1], zoom) : [k0, k1];
          };
  
          zoom.translateExtent = function(_) {
              return arguments.length ? (x0 = +_[0][0], x1 = +_[1][0], y0 = +_[0][1], y1 = +_[1][1], zoom) : [[x0, y0], [x1, y1]];
          };
  
          zoom.duration = function(_) {
              return arguments.length ? (duration = +_, zoom) : duration;
          };
  
          zoom.interpolate = function(_) {
              return arguments.length ? (interpolate$$1 = _, zoom) : interpolate$$1;
          };
  
          zoom.on = function() {
              var value = listeners.on.apply(listeners, arguments);
              return value === listeners ? zoom : value;
          };
  
          return zoom;
      };
  
      exports.version = version;
      exports.bisect = bisectRight;
      exports.bisectRight = bisectRight;
      exports.bisectLeft = bisectLeft;
      exports.ascending = ascending;
      exports.bisector = bisector;
      exports.cross = cross;
      exports.descending = descending;
      exports.deviation = deviation;
      exports.extent = extent;
      exports.histogram = histogram;
      exports.thresholdFreedmanDiaconis = freedmanDiaconis;
      exports.thresholdScott = scott;
      exports.thresholdSturges = sturges;
      exports.max = max;
      exports.mean = mean;
      exports.median = median;
      exports.merge = merge;
      exports.min = min;
      exports.pairs = pairs;
      exports.permute = permute;
      exports.quantile = threshold;
      exports.range = sequence;
      exports.scan = scan;
      exports.shuffle = shuffle;
      exports.sum = sum;
      exports.ticks = ticks;
      exports.tickIncrement = tickIncrement;
      exports.tickStep = tickStep;
      exports.transpose = transpose;
      exports.variance = variance;
      exports.zip = zip;
      exports.axisTop = axisTop;
      exports.axisRight = axisRight;
      exports.axisBottom = axisBottom;
      exports.axisLeft = axisLeft;
      exports.brush = brush;
      exports.brushX = brushX;
      exports.brushY = brushY;
      exports.brushSelection = brushSelection;
      exports.chord = chord;
      exports.ribbon = ribbon;
      exports.nest = nest;
      exports.set = set$2;
      exports.map = map$1;
      exports.keys = keys;
      exports.values = values;
      exports.entries = entries;
      exports.color = color;
      exports.rgb = rgb;
      exports.hsl = hsl;
      exports.lab = lab;
      exports.hcl = hcl;
      exports.cubehelix = cubehelix;
      exports.dispatch = dispatch;
      exports.drag = drag;
      exports.dragDisable = dragDisable;
      exports.dragEnable = yesdrag;
      exports.dsvFormat = dsv;
      exports.csvParse = csvParse;
      exports.csvParseRows = csvParseRows;
      exports.csvFormat = csvFormat;
      exports.csvFormatRows = csvFormatRows;
      exports.tsvParse = tsvParse;
      exports.tsvParseRows = tsvParseRows;
      exports.tsvFormat = tsvFormat;
      exports.tsvFormatRows = tsvFormatRows;
      exports.easeLinear = linear$1;
      exports.easeQuad = quadInOut;
      exports.easeQuadIn = quadIn;
      exports.easeQuadOut = quadOut;
      exports.easeQuadInOut = quadInOut;
      exports.easeCubic = cubicInOut;
      exports.easeCubicIn = cubicIn;
      exports.easeCubicOut = cubicOut;
      exports.easeCubicInOut = cubicInOut;
      exports.easePoly = polyInOut;
      exports.easePolyIn = polyIn;
      exports.easePolyOut = polyOut;
      exports.easePolyInOut = polyInOut;
      exports.easeSin = sinInOut;
      exports.easeSinIn = sinIn;
      exports.easeSinOut = sinOut;
      exports.easeSinInOut = sinInOut;
      exports.easeExp = expInOut;
      exports.easeExpIn = expIn;
      exports.easeExpOut = expOut;
      exports.easeExpInOut = expInOut;
      exports.easeCircle = circleInOut;
      exports.easeCircleIn = circleIn;
      exports.easeCircleOut = circleOut;
