text: // https://d3js.org v5.9.2 Copyright 2019 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 = "5.9.2";
    
    function ascending(a, b) {
      return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
    }
    
    function bisector(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;
    
    function pairs(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];
    }
    
    function cross(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;
    }
    
    function descending(a, b) {
      return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
    }
    
    function number(x) {
      return x === null ? NaN : +x;
    }
    
    function variance(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);
    }
    
    function deviation(array, f) {
      var v = variance(array, f);
      return v ? Math.sqrt(v) : v;
    }
    
    function extent(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;
    
    function constant(x) {
      return function() {
        return x;
      };
    }
    
    function identity(x) {
      return x;
    }
    
    function sequence(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),
        e5 = Math.sqrt(10),
        e2 = Math.sqrt(2);
    
    function ticks(start, stop, count) {
      var reverse,
          i = -1,
          n,
          ticks,
          step;
    
      stop = +stop, start = +start, count = +count;
      if (start === stop && count > 0) return [start];
      if (reverse = stop < start) 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;
    }
    
    function thresholdSturges(values) {
      return Math.ceil(Math.log(values.length) / Math.LN2) + 1;
    }
    
    function histogram() {
      var value = identity,
          domain = extent,
          threshold = thresholdSturges;
    
      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, x1, 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;
    }
    
    function threshold(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);
    }
    
    function freedmanDiaconis(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)));
    }
    
    function scott(values, min, max) {
      return Math.ceil((max - min) / (3.5 * deviation(values) * Math.pow(values.length, -1 / 3)));
    }
    
    function max(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;
    }
    
    function mean(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;
    }
    
    function median(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);
    }
    
    function merge(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;
    }
    
    function min(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;
    }
    
    function permute(array, indexes) {
      var i = indexes.length, permutes = new Array(i);
      while (i--) permutes[i] = array[indexes[i]];
      return permutes;
    }
    
    function scan(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;
    }
    
    function shuffle(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;
    }
    
    function sum(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;
    }
    
    function transpose(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;
    }
    
    function zip() {
      return transpose(arguments);
    }
    
    var slice$1 = Array.prototype.slice;
    
    function identity$1(x) {
      return x;
    }
    
    var top = 1,
        right = 2,
        bottom = 3,
        left = 4,
        epsilon = 1e-6;
    
    function translateX(x) {
      return "translate(" + (x + 0.5) + ",0)";
    }
    
    function translateY(y) {
      return "translate(0," + (y + 0.5) + ")";
    }
    
    function number$1(scale) {
      return function(d) {
        return +scale(d);
      };
    }
    
    function center(scale) {
      var offset = Math.max(0, scale.bandwidth() - 1) / 2; // Adjust for 0.5px offset.
      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 = orient === left || orient === right ? "x" : "y",
          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 : number$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", "currentColor"));
    
        tick = tick.merge(tickEnter);
    
        line = line.merge(tickEnter.append("line")
            .attr("stroke", "currentColor")
            .attr(x + "2", k * tickSizeInner));
    
        text = text.merge(tickEnter.append("text")
            .attr("fill", "currentColor")
            .attr(x, k * spacing)
            .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
                ? (tickSizeOuter ? "M" + k * tickSizeOuter + "," + range0 + "H0.5V" + range1 + "H" + k * tickSizeOuter : "M0.5," + range0 + "V" + range1)
                : (tickSizeOuter ? "M" + range0 + "," + k * tickSizeOuter + "V0.5H" + range1 + "V" + k * tickSizeOuter : "M" + range0 + ",0.5H" + range1));
    
        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/"
    };
    
    function namespace(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);
      };
    }
    
    function creator(name) {
      var fullname = namespace(name);
      return (fullname.local
          ? creatorFixed
          : creatorInherit)(fullname);
    }
    
    function none() {}
    
    function selector(selector) {
      return selector == null ? none : function() {
        return this.querySelector(selector);
      };
    }
    
    function selection_select(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() {
      return [];
    }
    
    function selectorAll(selector) {
      return selector == null ? empty : function() {
        return this.querySelectorAll(selector);
      };
    }
    
    function selection_selectAll(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);
    }
    
    function matcher(selector) {
      return function() {
        return this.matches(selector);
      };
    }
    
    function selection_filter(match) {
      if (typeof match !== "function") match = matcher(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);
    }
    
    function sparse(update) {
      return new Array(update.length);
    }
    
    function selection_enter() {
      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); }
    };
    
    function constant$1(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;
        }
      }
    }
    
    function selection_data(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;
    }
    
    function selection_exit() {
      return new Selection(this._exit || this._groups.map(sparse), this._parents);
    }
    
    function selection_join(onenter, onupdate, onexit) {
      var enter = this.enter(), update = this, exit = this.exit();
      enter = typeof onenter === "function" ? onenter(enter) : enter.append(onenter + "");
      if (onupdate != null) update = onupdate(update);
      if (onexit == null) exit.remove(); else onexit(exit);
      return enter && update ? enter.merge(update).order() : update;
    }
    
    function selection_merge(selection$$1) {
    
      for (var groups0 = this._groups, groups1 = selection$$1._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);
    }
    
    function selection_order() {
    
      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 && node.compareDocumentPosition(next) ^ 4) next.parentNode.insertBefore(node, next);
            next = node;
          }
        }
      }
    
      return this;
    }
    
    function selection_sort(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;
    }
    
    function selection_call() {
      var callback = arguments[0];
      arguments[0] = this;
      callback.apply(null, arguments);
      return this;
    }
    
    function selection_nodes() {
      var nodes = new Array(this.size()), i = -1;
      this.each(function() { nodes[++i] = this; });
      return nodes;
    }
    
    function selection_node() {
    
      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;
    }
    
    function selection_size() {
      var size = 0;
      this.each(function() { ++size; });
      return size;
    }
    
    function selection_empty() {
      return !this.node();
    }
    
    function selection_each(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);
      };
    }
    
    function selection_attr(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));
    }
    
    function defaultView(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);
      };
    }
    
    function selection_style(name, value, priority) {
      return arguments.length > 1
          ? this.each((value == null
                ? styleRemove : typeof value === "function"
                ? styleFunction
                : styleConstant)(name, value, priority == null ? "" : priority))
          : styleValue(this.node(), name);
    }
    
    function styleValue(node, name) {
      return node.style.getPropertyValue(name)
          || defaultView(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;
      };
    }
    
    function selection_property(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);
      };
    }
    
    function selection_classed(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;
      };
    }
    
    function selection_text(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;
      };
    }
    
    function selection_html(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);
    }
    
    function selection_raise() {
      return this.each(raise);
    }
    
    function lower() {
      if (this.previousSibling) this.parentNode.insertBefore(this, this.parentNode.firstChild);
    }
    
    function selection_lower() {
      return this.each(lower);
    }
    
    function selection_append(name) {
      var create = typeof name === "function" ? name : creator(name);
      return this.select(function() {
        return this.appendChild(create.apply(this, arguments));
      });
    }
    
    function constantNull() {
      return null;
    }
    
    function selection_insert(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);
    }
    
    function selection_remove() {
      return this.each(remove);
    }
    
    function selection_cloneShallow() {
      return this.parentNode.insertBefore(this.cloneNode(false), this.nextSibling);
    }
    
    function selection_cloneDeep() {
      return this.parentNode.insertBefore(this.cloneNode(true), this.nextSibling);
    }
    
    function selection_clone(deep) {
      return this.select(deep ? selection_cloneDeep : selection_cloneShallow);
    }
    
    function selection_datum(value) {
      return arguments.length
          ? this.property("__data__", value)
          : this.node().__data__;
    }
    
    var filterEvents = {};
    
    exports.event = null;
    
    if (typeof document !== "undefined") {
      var element = document.documentElement;
      if (!("onmouseenter" in element)) {
        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);
      };
    }
    
    function selection_on(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;
      }
    }
    
    function dispatchEvent(node, type, params) {
      var window = defaultView(node),
          event = window.CustomEvent;
    
      if (typeof event === "function") {
        event = new event(type, params);
      } else {
        event = window.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));
      };
    }
    
    function selection_dispatch(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,
      join: selection_join,
      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,
      clone: selection_clone,
      datum: selection_datum,
      on: selection_on,
      dispatch: selection_dispatch
    };
    
    function select(selector) {
      return typeof selector === "string"
          ? new Selection([[document.querySelector(selector)]], [document.documentElement])
          : new Selection([[selector]], root);
    }
    
    function create(name) {
      return select(creator(name).call(document.documentElement));
    }
    
    var nextId = 0;
    
    function local() {
      return new Local;
    }
    
    function Local() {
      this._ = "@" + (++nextId).toString(36);
    }
    
    Local.prototype = local.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._;
      }
    };
    
    function sourceEvent() {
      var current = exports.event, source;
      while (source = current.sourceEvent) current = source;
      return current;
    }
    
    function point(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];
    }
    
    function mouse(node) {
      var event = sourceEvent();
      if (event.changedTouches) event = event.changedTouches[0];
      return point(node, event);
    }
    
    function selectAll(selector) {
      return typeof selector === "string"
          ? new Selection([document.querySelectorAll(selector)], [document.documentElement])
          : new Selection([selector == null ? [] : selector], root);
    }
    
    function touch(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;
    }
    
    function touches(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();
    }
    
    function noevent() {
      exports.event.preventDefault();
      exports.event.stopImmediatePropagation();
    }
    
    function dragDisable(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;
      }
    }
    
    function constant$2(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() {
      return !exports.event.button;
    }
    
    function defaultContainer() {
      return this.parentNode;
    }
    
    function defaultSubject(d) {
      return d == null ? {x: exports.event.x, y: exports.event.y} : d;
    }
    
    function defaultTouchable() {
      return "ontouchstart" in this;
    }
    
    function drag() {
      var filter = defaultFilter,
          container = defaultContainer,
          subject = defaultSubject,
          touchable = defaultTouchable,
          gestures = {},
          listeners = dispatch("start", "drag", "end"),
          active = 0,
          mousedownx,
          mousedowny,
          mousemoving,
          touchending,
          clickDistance2 = 0;
    
      function drag(selection$$1) {
        selection$$1
            .on("mousedown.drag", mousedowned)
          .filter(touchable)
            .on("touchstart.drag", touchstarted)
            .on("touchmove.drag", touchmoved)
            .on("touchend.drag touchcancel.drag", touchended)
            .style("touch-action", "none")
            .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;
        mousedownx = exports.event.clientX;
        mousedowny = exports.event.clientY;
        gesture("start");
      }
    
      function mousemoved() {
        noevent();
        if (!mousemoving) {
          var dx = exports.event.clientX - mousedownx, dy = exports.event.clientY - mousedowny;
          mousemoving = dx * dx + dy * dy > clickDistance2;
        }
        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$$1, that, args) {
        var p = point$$1(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$$1(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.touchable = function(_) {
        return arguments.length ? (touchable = typeof _ === "function" ? _ : constant$2(!!_), drag) : touchable;
      };
    
      drag.on = function() {
        var value = listeners.on.apply(listeners, arguments);
        return value === listeners ? drag : value;
      };
    
      drag.clickDistance = function(_) {
        return arguments.length ? (clickDistance2 = (_ = +_) * _, drag) : Math.sqrt(clickDistance2);
      };
    
      return drag;
    }
    
    function define(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*",
        reN = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)\\s*",
        reP = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)%\\s*",
        reHex3 = /^#([0-9a-f]{3})$/,
        reHex6 = /^#([0-9a-f]{6})$/,
        reRgbInteger = new RegExp("^rgb\\(" + [reI, reI, reI] + "\\)$"),
        reRgbPercent = new RegExp("^rgb\\(" + [reP, reP, reP] + "\\)$"),
        reRgbaInteger = new RegExp("^rgba\\(" + [reI, reI, reI, reN] + "\\)$"),
        reRgbaPercent = new RegExp("^rgba\\(" + [reP, reP, reP, reN] + "\\)$"),
        reHslPercent = new RegExp("^hsl\\(" + [reN, reP, reP] + "\\)$"),
        reHslaPercent = new RegExp("^hsla\\(" + [reN, reP, reP, reN] + "\\)$");
    
    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();
      },
      hex: function() {
        return this.rgb().hex();
      },
      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);
      },
      hex: function() {
        return "#" + hex(this.r) + hex(this.g) + hex(this.b);
      },
      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 hex(value) {
      value = Math.max(0, Math.min(255, Math.round(value) || 0));
      return (value < 16 ? "0" : "") + value.toString(16);
    }
    
    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;
    
    // https://beta.observablehq.com/@mbostock/lab-and-rgb
    var K = 18,
        Xn = 0.96422,
        Yn = 1,
        Zn = 0.82521,
        t0 = 4 / 29,
        t1 = 6 / 29,
        t2 = 3 * t1 * t1,
        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) {
        if (isNaN(o.h)) return new Lab(o.l, 0, 0, o.opacity);
        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 r = rgb2lrgb(o.r),
          g = rgb2lrgb(o.g),
          b = rgb2lrgb(o.b),
          y = xyz2lab((0.2225045 * r + 0.7168786 * g + 0.0606169 * b) / Yn), x, z;
      if (r === g && g === b) x = z = y; else {
        x = xyz2lab((0.4360747 * r + 0.3850649 * g + 0.1430804 * b) / Xn);
        z = xyz2lab((0.0139322 * r + 0.0971045 * g + 0.7141733 * b) / Zn);
      }
      return new Lab(116 * y - 16, 500 * (x - y), 200 * (y - z), o.opacity);
    }
    
    function gray(l, opacity) {
      return new Lab(l, 0, 0, opacity == null ? 1 : 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 + K * (k == null ? 1 : k), this.a, this.b, this.opacity);
      },
      darker: function(k) {
        return new Lab(this.l - K * (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;
        x = Xn * lab2xyz(x);
        y = Yn * lab2xyz(y);
        z = Zn * lab2xyz(z);
        return new Rgb(
          lrgb2rgb( 3.1338561 * x - 1.6168667 * y - 0.4906146 * z),
          lrgb2rgb(-0.9787684 * x + 1.9161415 * y + 0.0334540 * z),
          lrgb2rgb( 0.0719453 * x - 0.2289914 * y + 1.4052427 * 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 lrgb2rgb(x) {
      return 255 * (x <= 0.0031308 ? 12.92 * x : 1.055 * Math.pow(x, 1 / 2.4) - 0.055);
    }
    
    function rgb2lrgb(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);
      if (o.a === 0 && o.b === 0) return new Hcl(NaN, 0, o.l, o.opacity);
      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 lch(l, c, h, opacity) {
      return arguments.length === 1 ? hclConvert(l) : new Hcl(h, c, l, opacity == null ? 1 : 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 + K * (k == null ? 1 : k), this.opacity);
      },
      darker: function(k) {
        return new Hcl(this.h, this.c, this.l - K * (k == null ? 1 : k), this.opacity);
      },
      rgb: function() {
        return labConvert(this).rgb();
      }
    }));
    
    var A = -0.14861,
        B = +1.78277,
        C = -0.29227,
        D = -0.90649,
        E = +1.97294,
        ED = E * D,
        EB = E * B,
        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;
    }
    
    function basis$1(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);
      };
    }
    
    function basisClosed(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);
      };
    }
    
    function constant$3(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);
    
    function array$1(a, b) {
      var nb = b ? b.length : 0,
          na = a ? Math.min(nb, a.length) : 0,
          x = new Array(na),
          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;
      };
    }
    
    function date(a, b) {
      var d = new Date;
      return a = +a, b -= a, function(t) {
        return d.setTime(a + b * t), d;
      };
    }
    
    function interpolateNumber(a, b) {
      return a = +a, b -= a, function(t) {
        return a + b * t;
      };
    }
    
    function object(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,
        reB = new RegExp(reA.source, "g");
    
    function zero(b) {
      return function() {
        return b;
      };
    }
    
    function one(b) {
      return function(t) {
        return b(t) + "";
      };
    }
    
    function interpolateString(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: interpolateNumber(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("");
            });
    }
    
    function interpolateValue(a, b) {
      var t = typeof b, c;
      return b == null || t === "boolean" ? constant$3(b)
          : (t === "number" ? interpolateNumber
          : t === "string" ? ((c = color(b)) ? (b = c, interpolateRgb) : interpolateString)
          : b instanceof color ? interpolateRgb
          : b instanceof Date ? date
          : Array.isArray(b) ? array$1
          : typeof b.valueOf !== "function" && typeof b.toString !== "function" || isNaN(b) ? object
          : interpolateNumber)(a, b);
    }
    
    function discrete(range) {
      var n = range.length;
      return function(t) {
        return range[Math.max(0, Math.min(n - 1, Math.floor(t * n)))];
      };
    }
    
    function hue$1(a, b) {
      var i = hue(+a, +b);
      return function(t) {
        var x = i(t);
        return x - 360 * Math.floor(x / 360);
      };
    }
    
    function interpolateRound(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
    };
    
    function decompose(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,
        cssRoot,
        cssView,
        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: interpolateNumber(xa, xb)}, {i: i - 2, x: interpolateNumber(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: interpolateNumber(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: interpolateNumber(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: interpolateNumber(xa, xb)}, {i: i - 2, x: interpolateNumber(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,
        rho2 = 2,
        rho4 = 4,
        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]
    function interpolateZoom(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);
    
    function piecewise(interpolate, values) {
      var i = 0, n = values.length - 1, v = values[0], I = new Array(n < 0 ? 0 : n);
      while (i < n) I[i] = interpolate(v, v = values[++i]);
      return function(t) {
        var i = Math.max(0, Math.min(n - 1, Math.floor(t *= n)));
        return I[i](t - i);
      };
    }
    
    function quantize(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, // is an animation frame pending?
        timeout = 0, // is a timeout pending?
        interval = 0, // are any timers active?
        pokeDelay = 1000, // how frequently we check for clock skew
        taskHead,
        taskTail,
        clockLast = 0,
        clockNow = 0,
        clockSkew = 0,
        clock = typeof performance === "object" && performance.now ? performance : Date,
        setFrame = typeof window === "object" && window.requestAnimationFrame ? window.requestAnimationFrame.bind(window) : 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; // Strictly less than if we recomputed clockNow.
      if (delay > 24) {
        if (time < Infinity) timeout = setTimeout(wake, time - clock.now() - clockSkew);
        if (interval) interval = clearInterval(interval);
      } else {
        if (!interval) clockLast = clock.now(), interval = setInterval(poke, pokeDelay);
        frame = 1, setFrame(wake);
      }
    }
    
    function timeout$1(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;
    }
    
    function interval$1(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", "cancel", "interrupt");
    var emptyTween = [];
    
    var CREATED = 0;
    var SCHEDULED = 1;
    var STARTING = 2;
    var STARTED = 3;
    var RUNNING = 4;
    var ENDING = 5;
    var ENDED = 6;
    
    function schedule(node, name, id, index, group, timing) {
      var schedules = node.__transition;
      if (!schedules) node.__transition = {};
      else if (id in schedules) return;
      create$1(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 = get$1(node, id);
      if (schedule.state > CREATED) throw new Error("too late; already scheduled");
      return schedule;
    }
    
    function set$1(node, id) {
      var schedule = get$1(node, id);
      if (schedule.state > STARTED) throw new Error("too late; already running");
      return schedule;
    }
    
    function get$1(node, id) {
      var schedule = node.__transition;
      if (!schedule || !(schedule = schedule[id])) throw new Error("transition not found");
      return schedule;
    }
    
    function create$1(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.
          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.
          else if (+i < id) {
            o.state = ENDED;
            o.timer.stop();
            o.on.call("cancel", node, node.__data__, o.index, o.group);
            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(node, 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;
      }
    }
    
    function interrupt(node, name) {
      var schedules = node.__transition,
          schedule$$1,
          active,
          empty = true,
          i;
    
      if (!schedules) return;
    
      name = name == null ? null : name + "";
    
      for (i in schedules) {
        if ((schedule$$1 = schedules[i]).name !== name) { empty = false; continue; }
        active = schedule$$1.state > STARTING && schedule$$1.state < ENDING;
        schedule$$1.state = ENDED;
        schedule$$1.timer.stop();
        schedule$$1.on.call(active ? "interrupt" : "cancel", node, node.__data__, schedule$$1.index, schedule$$1.group);
        delete schedules[i];
      }
    
      if (empty) delete node.__transition;
    }
    
    function selection_interrupt(name) {
      return this.each(function() {
        interrupt(this, name);
      });
    }
    
    function tweenRemove(id, name) {
      var tween0, tween1;
      return function() {
        var schedule$$1 = set$1(this, id),
            tween = schedule$$1.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$$1.tween = tween1;
      };
    }
    
    function tweenFunction(id, name, value) {
      var tween0, tween1;
      if (typeof value !== "function") throw new Error;
      return function() {
        var schedule$$1 = set$1(this, id),
            tween = schedule$$1.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$$1.tween = tween1;
      };
    }
    
    function transition_tween(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$$1 = set$1(this, id);
        (schedule$$1.value || (schedule$$1.value = {}))[name] = value.apply(this, arguments);
      });
    
      return function(node) {
        return get$1(node, id).value[name];
      };
    }
    
    function interpolate(a, b) {
      var c;
      return (typeof b === "number" ? interpolateNumber
          : 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$$1, value1) {
      var string00,
          string1 = value1 + "",
          interpolate0;
      return function() {
        var string0 = this.getAttribute(name);
        return string0 === string1 ? null
            : string0 === string00 ? interpolate0
            : interpolate0 = interpolate$$1(string00 = string0, value1);
      };
    }
    
    function attrConstantNS$1(fullname, interpolate$$1, value1) {
      var string00,
          string1 = value1 + "",
          interpolate0;
      return function() {
        var string0 = this.getAttributeNS(fullname.space, fullname.local);
        return string0 === string1 ? null
            : string0 === string00 ? interpolate0
            : interpolate0 = interpolate$$1(string00 = string0, value1);
      };
    }
    
    function attrFunction$1(name, interpolate$$1, value) {
      var string00,
          string10,
          interpolate0;
      return function() {
        var string0, value1 = value(this), string1;
        if (value1 == null) return void this.removeAttribute(name);
        string0 = this.getAttribute(name);
        string1 = value1 + "";
        return string0 === string1 ? null
            : string0 === string00 && string1 === string10 ? interpolate0
            : (string10 = string1, interpolate0 = interpolate$$1(string00 = string0, value1));
      };
    }
    
    function attrFunctionNS$1(fullname, interpolate$$1, value) {
      var string00,
          string10,
          interpolate0;
      return function() {
        var string0, value1 = value(this), string1;
        if (value1 == null) return void this.removeAttributeNS(fullname.space, fullname.local);
        string0 = this.getAttributeNS(fullname.space, fullname.local);
        string1 = value1 + "";
        return string0 === string1 ? null
            : string0 === string00 && string1 === string10 ? interpolate0
            : (string10 = string1, interpolate0 = interpolate$$1(string00 = string0, value1));
      };
    }
    
    function transition_attr(name, value) {
      var fullname = namespace(name), i = fullname === "transform" ? interpolateTransformSvg : interpolate;
      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 attrInterpolate(name, i) {
      return function(t) {
        this.setAttribute(name, i(t));
      };
    }
    
    function attrInterpolateNS(fullname, i) {
      return function(t) {
        this.setAttributeNS(fullname.space, fullname.local, i(t));
      };
    }
    
    function attrTweenNS(fullname, value) {
      var t0, i0;
      function tween() {
        var i = value.apply(this, arguments);
        if (i !== i0) t0 = (i0 = i) && attrInterpolateNS(fullname, i);
        return t0;
      }
      tween._value = value;
      return tween;
    }
    
    function attrTween(name, value) {
      var t0, i0;
      function tween() {
        var i = value.apply(this, arguments);
        if (i !== i0) t0 = (i0 = i) && attrInterpolate(name, i);
        return t0;
      }
      tween._value = value;
      return tween;
    }
    
    function transition_attrTween(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;
      };
    }
    
    function transition_delay(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;
      };
    }
    
    function transition_duration(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;
      };
    }
    
    function transition_ease(value) {
      var id = this._id;
    
      return arguments.length
          ? this.each(easeConstant(id, value))
          : get$1(this.node(), id).ease;
    }
    
    function transition_filter(match) {
      if (typeof match !== "function") match = matcher(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);
    }
    
    function transition_merge(transition$$1) {
      if (transition$$1._id !== this._id) throw new Error;
    
      for (var groups0 = this._groups, groups1 = transition$$1._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$$1 = sit(this, id),
            on = schedule$$1.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$$1.on = on1;
      };
    }
    
    function transition_on(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);
      };
    }
    
    function transition_remove() {
      return this.on("end.remove", removeFunction(this._id));
    }
    
    function transition_select(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);
    }
    
    function transition_selectAll(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;
    
    function transition_selection() {
      return new Selection$1(this._groups, this._parents);
    }
    
    function styleNull(name, interpolate$$1) {
      var string00,
          string10,
          interpolate0;
      return function() {
        var string0 = styleValue(this, name),
            string1 = (this.style.removeProperty(name), styleValue(this, name));
        return string0 === string1 ? null
            : string0 === string00 && string1 === string10 ? interpolate0
            : interpolate0 = interpolate$$1(string00 = string0, string10 = string1);
      };
    }
    
    function styleRemove$1(name) {
      return function() {
        this.style.removeProperty(name);
      };
    }
    
    function styleConstant$1(name, interpolate$$1, value1) {
      var string00,
          string1 = value1 + "",
          interpolate0;
      return function() {
        var string0 = styleValue(this, name);
        return string0 === string1 ? null
            : string0 === string00 ? interpolate0
            : interpolate0 = interpolate$$1(string00 = string0, value1);
      };
    }
    
    function styleFunction$1(name, interpolate$$1, value) {
      var string00,
          string10,
          interpolate0;
      return function() {
        var string0 = styleValue(this, name),
            value1 = value(this),
            string1 = value1 + "";
        if (value1 == null) string1 = value1 = (this.style.removeProperty(name), styleValue(this, name));
        return string0 === string1 ? null
            : string0 === string00 && string1 === string10 ? interpolate0
            : (string10 = string1, interpolate0 = interpolate$$1(string00 = string0, value1));
      };
    }
    
    function styleMaybeRemove(id, name) {
      var on0, on1, listener0, key = "style." + name, event = "end." + key, remove;
      return function() {
        var schedule$$1 = set$1(this, id),
            on = schedule$$1.on,
            listener = schedule$$1.value[key] == null ? remove || (remove = styleRemove$1(name)) : undefined;
    
        // 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 || listener0 !== listener) (on1 = (on0 = on).copy()).on(event, listener0 = listener);
    
        schedule$$1.on = on1;
      };
    }
    
    function transition_style(name, value, priority) {
      var i = (name += "") === "transform" ? interpolateTransformCss : interpolate;
      return value == null ? this
          .styleTween(name, styleNull(name, i))
          .on("end.style." + name, styleRemove$1(name))
        : typeof value === "function" ? this
          .styleTween(name, styleFunction$1(name, i, tweenValue(this, "style." + name, value)))
          .each(styleMaybeRemove(this._id, name))
        : this
          .styleTween(name, styleConstant$1(name, i, value), priority)
          .on("end.style." + name, null);
    }
    
    function styleInterpolate(name, i, priority) {
      return function(t) {
        this.style.setProperty(name, i(t), priority);
      };
    }
    
    function styleTween(name, value, priority) {
      var t, i0;
      function tween() {
        var i = value.apply(this, arguments);
        if (i !== i0) t = (i0 = i) && styleInterpolate(name, i, priority);
        return t;
      }
      tween._value = value;
      return tween;
    }
    
    function transition_styleTween(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;
      };
    }
    
    function transition_text(value) {
      return this.tween("text", typeof value === "function"
          ? textFunction$1(tweenValue(this, "text", value))
          : textConstant$1(value == null ? "" : value + ""));
    }
    
    function transition_transition() {
      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);
    }
    
    function transition_end() {
      var on0, on1, that = this, id = that._id, size = that.size();
      return new Promise(function(resolve, reject) {
        var cancel = {value: reject},
            end = {value: function() { if (--size === 0) resolve(); }};
    
        that.each(function() {
          var schedule$$1 = set$1(this, id),
              on = schedule$$1.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();
            on1._.cancel.push(cancel);
            on1._.interrupt.push(cancel);
            on1._.end.push(end);
          }
    
          schedule$$1.on = on1;
        });
      });
    }
    
    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,
      end: transition_end
    };
    
    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,
        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,
        b2 = 6 / 11,
        b3 = 8 / 11,
        b4 = 3 / 4,
        b5 = 9 / 11,
        b6 = 10 / 11,
        b7 = 15 / 16,
        b8 = 21 / 22,
        b9 = 63 / 64,
        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,
        amplitude = 1,
        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;
    }
    
    function selection_transition(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];
    
    function active(node, name) {
      var schedules = node.__transition,
          schedule$$1,
          i;
    
      if (schedules) {
        name = name == null ? null : name + "";
        for (i in schedules) {
          if ((schedule$$1 = schedules[i]).state > SCHEDULED && schedule$$1.name === name) {
            return new Transition([[node]], root$1, name, +i);
          }
        }
      }
    
      return null;
    }
    
    function constant$4(x) {
      return function() {
        return x;
      };
    }
    
    function BrushEvent(target, type, selection) {
      this.target = target;
      this.type = type;
      this.selection = selection;
    }
    
    function nopropagation$1() {
      exports.event.stopImmediatePropagation();
    }
    
    function noevent$1() {
      exports.event.preventDefault();
      exports.event.stopImmediatePropagation();
    }
    
    var MODE_DRAG = {name: "drag"},
        MODE_SPACE = {name: "space"},
        MODE_HANDLE = {name: "handle"},
        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$1() {
      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$1(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);
    }
    
    function brush() {
      return brush$1(XY);
    }
    
    function brush$1(dim) {
      var extent = defaultExtent,
          filter = defaultFilter$1,
          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$1(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$1(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$$1 = state.selection,
            W = extent[0][0], w0, w1,
            N = extent[0][1], n0, n1,
            E = extent[1][0], e0, e1,
            S = extent[1][1], s0, s1,
            dx,
            dy,
            moving,
            shifting = signX && signY && exports.event.shiftKey,
            lockX,
            lockY,
            point0 = mouse(that),
            point$$1 = 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$$1[0]) > Math.abs(point1[1] - point$$1[1])) lockY = true;
            else lockX = true;
          }
          point$$1 = point1;
          moving = true;
          noevent$1();
          move();
        }
    
        function move() {
          var t;
    
          dx = point$$1[0] - point0[0];
          dy = point$$1[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$$1 = state.selection; // May be set by brush.move (on start)!
          if (empty$1(selection$$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
        );
      };
    }
    
    function chord() {
      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;
    
    function constant$5(x) {
      return function() {
        return x;
      };
    }
    
    var pi$2 = Math.PI,
        tau$2 = 2 * pi$2,
        epsilon$1 = 1e-6,
        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;
    }
    
    function ribbon() {
      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;
    }
    
    function nest() {
      var keys = [],
          sortKeys = [],
          sortValues,
          rollup,
          nest;
    
      function apply(array, depth, createResult, setResult) {
        if (depth >= keys.length) {
          if (sortValues != null) array.sort(sortValues);
          return rollup != null ? rollup(array) : 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;
    }
    
    function keys(map) {
      var keys = [];
      for (var key in map) keys.push(key);
      return keys;
    }
    
    function values(map) {
      var values = [];
      for (var key in map) values.push(map[key]);
      return values;
    }
    
    function entries(map) {
      var entries = [];
      for (var key in map) entries.push({key: key, value: map[key]});
      return entries;
    }
    
    var array$2 = Array.prototype;
    
    var slice$3 = array$2.slice;
    
    function ascending$2(a, b) {
      return a - b;
    }
    
    function area(ring) {
      var i = 0, n = ring.length, area = ring[n - 1][1] * ring[0][0] - ring[n - 1][0] * ring[0][1];
      while (++i < n) area += ring[i - 1][1] * ring[i][0] - ring[i - 1][0] * ring[i][1];
      return area;
    }
    
    function constant$6(x) {
      return function() {
        return x;
      };
    }
    
    function contains(ring, hole) {
      var i = -1, n = hole.length, c;
      while (++i < n) if (c = ringContains(ring, hole[i])) return c;
      return 0;
    }
    
    function ringContains(ring, point) {
      var x = point[0], y = point[1], contains = -1;
      for (var i = 0, n = ring.length, j = n - 1; i < n; j = i++) {
        var pi = ring[i], xi = pi[0], yi = pi[1], pj = ring[j], xj = pj[0], yj = pj[1];
        if (segmentContains(pi, pj, point)) return 0;
        if (((yi > y) !== (yj > y)) && ((x < (xj - xi) * (y - yi) / (yj - yi) + xi))) contains = -contains;
      }
      return contains;
    }
    
    function segmentContains(a, b, c) {
      var i; return collinear(a, b, c) && within(a[i = +(a[0] === b[0])], c[i], b[i]);
    }
    
    function collinear(a, b, c) {
      return (b[0] - a[0]) * (c[1] - a[1]) === (c[0] - a[0]) * (b[1] - a[1]);
    }
    
    function within(p, q, r) {
      return p <= q && q <= r || r <= q && q <= p;
    }
    
    function noop$1() {}
    
    var cases = [
      [],
      [[[1.0, 1.5], [0.5, 1.0]]],
      [[[1.5, 1.0], [1.0, 1.5]]],
      [[[1.5, 1.0], [0.5, 1.0]]],
      [[[1.0, 0.5], [1.5, 1.0]]],
      [[[1.0, 1.5], [0.5, 1.0]], [[1.0, 0.5], [1.5, 1.0]]],
      [[[1.0, 0.5], [1.0, 1.5]]],
      [[[1.0, 0.5], [0.5, 1.0]]],
      [[[0.5, 1.0], [1.0, 0.5]]],
      [[[1.0, 1.5], [1.0, 0.5]]],
      [[[0.5, 1.0], [1.0, 0.5]], [[1.5, 1.0], [1.0, 1.5]]],
      [[[1.5, 1.0], [1.0, 0.5]]],
      [[[0.5, 1.0], [1.5, 1.0]]],
      [[[1.0, 1.5], [1.5, 1.0]]],
      [[[0.5, 1.0], [1.0, 1.5]]],
      []
    ];
    
    function contours() {
      var dx = 1,
          dy = 1,
          threshold$$1 = thresholdSturges,
          smooth = smoothLinear;
    
      function contours(values) {
        var tz = threshold$$1(values);
    
        // Convert number of thresholds into uniform thresholds.
        if (!Array.isArray(tz)) {
          var domain = extent(values), start = domain[0], stop = domain[1];
          tz = tickStep(start, stop, tz);
          tz = sequence(Math.floor(start / tz) * tz, Math.floor(stop / tz) * tz, tz);
        } else {
          tz = tz.slice().sort(ascending$2);
        }
    
        return tz.map(function(value) {
          return contour(values, value);
        });
      }
    
      // Accumulate, smooth contour rings, assign holes to exterior rings.
      // Based on https://github.com/mbostock/shapefile/blob/v0.6.2/shp/polygon.js
      function contour(values, value) {
        var polygons = [],
            holes = [];
    
        isorings(values, value, function(ring) {
          smooth(ring, values, value);
          if (area(ring) > 0) polygons.push([ring]);
          else holes.push(ring);
        });
    
        holes.forEach(function(hole) {
          for (var i = 0, n = polygons.length, polygon; i < n; ++i) {
            if (contains((polygon = polygons[i])[0], hole) !== -1) {
              polygon.push(hole);
              return;
            }
          }
        });
    
        return {
          type: "MultiPolygon",
          value: value,
          coordinates: polygons
        };
      }
    
      // Marching squares with isolines stitched into rings.
      // Based on https://github.com/topojson/topojson-client/blob/v3.0.0/src/stitch.js
      function isorings(values, value, callback) {
        var fragmentByStart = new Array,
            fragmentByEnd = new Array,
            x, y, t0, t1, t2, t3;
    
        // Special case for the first row (y = -1, t2 = t3 = 0).
        x = y = -1;
        t1 = values[0] >= value;
        cases[t1 << 1].forEach(stitch);
        while (++x < dx - 1) {
          t0 = t1, t1 = values[x + 1] >= value;
          cases[t0 | t1 << 1].forEach(stitch);
        }
        cases[t1 << 0].forEach(stitch);
    
        // General case for the intermediate rows.
        while (++y < dy - 1) {
          x = -1;
          t1 = values[y * dx + dx] >= value;
          t2 = values[y * dx] >= value;
          cases[t1 << 1 | t2 << 2].forEach(stitch);
          while (++x < dx - 1) {
            t0 = t1, t1 = values[y * dx + dx + x + 1] >= value;
            t3 = t2, t2 = values[y * dx + x + 1] >= value;
            cases[t0 | t1 << 1 | t2 << 2 | t3 << 3].forEach(stitch);
          }
          cases[t1 | t2 << 3].forEach(stitch);
        }
    
        // Special case for the last row (y = dy - 1, t0 = t1 = 0).
        x = -1;
        t2 = values[y * dx] >= value;
        cases[t2 << 2].forEach(stitch);
        while (++x < dx - 1) {
          t3 = t2, t2 = values[y * dx + x + 1] >= value;
          cases[t2 << 2 | t3 << 3].forEach(stitch);
        }
        cases[t2 << 3].forEach(stitch);
    
        function stitch(line) {
          var start = [line[0][0] + x, line[0][1] + y],
              end = [line[1][0] + x, line[1][1] + y],
              startIndex = index(start),
              endIndex = index(end),
              f, g;
          if (f = fragmentByEnd[startIndex]) {
            if (g = fragmentByStart[endIndex]) {
              delete fragmentByEnd[f.end];
              delete fragmentByStart[g.start];
              if (f === g) {
                f.ring.push(end);
                callback(f.ring);
              } else {
                fragmentByStart[f.start] = fragmentByEnd[g.end] = {start: f.start, end: g.end, ring: f.ring.concat(g.ring)};
              }
            } else {
              delete fragmentByEnd[f.end];
              f.ring.push(end);
              fragmentByEnd[f.end = endIndex] = f;
            }
          } else if (f = fragmentByStart[endIndex]) {
            if (g = fragmentByEnd[startIndex]) {
              delete fragmentByStart[f.start];
              delete fragmentByEnd[g.end];
              if (f === g) {
                f.ring.push(end);
                callback(f.ring);
              } else {
                fragmentByStart[g.start] = fragmentByEnd[f.end] = {start: g.start, end: f.end, ring: g.ring.concat(f.ring)};
              }
            } else {
              delete fragmentByStart[f.start];
              f.ring.unshift(start);
              fragmentByStart[f.start = startIndex] = f;
            }
          } else {
            fragmentByStart[startIndex] = fragmentByEnd[endIndex] = {start: startIndex, end: endIndex, ring: [start, end]};
          }
        }
      }
    
      function index(point) {
        return point[0] * 2 + point[1] * (dx + 1) * 4;
      }
    
      function smoothLinear(ring, values, value) {
        ring.forEach(function(point) {
          var x = point[0],
              y = point[1],
              xt = x | 0,
              yt = y | 0,
              v0,
              v1 = values[yt * dx + xt];
          if (x > 0 && x < dx && xt === x) {
            v0 = values[yt * dx + xt - 1];
            point[0] = x + (value - v0) / (v1 - v0) - 0.5;
          }
          if (y > 0 && y < dy && yt === y) {
            v0 = values[(yt - 1) * dx + xt];
            point[1] = y + (value - v0) / (v1 - v0) - 0.5;
          }
        });
      }
    
      contours.contour = contour;
    
      contours.size = function(_) {
        if (!arguments.length) return [dx, dy];
        var _0 = Math.ceil(_[0]), _1 = Math.ceil(_[1]);
        if (!(_0 > 0) || !(_1 > 0)) throw new Error("invalid size");
        return dx = _0, dy = _1, contours;
      };
    
      contours.thresholds = function(_) {
        return arguments.length ? (threshold$$1 = typeof _ === "function" ? _ : Array.isArray(_) ? constant$6(slice$3.call(_)) : constant$6(_), contours) : threshold$$1;
      };
    
      contours.smooth = function(_) {
        return arguments.length ? (smooth = _ ? smoothLinear : noop$1, contours) : smooth === smoothLinear;
      };
    
      return contours;
    }
    
    // TODO Optimize edge cases.
    // TODO Optimize index calculation.
    // TODO Optimize arguments.
    function blurX(source, target, r) {
      var n = source.width,
          m = source.height,
          w = (r << 1) + 1;
      for (var j = 0; j < m; ++j) {
        for (var i = 0, sr = 0; i < n + r; ++i) {
          if (i < n) {
            sr += source.data[i + j * n];
          }
          if (i >= r) {
            if (i >= w) {
              sr -= source.data[i - w + j * n];
            }
            target.data[i - r + j * n] = sr / Math.min(i + 1, n - 1 + w - i, w);
          }
        }
      }
    }
    
    // TODO Optimize edge cases.
    // TODO Optimize index calculation.
    // TODO Optimize arguments.
    function blurY(source, target, r) {
      var n = source.width,
          m = source.height,
          w = (r << 1) + 1;
      for (var i = 0; i < n; ++i) {
        for (var j = 0, sr = 0; j < m + r; ++j) {
          if (j < m) {
            sr += source.data[i + j * n];
          }
          if (j >= r) {
            if (j >= w) {
              sr -= source.data[i + (j - w) * n];
            }
            target.data[i + (j - r) * n] = sr / Math.min(j + 1, m - 1 + w - j, w);
          }
        }
      }
    }
    
    function defaultX(d) {
      return d[0];
    }
    
    function defaultY(d) {
      return d[1];
    }
    
    function defaultWeight() {
      return 1;
    }
    
    function density() {
      var x = defaultX,
          y = defaultY,
          weight = defaultWeight,
          dx = 960,
          dy = 500,
          r = 20, // blur radius
          k = 2, // log2(grid cell size)
          o = r * 3, // grid offset, to pad for blur
          n = (dx + o * 2) >> k, // grid width
          m = (dy + o * 2) >> k, // grid height
          threshold$$1 = constant$6(20);
    
      function density(data) {
        var values0 = new Float32Array(n * m),
            values1 = new Float32Array(n * m);
    
        data.forEach(function(d, i, data) {
          var xi = (+x(d, i, data) + o) >> k,
              yi = (+y(d, i, data) + o) >> k,
              wi = +weight(d, i, data);
          if (xi >= 0 && xi < n && yi >= 0 && yi < m) {
            values0[xi + yi * n] += wi;
          }
        });
    
        // TODO Optimize.
        blurX({width: n, height: m, data: values0}, {width: n, height: m, data: values1}, r >> k);
        blurY({width: n, height: m, data: values1}, {width: n, height: m, data: values0}, r >> k);
        blurX({width: n, height: m, data: values0}, {width: n, height: m, data: values1}, r >> k);
        blurY({width: n, height: m, data: values1}, {width: n, height: m, data: values0}, r >> k);
        blurX({width: n, height: m, data: values0}, {width: n, height: m, data: values1}, r >> k);
        blurY({width: n, height: m, data: values1}, {width: n, height: m, data: values0}, r >> k);
    
        var tz = threshold$$1(values0);
    