      exports.easeCircleInOut = circleInOut;
      exports.easeBounce = bounceOut;
      exports.easeBounceIn = bounceIn;
      exports.easeBounceOut = bounceOut;
      exports.easeBounceInOut = bounceInOut;
      exports.easeBack = backInOut;
      exports.easeBackIn = backIn;
      exports.easeBackOut = backOut;
      exports.easeBackInOut = backInOut;
      exports.easeElastic = elasticOut;
      exports.easeElasticIn = elasticIn;
      exports.easeElasticOut = elasticOut;
      exports.easeElasticInOut = elasticInOut;
      exports.forceCenter = center$1;
      exports.forceCollide = collide;
      exports.forceLink = link;
      exports.forceManyBody = manyBody;
      exports.forceSimulation = simulation;
      exports.forceX = x$2;
      exports.forceY = y$2;
      exports.formatDefaultLocale = defaultLocale;
      exports.formatLocale = formatLocale;
      exports.formatSpecifier = formatSpecifier;
      exports.precisionFixed = precisionFixed;
      exports.precisionPrefix = precisionPrefix;
      exports.precisionRound = precisionRound;
      exports.geoArea = area;
      exports.geoBounds = bounds;
      exports.geoCentroid = centroid;
      exports.geoCircle = circle;
      exports.geoClipExtent = extent$1;
      exports.geoContains = contains;
      exports.geoDistance = distance;
      exports.geoGraticule = graticule;
      exports.geoGraticule10 = graticule10;
      exports.geoInterpolate = interpolate$1;
      exports.geoLength = length$1;
      exports.geoPath = index$1;
      exports.geoAlbers = albers;
      exports.geoAlbersUsa = albersUsa;
      exports.geoAzimuthalEqualArea = azimuthalEqualArea;
      exports.geoAzimuthalEqualAreaRaw = azimuthalEqualAreaRaw;
      exports.geoAzimuthalEquidistant = azimuthalEquidistant;
      exports.geoAzimuthalEquidistantRaw = azimuthalEquidistantRaw;
      exports.geoConicConformal = conicConformal;
      exports.geoConicConformalRaw = conicConformalRaw;
      exports.geoConicEqualArea = conicEqualArea;
      exports.geoConicEqualAreaRaw = conicEqualAreaRaw;
      exports.geoConicEquidistant = conicEquidistant;
      exports.geoConicEquidistantRaw = conicEquidistantRaw;
      exports.geoEquirectangular = equirectangular;
      exports.geoEquirectangularRaw = equirectangularRaw;
      exports.geoGnomonic = gnomonic;
      exports.geoGnomonicRaw = gnomonicRaw;
      exports.geoIdentity = identity$5;
      exports.geoProjection = projection;
      exports.geoProjectionMutator = projectionMutator;
      exports.geoMercator = mercator;
      exports.geoMercatorRaw = mercatorRaw;
      exports.geoOrthographic = orthographic;
      exports.geoOrthographicRaw = orthographicRaw;
      exports.geoStereographic = stereographic;
      exports.geoStereographicRaw = stereographicRaw;
      exports.geoTransverseMercator = transverseMercator;
      exports.geoTransverseMercatorRaw = transverseMercatorRaw;
      exports.geoRotation = rotation;
      exports.geoStream = geoStream;
      exports.geoTransform = transform;
      exports.cluster = cluster;
      exports.hierarchy = hierarchy;
      exports.pack = index$2;
      exports.packSiblings = siblings;
      exports.packEnclose = enclose;
      exports.partition = partition;
      exports.stratify = stratify;
      exports.tree = tree;
      exports.treemap = index$3;
      exports.treemapBinary = binary;
      exports.treemapDice = treemapDice;
      exports.treemapSlice = treemapSlice;
      exports.treemapSliceDice = sliceDice;
      exports.treemapSquarify = squarify;
      exports.treemapResquarify = resquarify;
      exports.interpolate = interpolateValue;
      exports.interpolateArray = array$1;
      exports.interpolateBasis = basis$1;
      exports.interpolateBasisClosed = basisClosed;
      exports.interpolateDate = date;
      exports.interpolateNumber = reinterpolate;
      exports.interpolateObject = object;