        // Convert number of thresholds into uniform thresholds.
        if (!Array.isArray(tz)) {
          var stop = max(values0);
          tz = tickStep(0, stop, tz);
          tz = sequence(0, Math.floor(stop / tz) * tz, tz);
          tz.shift();
        }
    
        return contours()
            .thresholds(tz)
            .size([n, m])
          (values0)
            .map(transform);
      }
    
      function transform(geometry) {
        geometry.value *= Math.pow(2, -2 * k); // Density in points per square pixel.
        geometry.coordinates.forEach(transformPolygon);
        return geometry;
      }
    
      function transformPolygon(coordinates) {
        coordinates.forEach(transformRing);
      }
    
      function transformRing(coordinates) {
        coordinates.forEach(transformPoint);
      }
    
      // TODO Optimize.
      function transformPoint(coordinates) {
        coordinates[0] = coordinates[0] * Math.pow(2, k) - o;
        coordinates[1] = coordinates[1] * Math.pow(2, k) - o;
      }
    
      function resize() {
        o = r * 3;
        n = (dx + o * 2) >> k;
        m = (dy + o * 2) >> k;
        return density;
      }
    
      density.x = function(_) {
        return arguments.length ? (x = typeof _ === "function" ? _ : constant$6(+_), density) : x;
      };
    
      density.y = function(_) {
        return arguments.length ? (y = typeof _ === "function" ? _ : constant$6(+_), density) : y;
      };
    
      density.weight = function(_) {
        return arguments.length ? (weight = typeof _ === "function" ? _ : constant$6(+_), density) : weight;
      };
    
      density.size = function(_) {
        if (!arguments.length) return [dx, dy];
        var _0 = Math.ceil(_[0]), _1 = Math.ceil(_[1]);
        if (!(_0 >= 0) && !(_0 >= 0)) throw new Error("invalid size");
        return dx = _0, dy = _1, resize();
      };
    
      density.cellSize = function(_) {
        if (!arguments.length) return 1 << k;
        if (!((_ = +_) >= 1)) throw new Error("invalid cell size");
        return k = Math.floor(Math.log(_) / Math.LN2), resize();
      };
    
      density.thresholds = function(_) {
        return arguments.length ? (threshold$$1 = typeof _ === "function" ? _ : Array.isArray(_) ? constant$6(slice$3.call(_)) : constant$6(_), density) : threshold$$1;
      };
    
      density.bandwidth = function(_) {
        if (!arguments.length) return Math.sqrt(r * (r + 1));
        if (!((_ = +_) >= 0)) throw new Error("invalid bandwidth");
        return r = Math.round((Math.sqrt(4 * _ * _ + 1) - 1) / 2), resize();
      };
    
      return density;
    }
    
    var EOL = {},
        EOF = {},
        QUOTE = 34,
        NEWLINE = 10,
        RETURN = 13;
    
    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;
    }
    
    function pad(value, width) {
      var s = value + "", length = s.length;
      return length < width ? new Array(width - length + 1).join(0) + s : s;
    }
    
    function formatYear(year) {
      return year < 0 ? "-" + pad(-year, 6)
        : year > 9999 ? "+" + pad(year, 6)
        : pad(year, 4);
    }
    
    function formatDate(date) {
      var hours = date.getUTCHours(),
          minutes = date.getUTCMinutes(),
          seconds = date.getUTCSeconds(),
          milliseconds = date.getUTCMilliseconds();
      return isNaN(date) ? "Invalid Date"
          : formatYear(date.getUTCFullYear(), 4) + "-" + pad(date.getUTCMonth() + 1, 2) + "-" + pad(date.getUTCDate(), 2)
          + (milliseconds ? "T" + pad(hours, 2) + ":" + pad(minutes, 2) + ":" + pad(seconds, 2) + "." + pad(milliseconds, 3) + "Z"
          : seconds ? "T" + pad(hours, 2) + ":" + pad(minutes, 2) + ":" + pad(seconds, 2) + "Z"
          : minutes || hours ? "T" + pad(hours, 2) + ":" + pad(minutes, 2) + "Z"
          : "");
    }
    
    function dsvFormat(delimiter) {
      var reFormat = new RegExp("[\"" + delimiter + "\n\r]"),
          DELIMITER = 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 rows = [], // output rows
            N = text.length,
            I = 0, // current character index
            n = 0, // current line number
            t, // current token
            eof = N <= 0, // current token followed by EOF?
            eol = false; // current token followed by EOL?
    
        // Strip the trailing newline.
        if (text.charCodeAt(N - 1) === NEWLINE) --N;
        if (text.charCodeAt(N - 1) === RETURN) --N;
    
        function token() {
          if (eof) return EOF;
          if (eol) return eol = false, EOL;
    
          // Unescape quotes.
          var i, j = I, c;
          if (text.charCodeAt(j) === QUOTE) {
            while (I++ < N && text.charCodeAt(I) !== QUOTE || text.charCodeAt(++I) === QUOTE);
            if ((i = I) >= N) eof = true;
            else if ((c = text.charCodeAt(I++)) === NEWLINE) eol = true;
            else if (c === RETURN) { eol = true; if (text.charCodeAt(I) === NEWLINE) ++I; }
            return text.slice(j + 1, i - 1).replace(/""/g, "\"");
          }
    
          // Find next delimiter or newline.
          while (I < N) {
            if ((c = text.charCodeAt(i = I++)) === NEWLINE) eol = true;
            else if (c === RETURN) { eol = true; if (text.charCodeAt(I) === NEWLINE) ++I; }
            else if (c !== DELIMITER) continue;
            return text.slice(j, i);
          }
    
          // Return last token before EOF.
          return eof = true, text.slice(j, N);
        }
    
        while ((t = token()) !== EOF) {
          var row = [];
          while (t !== EOL && t !== EOF) row.push(t), t = token();
          if (f && (row = f(row, n++)) == null) continue;
          rows.push(row);
        }
    
        return rows;
      }
    
      function preformatBody(rows, columns) {
        return rows.map(function(row) {
          return columns.map(function(column) {
            return formatValue(row[column]);
          }).join(delimiter);
        });
      }
    
      function format(rows, columns) {
        if (columns == null) columns = inferColumns(rows);
        return [columns.map(formatValue).join(delimiter)].concat(preformatBody(rows, columns)).join("\n");
      }
    
      function formatBody(rows, columns) {
        if (columns == null) columns = inferColumns(rows);
        return preformatBody(rows, columns).join("\n");
      }
    
      function formatRows(rows) {
        return rows.map(formatRow).join("\n");
      }
    
      function formatRow(row) {
        return row.map(formatValue).join(delimiter);
      }
    
      function formatValue(value) {
        return value == null ? ""
            : value instanceof Date ? formatDate(value)
            : reFormat.test(value += "") ? "\"" + value.replace(/"/g, "\"\"") + "\""
            : value;
      }
    
      return {
        parse: parse,
        parseRows: parseRows,
        format: format,
        formatBody: formatBody,
        formatRows: formatRows
      };
    }
    
    var csv = dsvFormat(",");
    
    var csvParse = csv.parse;
    var csvParseRows = csv.parseRows;
    var csvFormat = csv.format;
    var csvFormatBody = csv.formatBody;
    var csvFormatRows = csv.formatRows;
    
    var tsv = dsvFormat("\t");
    
    var tsvParse = tsv.parse;
    var tsvParseRows = tsv.parseRows;
    var tsvFormat = tsv.format;
    var tsvFormatBody = tsv.formatBody;
    var tsvFormatRows = tsv.formatRows;
    
    function autoType(object) {
      for (var key in object) {
        var value = object[key].trim(), number;
        if (!value) value = null;
        else if (value === "true") value = true;
        else if (value === "false") value = false;
        else if (value === "NaN") value = NaN;
        else if (!isNaN(number = +value)) value = number;
        else if (/^([-+]\d{2})?\d{4}(-\d{2}(-\d{2})?)?(T\d{2}:\d{2}(:\d{2}(\.\d{3})?)?(Z|[-+]\d{2}:\d{2})?)?$/.test(value)) value = new Date(value);
        else continue;
        object[key] = value;
      }
      return object;
    }
    
    function responseBlob(response) {
      if (!response.ok) throw new Error(response.status + " " + response.statusText);
      return response.blob();
    }
    
    function blob(input, init) {
      return fetch(input, init).then(responseBlob);
    }
    
    function responseArrayBuffer(response) {
      if (!response.ok) throw new Error(response.status + " " + response.statusText);
      return response.arrayBuffer();
    }
    
    function buffer(input, init) {
      return fetch(input, init).then(responseArrayBuffer);
    }
    
    function responseText(response) {
      if (!response.ok) throw new Error(response.status + " " + response.statusText);
      return response.text();
    }
    
    function text(input, init) {
      return fetch(input, init).then(responseText);
    }
    
    function dsvParse(parse) {
      return function(input, init, row) {
        if (arguments.length === 2 && typeof init === "function") row = init, init = undefined;
        return text(input, init).then(function(response) {
          return parse(response, row);
        });
      };
    }
    
    function dsv(delimiter, input, init, row) {
      if (arguments.length === 3 && typeof init === "function") row = init, init = undefined;
      var format = dsvFormat(delimiter);
      return text(input, init).then(function(response) {
        return format.parse(response, row);
      });
    }
    
    var csv$1 = dsvParse(csvParse);
    var tsv$1 = dsvParse(tsvParse);
    
    function image(input, init) {
      return new Promise(function(resolve, reject) {
        var image = new Image;
        for (var key in init) image[key] = init[key];
        image.onerror = reject;
        image.onload = function() { resolve(image); };
        image.src = input;
      });
    }
    
    function responseJson(response) {
      if (!response.ok) throw new Error(response.status + " " + response.statusText);
      return response.json();
    }
    
    function json(input, init) {
      return fetch(input, init).then(responseJson);
    }
    
    function parser(type) {
      return function(input, init)  {
        return text(input, init).then(function(text$$1) {
          return (new DOMParser).parseFromString(text$$1, type);
        });
      };
    }
    
    var xml = parser("application/xml");
    
    var html = parser("text/html");
    
    var svg = parser("image/svg+xml");
    
    function center$1(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;
    }
    
    function constant$7(x) {
      return function() {
        return x;
      };
    }
    
    function jiggle() {
      return (Math.random() - 0.5) * 1e-6;
    }
    
    function tree_add(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, abort.
      if (x0 > x1 || y0 > y1) return this;
    
      // 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;
    }
    
    function tree_cover(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 {
        var z = x1 - x0,
            node = this._root,
            parent,
            i;
    
        while (x0 > x || x >= x1 || y0 > y || y >= y1) {
          i = (y < y0) << 1 | (x < x0);
          parent = new Array(4), parent[i] = node, node = parent, z *= 2;
          switch (i) {
            case 0: x1 = x0 + z, y1 = y0 + z; break;
            case 1: x0 = x1 - z, y1 = y0 + z; break;
            case 2: x1 = x0 + z, y0 = y1 - z; break;
            case 3: x0 = x1 - z, y0 = y1 - z; break;
          }
        }
    
        if (this._root && this._root.length) this._root = node;
      }
    
      this._x0 = x0;
      this._y0 = y0;
      this._x1 = x1;
      this._y1 = y1;
      return this;
    }
    
    function tree_data() {
      var data = [];
      this.visit(function(node) {
        if (!node.length) do data.push(node.data); while (node = node.next)
      });
      return data;
    }
    
    function tree_extent(_) {
      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]];
    }
    
    function Quad(node, x0, y0, x1, y1) {
      this.node = node;
      this.x0 = x0;
      this.y0 = y0;
      this.x1 = x1;
      this.y1 = y1;
    }
    
    function tree_find(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;
    }
    
    function tree_remove(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;
    }
    
    function tree_root() {
      return this._root;
    }
    
    function tree_size() {
      var size = 0;
      this.visit(function(node) {
        if (!node.length) do ++size; while (node = node.next)
      });
      return size;
    }
    
    function tree_visit(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;
    }
    
    function tree_visitAfter(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$1(d) {
      return d[0];
    }
    
    function tree_x(_) {
      return arguments.length ? (this._x = _, this) : this._x;
    }
    
    function defaultY$1(d) {
      return d[1];
    }
    
    function tree_y(_) {
      return arguments.length ? (this._y = _, this) : this._y;
    }
    
    function quadtree(nodes, x, y) {
      var tree = new Quadtree(x == null ? defaultX$1 : x, y == null ? defaultY$1 : 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;
    }
    
    function collide(radius) {
      var nodes,
          radii,
          strength = 1,
          iterations = 1;
    
      if (typeof radius !== "function") radius = constant$7(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$7(+_), 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;
    }
    
    function link(links) {
      var id = index,
          strength = defaultStrength,
          strengths,
          distance = constant$7(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$7(+_), initializeStrength(), force) : strength;
      };
    
      force.distance = function(_) {
        return arguments.length ? (distance = typeof _ === "function" ? _ : constant$7(+_), initializeDistance(), force) : distance;
      };
    
      return force;
    }
    
    function x$1(d) {
      return d.x;
    }
    
    function y$1(d) {
      return d.y;
    }
    
    var initialRadius = 10,
        initialAngle = Math.PI * (3 - Math.sqrt(5));
    
    function simulation(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(iterations) {
        var i, n = nodes.length, node;
    
        if (iterations === undefined) iterations = 1;
    
        for (var k = 0; k < iterations; ++k) {
          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;
          }
        }
    
        return simulation;
      }
    
      function initializeNodes() {
        for (var i = 0, n = nodes.length, node; i < n; ++i) {
          node = nodes[i], node.index = i;
          if (node.fx != null) node.x = node.fx;
          if (node.fy != null) node.y = node.fy;
          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);
        }
      };
    }
    
    function manyBody() {
      var nodes,
          node,
          alpha,
          strength = constant$7(-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, weight = 0, x, y, i;
    
        // For internal nodes, accumulate forces from child quadrants.
        if (quad.length) {
          for (x = y = i = 0; i < 4; ++i) {
            if ((q = quad[i]) && (c = Math.abs(q.value))) {
              strength += q.value, weight += c, x += c * q.x, y += c * q.y;
            }
          }
          quad.x = x / weight;
          quad.y = y / weight;
        }
    
        // 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 = quad.x - node.x,
            y = quad.y - node.y,
            w = x2 - x1,
            l = x * x + y * y;
    
        // 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 === 0) x = jiggle(), l += x * x;
            if (y === 0) y = jiggle(), l += y * y;
            if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
            node.vx += x * quad.value * alpha / l;
            node.vy += y * 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 === 0) x = jiggle(), l += x * x;
          if (y === 0) y = jiggle(), l += y * y;
          if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
        }
    
        do if (quad.data !== node) {
          w = strengths[quad.data.index] * alpha / l;
          node.vx += x * w;
          node.vy += y * w;
        } while (quad = quad.next);
      }
    
      force.initialize = function(_) {
        nodes = _;
        initialize();
      };
    
      force.strength = function(_) {
        return arguments.length ? (strength = typeof _ === "function" ? _ : constant$7(+_), 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;
    }
    
    function radial(radius, x, y) {
      var nodes,
          strength = constant$7(0.1),
          strengths,
          radiuses;
    
      if (typeof radius !== "function") radius = constant$7(+radius);
      if (x == null) x = 0;
      if (y == null) y = 0;
    
      function force(alpha) {
        for (var i = 0, n = nodes.length; i < n; ++i) {
          var node = nodes[i],
              dx = node.x - x || 1e-6,
              dy = node.y - y || 1e-6,
              r = Math.sqrt(dx * dx + dy * dy),
              k = (radiuses[i] - r) * strengths[i] * alpha / r;
          node.vx += dx * k;
          node.vy += dy * k;
        }
      }
    
      function initialize() {
        if (!nodes) return;
        var i, n = nodes.length;
        strengths = new Array(n);
        radiuses = new Array(n);
        for (i = 0; i < n; ++i) {
          radiuses[i] = +radius(nodes[i], i, nodes);
          strengths[i] = isNaN(radiuses[i]) ? 0 : +strength(nodes[i], i, nodes);
        }
      }
    
      force.initialize = function(_) {
        nodes = _, initialize();
      };
    
      force.strength = function(_) {
        return arguments.length ? (strength = typeof _ === "function" ? _ : constant$7(+_), initialize(), force) : strength;
      };
    
      force.radius = function(_) {
        return arguments.length ? (radius = typeof _ === "function" ? _ : constant$7(+_), initialize(), force) : radius;
      };
    
      force.x = function(_) {
        return arguments.length ? (x = +_, force) : x;
      };
    
      force.y = function(_) {
        return arguments.length ? (y = +_, force) : y;
      };
    
      return force;
    }
    
    function x$2(x) {
      var strength = constant$7(0.1),
          nodes,
          strengths,
          xz;
    
      if (typeof x !== "function") x = constant$7(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$7(+_), initialize(), force) : strength;
      };
    
      force.x = function(_) {
        return arguments.length ? (x = typeof _ === "function" ? _ : constant$7(+_), initialize(), force) : x;
      };
    
      return force;
    }
    
    function y$2(y) {
      var strength = constant$7(0.1),
          nodes,
          strengths,
          yz;
    
      if (typeof y !== "function") y = constant$7(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$7(+_), initialize(), force) : strength;
      };
    
      force.y = function(_) {
        return arguments.length ? (y = typeof _ === "function" ? _ : constant$7(+_), 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].
    function formatDecimal(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)
      ];
    }
    
    function exponent$1(x) {
      return x = formatDecimal(Math.abs(x)), x ? x[1] : NaN;
    }
    
    function formatGroup(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);
      };
    }
    
    function formatNumerals(numerals) {
      return function(value) {
        return value.replace(/[0-9]/g, function(i) {
          return numerals[+i];
        });
      };
    }
    
    // [[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;
      this.fill = match[1] || " ";
      this.align = match[2] || ">";
      this.sign = match[3] || "-";
      this.symbol = match[4] || "";
      this.zero = !!match[5];
      this.width = match[6] && +match[6];
      this.comma = !!match[7];
      this.precision = match[8] && +match[8].slice(1);
      this.trim = !!match[9];
      this.type = match[10] || "";
    }
    
    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.trim ? "~" : "")
          + this.type;
    };
    
    // Trims insignificant zeros, e.g., replaces 1.2000k with 1.2k.
    function formatTrim(s) {
      out: for (var n = s.length, i = 1, i0 = -1, i1; i < n; ++i) {
        switch (s[i]) {
          case ".": i0 = i1 = i; break;
          case "0": if (i0 === 0) i0 = i; i1 = i; break;
          default: if (i0 > 0) { if (!+s[i]) break out; i0 = 0; } break;
        }
      }
      return i0 > 0 ? s.slice(0, i0) + s.slice(i1 + 1) : s;
    }
    
    var prefixExponent;
    
    function formatPrefixAuto(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!
    }
    
    function formatRounded(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 = {
      "%": 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); }
    };
    
    function identity$3(x) {
      return x;
    }
    
    var prefixes = ["y","z","a","f","p","n","\xB5","m","","k","M","G","T","P","E","Z","Y"];
    
    function formatLocale(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,
            trim = specifier.trim,
            type = specifier.type;
    
        // The "n" type is an alias for ",g".
        if (type === "n") comma = true, type = "g";
    
        // The "" type, and any invalid type, is an alias for ".12~g".
        else if (!formatTypes[type]) precision == null && (precision = 12), trim = true, type = "g";
    
        // If zero fill is specified, padding goes after sign and before digits.
        if (zero || (fill === "0" && align === "=")) zero = true, fill = "0", align = "=";
    
        // 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 = /[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 ? 6
            : /[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);
    
            // Trim insignificant zeros.
            if (trim) value = formatTrim(value);
    
            // 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 = (type === "s" ? prefixes[8 + prefixExponent / 3] : "") + valueSuffix + (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;
    
    defaultLocale({
      decimal: ".",
      thousands: ",",
      grouping: [3],
      currency: ["$", ""]
    });
    
    function defaultLocale(definition) {
      locale = formatLocale(definition);
      exports.format = locale.format;
      exports.formatPrefix = locale.formatPrefix;
      return locale;
    }
    
    function precisionFixed(step) {
      return Math.max(0, -exponent$1(Math.abs(step)));
    }
    
    function precisionPrefix(step, value) {
      return Math.max(0, Math.max(-8, Math.min(8, Math.floor(exponent$1(value) / 3))) * 3 - exponent$1(Math.abs(step)));
    }
    
    function precisionRound(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/
    
    function adder() {
      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$2() {}
    
    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();
    }
    
    function geoStream(object, stream) {
      if (object && streamObjectType.hasOwnProperty(object.type)) {
        streamObjectType[object.type](object, stream);
      } else {
        streamGeometry(object, stream);
      }
    }
    
    var areaRingSum = adder();
    
    var areaSum = adder(),
        lambda00,
        phi00,
        lambda0,
        cosPhi0,
        sinPhi0;
    
    var areaStream = {
      point: noop$2,
      lineStart: noop$2,
      lineEnd: noop$2,
      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$2;
      },
      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;
    }
    
    function area$1(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, phi0, lambda1, phi1, // bounds
        lambda2, // previous lambda-coordinate
        lambda00$1, phi00$1, // first point
        p0, // previous 3D point
        deltaSum = adder(),
        ranges,
        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;
    }
    
    function bounds(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, W1,
        X0, Y0, Z0,
        X1, Y1, Z1,
        X2, Y2, Z2,
        lambda00$2, phi00$2, // first point
        x0, y0, z0; // previous point
    
    var centroidStream = {
      sphere: noop$2,
      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);
    }
    
    function centroid(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];
    }
    
    function constant$8(x) {
      return function() {
        return x;
      };
    }
    
    function compose(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 [abs(lambda) > pi$3 ? lambda + Math.round(-lambda / tau$3) * 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;
    }
    
    function rotation(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;
    }
    
    function circle() {
      var center = constant$8([0, 0]),
          radius = constant$8(90),
          precision = constant$8(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$8([+_[0], +_[1]]), circle) : center;
      };
    
      circle.radius = function(_) {
        return arguments.length ? (radius = typeof _ === "function" ? _ : constant$8(+_), circle) : radius;
      };
    
      circle.precision = function(_) {
        return arguments.length ? (precision = typeof _ === "function" ? _ : constant$8(+_), circle) : precision;
      };
    
      return circle;
    }
    
    function clipBuffer() {
      var lines = [],
          line;
      return {
        point: function(x, y) {
          line.push([x, y]);
        },
        lineStart: function() {
          lines.push(line = []);
        },
        lineEnd: noop$2,
        rejoin: function() {
          if (lines.length > 1) lines.push(lines.pop().concat(lines.shift()));
        },
        result: function() {
          var result = lines;
          lines = [];
          line = null;
          return result;
        }
      };
    }
    
    function pointEqual(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.
    function clipRejoin(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 sum$1 = adder();
    
    function polygonContains(polygon, point) {
      var lambda = point[0],
          phi = point[1],
          sinPhi = sin$1(phi),
          normal = [sin$1(lambda), -cos$1(lambda), 0],
          angle = 0,
          winding = 0;
    
      sum$1.reset();
    
      if (sinPhi === 1) phi = halfPi$2 + epsilon$2;
      else if (sinPhi === -1) phi = -halfPi$2 - epsilon$2;
    
      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);
    }
    
    function clip(pointVisible, clipLine, interpolate, start) {
      return function(sink) {
        var line = clipLine(sink),
            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, start);
            if (segments.length) {
              if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
              clipRejoin(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) {
          if (pointVisible(lambda, phi)) sink.point(lambda, phi);
        }
    
        function pointLine(lambda, phi) {
          line.point(lambda, phi);
        }
    
        function lineStart() {
          clip.point = pointLine;
          line.lineStart();
        }
    
        function lineEnd() {
          clip.point = point;
          line.lineEnd();
        }
    
        function pointRing(lambda, phi) {
          ring.push([lambda, phi]);
          ringSink.point(lambda, phi);
        }
    
        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]);
      }
    }
    
    function clipCircle(radius) {
      var cr = cos$1(radius),
          delta = 6 * radians,
          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 (!point2 || 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]);
    }
    
    function clipLine(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 clipMax = 1e9, clipMin = -clipMax;
    
    // TODO Use d3-polygon’s polygonContains here for the ring check?
    // TODO Eliminate duplicate buffering in clipBuffer and polygon.push?
    
    function clipRectangle(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) {
              clipRejoin(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;
      };
    }
    
    function extent$1() {
      var x0 = 0,
          y0 = 0,
          x1 = 960,
          y1 = 500,
          cache,
          cacheStream,
          clip;
    
      return clip = {
        stream: function(stream) {
          return cache && cacheStream === stream ? cache : cache = clipRectangle(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 lengthSum = adder(),
        lambda0$2,
        sinPhi0$1,
        cosPhi0$1;
    
    var lengthStream = {
      sphere: noop$2,
      point: noop$2,
      lineStart: lengthLineStart,
      lineEnd: noop$2,
      polygonStart: noop$2,
      polygonEnd: noop$2
    };
    
    function lengthLineStart() {
      lengthStream.point = lengthPointFirst;
      lengthStream.lineEnd = lengthLineEnd;
    }
    
    function lengthLineEnd() {
      lengthStream.point = lengthStream.lineEnd = noop$2;
    }
    
    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;
    }
    
    function length$1(object) {
      lengthSum.reset();
      geoStream(object, lengthStream);
      return +lengthSum;
    }
    
    var coordinates = [null, null],
        object$1 = {type: "LineString", coordinates: coordinates};
    
    function distance(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];
    }
    
    function contains$1(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()();
    }
    
    function interpolate$1(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;
    }
    
    function identity$4(x) {
      return x;
    }
    
    var areaSum$1 = adder(),
        areaRingSum$1 = adder(),
        x00,
        y00,
        x0$1,
        y0$1;
    
    var areaStream$1 = {
      point: noop$2,
      lineStart: noop$2,
      lineEnd: noop$2,
      polygonStart: function() {
        areaStream$1.lineStart = areaRingStart$1;
        areaStream$1.lineEnd = areaRingEnd$1;
      },
      polygonEnd: function() {
        areaStream$1.lineStart = areaStream$1.lineEnd = areaStream$1.point = noop$2;
        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,
        y0$2 = x0$2,
        x1 = -x0$2,
        y1 = x1;
    
    var boundsStream$1 = {
      point: boundsPoint$1,
      lineStart: noop$2,
      lineEnd: noop$2,
      polygonStart: noop$2,
      polygonEnd: noop$2,
      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,
        Y0$1 = 0,
        Z0$1 = 0,
        X1$1 = 0,
        Y1$1 = 0,
        Z1$1 = 0,
        X2$1 = 0,
        Y2$1 = 0,
        Z2$1 = 0,
        x00$1,
        y00$1,
        x0$3,
        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$2
    };
    
    var lengthSum$1 = adder(),
        lengthRing,
        x00$2,
        y00$2,
        x0$4,
        y0$4;
    
    var lengthStream$1 = {
      point: noop$2,
      lineStart: function() {
        lengthStream$1.point = lengthPointFirst$1;
      },
      lineEnd: function() {
        if (lengthRing) lengthPoint$1(x00$2, y00$2);
        lengthStream$1.point = noop$2;
      },
      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 = {
      _radius: 4.5,
      _circle: circle$1(4.5),
      pointRadius: function(_) {
        if ((_ = +_) !== this._radius) this._radius = _, this._circle = null;
        return 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: {
            if (this._circle == null) this._circle = circle$1(this._radius);
            this._string.push("M", x, ",", y, this._circle);
            break;
          }
        }
      },
      result: function() {
        if (this._string.length) {
          var result = this._string.join("");
          this._string = [];
          return result;
        } else {
          return null;
        }
      }
    };
    
    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";
    }
    
    function index$1(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);
    }
    
    function transform(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 fit(projection, fitBounds, object) {
      var clip = projection.clipExtent && projection.clipExtent();
      projection.scale(150).translate([0, 0]);
      if (clip != null) projection.clipExtent(null);
      geoStream(object, projection.stream(boundsStream$1));
      fitBounds(boundsStream$1.result());
      if (clip != null) projection.clipExtent(clip);
      return projection;
    }
    
    function fitExtent(projection, extent, object) {
      return fit(projection, function(b) {
        var w = extent[1][0] - extent[0][0],
            h = extent[1][1] - extent[0][1],
            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;
        projection.scale(150 * k).translate([x, y]);
      }, object);
    }
    
    function fitSize(projection, size, object) {
      return fitExtent(projection, [[0, 0], size], object);
    }
    
    function fitWidth(projection, width, object) {
      return fit(projection, function(b) {
        var w = +width,
            k = w / (b[1][0] - b[0][0]),
            x = (w - k * (b[1][0] + b[0][0])) / 2,
            y = -k * b[0][1];
        projection.scale(150 * k).translate([x, y]);
      }, object);
    }
    
    function fitHeight(projection, height, object) {
      return fit(projection, function(b) {
        var h = +height,
            k = h / (b[1][1] - b[0][1]),
            x = -k * b[0][0],
            y = (h - k * (b[1][1] + b[0][1])) / 2;
        projection.scale(150 * k).translate([x, y]);
      }, object);
    }
    
    var maxDepth = 16, // maximum depth of subdivision
        cosMinDistance = cos$1(30 * radians); // cos(minimum angular distance)
    
    function resample(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 transformRotate(rotate) {
      return transformer({
        point: function(x, y) {
          var r = rotate(x, y);
          return this.stream.point(r[0], r[1]);
        }
      });
    }
    
    function scaleTranslate(k, dx, dy) {
      function transform$$1(x, y) {
        return [dx + k * x, dy - k * y];
      }
      transform$$1.invert = function(x, y) {
        return [(x - dx) / k, (dy - y) / k];
      };
      return transform$$1;
    }
    
    function scaleTranslateRotate(k, dx, dy, alpha) {
      var cosAlpha = cos$1(alpha),
          sinAlpha = sin$1(alpha),
          a = cosAlpha * k,
          b = sinAlpha * k,
          ai = cosAlpha / k,
          bi = sinAlpha / k,
          ci = (sinAlpha * dy - cosAlpha * dx) / k,
          fi = (sinAlpha * dx + cosAlpha * dy) / k;
      function transform$$1(x, y) {
        return [a * x - b * y + dx, dy - b * x - a * y];
      }
      transform$$1.invert = function(x, y) {
        return [ai * x - bi * y + ci, fi - bi * x - ai * y];
      };
      return transform$$1;
    }
    
    function projection(project) {
      return projectionMutator(function() { return project; })();
    }
    
    function projectionMutator(projectAt) {
      var project,
          k = 150, // scale
          x = 480, y = 250, // translate
          lambda = 0, phi = 0, // center
          deltaLambda = 0, deltaPhi = 0, deltaGamma = 0, rotate, // pre-rotate
          alpha = 0, // post-rotate
          theta = null, preclip = clipAntimeridian, // pre-clip angle
          x0 = null, y0, x1, y1, postclip = identity$4, // post-clip extent
          delta2 = 0.5, // precision
          projectResample,
          projectTransform,
          projectRotateTransform,
          cache,
          cacheStream;
    
      function projection(point) {
        return projectRotateTransform(point[0] * radians, point[1] * radians);
      }
    
      function invert(point) {
        point = projectRotateTransform.invert(point[0], point[1]);
        return point && [point[0] * degrees$1, point[1] * degrees$1];
      }
    
      projection.stream = function(stream) {
        return cache && cacheStream === stream ? cache : cache = transformRadians(transformRotate(rotate)(preclip(projectResample(postclip(cacheStream = stream)))));
      };
    
      projection.preclip = function(_) {
        return arguments.length ? (preclip = _, theta = undefined, reset()) : preclip;
      };
    
      projection.postclip = function(_) {
        return arguments.length ? (postclip = _, x0 = y0 = x1 = y1 = null, reset()) : postclip;
      };
    
      projection.clipAngle = function(_) {
        return arguments.length ? (preclip = +_ ? clipCircle(theta = _ * radians) : (theta = null, clipAntimeridian), reset()) : theta * degrees$1;
      };
    
      projection.clipExtent = function(_) {
        return arguments.length ? (postclip = _ == null ? (x0 = y0 = x1 = y1 = null, identity$4) : clipRectangle(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.angle = function(_) {
        return arguments.length ? (alpha = _ % 360 * radians, recenter()) : alpha * 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);
      };
    
      projection.fitWidth = function(width, object) {
        return fitWidth(projection, width, object);
      };
    
      projection.fitHeight = function(height, object) {
        return fitHeight(projection, height, object);
      };
    
      function recenter() {
        var center = scaleTranslateRotate(k, 0, 0, alpha).apply(null, project(lambda, phi)),
            transform$$1 = (alpha ? scaleTranslateRotate : scaleTranslate)(k, x - center[0], y - center[1], alpha);
        rotate = rotateRadians(deltaLambda, deltaPhi, deltaGamma);
        projectTransform = compose(project, transform$$1);
        projectRotateTransform = compose(rotate, projectTransform);
        projectResample = resample(projectTransform, delta2);
        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;
    }
    
    function conicEqualArea() {
      return conicProjection(conicEqualAreaRaw)
          .scale(155.424)
          .center([0, 33.6442]);
    }
    
    function albers() {
      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
    function albersUsa() {
      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);
      };
    
      albersUsa.fitWidth = function(width, object) {
        return fitWidth(albersUsa, width, object);
      };
    
      albersUsa.fitHeight = function(height, object) {
        return fitHeight(albersUsa, height, 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);
    });
    
    function azimuthalEqualArea() {
      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;
    });
    
    function azimuthalEquidistant() {
      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];
    };
    
    function mercator() {
      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;
    }
    
    function conicConformal() {
      return conicProjection(conicConformalRaw)
          .scale(109.5)
          .parallels([30, 30]);
    }
    
    function equirectangularRaw(lambda, phi) {
      return [lambda, phi];
    }
    
    equirectangularRaw.invert = equirectangularRaw;
    
    function equirectangular() {
      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;
    }
    
    function conicEquidistant() {
      return conicProjection(conicEquidistantRaw)
          .scale(131.154)
          .center([0, 13.9389]);
    }
    
    var A1 = 1.340264,
        A2 = -0.081106,
        A3 = 0.000893,
        A4 = 0.003796,
        M = sqrt(3) / 2,
        iterations = 12;
    
    function equalEarthRaw(lambda, phi) {
      var l = asin(M * sin$1(phi)), l2 = l * l, l6 = l2 * l2 * l2;
      return [
        lambda * cos$1(l) / (M * (A1 + 3 * A2 * l2 + l6 * (7 * A3 + 9 * A4 * l2))),
        l * (A1 + A2 * l2 + l6 * (A3 + A4 * l2))
      ];
    }
    
    equalEarthRaw.invert = function(x, y) {
      var l = y, l2 = l * l, l6 = l2 * l2 * l2;
      for (var i = 0, delta, fy, fpy; i < iterations; ++i) {
        fy = l * (A1 + A2 * l2 + l6 * (A3 + A4 * l2)) - y;
        fpy = A1 + 3 * A2 * l2 + l6 * (7 * A3 + 9 * A4 * l2);
        l -= delta = fy / fpy, l2 = l * l, l6 = l2 * l2 * l2;
        if (abs(delta) < epsilon2$1) break;
      }
      return [
        M * x * (A1 + 3 * A2 * l2 + l6 * (7 * A3 + 9 * A4 * l2)) / cos$1(l),
        asin(sin$1(l) / M)
      ];
    };
    
    function equalEarth() {
      return projection(equalEarthRaw)
          .scale(177.158);
    }
    
    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);
    
    function gnomonic() {
      return projection(gnomonicRaw)
          .scale(144.049)
          .clipAngle(60);
    }
    
    function scaleTranslate$1(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);
        }
      });
    }
    
    function identity$5() {
      var k = 1, tx = 0, ty = 0, sx = 1, sy = 1, transform$$1 = identity$4, // scale, translate and reflect
          x0 = null, y0, x1, y1, // clip extent
          postclip = identity$4,
          cache,
          cacheStream,
          projection;
    
      function reset() {
        cache = cacheStream = null;
        return projection;
      }
    
      return projection = {
        stream: function(stream) {
          return cache && cacheStream === stream ? cache : cache = transform$$1(postclip(cacheStream = stream));
        },
        postclip: function(_) {
          return arguments.length ? (postclip = _, x0 = y0 = x1 = y1 = null, reset()) : postclip;
        },
        clipExtent: function(_) {
          return arguments.length ? (postclip = _ == null ? (x0 = y0 = x1 = y1 = null, identity$4) : clipRectangle(x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]), reset()) : x0 == null ? null : [[x0, y0], [x1, y1]];
        },
        scale: function(_) {
          return arguments.length ? (transform$$1 = scaleTranslate$1((k = +_) * sx, k * sy, tx, ty), reset()) : k;
        },
        translate: function(_) {
          return arguments.length ? (transform$$1 = scaleTranslate$1(k * sx, k * sy, tx = +_[0], ty = +_[1]), reset()) : [tx, ty];
        },
        reflectX: function(_) {
          return arguments.length ? (transform$$1 = scaleTranslate$1(k * (sx = _ ? -1 : 1), k * sy, tx, ty), reset()) : sx < 0;
        },
        reflectY: function(_) {
          return arguments.length ? (transform$$1 = scaleTranslate$1(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);
        },
        fitWidth: function(width, object) {
          return fitWidth(projection, width, object);
        },
        fitHeight: function(height, object) {
          return fitHeight(projection, height, object);
        }
      };
    }
    
    function naturalEarth1Raw(lambda, phi) {
      var phi2 = phi * phi, phi4 = phi2 * phi2;
      return [
        lambda * (0.8707 - 0.131979 * phi2 + phi4 * (-0.013791 + phi4 * (0.003971 * phi2 - 0.001529 * phi4))),
        phi * (1.007226 + phi2 * (0.015085 + phi4 * (-0.044475 + 0.028874 * phi2 - 0.005916 * phi4)))
      ];
    }
    
    naturalEarth1Raw.invert = function(x, y) {
      var phi = y, i = 25, delta;
      do {
        var phi2 = phi * phi, phi4 = phi2 * phi2;
        phi -= delta = (phi * (1.007226 + phi2 * (0.015085 + phi4 * (-0.044475 + 0.028874 * phi2 - 0.005916 * phi4))) - y) /
            (1.007226 + phi2 * (0.015085 * 3 + phi4 * (-0.044475 * 7 + 0.028874 * 9 * phi2 - 0.005916 * 11 * phi4)));
      } while (abs(delta) > epsilon$2 && --i > 0);
      return [
        x / (0.8707 + (phi2 = phi * phi) * (-0.131979 + phi2 * (-0.013791 + phi2 * phi2 * phi2 * (0.003971 - 0.001529 * phi2)))),
        phi
      ];
    };
    
    function naturalEarth1() {
      return projection(naturalEarth1Raw)
          .scale(175.295);
    }
    
    function orthographicRaw(x, y) {
      return [cos$1(y) * sin$1(x), sin$1(y)];
    }
    
    orthographicRaw.invert = azimuthalInvert(asin);
    
    function orthographic() {
      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);
    });
    
    function stereographic() {
      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];
    };
    
    function transverseMercator() {
      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;
    }
    
    function cluster() {
      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;
    }
    
    function node_count() {
      return this.eachAfter(count);
    }
    
    function node_each(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;
    }
    
    function node_eachBefore(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;
    }
    
    function node_eachAfter(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;
    }
    
    function node_sum(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;
      });
    }
    
    function node_sort(compare) {
      return this.eachBefore(function(node) {
        if (node.children) {
          node.children.sort(compare);
        }
      });
    }
    
    function node_path(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;
    }
    
    function node_ancestors() {
      var node = this, nodes = [node];
      while (node = node.parent) {
        nodes.push(node);
      }
      return nodes;
    }
    
    function node_descendants() {
      var nodes = [];
      this.each(function(node) {
        nodes.push(node);
      });
      return nodes;
    }
    
    function node_leaves() {
      var leaves = [];
      this.eachBefore(function(node) {
        if (!node.children) {
          leaves.push(node);
        }
      });
      return leaves;
    }
    
    function node_links() {
      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
    };
    
    var slice$4 = Array.prototype.slice;
    
    function shuffle$1(array) {
      var m = array.length,
          t,
          i;
    
      while (m) {
        i = Math.random() * m-- | 0;
        t = array[m];
        array[m] = array[i];
        array[i] = t;
      }
    
      return array;
    }
    
    function enclose(circles) {
      var i = 0, n = (circles = shuffle$1(slice$4.call(circles))).length, B = [], p, e;
    
      while (i < n) {
        p = circles[i];
        if (e && enclosesWeak(e, p)) ++i;
        else e = encloseBasis(B = extendBasis(B, p)), i = 0;
      }
    
      return e;
    }
    
    function extendBasis(B, p) {
      var i, j;
    
      if (enclosesWeakAll(p, B)) return [p];
    
      // If we get here then B must have at least one element.
      for (i = 0; i < B.length; ++i) {
        if (enclosesNot(p, B[i])
            && enclosesWeakAll(encloseBasis2(B[i], p), B)) {
          return [B[i], p];
        }
      }
    
      // If we get here then B must have at least two elements.
      for (i = 0; i < B.length - 1; ++i) {
        for (j = i + 1; j < B.length; ++j) {
          if (enclosesNot(encloseBasis2(B[i], B[j]), p)
              && enclosesNot(encloseBasis2(B[i], p), B[j])
              && enclosesNot(encloseBasis2(B[j], p), B[i])
              && enclosesWeakAll(encloseBasis3(B[i], B[j], p), B)) {
            return [B[i], B[j], p];
          }
        }
      }
    
      // If we get here then something is very wrong.
      throw new Error;
    }
    
    function enclosesNot(a, b) {
      var dr = a.r - b.r, dx = b.x - a.x, dy = b.y - a.y;
      return dr < 0 || dr * dr < dx * dx + dy * dy;
    }
    
    function enclosesWeak(a, b) {
      var dr = a.r - b.r + 1e-6, dx = b.x - a.x, dy = b.y - a.y;
      return dr > 0 && dr * dr > dx * dx + dy * dy;
    }
    
    function enclosesWeakAll(a, B) {
      for (var i = 0; i < B.length; ++i) {
        if (!enclosesWeak(a, B[i])) {
          return false;
        }
      }
      return true;
    }
    
    function encloseBasis(B) {
      switch (B.length) {
        case 1: return encloseBasis1(B[0]);
        case 2: return encloseBasis2(B[0], B[1]);
        case 3: return encloseBasis3(B[0], B[1], B[2]);
      }
    }
    
    function encloseBasis1(a) {
      return {
        x: a.x,
        y: a.y,
        r: a.r
      };
    }
    
    function encloseBasis2(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 encloseBasis3(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 = x1 - x2,
          a3 = x1 - x3,
          b2 = y1 - y2,
          b3 = y1 - y3,
          c2 = r2 - r1,
          c3 = r3 - r1,
          d1 = x1 * x1 + y1 * y1 - r1 * r1,
          d2 = d1 - x2 * x2 - y2 * y2 + r2 * r2,
          d3 = d1 - x3 * x3 - y3 * y3 + r3 * r3,
          ab = a3 * b2 - a2 * b3,
          xa = (b2 * d3 - b3 * d2) / (ab * 2) - x1,
          xb = (b3 * c2 - b2 * c3) / ab,
          ya = (a3 * d2 - a2 * d3) / (ab * 2) - y1,
          yb = (a2 * c3 - a3 * c2) / ab,
          A = xb * xb + yb * yb - 1,
          B = 2 * (r1 + xa * xb + ya * yb),
          C = xa * xa + ya * ya - r1 * r1,
          r = -(A ? (B + Math.sqrt(B * B - 4 * A * C)) / (2 * A) : C / B);
      return {
        x: x1 + xa + xb * r,
        y: y1 + ya + yb * r,
        r: r
      };
    }
    
    function place(b, a, c) {
      var dx = b.x - a.x, x, a2,
          dy = b.y - a.y, y, b2,
          d2 = dx * dx + dy * dy;
      if (d2) {
        a2 = a.r + c.r, a2 *= a2;
        b2 = b.r + c.r, b2 *= b2;
        if (a2 > b2) {
          x = (d2 + b2 - a2) / (2 * d2);
          y = Math.sqrt(Math.max(0, b2 / d2 - x * x));
          c.x = b.x - x * dx - y * dy;
          c.y = b.y - x * dy + y * dx;
        } else {
          x = (d2 + a2 - b2) / (2 * d2);
          y = Math.sqrt(Math.max(0, a2 / d2 - x * x));
          c.x = a.x + x * dx - y * dy;
          c.y = a.y + x * dy + y * dx;
        }
      } else {
        c.x = a.x + c.r;
        c.y = a.y;
      }
    }
    
    function intersects(a, b) {
      var dr = a.r + b.r - 1e-6, dx = b.x - a.x, dy = b.y - a.y;
      return dr > 0 && dr * dr > dx * dx + dy * dy;
    }
    
    function score(node) {
      var a = node._,
          b = node.next._,
          ab = a.r + b.r,
          dx = (a.x * b.r + b.x * a.r) / ab,
          dy = (a.y * b.r + b.y * a.r) / ab;
      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, aa, ca, i, j, k, sj, sk;
    