      exports.interpolateRound = interpolateRound;
      exports.interpolateString = interpolateString;
      exports.interpolateTransformCss = interpolateTransformCss;
      exports.interpolateTransformSvg = interpolateTransformSvg;
      exports.interpolateZoom = interpolateZoom;
      exports.interpolateRgb = interpolateRgb;
      exports.interpolateRgbBasis = rgbBasis;
      exports.interpolateRgbBasisClosed = rgbBasisClosed;
      exports.interpolateHsl = hsl$2;
      exports.interpolateHslLong = hslLong;
      exports.interpolateLab = lab$1;
      exports.interpolateHcl = hcl$2;
      exports.interpolateHclLong = hclLong;
      exports.interpolateCubehelix = cubehelix$2;
      exports.interpolateCubehelixLong = cubehelixLong;
      exports.quantize = quantize;
      exports.path = path;
      exports.polygonArea = area$1;
      exports.polygonCentroid = centroid$1;
      exports.polygonHull = hull;
      exports.polygonContains = contains$1;
      exports.polygonLength = length$2;
      exports.quadtree = quadtree;
      exports.queue = queue;
      exports.randomUniform = uniform;
      exports.randomNormal = normal;
      exports.randomLogNormal = logNormal;
      exports.randomBates = bates;
      exports.randomIrwinHall = irwinHall;
      exports.randomExponential = exponential$1;
      exports.request = request;
      exports.html = html;
      exports.json = json;
      exports.text = text;
      exports.xml = xml;
      exports.csv = csv$1;
      exports.tsv = tsv$1;
      exports.scaleBand = band;
      exports.scalePoint = point$1;
      exports.scaleIdentity = identity$6;
      exports.scaleLinear = linear$2;
      exports.scaleLog = log$1;
      exports.scaleOrdinal = ordinal;
      exports.scaleImplicit = implicit;
      exports.scalePow = pow$1;
      exports.scaleSqrt = sqrt$1;
      exports.scaleQuantile = quantile$$1;
      exports.scaleQuantize = quantize$1;
      exports.scaleThreshold = threshold$1;
      exports.scaleTime = time;
      exports.scaleUtc = utcTime;
      exports.schemeCategory10 = category10;
      exports.schemeCategory20b = category20b;
      exports.schemeCategory20c = category20c;
      exports.schemeCategory20 = category20;
      exports.interpolateCubehelixDefault = cubehelix$3;
      exports.interpolateRainbow = rainbow$1;
      exports.interpolateWarm = warm;
      exports.interpolateCool = cool;
      exports.interpolateViridis = viridis;
      exports.interpolateMagma = magma;
      exports.interpolateInferno = inferno;
      exports.interpolatePlasma = plasma;
      exports.scaleSequential = sequential;
      exports.creator = creator;
      exports.local = local$1;
      exports.matcher = matcher$1;
      exports.mouse = mouse;
      exports.namespace = namespace;
      exports.namespaces = namespaces;
      exports.select = select;
      exports.selectAll = selectAll;
      exports.selection = selection;
      exports.selector = selector;
      exports.selectorAll = selectorAll;
      exports.touch = touch;
      exports.touches = touches;
      exports.window = window;
      exports.customEvent = customEvent;
      exports.arc = arc;
      exports.area = area$2;
      exports.line = line;
      exports.pie = pie;
      exports.radialArea = radialArea;
      exports.radialLine = radialLine$1;
      exports.symbol = symbol;
      exports.symbols = symbols;
      exports.symbolCircle = circle$2;
      exports.symbolCross = cross$2;
      exports.symbolDiamond = diamond;
      exports.symbolSquare = square;
      exports.symbolStar = star;
      exports.symbolTriangle = triangle;
      exports.symbolWye = wye;
      exports.curveBasisClosed = basisClosed$1;
      exports.curveBasisOpen = basisOpen;
      exports.curveBasis = basis$2;
      exports.curveBundle = bundle;
      exports.curveCardinalClosed = cardinalClosed;
      exports.curveCardinalOpen = cardinalOpen;
      exports.curveCardinal = cardinal;