      // 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 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;
    
        // Compute the new closest circle pair to the centroid.
        aa = score(a);
        while ((c = c.next) !== b) {
          if ((ca = score(c)) < 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;
    }
    
    function siblings(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;
    }
    
    function constant$9(x) {
      return function() {
        return x;
      };
    }
    
    function defaultRadius$1(d) {
      return Math.sqrt(d.value);
    }
    
    function index$2() {
      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$9(+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;
        }
      };
    }
    
    function roundNode(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);
    }
    
    function treemapDice(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;
      }
    }
    
    function partition() {
      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$1 = "$", // Protect against keys like “__proto__”.
        preroot = {depth: -1},
        ambiguous = {};
    
    function defaultId(d) {
      return d.id;
    }
    
    function defaultParentId(d) {
      return d.parentId;
    }
    
    function stratify() {
      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
    function tree() {
      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;
    }
    
    function treemapSlice(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);
    
    function index$3() {
      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$9(+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$9(+x), treemap) : paddingTop;
      };
    
      treemap.paddingRight = function(x) {
        return arguments.length ? (paddingRight = typeof x === "function" ? x : constant$9(+x), treemap) : paddingRight;
      };
    
      treemap.paddingBottom = function(x) {
        return arguments.length ? (paddingBottom = typeof x === "function" ? x : constant$9(+x), treemap) : paddingBottom;
      };
    
      treemap.paddingLeft = function(x) {
        return arguments.length ? (paddingLeft = typeof x === "function" ? x : constant$9(+x), treemap) : paddingLeft;
      };
    
      return treemap;
    }
    
    function binary(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);
        }
      }
    }
    
    function sliceDice(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);
    
    function area$2(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;
    }
    
    function centroid$1(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.
    function cross$1(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
    }
    
    function hull(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;
    }
    
    function contains$2(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;
    }
    
    function length$2(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;
    }
    
    function defaultSource$1() {
      return Math.random();
    }
    
    var uniform = (function sourceRandomUniform(source) {
      function randomUniform(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 source() * max + min;
        };
      }
    
      randomUniform.source = sourceRandomUniform;
    
      return randomUniform;
    })(defaultSource$1);
    
    var normal = (function sourceRandomNormal(source) {
      function randomNormal(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 = source() * 2 - 1;
            y = source() * 2 - 1;
            r = x * x + y * y;
          } while (!r || r > 1);
    
          return mu + sigma * y * Math.sqrt(-2 * Math.log(r) / r);
        };
      }
    
      randomNormal.source = sourceRandomNormal;
    
      return randomNormal;
    })(defaultSource$1);
    
    var logNormal = (function sourceRandomLogNormal(source) {
      function randomLogNormal() {
        var randomNormal = normal.source(source).apply(this, arguments);
        return function() {
          return Math.exp(randomNormal());
        };
      }
    
      randomLogNormal.source = sourceRandomLogNormal;
    
      return randomLogNormal;
    })(defaultSource$1);
    
    var irwinHall = (function sourceRandomIrwinHall(source) {
      function randomIrwinHall(n) {
        return function() {
          for (var sum = 0, i = 0; i < n; ++i) sum += source();
          return sum;
        };
      }
    
      randomIrwinHall.source = sourceRandomIrwinHall;
    
      return randomIrwinHall;
    })(defaultSource$1);
    
    var bates = (function sourceRandomBates(source) {
      function randomBates(n) {
        var randomIrwinHall = irwinHall.source(source)(n);
        return function() {
          return randomIrwinHall() / n;
        };
      }
    
      randomBates.source = sourceRandomBates;
    
      return randomBates;
    })(defaultSource$1);
    
    var exponential$1 = (function sourceRandomExponential(source) {
      function randomExponential(lambda) {
        return function() {
          return -Math.log(1 - source()) / lambda;
        };
      }
    
      randomExponential.source = sourceRandomExponential;
    
      return randomExponential;
    })(defaultSource$1);
    
    function initRange(domain, range) {
      switch (arguments.length) {
        case 0: break;
        case 1: this.range(domain); break;
        default: this.range(range).domain(domain); break;
      }
      return this;
    }
    
    function initInterpolator(domain, interpolator) {
      switch (arguments.length) {
        case 0: break;
        case 1: this.interpolator(domain); break;
        default: this.interpolator(interpolator).domain(domain); break;
      }
      return this;
    }
    
    var array$3 = Array.prototype;
    
    var map$2 = array$3.map;
    var slice$5 = array$3.slice;
    
    var implicit = {name: "implicit"};
    
    function ordinal() {
      var index = map$1(),
          domain = [],
          range = [],
          unknown = implicit;
    
      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$5.call(_), scale) : range.slice();
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      scale.copy = function() {
        return ordinal(domain, range).unknown(unknown);
      };
    
      initRange.apply(scale, arguments);
    
      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 = Math.min(1, paddingOuter = +_), rescale()) : paddingInner;
      };
    
      scale.paddingInner = function(_) {
        return arguments.length ? (paddingInner = Math.min(1, _), rescale()) : paddingInner;
      };
    
      scale.paddingOuter = function(_) {
        return arguments.length ? (paddingOuter = +_, rescale()) : paddingOuter;
      };
    
      scale.align = function(_) {
        return arguments.length ? (align = Math.max(0, Math.min(1, _)), rescale()) : align;
      };
    
      scale.copy = function() {
        return band(domain(), range$$1)
            .round(round)
            .paddingInner(paddingInner)
            .paddingOuter(paddingOuter)
            .align(align);
      };
    
      return initRange.apply(rescale(), arguments);
    }
    
    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.apply(null, arguments).paddingInner(1));
    }
    
    function constant$a(x) {
      return function() {
        return x;
      };
    }
    
    function number$2(x) {
      return +x;
    }
    
    var unit = [0, 1];
    
    function identity$6(x) {
      return x;
    }
    
    function normalize(a, b) {
      return (b -= (a = +a))
          ? function(x) { return (x - a) / b; }
          : constant$a(isNaN(b) ? NaN : 0.5);
    }
    
    function clamper(domain) {
      var a = domain[0], b = domain[domain.length - 1], t;
      if (a > b) t = a, a = b, b = t;
      return function(x) { return Math.max(a, Math.min(b, x)); };
    }
    
    // normalize(a, b)(x) takes a domain value x in [a,b] and returns the corresponding parameter t in [0,1].
    // interpolate(a, b)(t) takes a parameter t in [0,1] and returns the corresponding range value x in [a,b].
    function bimap(domain, range, interpolate$$1) {
      var d0 = domain[0], d1 = domain[1], r0 = range[0], r1 = range[1];
      if (d1 < d0) d0 = normalize(d1, d0), r0 = interpolate$$1(r1, r0);
      else d0 = normalize(d0, d1), r0 = interpolate$$1(r0, r1);
      return function(x) { return r0(d0(x)); };
    }
    
    function polymap(domain, range, interpolate$$1) {
      var j = Math.min(domain.length, range.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 = range.slice().reverse();
      }
    
      while (++i < j) {
        d[i] = normalize(domain[i], domain[i + 1]);
        r[i] = interpolate$$1(range[i], range[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())
          .unknown(source.unknown());
    }
    
    function transformer$1() {
      var domain = unit,
          range = unit,
          interpolate$$1 = interpolateValue,
          transform,
          untransform,
          unknown,
          clamp = identity$6,
          piecewise$$1,
          output,
          input;
    
      function rescale() {
        piecewise$$1 = Math.min(domain.length, range.length) > 2 ? polymap : bimap;
        output = input = null;
        return scale;
      }
    
      function scale(x) {
        return isNaN(x = +x) ? unknown : (output || (output = piecewise$$1(domain.map(transform), range, interpolate$$1)))(transform(clamp(x)));
      }
    
      scale.invert = function(y) {
        return clamp(untransform((input || (input = piecewise$$1(range, domain.map(transform), interpolateNumber)))(y)));
      };
    
      scale.domain = function(_) {
        return arguments.length ? (domain = map$2.call(_, number$2), clamp === identity$6 || (clamp = clamper(domain)), rescale()) : domain.slice();
      };
    
      scale.range = function(_) {
        return arguments.length ? (range = slice$5.call(_), rescale()) : range.slice();
      };
    
      scale.rangeRound = function(_) {
        return range = slice$5.call(_), interpolate$$1 = interpolateRound, rescale();
      };
    
      scale.clamp = function(_) {
        return arguments.length ? (clamp = _ ? clamper(domain) : identity$6, scale) : clamp !== identity$6;
      };
    
      scale.interpolate = function(_) {
        return arguments.length ? (interpolate$$1 = _, rescale()) : interpolate$$1;
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      return function(t, u) {
        transform = t, untransform = u;
        return rescale();
      };
    }
    
    function continuous(transform, untransform) {
      return transformer$1()(transform, untransform);
    }
    
    function tickFormat(start, stop, count, specifier) {
      var step = tickStep(start, stop, 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) {
        var d = domain();
        return tickFormat(d[0], d[d.length - 1], count == null ? 10 : count, specifier);
      };
    
      scale.nice = function(count) {
        if (count == null) count = 10;
    
        var d = domain(),
            i0 = 0,
            i1 = d.length - 1,
            start = d[i0],
            stop = d[i1],
            step;
    
        if (stop < start) {
          step = start, start = stop, stop = step;
          step = i0, i0 = i1, i1 = step;
        }
    
        step = tickIncrement(start, stop, count);
    
        if (step > 0) {
          start = Math.floor(start / step) * step;
          stop = Math.ceil(stop / step) * step;
          step = tickIncrement(start, stop, count);
        } else if (step < 0) {
          start = Math.ceil(start * step) / step;
          stop = Math.floor(stop * step) / step;
          step = tickIncrement(start, stop, count);
        }
    
        if (step > 0) {
          d[i0] = Math.floor(start / step) * step;
          d[i1] = Math.ceil(stop / step) * step;
          domain(d);
        } else if (step < 0) {
          d[i0] = Math.ceil(start * step) / step;
          d[i1] = Math.floor(stop * step) / step;
          domain(d);
        }
    
        return scale;
      };
    
      return scale;
    }
    
    function linear$2() {
      var scale = continuous(identity$6, identity$6);
    
      scale.copy = function() {
        return copy(scale, linear$2());
      };
    
      initRange.apply(scale, arguments);
    
      return linearish(scale);
    }
    
    function identity$7(domain) {
      var unknown;
    
      function scale(x) {
        return isNaN(x = +x) ? unknown : x;
      }
    
      scale.invert = scale;
    
      scale.domain = scale.range = function(_) {
        return arguments.length ? (domain = map$2.call(_, number$2), scale) : domain.slice();
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      scale.copy = function() {
        return identity$7(domain).unknown(unknown);
      };
    
      domain = arguments.length ? map$2.call(domain, number$2) : [0, 1];
    
      return linearish(scale);
    }
    
    function nice(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 transformLog(x) {
      return Math.log(x);
    }
    
    function transformExp(x) {
      return Math.exp(x);
    }
    
    function transformLogn(x) {
      return -Math.log(-x);
    }
    
    function transformExpn(x) {
      return -Math.exp(-x);
    }
    
    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 loggish(transform) {
      var scale = transform(transformLog, transformExp),
          domain = scale.domain,
          base = 10,
          logs,
          pows;
    
      function rescale() {
        logs = logp(base), pows = powp(base);
        if (domain()[0] < 0) {
          logs = reflect(logs), pows = reflect(pows);
          transform(transformLogn, transformExpn);
        } else {
          transform(transformLog, transformExp);
        }
        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))); }
        }));
      };
    
      return scale;
    }
    
    function log$1() {
      var scale = loggish(transformer$1()).domain([1, 10]);
    
      scale.copy = function() {
        return copy(scale, log$1()).base(scale.base());
      };
    
      initRange.apply(scale, arguments);
    
      return scale;
    }
    
    function transformSymlog(c) {
      return function(x) {
        return Math.sign(x) * Math.log1p(Math.abs(x / c));
      };
    }
    
    function transformSymexp(c) {
      return function(x) {
        return Math.sign(x) * Math.expm1(Math.abs(x)) * c;
      };
    }
    
    function symlogish(transform) {
      var c = 1, scale = transform(transformSymlog(c), transformSymexp(c));
    
      scale.constant = function(_) {
        return arguments.length ? transform(transformSymlog(c = +_), transformSymexp(c)) : c;
      };
    
      return linearish(scale);
    }
    
    function symlog() {
      var scale = symlogish(transformer$1());
    
      scale.copy = function() {
        return copy(scale, symlog()).constant(scale.constant());
      };
    
      return initRange.apply(scale, arguments);
    }
    
    function transformPow(exponent) {
      return function(x) {
        return x < 0 ? -Math.pow(-x, exponent) : Math.pow(x, exponent);
      };
    }
    
    function transformSqrt(x) {
      return x < 0 ? -Math.sqrt(-x) : Math.sqrt(x);
    }
    
    function transformSquare(x) {
      return x < 0 ? -x * x : x * x;
    }
    
    function powish(transform) {
      var scale = transform(identity$6, identity$6),
          exponent = 1;
    
      function rescale() {
        return exponent === 1 ? transform(identity$6, identity$6)
            : exponent === 0.5 ? transform(transformSqrt, transformSquare)
            : transform(transformPow(exponent), transformPow(1 / exponent));
      }
    
      scale.exponent = function(_) {
        return arguments.length ? (exponent = +_, rescale()) : exponent;
      };
    
      return linearish(scale);
    }
    
    function pow$1() {
      var scale = powish(transformer$1());
    
      scale.copy = function() {
        return copy(scale, pow$1()).exponent(scale.exponent());
      };
    
      initRange.apply(scale, arguments);
    
      return scale;
    }
    
    function sqrt$1() {
      return pow$1.apply(null, arguments).exponent(0.5);
    }
    
    function quantile$$1() {
      var domain = [],
          range = [],
          thresholds = [],
          unknown;
    
      function rescale() {
        var i = 0, n = Math.max(1, range.length);
        thresholds = new Array(n - 1);
        while (++i < n) thresholds[i - 1] = threshold(domain, i / n);
        return scale;
      }
    
      function scale(x) {
        return isNaN(x = +x) ? unknown : range[bisectRight(thresholds, x)];
      }
    
      scale.invertExtent = function(y) {
        var i = range.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 = slice$5.call(_), rescale()) : range.slice();
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      scale.quantiles = function() {
        return thresholds.slice();
      };
    
      scale.copy = function() {
        return quantile$$1()
            .domain(domain)
            .range(range)
            .unknown(unknown);
      };
    
      return initRange.apply(scale, arguments);
    }
    
    function quantize$1() {
      var x0 = 0,
          x1 = 1,
          n = 1,
          domain = [0.5],
          range = [0, 1],
          unknown;
    
      function scale(x) {
        return x <= x ? range[bisectRight(domain, x, 0, n)] : unknown;
      }
    
      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 = slice$5.call(_)).length - 1, rescale()) : range.slice();
      };
    
      scale.invertExtent = function(y) {
        var i = range.indexOf(y);
        return i < 0 ? [NaN, NaN]
            : i < 1 ? [x0, domain[0]]
            : i >= n ? [domain[n - 1], x1]
            : [domain[i - 1], domain[i]];
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : scale;
      };
    
      scale.thresholds = function() {
        return domain.slice();
      };
    
      scale.copy = function() {
        return quantize$1()
            .domain([x0, x1])
            .range(range)
            .unknown(unknown);
      };
    
      return initRange.apply(linearish(scale), arguments);
    }
    
    function threshold$1() {
      var domain = [0.5],
          range = [0, 1],
          unknown,
          n = 1;
    
      function scale(x) {
        return x <= x ? range[bisectRight(domain, x, 0, n)] : unknown;
      }
    
      scale.domain = function(_) {
        return arguments.length ? (domain = slice$5.call(_), n = Math.min(domain.length, range.length - 1), scale) : domain.slice();
      };
    
      scale.range = function(_) {
        return arguments.length ? (range = slice$5.call(_), n = Math.min(domain.length, range.length - 1), scale) : range.slice();
      };
    
      scale.invertExtent = function(y) {
        var i = range.indexOf(y);
        return [domain[i - 1], domain[i]];
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      scale.copy = function() {
        return threshold$1()
            .domain(domain)
            .range(range)
            .unknown(unknown);
      };
    
      return initRange.apply(scale, arguments);
    }
    
    var t0$1 = new Date,
        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 = [], previous;
        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(previous = new Date(+start)), offseti(start, step), floori(start);
        while (previous < 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) {
            if (step < 0) while (++step <= 0) {
              while (offseti(date, -1), !test(date)) {} // eslint-disable-line no-empty
            } else 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 = 1e3;
    var durationMinute = 6e4;
    var durationHour = 36e5;
    var durationDay = 864e5;
    var durationWeek = 6048e5;
    
    var second = newInterval(function(date) {
      date.setTime(date - date.getMilliseconds());
    }, function(date, step) {
      date.setTime(+date + step * durationSecond);
    }, function(start, end) {
      return (end - start) / durationSecond;
    }, function(date) {
      return date.getUTCSeconds();
    });
    var seconds = second.range;
    
    var minute = newInterval(function(date) {
      date.setTime(date - date.getMilliseconds() - date.getSeconds() * durationSecond);
    }, function(date, step) {
      date.setTime(+date + step * durationMinute);
    }, function(start, end) {
      return (end - start) / durationMinute;
    }, function(date) {
      return date.getMinutes();
    });
    var minutes = minute.range;
    
    var hour = newInterval(function(date) {
      date.setTime(date - date.getMilliseconds() - date.getSeconds() * durationSecond - date.getMinutes() * durationMinute);
    }, function(date, step) {
      date.setTime(+date + step * durationHour);
    }, function(start, end) {
      return (end - start) / durationHour;
    }, 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) / durationDay;
    }, 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) / durationWeek;
      });
    }
    
    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);
    }, function(start, end) {
      return (end - start) / durationMinute;
    }, 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);
    }, function(start, end) {
      return (end - start) / durationHour;
    }, 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;
    }, 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;
      });
    }
    
    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,
        "f": formatMicroseconds,
        "H": formatHour24,
        "I": formatHour12,
        "j": formatDayOfYear,
        "L": formatMilliseconds,
        "m": formatMonthNumber,
        "M": formatMinutes,
        "p": formatPeriod,
        "Q": formatUnixTimestamp,
        "s": formatUnixTimestampSeconds,
        "S": formatSeconds,
        "u": formatWeekdayNumberMonday,
        "U": formatWeekNumberSunday,
        "V": formatWeekNumberISO,
        "w": formatWeekdayNumberSunday,
        "W": formatWeekNumberMonday,
        "x": null,
        "X": null,
        "y": formatYear$1,
        "Y": formatFullYear,
        "Z": formatZone,
        "%": formatLiteralPercent
      };
    
      var utcFormats = {
        "a": formatUTCShortWeekday,
        "A": formatUTCWeekday,
        "b": formatUTCShortMonth,
        "B": formatUTCMonth,
        "c": null,
        "d": formatUTCDayOfMonth,
        "e": formatUTCDayOfMonth,
        "f": formatUTCMicroseconds,
        "H": formatUTCHour24,
        "I": formatUTCHour12,
        "j": formatUTCDayOfYear,
        "L": formatUTCMilliseconds,
        "m": formatUTCMonthNumber,
        "M": formatUTCMinutes,
        "p": formatUTCPeriod,
        "Q": formatUnixTimestamp,
        "s": formatUnixTimestampSeconds,
        "S": formatUTCSeconds,
        "u": formatUTCWeekdayNumberMonday,
        "U": formatUTCWeekNumberSunday,
        "V": formatUTCWeekNumberISO,
        "w": formatUTCWeekdayNumberSunday,
        "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,
        "f": parseMicroseconds,
        "H": parseHour24,
        "I": parseHour24,
        "j": parseDayOfYear,
        "L": parseMilliseconds,
        "m": parseMonthNumber,
        "M": parseMinutes,
        "p": parsePeriod,
        "Q": parseUnixTimestamp,
        "s": parseUnixTimestampSeconds,
        "S": parseSeconds,
        "u": parseWeekdayNumberMonday,
        "U": parseWeekNumberSunday,
        "V": parseWeekNumberISO,
        "w": parseWeekdayNumberSunday,
        "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),
              week, day$$1;
          if (i != string.length) return null;
    
          // If a UNIX timestamp is specified, return it.
          if ("Q" in d) return new Date(d.Q);
    
          // 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 ("V" in d) {
            if (d.V < 1 || d.V > 53) return null;
            if (!("w" in d)) d.w = 1;
            if ("Z" in d) {
              week = utcDate(newYear(d.y)), day$$1 = week.getUTCDay();
              week = day$$1 > 4 || day$$1 === 0 ? utcMonday.ceil(week) : utcMonday(week);
              week = utcDay.offset(week, (d.V - 1) * 7);
              d.y = week.getUTCFullYear();
              d.m = week.getUTCMonth();
              d.d = week.getUTCDate() + (d.w + 6) % 7;
            } else {
              week = newDate(newYear(d.y)), day$$1 = week.getDay();
              week = day$$1 > 4 || day$$1 === 0 ? monday.ceil(week) : monday(week);
              week = day.offset(week, (d.V - 1) * 7);
              d.y = week.getFullYear();
              d.m = week.getMonth();
              d.d = week.getDate() + (d.w + 6) % 7;
            }
          } else if ("W" in d || "U" in d) {
            if (!("w" in d)) d.w = "u" in d ? d.u % 7 : "W" in d ? 1 : 0;
            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"},
        numberRe = /^\s*\d+/, // note: ignores next directive
        percentRe = /^%/,
        requoteRe = /[\\^$*+?|[\]().{}]/g;
    
    function pad$1(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 parseWeekdayNumberSunday(d, string, i) {
      var n = numberRe.exec(string.slice(i, i + 1));
      return n ? (d.w = +n[0], i + n[0].length) : -1;
    }
    
    function parseWeekdayNumberMonday(d, string, i) {
      var n = numberRe.exec(string.slice(i, i + 1));
      return n ? (d.u = +n[0], i + n[0].length) : -1;
    }
    
    function parseWeekNumberSunday(d, string, i) {
      var n = numberRe.exec(string.slice(i, i + 2));
      return n ? (d.U = +n[0], i + n[0].length) : -1;
    }
    
    function parseWeekNumberISO(d, string, i) {
      var n = numberRe.exec(string.slice(i, i + 2));
      return n ? (d.V = +n[0], i + n[0].length) : -1;
    }
    
    function parseWeekNumberMonday(d, string, i) {
      var n = numberRe.exec(string.slice(i, i + 2));
      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 parseMicroseconds(d, string, i) {
      var n = numberRe.exec(string.slice(i, i + 6));
      return n ? (d.L = Math.floor(n[0] / 1000), 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 parseUnixTimestamp(d, string, i) {
      var n = numberRe.exec(string.slice(i));
      return n ? (d.Q = +n[0], i + n[0].length) : -1;
    }
    
    function parseUnixTimestampSeconds(d, string, i) {
      var n = numberRe.exec(string.slice(i));
      return n ? (d.Q = (+n[0]) * 1000, i + n[0].length) : -1;
    }
    
    function formatDayOfMonth(d, p) {
      return pad$1(d.getDate(), p, 2);
    }
    
    function formatHour24(d, p) {
      return pad$1(d.getHours(), p, 2);
    }
    
    function formatHour12(d, p) {
      return pad$1(d.getHours() % 12 || 12, p, 2);
    }
    
    function formatDayOfYear(d, p) {
      return pad$1(1 + day.count(year(d), d), p, 3);
    }
    
    function formatMilliseconds(d, p) {
      return pad$1(d.getMilliseconds(), p, 3);
    }
    
    function formatMicroseconds(d, p) {
      return formatMilliseconds(d, p) + "000";
    }
    
    function formatMonthNumber(d, p) {
      return pad$1(d.getMonth() + 1, p, 2);
    }
    
    function formatMinutes(d, p) {
      return pad$1(d.getMinutes(), p, 2);
    }
    
    function formatSeconds(d, p) {
      return pad$1(d.getSeconds(), p, 2);
    }
    
    function formatWeekdayNumberMonday(d) {
      var day$$1 = d.getDay();
      return day$$1 === 0 ? 7 : day$$1;
    }
    
    function formatWeekNumberSunday(d, p) {
      return pad$1(sunday.count(year(d), d), p, 2);
    }
    
    function formatWeekNumberISO(d, p) {
      var day$$1 = d.getDay();
      d = (day$$1 >= 4 || day$$1 === 0) ? thursday(d) : thursday.ceil(d);
      return pad$1(thursday.count(year(d), d) + (year(d).getDay() === 4), p, 2);
    }
    
    function formatWeekdayNumberSunday(d) {
      return d.getDay();
    }
    
    function formatWeekNumberMonday(d, p) {
      return pad$1(monday.count(year(d), d), p, 2);
    }
    
    function formatYear$1(d, p) {
      return pad$1(d.getFullYear() % 100, p, 2);
    }
    
    function formatFullYear(d, p) {
      return pad$1(d.getFullYear() % 10000, p, 4);
    }
    
    function formatZone(d) {
      var z = d.getTimezoneOffset();
      return (z > 0 ? "-" : (z *= -1, "+"))
          + pad$1(z / 60 | 0, "0", 2)
          + pad$1(z % 60, "0", 2);
    }
    
    function formatUTCDayOfMonth(d, p) {
      return pad$1(d.getUTCDate(), p, 2);
    }
    
    function formatUTCHour24(d, p) {
      return pad$1(d.getUTCHours(), p, 2);
    }
    
    function formatUTCHour12(d, p) {
      return pad$1(d.getUTCHours() % 12 || 12, p, 2);
    }
    
    function formatUTCDayOfYear(d, p) {
      return pad$1(1 + utcDay.count(utcYear(d), d), p, 3);
    }
    
    function formatUTCMilliseconds(d, p) {
      return pad$1(d.getUTCMilliseconds(), p, 3);
    }
    
    function formatUTCMicroseconds(d, p) {
      return formatUTCMilliseconds(d, p) + "000";
    }
    
    function formatUTCMonthNumber(d, p) {
      return pad$1(d.getUTCMonth() + 1, p, 2);
    }
    
    function formatUTCMinutes(d, p) {
      return pad$1(d.getUTCMinutes(), p, 2);
    }
    
    function formatUTCSeconds(d, p) {
      return pad$1(d.getUTCSeconds(), p, 2);
    }
    
    function formatUTCWeekdayNumberMonday(d) {
      var dow = d.getUTCDay();
      return dow === 0 ? 7 : dow;
    }
    
    function formatUTCWeekNumberSunday(d, p) {
      return pad$1(utcSunday.count(utcYear(d), d), p, 2);
    }
    
    function formatUTCWeekNumberISO(d, p) {
      var day$$1 = d.getUTCDay();
      d = (day$$1 >= 4 || day$$1 === 0) ? utcThursday(d) : utcThursday.ceil(d);
      return pad$1(utcThursday.count(utcYear(d), d) + (utcYear(d).getUTCDay() === 4), p, 2);
    }
    
    function formatUTCWeekdayNumberSunday(d) {
      return d.getUTCDay();
    }
    
    function formatUTCWeekNumberMonday(d, p) {
      return pad$1(utcMonday.count(utcYear(d), d), p, 2);
    }
    
    function formatUTCYear(d, p) {
      return pad$1(d.getUTCFullYear() % 100, p, 2);
    }
    
    function formatUTCFullYear(d, p) {
      return pad$1(d.getUTCFullYear() % 10000, p, 4);
    }
    
    function formatUTCZone() {
      return "+0000";
    }
    
    function formatLiteralPercent() {
      return "%";
    }
    
    function formatUnixTimestamp(d) {
      return +d;
    }
    
    function formatUnixTimestampSeconds(d) {
      return Math.floor(+d / 1000);
    }
    
    var locale$1;
    
    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$1 = formatLocale$1(definition);
      exports.timeFormat = locale$1.format;
      exports.timeParse = locale$1.parse;
      exports.utcFormat = locale$1.utcFormat;
      exports.utcParse = locale$1.utcParse;
      return locale$1;
    }
    
    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$1 = 1000,
        durationMinute$1 = durationSecond$1 * 60,
        durationHour$1 = durationMinute$1 * 60,
        durationDay$1 = durationHour$1 * 24,
        durationWeek$1 = durationDay$1 * 7,
        durationMonth = durationDay$1 * 30,
        durationYear = durationDay$1 * 365;
    
    function date$1(t) {
      return new Date(t);
    }
    
    function number$3(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(identity$6, identity$6),
          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$$1,  1,      durationSecond$1],
        [second$$1,  5,  5 * durationSecond$1],
        [second$$1, 15, 15 * durationSecond$1],
        [second$$1, 30, 30 * durationSecond$1],
        [minute$$1,  1,      durationMinute$1],
        [minute$$1,  5,  5 * durationMinute$1],
        [minute$$1, 15, 15 * durationMinute$1],
        [minute$$1, 30, 30 * durationMinute$1],
        [  hour$$1,  1,      durationHour$1  ],
        [  hour$$1,  3,  3 * durationHour$1  ],
        [  hour$$1,  6,  6 * durationHour$1  ],
        [  hour$$1, 12, 12 * durationHour$1  ],
        [   day$$1,  1,      durationDay$1   ],
        [   day$$1,  2,  2 * durationDay$1   ],
        [  week,  1,      durationWeek$1  ],
        [ 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$$1;
          } else if (i) {
            i = tickIntervals[target / tickIntervals[i - 1][2] < tickIntervals[i][2] / target ? i - 1 : i];
            step = i[1];
            interval = i[0];
          } else {
            step = Math.max(tickStep(start, stop, interval), 1);
            interval = millisecond$$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$2.call(_, number$3)) : 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;
    }
    
    function time() {
      return initRange.apply(calendar(year, month, sunday, day, hour, minute, second, millisecond, exports.timeFormat).domain([new Date(2000, 0, 1), new Date(2000, 0, 2)]), arguments);
    }
    
    function utcTime() {
      return initRange.apply(calendar(utcYear, utcMonth, utcSunday, utcDay, utcHour, utcMinute, second, millisecond, exports.utcFormat).domain([Date.UTC(2000, 0, 1), Date.UTC(2000, 0, 2)]), arguments);
    }
    
    function transformer$2() {
      var x0 = 0,
          x1 = 1,
          t0,
          t1,
          k10,
          transform,
          interpolator = identity$6,
          clamp = false,
          unknown;
    
      function scale(x) {
        return isNaN(x = +x) ? unknown : interpolator(k10 === 0 ? 0.5 : (x = (transform(x) - t0) * k10, clamp ? Math.max(0, Math.min(1, x)) : x));
      }
    
      scale.domain = function(_) {
        return arguments.length ? (t0 = transform(x0 = +_[0]), t1 = transform(x1 = +_[1]), k10 = t0 === t1 ? 0 : 1 / (t1 - t0), scale) : [x0, x1];
      };
    
      scale.clamp = function(_) {
        return arguments.length ? (clamp = !!_, scale) : clamp;
      };
    
      scale.interpolator = function(_) {
        return arguments.length ? (interpolator = _, scale) : interpolator;
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      return function(t) {
        transform = t, t0 = t(x0), t1 = t(x1), k10 = t0 === t1 ? 0 : 1 / (t1 - t0);
        return scale;
      };
    }
    
    function copy$1(source, target) {
      return target
          .domain(source.domain())
          .interpolator(source.interpolator())
          .clamp(source.clamp())
          .unknown(source.unknown());
    }
    
    function sequential() {
      var scale = linearish(transformer$2()(identity$6));
    
      scale.copy = function() {
        return copy$1(scale, sequential());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function sequentialLog() {
      var scale = loggish(transformer$2()).domain([1, 10]);
    
      scale.copy = function() {
        return copy$1(scale, sequentialLog()).base(scale.base());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function sequentialSymlog() {
      var scale = symlogish(transformer$2());
    
      scale.copy = function() {
        return copy$1(scale, sequentialSymlog()).constant(scale.constant());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function sequentialPow() {
      var scale = powish(transformer$2());
    
      scale.copy = function() {
        return copy$1(scale, sequentialPow()).exponent(scale.exponent());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function sequentialSqrt() {
      return sequentialPow.apply(null, arguments).exponent(0.5);
    }
    
    function sequentialQuantile() {
      var domain = [],
          interpolator = identity$6;
    
      function scale(x) {
        if (!isNaN(x = +x)) return interpolator((bisectRight(domain, x) - 1) / (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 scale;
      };
    
      scale.interpolator = function(_) {
        return arguments.length ? (interpolator = _, scale) : interpolator;
      };
    
      scale.copy = function() {
        return sequentialQuantile(interpolator).domain(domain);
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function transformer$3() {
      var x0 = 0,
          x1 = 0.5,
          x2 = 1,
          t0,
          t1,
          t2,
          k10,
          k21,
          interpolator = identity$6,
          transform,
          clamp = false,
          unknown;
    
      function scale(x) {
        return isNaN(x = +x) ? unknown : (x = 0.5 + ((x = +transform(x)) - t1) * (x < t1 ? k10 : k21), interpolator(clamp ? Math.max(0, Math.min(1, x)) : x));
      }
    
      scale.domain = function(_) {
        return arguments.length ? (t0 = transform(x0 = +_[0]), t1 = transform(x1 = +_[1]), t2 = transform(x2 = +_[2]), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1), scale) : [x0, x1, x2];
      };
    
      scale.clamp = function(_) {
        return arguments.length ? (clamp = !!_, scale) : clamp;
      };
    
      scale.interpolator = function(_) {
        return arguments.length ? (interpolator = _, scale) : interpolator;
      };
    
      scale.unknown = function(_) {
        return arguments.length ? (unknown = _, scale) : unknown;
      };
    
      return function(t) {
        transform = t, t0 = t(x0), t1 = t(x1), t2 = t(x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1);
        return scale;
      };
    }
    
    function diverging() {
      var scale = linearish(transformer$3()(identity$6));
    
      scale.copy = function() {
        return copy$1(scale, diverging());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function divergingLog() {
      var scale = loggish(transformer$3()).domain([0.1, 1, 10]);
    
      scale.copy = function() {
        return copy$1(scale, divergingLog()).base(scale.base());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function divergingSymlog() {
      var scale = symlogish(transformer$3());
    
      scale.copy = function() {
        return copy$1(scale, divergingSymlog()).constant(scale.constant());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function divergingPow() {
      var scale = powish(transformer$3());
    
      scale.copy = function() {
        return copy$1(scale, divergingPow()).exponent(scale.exponent());
      };
    
      return initInterpolator.apply(scale, arguments);
    }
    
    function divergingSqrt() {
      return divergingPow.apply(null, arguments).exponent(0.5);
    }
    
    function colors(specifier) {
      var n = specifier.length / 6 | 0, colors = new Array(n), i = 0;
      while (i < n) colors[i] = "#" + specifier.slice(i * 6, ++i * 6);
      return colors;
    }
    
    var category10 = colors("1f77b4ff7f0e2ca02cd627289467bd8c564be377c27f7f7fbcbd2217becf");
    
    var Accent = colors("7fc97fbeaed4fdc086ffff99386cb0f0027fbf5b17666666");
    
    var Dark2 = colors("1b9e77d95f027570b3e7298a66a61ee6ab02a6761d666666");
    
    var Paired = colors("a6cee31f78b4b2df8a33a02cfb9a99e31a1cfdbf6fff7f00cab2d66a3d9affff99b15928");
    
    var Pastel1 = colors("fbb4aeb3cde3ccebc5decbe4fed9a6ffffcce5d8bdfddaecf2f2f2");
    
    var Pastel2 = colors("b3e2cdfdcdaccbd5e8f4cae4e6f5c9fff2aef1e2cccccccc");
    
    var Set1 = colors("e41a1c377eb84daf4a984ea3ff7f00ffff33a65628f781bf999999");
    
    var Set2 = colors("66c2a5fc8d628da0cbe78ac3a6d854ffd92fe5c494b3b3b3");
    
    var Set3 = colors("8dd3c7ffffb3bebadafb807280b1d3fdb462b3de69fccde5d9d9d9bc80bdccebc5ffed6f");
    
    function ramp(scheme) {
      return rgbBasis(scheme[scheme.length - 1]);
    }
    
    var scheme = new Array(3).concat(
      "d8b365f5f5f55ab4ac",
      "a6611adfc27d80cdc1018571",
      "a6611adfc27df5f5f580cdc1018571",
      "8c510ad8b365f6e8c3c7eae55ab4ac01665e",
      "8c510ad8b365f6e8c3f5f5f5c7eae55ab4ac01665e",
      "8c510abf812ddfc27df6e8c3c7eae580cdc135978f01665e",
      "8c510abf812ddfc27df6e8c3f5f5f5c7eae580cdc135978f01665e",
      "5430058c510abf812ddfc27df6e8c3c7eae580cdc135978f01665e003c30",
      "5430058c510abf812ddfc27df6e8c3f5f5f5c7eae580cdc135978f01665e003c30"
    ).map(colors);
    
    var BrBG = ramp(scheme);
    
    var scheme$1 = new Array(3).concat(
      "af8dc3f7f7f77fbf7b",
      "7b3294c2a5cfa6dba0008837",
      "7b3294c2a5cff7f7f7a6dba0008837",
      "762a83af8dc3e7d4e8d9f0d37fbf7b1b7837",
      "762a83af8dc3e7d4e8f7f7f7d9f0d37fbf7b1b7837",
      "762a839970abc2a5cfe7d4e8d9f0d3a6dba05aae611b7837",
      "762a839970abc2a5cfe7d4e8f7f7f7d9f0d3a6dba05aae611b7837",
      "40004b762a839970abc2a5cfe7d4e8d9f0d3a6dba05aae611b783700441b",
      "40004b762a839970abc2a5cfe7d4e8f7f7f7d9f0d3a6dba05aae611b783700441b"
    ).map(colors);
    
    var PRGn = ramp(scheme$1);
    
    var scheme$2 = new Array(3).concat(
      "e9a3c9f7f7f7a1d76a",
      "d01c8bf1b6dab8e1864dac26",
      "d01c8bf1b6daf7f7f7b8e1864dac26",
      "c51b7de9a3c9fde0efe6f5d0a1d76a4d9221",
      "c51b7de9a3c9fde0eff7f7f7e6f5d0a1d76a4d9221",
      "c51b7dde77aef1b6dafde0efe6f5d0b8e1867fbc414d9221",
      "c51b7dde77aef1b6dafde0eff7f7f7e6f5d0b8e1867fbc414d9221",
      "8e0152c51b7dde77aef1b6dafde0efe6f5d0b8e1867fbc414d9221276419",
      "8e0152c51b7dde77aef1b6dafde0eff7f7f7e6f5d0b8e1867fbc414d9221276419"
    ).map(colors);
    
    var PiYG = ramp(scheme$2);
    
    var scheme$3 = new Array(3).concat(
      "998ec3f7f7f7f1a340",
      "5e3c99b2abd2fdb863e66101",
      "5e3c99b2abd2f7f7f7fdb863e66101",
      "542788998ec3d8daebfee0b6f1a340b35806",
      "542788998ec3d8daebf7f7f7fee0b6f1a340b35806",
      "5427888073acb2abd2d8daebfee0b6fdb863e08214b35806",
      "5427888073acb2abd2d8daebf7f7f7fee0b6fdb863e08214b35806",
      "2d004b5427888073acb2abd2d8daebfee0b6fdb863e08214b358067f3b08",
      "2d004b5427888073acb2abd2d8daebf7f7f7fee0b6fdb863e08214b358067f3b08"
    ).map(colors);
    
    var PuOr = ramp(scheme$3);
    
    var scheme$4 = new Array(3).concat(
      "ef8a62f7f7f767a9cf",
      "ca0020f4a58292c5de0571b0",
      "ca0020f4a582f7f7f792c5de0571b0",
      "b2182bef8a62fddbc7d1e5f067a9cf2166ac",
      "b2182bef8a62fddbc7f7f7f7d1e5f067a9cf2166ac",
      "b2182bd6604df4a582fddbc7d1e5f092c5de4393c32166ac",
      "b2182bd6604df4a582fddbc7f7f7f7d1e5f092c5de4393c32166ac",
      "67001fb2182bd6604df4a582fddbc7d1e5f092c5de4393c32166ac053061",
      "67001fb2182bd6604df4a582fddbc7f7f7f7d1e5f092c5de4393c32166ac053061"
    ).map(colors);
    
    var RdBu = ramp(scheme$4);
    
    var scheme$5 = new Array(3).concat(
      "ef8a62ffffff999999",
      "ca0020f4a582bababa404040",
      "ca0020f4a582ffffffbababa404040",
      "b2182bef8a62fddbc7e0e0e09999994d4d4d",
      "b2182bef8a62fddbc7ffffffe0e0e09999994d4d4d",
      "b2182bd6604df4a582fddbc7e0e0e0bababa8787874d4d4d",
      "b2182bd6604df4a582fddbc7ffffffe0e0e0bababa8787874d4d4d",
      "67001fb2182bd6604df4a582fddbc7e0e0e0bababa8787874d4d4d1a1a1a",
      "67001fb2182bd6604df4a582fddbc7ffffffe0e0e0bababa8787874d4d4d1a1a1a"
    ).map(colors);
    
    var RdGy = ramp(scheme$5);
    