      exports.curveCatmullRomClosed = catmullRomClosed;
      exports.curveCatmullRomOpen = catmullRomOpen;
      exports.curveCatmullRom = catmullRom;
      exports.curveLinearClosed = linearClosed;
      exports.curveLinear = curveLinear;
      exports.curveMonotoneX = monotoneX;
      exports.curveMonotoneY = monotoneY;
      exports.curveNatural = natural;
      exports.curveStep = step;
      exports.curveStepAfter = stepAfter;
      exports.curveStepBefore = stepBefore;
      exports.stack = stack;
      exports.stackOffsetExpand = expand;
      exports.stackOffsetNone = none$1;
      exports.stackOffsetSilhouette = silhouette;
      exports.stackOffsetWiggle = wiggle;
      exports.stackOrderAscending = ascending$2;
      exports.stackOrderDescending = descending$2;
      exports.stackOrderInsideOut = insideOut;
      exports.stackOrderNone = none$2;
      exports.stackOrderReverse = reverse;
      exports.timeInterval = newInterval;
      exports.timeMillisecond = millisecond;
      exports.timeMilliseconds = milliseconds;
      exports.utcMillisecond = millisecond;
      exports.utcMilliseconds = milliseconds;
      exports.timeSecond = second;
      exports.timeSeconds = seconds;
      exports.utcSecond = second;
      exports.utcSeconds = seconds;
      exports.timeMinute = minute;
      exports.timeMinutes = minutes;
      exports.timeHour = hour;
      exports.timeHours = hours;
      exports.timeDay = day;
      exports.timeDays = days;
      exports.timeWeek = sunday;
      exports.timeWeeks = sundays;
      exports.timeSunday = sunday;
      exports.timeSundays = sundays;
      exports.timeMonday = monday;
      exports.timeMondays = mondays;
      exports.timeTuesday = tuesday;
      exports.timeTuesdays = tuesdays;
      exports.timeWednesday = wednesday;
      exports.timeWednesdays = wednesdays;
      exports.timeThursday = thursday;
      exports.timeThursdays = thursdays;
      exports.timeFriday = friday;
      exports.timeFridays = fridays;
      exports.timeSaturday = saturday;
      exports.timeSaturdays = saturdays;
      exports.timeMonth = month;
      exports.timeMonths = months;
      exports.timeYear = year;
      exports.timeYears = years;
      exports.utcMinute = utcMinute;
      exports.utcMinutes = utcMinutes;
      exports.utcHour = utcHour;
      exports.utcHours = utcHours;
      exports.utcDay = utcDay;
      exports.utcDays = utcDays;
      exports.utcWeek = utcSunday;
      exports.utcWeeks = utcSundays;
      exports.utcSunday = utcSunday;
      exports.utcSundays = utcSundays;
      exports.utcMonday = utcMonday;
      exports.utcMondays = utcMondays;
      exports.utcTuesday = utcTuesday;
      exports.utcTuesdays = utcTuesdays;
      exports.utcWednesday = utcWednesday;
      exports.utcWednesdays = utcWednesdays;
      exports.utcThursday = utcThursday;
      exports.utcThursdays = utcThursdays;
      exports.utcFriday = utcFriday;
      exports.utcFridays = utcFridays;
      exports.utcSaturday = utcSaturday;
      exports.utcSaturdays = utcSaturdays;
      exports.utcMonth = utcMonth;
      exports.utcMonths = utcMonths;
      exports.utcYear = utcYear;
      exports.utcYears = utcYears;
      exports.timeFormatDefaultLocale = defaultLocale$1;
      exports.timeFormatLocale = formatLocale$1;
      exports.isoFormat = formatIso;
      exports.isoParse = parseIso;
      exports.now = now;
      exports.timer = timer;
      exports.timerFlush = timerFlush;
      exports.timeout = timeout$1;
      exports.interval = interval$1;
      exports.transition = transition;
      exports.active = active;
      exports.interrupt = interrupt;
      exports.voronoi = voronoi;
      exports.zoom = zoom;
      exports.zoomTransform = transform$1;
      exports.zoomIdentity = identity$8;
  
      Object.defineProperty(exports, '__esModule', { value: true });
  
  })));