    var scheme$6 = new Array(3).concat(
      "fc8d59ffffbf91bfdb",
      "d7191cfdae61abd9e92c7bb6",
      "d7191cfdae61ffffbfabd9e92c7bb6",
      "d73027fc8d59fee090e0f3f891bfdb4575b4",
      "d73027fc8d59fee090ffffbfe0f3f891bfdb4575b4",
      "d73027f46d43fdae61fee090e0f3f8abd9e974add14575b4",
      "d73027f46d43fdae61fee090ffffbfe0f3f8abd9e974add14575b4",
      "a50026d73027f46d43fdae61fee090e0f3f8abd9e974add14575b4313695",
      "a50026d73027f46d43fdae61fee090ffffbfe0f3f8abd9e974add14575b4313695"
    ).map(colors);
    
    var RdYlBu = ramp(scheme$6);
    
    var scheme$7 = new Array(3).concat(
      "fc8d59ffffbf91cf60",
      "d7191cfdae61a6d96a1a9641",
      "d7191cfdae61ffffbfa6d96a1a9641",
      "d73027fc8d59fee08bd9ef8b91cf601a9850",
      "d73027fc8d59fee08bffffbfd9ef8b91cf601a9850",
      "d73027f46d43fdae61fee08bd9ef8ba6d96a66bd631a9850",
      "d73027f46d43fdae61fee08bffffbfd9ef8ba6d96a66bd631a9850",
      "a50026d73027f46d43fdae61fee08bd9ef8ba6d96a66bd631a9850006837",
      "a50026d73027f46d43fdae61fee08bffffbfd9ef8ba6d96a66bd631a9850006837"
    ).map(colors);
    
    var RdYlGn = ramp(scheme$7);
    
    var scheme$8 = new Array(3).concat(
      "fc8d59ffffbf99d594",
      "d7191cfdae61abdda42b83ba",
      "d7191cfdae61ffffbfabdda42b83ba",
      "d53e4ffc8d59fee08be6f59899d5943288bd",
      "d53e4ffc8d59fee08bffffbfe6f59899d5943288bd",
      "d53e4ff46d43fdae61fee08be6f598abdda466c2a53288bd",
      "d53e4ff46d43fdae61fee08bffffbfe6f598abdda466c2a53288bd",
      "9e0142d53e4ff46d43fdae61fee08be6f598abdda466c2a53288bd5e4fa2",
      "9e0142d53e4ff46d43fdae61fee08bffffbfe6f598abdda466c2a53288bd5e4fa2"
    ).map(colors);
    
    var Spectral = ramp(scheme$8);
    
    var scheme$9 = new Array(3).concat(
      "e5f5f999d8c92ca25f",
      "edf8fbb2e2e266c2a4238b45",
      "edf8fbb2e2e266c2a42ca25f006d2c",
      "edf8fbccece699d8c966c2a42ca25f006d2c",
      "edf8fbccece699d8c966c2a441ae76238b45005824",
      "f7fcfde5f5f9ccece699d8c966c2a441ae76238b45005824",
      "f7fcfde5f5f9ccece699d8c966c2a441ae76238b45006d2c00441b"
    ).map(colors);
    
    var BuGn = ramp(scheme$9);
    
    var scheme$a = new Array(3).concat(
      "e0ecf49ebcda8856a7",
      "edf8fbb3cde38c96c688419d",
      "edf8fbb3cde38c96c68856a7810f7c",
      "edf8fbbfd3e69ebcda8c96c68856a7810f7c",
      "edf8fbbfd3e69ebcda8c96c68c6bb188419d6e016b",
      "f7fcfde0ecf4bfd3e69ebcda8c96c68c6bb188419d6e016b",
      "f7fcfde0ecf4bfd3e69ebcda8c96c68c6bb188419d810f7c4d004b"
    ).map(colors);
    
    var BuPu = ramp(scheme$a);
    
    var scheme$b = new Array(3).concat(
      "e0f3dba8ddb543a2ca",
      "f0f9e8bae4bc7bccc42b8cbe",
      "f0f9e8bae4bc7bccc443a2ca0868ac",
      "f0f9e8ccebc5a8ddb57bccc443a2ca0868ac",
      "f0f9e8ccebc5a8ddb57bccc44eb3d32b8cbe08589e",
      "f7fcf0e0f3dbccebc5a8ddb57bccc44eb3d32b8cbe08589e",
      "f7fcf0e0f3dbccebc5a8ddb57bccc44eb3d32b8cbe0868ac084081"
    ).map(colors);
    
    var GnBu = ramp(scheme$b);
    
    var scheme$c = new Array(3).concat(
      "fee8c8fdbb84e34a33",
      "fef0d9fdcc8afc8d59d7301f",
      "fef0d9fdcc8afc8d59e34a33b30000",
      "fef0d9fdd49efdbb84fc8d59e34a33b30000",
      "fef0d9fdd49efdbb84fc8d59ef6548d7301f990000",
      "fff7ecfee8c8fdd49efdbb84fc8d59ef6548d7301f990000",
      "fff7ecfee8c8fdd49efdbb84fc8d59ef6548d7301fb300007f0000"
    ).map(colors);
    
    var OrRd = ramp(scheme$c);
    
    var scheme$d = new Array(3).concat(
      "ece2f0a6bddb1c9099",
      "f6eff7bdc9e167a9cf02818a",
      "f6eff7bdc9e167a9cf1c9099016c59",
      "f6eff7d0d1e6a6bddb67a9cf1c9099016c59",
      "f6eff7d0d1e6a6bddb67a9cf3690c002818a016450",
      "fff7fbece2f0d0d1e6a6bddb67a9cf3690c002818a016450",
      "fff7fbece2f0d0d1e6a6bddb67a9cf3690c002818a016c59014636"
    ).map(colors);
    
    var PuBuGn = ramp(scheme$d);
    
    var scheme$e = new Array(3).concat(
      "ece7f2a6bddb2b8cbe",
      "f1eef6bdc9e174a9cf0570b0",
      "f1eef6bdc9e174a9cf2b8cbe045a8d",
      "f1eef6d0d1e6a6bddb74a9cf2b8cbe045a8d",
      "f1eef6d0d1e6a6bddb74a9cf3690c00570b0034e7b",
      "fff7fbece7f2d0d1e6a6bddb74a9cf3690c00570b0034e7b",
      "fff7fbece7f2d0d1e6a6bddb74a9cf3690c00570b0045a8d023858"
    ).map(colors);
    
    var PuBu = ramp(scheme$e);
    
    var scheme$f = new Array(3).concat(
      "e7e1efc994c7dd1c77",
      "f1eef6d7b5d8df65b0ce1256",
      "f1eef6d7b5d8df65b0dd1c77980043",
      "f1eef6d4b9dac994c7df65b0dd1c77980043",
      "f1eef6d4b9dac994c7df65b0e7298ace125691003f",
      "f7f4f9e7e1efd4b9dac994c7df65b0e7298ace125691003f",
      "f7f4f9e7e1efd4b9dac994c7df65b0e7298ace125698004367001f"
    ).map(colors);
    
    var PuRd = ramp(scheme$f);
    
    var scheme$g = new Array(3).concat(
      "fde0ddfa9fb5c51b8a",
      "feebe2fbb4b9f768a1ae017e",
      "feebe2fbb4b9f768a1c51b8a7a0177",
      "feebe2fcc5c0fa9fb5f768a1c51b8a7a0177",
      "feebe2fcc5c0fa9fb5f768a1dd3497ae017e7a0177",
      "fff7f3fde0ddfcc5c0fa9fb5f768a1dd3497ae017e7a0177",
      "fff7f3fde0ddfcc5c0fa9fb5f768a1dd3497ae017e7a017749006a"
    ).map(colors);
    
    var RdPu = ramp(scheme$g);
    
    var scheme$h = new Array(3).concat(
      "edf8b17fcdbb2c7fb8",
      "ffffcca1dab441b6c4225ea8",
      "ffffcca1dab441b6c42c7fb8253494",
      "ffffccc7e9b47fcdbb41b6c42c7fb8253494",
      "ffffccc7e9b47fcdbb41b6c41d91c0225ea80c2c84",
      "ffffd9edf8b1c7e9b47fcdbb41b6c41d91c0225ea80c2c84",
      "ffffd9edf8b1c7e9b47fcdbb41b6c41d91c0225ea8253494081d58"
    ).map(colors);
    
    var YlGnBu = ramp(scheme$h);
    
    var scheme$i = new Array(3).concat(
      "f7fcb9addd8e31a354",
      "ffffccc2e69978c679238443",
      "ffffccc2e69978c67931a354006837",
      "ffffccd9f0a3addd8e78c67931a354006837",
      "ffffccd9f0a3addd8e78c67941ab5d238443005a32",
      "ffffe5f7fcb9d9f0a3addd8e78c67941ab5d238443005a32",
      "ffffe5f7fcb9d9f0a3addd8e78c67941ab5d238443006837004529"
    ).map(colors);
    
    var YlGn = ramp(scheme$i);
    
    var scheme$j = new Array(3).concat(
      "fff7bcfec44fd95f0e",
      "ffffd4fed98efe9929cc4c02",
      "ffffd4fed98efe9929d95f0e993404",
      "ffffd4fee391fec44ffe9929d95f0e993404",
      "ffffd4fee391fec44ffe9929ec7014cc4c028c2d04",
      "ffffe5fff7bcfee391fec44ffe9929ec7014cc4c028c2d04",
      "ffffe5fff7bcfee391fec44ffe9929ec7014cc4c02993404662506"
    ).map(colors);
    
    var YlOrBr = ramp(scheme$j);
    
    var scheme$k = new Array(3).concat(
      "ffeda0feb24cf03b20",
      "ffffb2fecc5cfd8d3ce31a1c",
      "ffffb2fecc5cfd8d3cf03b20bd0026",
      "ffffb2fed976feb24cfd8d3cf03b20bd0026",
      "ffffb2fed976feb24cfd8d3cfc4e2ae31a1cb10026",
      "ffffccffeda0fed976feb24cfd8d3cfc4e2ae31a1cb10026",
      "ffffccffeda0fed976feb24cfd8d3cfc4e2ae31a1cbd0026800026"
    ).map(colors);
    
    var YlOrRd = ramp(scheme$k);
    
    var scheme$l = new Array(3).concat(
      "deebf79ecae13182bd",
      "eff3ffbdd7e76baed62171b5",
      "eff3ffbdd7e76baed63182bd08519c",
      "eff3ffc6dbef9ecae16baed63182bd08519c",
      "eff3ffc6dbef9ecae16baed64292c62171b5084594",
      "f7fbffdeebf7c6dbef9ecae16baed64292c62171b5084594",
      "f7fbffdeebf7c6dbef9ecae16baed64292c62171b508519c08306b"
    ).map(colors);
    
    var Blues = ramp(scheme$l);
    
    var scheme$m = new Array(3).concat(
      "e5f5e0a1d99b31a354",
      "edf8e9bae4b374c476238b45",
      "edf8e9bae4b374c47631a354006d2c",
      "edf8e9c7e9c0a1d99b74c47631a354006d2c",
      "edf8e9c7e9c0a1d99b74c47641ab5d238b45005a32",
      "f7fcf5e5f5e0c7e9c0a1d99b74c47641ab5d238b45005a32",
      "f7fcf5e5f5e0c7e9c0a1d99b74c47641ab5d238b45006d2c00441b"
    ).map(colors);
    
    var Greens = ramp(scheme$m);
    
    var scheme$n = new Array(3).concat(
      "f0f0f0bdbdbd636363",
      "f7f7f7cccccc969696525252",
      "f7f7f7cccccc969696636363252525",
      "f7f7f7d9d9d9bdbdbd969696636363252525",
      "f7f7f7d9d9d9bdbdbd969696737373525252252525",
      "fffffff0f0f0d9d9d9bdbdbd969696737373525252252525",
      "fffffff0f0f0d9d9d9bdbdbd969696737373525252252525000000"
    ).map(colors);
    
    var Greys = ramp(scheme$n);
    
    var scheme$o = new Array(3).concat(
      "efedf5bcbddc756bb1",
      "f2f0f7cbc9e29e9ac86a51a3",
      "f2f0f7cbc9e29e9ac8756bb154278f",
      "f2f0f7dadaebbcbddc9e9ac8756bb154278f",
      "f2f0f7dadaebbcbddc9e9ac8807dba6a51a34a1486",
      "fcfbfdefedf5dadaebbcbddc9e9ac8807dba6a51a34a1486",
      "fcfbfdefedf5dadaebbcbddc9e9ac8807dba6a51a354278f3f007d"
    ).map(colors);
    
    var Purples = ramp(scheme$o);
    
    var scheme$p = new Array(3).concat(
      "fee0d2fc9272de2d26",
      "fee5d9fcae91fb6a4acb181d",
      "fee5d9fcae91fb6a4ade2d26a50f15",
      "fee5d9fcbba1fc9272fb6a4ade2d26a50f15",
      "fee5d9fcbba1fc9272fb6a4aef3b2ccb181d99000d",
      "fff5f0fee0d2fcbba1fc9272fb6a4aef3b2ccb181d99000d",
      "fff5f0fee0d2fcbba1fc9272fb6a4aef3b2ccb181da50f1567000d"
    ).map(colors);
    
    var Reds = ramp(scheme$p);
    
    var scheme$q = new Array(3).concat(
      "fee6cefdae6be6550d",
      "feeddefdbe85fd8d3cd94701",
      "feeddefdbe85fd8d3ce6550da63603",
      "feeddefdd0a2fdae6bfd8d3ce6550da63603",
      "feeddefdd0a2fdae6bfd8d3cf16913d948018c2d04",
      "fff5ebfee6cefdd0a2fdae6bfd8d3cf16913d948018c2d04",
      "fff5ebfee6cefdd0a2fdae6bfd8d3cf16913d94801a636037f2704"
    ).map(colors);
    
    var Oranges = ramp(scheme$q);
    
    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 c = cubehelix();
    
    function rainbow(t) {
      if (t < 0 || t > 1) t -= Math.floor(t);
      var ts = Math.abs(t - 0.5);
      c.h = 360 * t - 100;
      c.s = 1.5 - 1.5 * ts;
      c.l = 0.8 - 0.9 * ts;
      return c + "";
    }
    
    var c$1 = rgb(),
        pi_1_3 = Math.PI / 3,
        pi_2_3 = Math.PI * 2 / 3;
    
    function sinebow(t) {
      var x;
      t = (0.5 - t) * Math.PI;
      c$1.r = 255 * (x = Math.sin(t)) * x;
      c$1.g = 255 * (x = Math.sin(t + pi_1_3)) * x;
      c$1.b = 255 * (x = Math.sin(t + pi_2_3)) * x;
      return c$1 + "";
    }
    
    function ramp$1(range) {
      var n = range.length;
      return function(t) {
        return range[Math.max(0, Math.min(n - 1, Math.floor(t * n)))];
      };
    }
    
    var viridis = ramp$1(colors("44015444025645045745055946075a46085c460a5d460b5e470d60470e6147106347116447136548146748166848176948186a481a6c481b6d481c6e481d6f481f70482071482173482374482475482576482677482878482979472a7a472c7a472d7b472e7c472f7d46307e46327e46337f463480453581453781453882443983443a83443b84433d84433e85423f854240864241864142874144874045884046883f47883f48893e49893e4a893e4c8a3d4d8a3d4e8a3c4f8a3c508b3b518b3b528b3a538b3a548c39558c39568c38588c38598c375a8c375b8d365c8d365d8d355e8d355f8d34608d34618d33628d33638d32648e32658e31668e31678e31688e30698e306a8e2f6b8e2f6c8e2e6d8e2e6e8e2e6f8e2d708e2d718e2c718e2c728e2c738e2b748e2b758e2a768e2a778e2a788e29798e297a8e297b8e287c8e287d8e277e8e277f8e27808e26818e26828e26828e25838e25848e25858e24868e24878e23888e23898e238a8d228b8d228c8d228d8d218e8d218f8d21908d21918c20928c20928c20938c1f948c1f958b1f968b1f978b1f988b1f998a1f9a8a1e9b8a1e9c891e9d891f9e891f9f881fa0881fa1881fa1871fa28720a38620a48621a58521a68522a78522a88423a98324aa8325ab8225ac8226ad8127ad8128ae8029af7f2ab07f2cb17e2db27d2eb37c2fb47c31b57b32b67a34b67935b77937b87838b9773aba763bbb753dbc743fbc7340bd7242be7144bf7046c06f48c16e4ac16d4cc26c4ec36b50c46a52c56954c56856c66758c7655ac8645cc8635ec96260ca6063cb5f65cb5e67cc5c69cd5b6ccd5a6ece5870cf5773d05675d05477d1537ad1517cd2507fd34e81d34d84d44b86d54989d5488bd6468ed64590d74393d74195d84098d83e9bd93c9dd93ba0da39a2da37a5db36a8db34aadc32addc30b0dd2fb2dd2db5de2bb8de29bade28bddf26c0df25c2df23c5e021c8e020cae11fcde11dd0e11cd2e21bd5e21ad8e219dae319dde318dfe318e2e418e5e419e7e419eae51aece51befe51cf1e51df4e61ef6e620f8e621fbe723fde725"));
    
    var magma = ramp$1(colors("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"));
    
    var inferno = ramp$1(colors("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"));
    
    var plasma = ramp$1(colors("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"));
    
    function constant$b(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 = y32 * x10 - x32 * y10;
      if (t * t < epsilon$3) return;
      t = (x32 * (y0 - y2) - y32 * (x0 - x2)) / t;
      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)
      };
    }
    
    function arc() {
      var innerRadius = arcInnerRadius,
          outerRadius = arcOuterRadius,
          cornerRadius = constant$b(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),
                oc;
    
            // Restrict the corner radius according to the sector angle.
            if (da < pi$4 && (oc = intersect(x01, y01, x00, y00, x11, y11, x10, y10))) {
              var 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$b(+_), arc) : innerRadius;
      };
    
      arc.outerRadius = function(_) {
        return arguments.length ? (outerRadius = typeof _ === "function" ? _ : constant$b(+_), arc) : outerRadius;
      };
    
      arc.cornerRadius = function(_) {
        return arguments.length ? (cornerRadius = typeof _ === "function" ? _ : constant$b(+_), arc) : cornerRadius;
      };
    
      arc.padRadius = function(_) {
        return arguments.length ? (padRadius = _ == null ? null : typeof _ === "function" ? _ : constant$b(+_), arc) : padRadius;
      };
    
      arc.startAngle = function(_) {
        return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$b(+_), arc) : startAngle;
      };
    
      arc.endAngle = function(_) {
        return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$b(+_), arc) : endAngle;
      };
    
      arc.padAngle = function(_) {
        return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant$b(+_), 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;
        }
      }
    };
    
    function curveLinear(context) {
      return new Linear(context);
    }
    
    function x$3(p) {
      return p[0];
    }
    
    function y$3(p) {
      return p[1];
    }
    
    function line() {
      var x$$1 = x$3,
          y$$1 = y$3,
          defined = constant$b(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$$1 = typeof _ === "function" ? _ : constant$b(+_), line) : x$$1;
      };
    
      line.y = function(_) {
        return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$b(+_), line) : y$$1;
      };
    
      line.defined = function(_) {
        return arguments.length ? (defined = typeof _ === "function" ? _ : constant$b(!!_), 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;
    }
    
    function area$3() {
      var x0 = x$3,
          x1 = null,
          y0 = constant$b(0),
          y1 = y$3,
          defined = constant$b(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$b(+_), x1 = null, area) : x0;
      };
    
      area.x0 = function(_) {
        return arguments.length ? (x0 = typeof _ === "function" ? _ : constant$b(+_), area) : x0;
      };
    
      area.x1 = function(_) {
        return arguments.length ? (x1 = _ == null ? null : typeof _ === "function" ? _ : constant$b(+_), area) : x1;
      };
    
      area.y = function(_) {
        return arguments.length ? (y0 = typeof _ === "function" ? _ : constant$b(+_), y1 = null, area) : y0;
      };
    
      area.y0 = function(_) {
        return arguments.length ? (y0 = typeof _ === "function" ? _ : constant$b(+_), area) : y0;
      };
    
      area.y1 = function(_) {
        return arguments.length ? (y1 = _ == null ? null : typeof _ === "function" ? _ : constant$b(+_), 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$b(!!_), 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;
    }
    
    function descending$1(a, b) {
      return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
    }
    
    function identity$8(d) {
      return d;
    }
    
    function pie() {
      var value = identity$8,
          sortValues = descending$1,
          sort = null,
          startAngle = constant$b(0),
          endAngle = constant$b(tau$4),
          padAngle = constant$b(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$b(+_), 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$b(+_), pie) : startAngle;
      };
    
      pie.endAngle = function(_) {
        return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$b(+_), pie) : endAngle;
      };
    
      pie.padAngle = function(_) {
        return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant$b(+_), 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 lineRadial(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;
    }
    
    function lineRadial$1() {
      return lineRadial(line().curve(curveRadialLinear));
    }
    
    function areaRadial() {
      var a = area$3().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 lineRadial(x0()); }, delete a.lineX0;
      a.lineEndAngle = function() { return lineRadial(x1()); }, delete a.lineX1;
      a.lineInnerRadius = function() { return lineRadial(y0()); }, delete a.lineY0;
      a.lineOuterRadius = function() { return lineRadial(y1()); }, delete a.lineY1;
    
      a.curve = function(_) {
        return arguments.length ? c(curveRadial(_)) : c()._curve;
      };
    
      return a;
    }
    
    function pointRadial(x, y) {
      return [(y = +y) * Math.cos(x -= Math.PI / 2), y * Math.sin(x)];
    }
    
    var slice$6 = Array.prototype.slice;
    
    function linkSource(d) {
      return d.source;
    }
    
    function linkTarget(d) {
      return d.target;
    }
    
    function link$2(curve) {
      var source = linkSource,
          target = linkTarget,
          x$$1 = x$3,
          y$$1 = y$3,
          context = null;
    
      function link() {
        var buffer, argv = slice$6.call(arguments), s = source.apply(this, argv), t = target.apply(this, argv);
        if (!context) context = buffer = path();
        curve(context, +x$$1.apply(this, (argv[0] = s, argv)), +y$$1.apply(this, argv), +x$$1.apply(this, (argv[0] = t, argv)), +y$$1.apply(this, argv));
        if (buffer) return context = null, buffer + "" || null;
      }
    
      link.source = function(_) {
        return arguments.length ? (source = _, link) : source;
      };
    
      link.target = function(_) {
        return arguments.length ? (target = _, link) : target;
      };
    
      link.x = function(_) {
        return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant$b(+_), link) : x$$1;
      };
    
      link.y = function(_) {
        return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$b(+_), link) : y$$1;
      };
    
      link.context = function(_) {
        return arguments.length ? ((context = _ == null ? null : _), link) : context;
      };
    
      return link;
    }
    
    function curveHorizontal(context, x0, y0, x1, y1) {
      context.moveTo(x0, y0);
      context.bezierCurveTo(x0 = (x0 + x1) / 2, y0, x0, y1, x1, y1);
    }
    
    function curveVertical(context, x0, y0, x1, y1) {
      context.moveTo(x0, y0);
      context.bezierCurveTo(x0, y0 = (y0 + y1) / 2, x1, y0, x1, y1);
    }
    
    function curveRadial$1(context, x0, y0, x1, y1) {
      var p0 = pointRadial(x0, y0),
          p1 = pointRadial(x0, y0 = (y0 + y1) / 2),
          p2 = pointRadial(x1, y0),
          p3 = pointRadial(x1, y1);
      context.moveTo(p0[0], p0[1]);
      context.bezierCurveTo(p1[0], p1[1], p2[0], p2[1], p3[0], p3[1]);
    }
    
    function linkHorizontal() {
      return link$2(curveHorizontal);
    }
    
    function linkVertical() {
      return link$2(curveVertical);
    }
    
    function linkRadial() {
      var l = link$2(curveRadial$1);
      l.angle = l.x, delete l.x;
      l.radius = l.y, delete l.y;
      return l;
    }
    
    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),
        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,
        kr = Math.sin(pi$4 / 10) / Math.sin(7 * pi$4 / 10),
        kx = Math.sin(tau$4 / 10) * kr,
        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$2 = -0.5,
        s = Math.sqrt(3) / 2,
        k = 1 / Math.sqrt(12),
        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$2 * x0 - s * y0, s * x0 + c$2 * y0);
        context.lineTo(c$2 * x1 - s * y1, s * x1 + c$2 * y1);
        context.lineTo(c$2 * x2 - s * y2, s * x2 + c$2 * y2);
        context.lineTo(c$2 * x0 + s * y0, c$2 * y0 - s * x0);
        context.lineTo(c$2 * x1 + s * y1, c$2 * y1 - s * x1);
        context.lineTo(c$2 * x2 + s * y2, c$2 * y2 - s * x2);
        context.closePath();
      }
    };
    
    var symbols = [
      circle$2,
      cross$2,
      diamond,
      square,
      star,
      triangle,
      wye
    ];
    
    function symbol() {
      var type = constant$b(circle$2),
          size = constant$b(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$b(_), symbol) : type;
      };
    
      symbol.size = function(_) {
        return arguments.length ? (size = typeof _ === "function" ? _ : constant$b(+_), symbol) : size;
      };
    
      symbol.context = function(_) {
        return arguments.length ? (context = _ == null ? null : _, symbol) : context;
      };
    
      return symbol;
    }
    
    function noop$3() {}
    
    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;
      }
    };
    
    function basis$2(context) {
      return new Basis(context);
    }
    
    function BasisClosed(context) {
      this._context = context;
    }
    
    BasisClosed.prototype = {
      areaStart: noop$3,
      areaEnd: noop$3,
      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;
      }
    };
    
    function basisClosed$1(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;
      }
    };
    
    function basisOpen(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$3,
      areaEnd: noop$3,
      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$$1(context) {
        return new CardinalClosed(context, tension);
      }
    
      cardinal$$1.tension = function(tension) {
        return custom(+tension);
      };
    
      return cardinal$$1;
    })(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$$1(context) {
        return new CardinalOpen(context, tension);
      }
    
      cardinal$$1.tension = function(tension) {
        return custom(+tension);
      };
    
      return cardinal$$1;
    })(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$3,
      areaEnd: noop$3,
      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$$1(context) {
        return alpha ? new CatmullRomClosed(context, alpha) : new CardinalClosed(context, 0);
      }
    
      catmullRom$$1.alpha = function(alpha) {
        return custom(+alpha);
      };
    
      return catmullRom$$1;
    })(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$$1(context) {
        return alpha ? new CatmullRomOpen(context, alpha) : new CardinalOpen(context, 0);
      }
    
      catmullRom$$1.alpha = function(alpha) {
        return custom(+alpha);
      };
    
      return catmullRom$$1;
    })(0.5);
    
    function LinearClosed(context) {
      this._context = context;
    }
    
    LinearClosed.prototype = {
      areaStart: noop$3,
      areaEnd: noop$3,
      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);
      }
    };
    
    function linearClosed(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];
    }
    
    function natural(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;
      }
    };
    
    function step(context) {
      return new Step(context, 0.5);
    }
    
    function stepBefore(context) {
      return new Step(context, 0);
    }
    
    function stepAfter(context) {
      return new Step(context, 1);
    }
    
    function none$1(series, order) {
      if (!((n = series.length) > 1)) return;
      for (var i = 1, j, s0, s1 = series[order[0]], n, m = s1.length; i < n; ++i) {
        s0 = s1, s1 = series[order[i]];
        for (j = 0; j < m; ++j) {
          s1[j][1] += s1[j][0] = isNaN(s0[j][1]) ? s0[j][0] : s0[j][1];
        }
      }
    }
    
    function none$2(series) {
      var n = series.length, o = new Array(n);
      while (--n >= 0) o[n] = n;
      return o;
    }
    
    function stackValue(d, key) {
      return d[key];
    }
    
    function stack() {
      var keys = constant$b([]),
          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$b(slice$6.call(_)), stack) : keys;
      };
    
      stack.value = function(_) {
        return arguments.length ? (value = typeof _ === "function" ? _ : constant$b(+_), stack) : value;
      };
    
      stack.order = function(_) {
        return arguments.length ? (order = _ == null ? none$2 : typeof _ === "function" ? _ : constant$b(slice$6.call(_)), stack) : order;
      };
    
      stack.offset = function(_) {
        return arguments.length ? (offset = _ == null ? none$1 : _, stack) : offset;
      };
    
      return stack;
    }
    
    function expand(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);
    }
    
    function diverging$1(series, order) {
      if (!((n = series.length) > 1)) return;
      for (var i, j = 0, d, dy, yp, yn, n, m = series[order[0]].length; j < m; ++j) {
        for (yp = yn = 0, i = 0; i < n; ++i) {
          if ((dy = (d = series[order[i]][j])[1] - d[0]) >= 0) {
            d[0] = yp, d[1] = yp += dy;
          } else if (dy < 0) {
            d[1] = yn, d[0] = yn += dy;
          } else {
            d[0] = yp;
          }
        }
      }
    }
    
    function silhouette(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);
    }
    
    function wiggle(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);
    }
    
    function appearance(series) {
      var peaks = series.map(peak);
      return none$2(series).sort(function(a, b) { return peaks[a] - peaks[b]; });
    }
    
    function peak(series) {
      var i = -1, j = 0, n = series.length, vi, vj = -Infinity;
      while (++i < n) if ((vi = +series[i][1]) > vj) vj = vi, j = i;
      return j;
    }
    
    function ascending$3(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;
    }
    
    function descending$2(series) {
      return ascending$3(series).reverse();
    }
    
    function insideOut(series) {
      var n = series.length,
          i,
          j,
          sums = series.map(sum$2),
          order = appearance(series),
          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);
    }
    
    function reverse(series) {
      return none$2(series).reverse();
    }
    
    function constant$c(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;
      }
    };
    
    function voronoi() {
      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$$1 = typeof _ === "function" ? _ : constant$c(+_), voronoi) : x$$1;
      };
    
      voronoi.y = function(_) {
        return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$c(+_), voronoi) : y$$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;
    }
    
    function constant$d(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$9 = new Transform(1, 0, 0);
    
    transform$1.prototype = Transform.prototype;
    
    function transform$1(node) {
      return node.__zoom || identity$9;
    }
    
    function nopropagation$2() {
      exports.event.stopImmediatePropagation();
    }
    
    function noevent$2() {
      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$9;
    }
    
    function defaultWheelDelta() {
      return -exports.event.deltaY * (exports.event.deltaMode ? 120 : 1) / 500;
    }
    
    function defaultTouchable$1() {
      return "ontouchstart" in this;
    }
    
    function defaultConstrain(transform, extent, translateExtent) {
      var dx0 = transform.invertX(extent[0][0]) - translateExtent[0][0],
          dx1 = transform.invertX(extent[1][0]) - translateExtent[1][0],
          dy0 = transform.invertY(extent[0][1]) - translateExtent[0][1],
          dy1 = transform.invertY(extent[1][1]) - translateExtent[1][1];
      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 zoom() {
      var filter = defaultFilter$2,
          extent = defaultExtent$1,
          constrain = defaultConstrain,
          wheelDelta = defaultWheelDelta,
          touchable = defaultTouchable$1,
          scaleExtent = [0, Infinity],
          translateExtent = [[-Infinity, -Infinity], [Infinity, Infinity]],
          duration = 250,
          interpolate = interpolateZoom,
          gestures = [],
          listeners = dispatch("start", "zoom", "end"),
          touchstarting,
          touchending,
          touchDelay = 500,
          wheelDelay = 150,
          clickDistance2 = 0;
    
      function zoom(selection$$1) {
        selection$$1
            .property("__zoom", defaultTransform)
            .on("wheel.zoom", wheeled)
            .on("mousedown.zoom", mousedowned)
            .on("dblclick.zoom", dblclicked)
          .filter(touchable)
            .on("touchstart.zoom", touchstarted)
            .on("touchmove.zoom", touchmoved)
            .on("touchend.zoom touchcancel.zoom", touchended)
            .style("touch-action", "none")
            .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
      }
    
      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, translateExtent);
        });
      };
    
      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), translateExtent);
        });
      };
    
      zoom.translateTo = function(selection$$1, x, y) {
        zoom.transform(selection$$1, function() {
          var e = extent.apply(this, arguments),
              t = this.__zoom,
              p = centroid(e);
          return constrain(identity$9.translate(p[0], p[1]).scale(t.k).translate(
            typeof x === "function" ? -x.apply(this, arguments) : -x,
            typeof y === "function" ? -y.apply(this, arguments) : -y
          ), e, translateExtent);
        });
      };
    
      function scale(transform, k) {
        k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], 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 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(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(scaleExtent[0], Math.min(scaleExtent[1], t.k * Math.pow(2, wheelDelta.apply(this, arguments)))),
            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, translateExtent));
    
        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),
            x0 = exports.event.clientX,
            y0 = exports.event.clientY;
    
        dragDisable(exports.event.view);
        nopropagation$2();
        g.mouse = [p, this.__zoom.invert(p)];
        interrupt(this);
        g.start();
    
        function mousemoved() {
          noevent$2();
          if (!g.moved) {
            var dx = exports.event.clientX - x0, dy = exports.event.clientY - y0;
            g.moved = dx * dx + dy * dy > clickDistance2;
          }
          g.zoom("mouse", constrain(translate(g.that.__zoom, g.mouse[0] = mouse(g.that), g.mouse[1]), g.extent, translateExtent));
        }
    
        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), translateExtent);
    
        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, translateExtent));
      }
    
      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.wheelDelta = function(_) {
        return arguments.length ? (wheelDelta = typeof _ === "function" ? _ : constant$d(+_), zoom) : wheelDelta;
      };
    
      zoom.filter = function(_) {
        return arguments.length ? (filter = typeof _ === "function" ? _ : constant$d(!!_), zoom) : filter;
      };
    
      zoom.touchable = function(_) {
        return arguments.length ? (touchable = typeof _ === "function" ? _ : constant$d(!!_), zoom) : touchable;
      };
    
      zoom.extent = function(_) {
        return arguments.length ? (extent = typeof _ === "function" ? _ : constant$d([[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]]), zoom) : extent;
      };
    
      zoom.scaleExtent = function(_) {
        return arguments.length ? (scaleExtent[0] = +_[0], scaleExtent[1] = +_[1], zoom) : [scaleExtent[0], scaleExtent[1]];
      };
    
      zoom.translateExtent = function(_) {
        return arguments.length ? (translateExtent[0][0] = +_[0][0], translateExtent[1][0] = +_[1][0], translateExtent[0][1] = +_[0][1], translateExtent[1][1] = +_[1][1], zoom) : [[translateExtent[0][0], translateExtent[0][1]], [translateExtent[1][0], translateExtent[1][1]]];
      };
    
      zoom.constrain = function(_) {
        return arguments.length ? (constrain = _, zoom) : constrain;
      };
    
      zoom.duration = function(_) {
        return arguments.length ? (duration = +_, zoom) : duration;
      };
    
      zoom.interpolate = function(_) {
        return arguments.length ? (interpolate = _, zoom) : interpolate;
      };
    
      zoom.on = function() {
        var value = listeners.on.apply(listeners, arguments);
        return value === listeners ? zoom : value;
      };
    
      zoom.clickDistance = function(_) {
        return arguments.length ? (clickDistance2 = (_ = +_) * _, zoom) : Math.sqrt(clickDistance2);
      };
    
      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 = thresholdSturges;
    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.lch = lch;
    exports.gray = gray;
    exports.cubehelix = cubehelix;
    exports.contours = contours;
    exports.contourDensity = density;
    exports.dispatch = dispatch;
    exports.drag = drag;
    exports.dragDisable = dragDisable;
    exports.dragEnable = yesdrag;
    exports.dsvFormat = dsvFormat;
    exports.csvParse = csvParse;
    exports.csvParseRows = csvParseRows;
    exports.csvFormat = csvFormat;
    exports.csvFormatBody = csvFormatBody;
    exports.csvFormatRows = csvFormatRows;
    exports.tsvParse = tsvParse;
    exports.tsvParseRows = tsvParseRows;
    exports.tsvFormat = tsvFormat;
    exports.tsvFormatBody = tsvFormatBody;
    exports.tsvFormatRows = tsvFormatRows;
    exports.autoType = autoType;
    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.blob = blob;
    exports.buffer = buffer;
    exports.dsv = dsv;
    exports.csv = csv$1;
    exports.tsv = tsv$1;
    exports.image = image;
    exports.json = json;
    exports.text = text;
    exports.xml = xml;
    exports.html = html;
    exports.svg = svg;
    exports.forceCenter = center$1;
    exports.forceCollide = collide;
    exports.forceLink = link;
    exports.forceManyBody = manyBody;
    exports.forceRadial = radial;
    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$1;
    exports.geoBounds = bounds;
    exports.geoCentroid = centroid;
    exports.geoCircle = circle;
    exports.geoClipAntimeridian = clipAntimeridian;
    exports.geoClipCircle = clipCircle;
    exports.geoClipExtent = extent$1;
    exports.geoClipRectangle = clipRectangle;
    exports.geoContains = contains$1;
    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.geoEqualEarth = equalEarth;
    exports.geoEqualEarthRaw = equalEarthRaw;
    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.geoNaturalEarth1 = naturalEarth1;
    exports.geoNaturalEarth1Raw = naturalEarth1Raw;
    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.interpolateDiscrete = discrete;
    exports.interpolateHue = hue$1;
    exports.interpolateNumber = interpolateNumber;
    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.piecewise = piecewise;
    exports.quantize = quantize;
    exports.path = path;
    exports.polygonArea = area$2;
    exports.polygonCentroid = centroid$1;
    exports.polygonHull = hull;
    exports.polygonContains = contains$2;
    exports.polygonLength = length$2;
    exports.quadtree = quadtree;
    exports.randomUniform = uniform;
    exports.randomNormal = normal;
    exports.randomLogNormal = logNormal;
    exports.randomBates = bates;
    exports.randomIrwinHall = irwinHall;
    exports.randomExponential = exponential$1;
    exports.scaleBand = band;
    exports.scalePoint = point$1;
    exports.scaleIdentity = identity$7;
    exports.scaleLinear = linear$2;
    exports.scaleLog = log$1;
    exports.scaleSymlog = symlog;
    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.scaleSequential = sequential;
    exports.scaleSequentialLog = sequentialLog;
    exports.scaleSequentialPow = sequentialPow;
    exports.scaleSequentialSqrt = sequentialSqrt;
    exports.scaleSequentialSymlog = sequentialSymlog;
    exports.scaleSequentialQuantile = sequentialQuantile;
    exports.scaleDiverging = diverging;
    exports.scaleDivergingLog = divergingLog;
    exports.scaleDivergingPow = divergingPow;
    exports.scaleDivergingSqrt = divergingSqrt;
    exports.scaleDivergingSymlog = divergingSymlog;
    exports.tickFormat = tickFormat;
    exports.schemeCategory10 = category10;
    exports.schemeAccent = Accent;
    exports.schemeDark2 = Dark2;
    exports.schemePaired = Paired;
    exports.schemePastel1 = Pastel1;
    exports.schemePastel2 = Pastel2;
    exports.schemeSet1 = Set1;
    exports.schemeSet2 = Set2;
    exports.schemeSet3 = Set3;
    exports.interpolateBrBG = BrBG;
    exports.schemeBrBG = scheme;
    exports.interpolatePRGn = PRGn;
    exports.schemePRGn = scheme$1;
    exports.interpolatePiYG = PiYG;
    exports.schemePiYG = scheme$2;
    exports.interpolatePuOr = PuOr;
    exports.schemePuOr = scheme$3;
    exports.interpolateRdBu = RdBu;
    exports.schemeRdBu = scheme$4;
    exports.interpolateRdGy = RdGy;
    exports.schemeRdGy = scheme$5;
    exports.interpolateRdYlBu = RdYlBu;
    exports.schemeRdYlBu = scheme$6;
    exports.interpolateRdYlGn = RdYlGn;
    exports.schemeRdYlGn = scheme$7;
    exports.interpolateSpectral = Spectral;
    exports.schemeSpectral = scheme$8;
    exports.interpolateBuGn = BuGn;
    exports.schemeBuGn = scheme$9;
    exports.interpolateBuPu = BuPu;
    exports.schemeBuPu = scheme$a;
    exports.interpolateGnBu = GnBu;
    exports.schemeGnBu = scheme$b;
    exports.interpolateOrRd = OrRd;
    exports.schemeOrRd = scheme$c;
    exports.interpolatePuBuGn = PuBuGn;
    exports.schemePuBuGn = scheme$d;
    exports.interpolatePuBu = PuBu;
    exports.schemePuBu = scheme$e;
    exports.interpolatePuRd = PuRd;
    exports.schemePuRd = scheme$f;
    exports.interpolateRdPu = RdPu;
    exports.schemeRdPu = scheme$g;
    exports.interpolateYlGnBu = YlGnBu;
    exports.schemeYlGnBu = scheme$h;
    exports.interpolateYlGn = YlGn;
    exports.schemeYlGn = scheme$i;
    exports.interpolateYlOrBr = YlOrBr;
    exports.schemeYlOrBr = scheme$j;
    exports.interpolateYlOrRd = YlOrRd;
    exports.schemeYlOrRd = scheme$k;
    exports.interpolateBlues = Blues;
    exports.schemeBlues = scheme$l;
    exports.interpolateGreens = Greens;
    exports.schemeGreens = scheme$m;
    exports.interpolateGreys = Greys;
    exports.schemeGreys = scheme$n;
    exports.interpolatePurples = Purples;
    exports.schemePurples = scheme$o;
    exports.interpolateReds = Reds;
    exports.schemeReds = scheme$p;
    exports.interpolateOranges = Oranges;
    exports.schemeOranges = scheme$q;
    exports.interpolateCubehelixDefault = cubehelix$3;
    exports.interpolateRainbow = rainbow;
    exports.interpolateWarm = warm;
    exports.interpolateCool = cool;
    exports.interpolateSinebow = sinebow;
    exports.interpolateViridis = viridis;
    exports.interpolateMagma = magma;
    exports.interpolateInferno = inferno;
    exports.interpolatePlasma = plasma;
    exports.create = create;
    exports.creator = creator;
    exports.local = local;
    exports.matcher = matcher;
    exports.mouse = mouse;
    exports.namespace = namespace;
    exports.namespaces = namespaces;
    exports.clientPoint = point;
    exports.select = select;
    exports.selectAll = selectAll;
    exports.selection = selection;
    exports.selector = selector;
    exports.selectorAll = selectorAll;
    exports.style = styleValue;
    exports.touch = touch;
    exports.touches = touches;
    exports.window = defaultView;
    exports.customEvent = customEvent;
    exports.arc = arc;
    exports.area = area$3;
    exports.line = line;
    exports.pie = pie;
    exports.areaRadial = areaRadial;
    exports.radialArea = areaRadial;
    exports.lineRadial = lineRadial$1;
    exports.radialLine = lineRadial$1;
    exports.pointRadial = pointRadial;
    exports.linkHorizontal = linkHorizontal;
    exports.linkVertical = linkVertical;
    exports.linkRadial = linkRadial;
    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.stackOffsetDiverging = diverging$1;
    exports.stackOffsetNone = none$1;
    exports.stackOffsetSilhouette = silhouette;
    exports.stackOffsetWiggle = wiggle;
    exports.stackOrderAppearance = appearance;
    exports.stackOrderAscending = ascending$3;
    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$9;
    
    Object.defineProperty(exports, '__esModule', { value: true });
    
    })));