text: // https://github.com/d3/d3-sankey Version 0.4.2. Copyright 2017 Mike Bostock.
  (function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('d3-array'), require('d3-collection'), require('d3-interpolate')) :
    typeof define === 'function' && define.amd ? define(['exports', 'd3-array', 'd3-collection', 'd3-interpolate'], factory) :
    (factory((global.d3 = global.d3 || {}),global.d3,global.d3,global.d3));
  }(this, (function (exports,d3Array,d3Collection,d3Interpolate) { 'use strict';
  
  var sankey = function() {
    var sankey = {},
        nodeWidth = 24,
        nodePadding = 8,
        size = [1, 1],
        nodes = [],
        links = [];
  
    sankey.nodeWidth = function(_) {
      if (!arguments.length) return nodeWidth;
      nodeWidth = +_;
      return sankey;
    };
  
    sankey.nodePadding = function(_) {
      if (!arguments.length) return nodePadding;
      nodePadding = +_;
      return sankey;
    };
  
    sankey.nodes = function(_) {
      if (!arguments.length) return nodes;
      nodes = _;
      return sankey;
    };
  
    sankey.links = function(_) {
      if (!arguments.length) return links;
      links = _;
      return sankey;
    };
  
    sankey.size = function(_) {
      if (!arguments.length) return size;
      size = _;
      return sankey;
    };
  
    sankey.layout = function(iterations) {
      computeNodeLinks();
      computeNodeValues();
      computeNodeBreadths();
      computeNodeDepths(iterations);
      computeLinkDepths();
      return sankey;
    };
  
    sankey.relayout = function() {
      computeLinkDepths();
      return sankey;
    };
  
    sankey.link = function() {
      var curvature = .5;
  
      function link(d) {
        var x0 = d.source.x + d.source.dx,
            x1 = d.target.x,
            xi = d3Interpolate.interpolateNumber(x0, x1),
            x2 = xi(curvature),
            x3 = xi(1 - curvature),
            y0 = d.source.y + d.sy + d.dy / 2,
            y1 = d.target.y + d.ty + d.dy / 2;
        return "M" + x0 + "," + y0
             + "C" + x2 + "," + y0
             + " " + x3 + "," + y1
             + " " + x1 + "," + y1;
      }
  
      link.curvature = function(_) {
        if (!arguments.length) return curvature;
        curvature = +_;
        return link;
      };
  
      return link;
    };
  
    // Populate the sourceLinks and targetLinks for each node.
    // Also, if the source and target are not objects, assume they are indices.
    function computeNodeLinks() {
      nodes.forEach(function(node) {
        node.sourceLinks = [];
        node.targetLinks = [];
      });
      links.forEach(function(link) {
        var source = link.source,
            target = link.target;
        if (typeof source === "number") source = link.source = nodes[link.source];
        if (typeof target === "number") target = link.target = nodes[link.target];
        source.sourceLinks.push(link);
        target.targetLinks.push(link);
      });
    }
  
    // Compute the value (size) of each node by summing the associated links.
    function computeNodeValues() {
      nodes.forEach(function(node) {
        node.value = Math.max(
          d3Array.sum(node.sourceLinks, value),
          d3Array.sum(node.targetLinks, value)
        );
      });
    }
  
    // Iteratively assign the breadth (x-position) for each node.
    // Nodes are assigned the maximum breadth of incoming neighbors plus one;
    // nodes with no incoming links are assigned breadth zero, while
    // nodes with no outgoing links are assigned the maximum breadth.
    function computeNodeBreadths() {
      var remainingNodes = nodes,
          nextNodes,
          x = 0;
  
      while (remainingNodes.length) {
        nextNodes = [];
        remainingNodes.forEach(function(node) {
          node.x = x;
          node.dx = nodeWidth;
          node.sourceLinks.forEach(function(link) {
            if (nextNodes.indexOf(link.target) < 0) {
              nextNodes.push(link.target);
            }
          });
        });
        remainingNodes = nextNodes;
        ++x;
      }
  
      //
      moveSinksRight(x);
      scaleNodeBreadths((size[0] - nodeWidth) / (x - 1));
    }
  
    // function moveSourcesRight() {
    //   nodes.forEach(function(node) {
    //     if (!node.targetLinks.length) {
    //       node.x = min(node.sourceLinks, function(d) { return d.target.x; }) - 1;
    //     }
    //   });
    // }
  
    function moveSinksRight(x) {
      nodes.forEach(function(node) {
        if (!node.sourceLinks.length) {
          node.x = x - 1;
        }
      });
    }
  
    function scaleNodeBreadths(kx) {
      nodes.forEach(function(node) {
        node.x *= kx;
      });
    }
  
    function computeNodeDepths(iterations) {
      var nodesByBreadth = d3Collection.nest()
          .key(function(d) { return d.x; })
          .sortKeys(d3Array.ascending)
          .entries(nodes)
          .map(function(d) { return d.values; });
  
      //
      initializeNodeDepth();
      resolveCollisions();
      for (var alpha = 1; iterations > 0; --iterations) {
        relaxRightToLeft(alpha *= .99);
        resolveCollisions();
        relaxLeftToRight(alpha);
        resolveCollisions();
      }
  
      function initializeNodeDepth() {
        var ky = d3Array.min(nodesByBreadth, function(nodes) {
          return (size[1] - (nodes.length - 1) * nodePadding) / d3Array.sum(nodes, value);
        });
  
        nodesByBreadth.forEach(function(nodes) {
          nodes.forEach(function(node, i) {
            node.y = i;
            node.dy = node.value * ky;
          });
        });
  
        links.forEach(function(link) {
          link.dy = link.value * ky;
        });
      }
  
      function relaxLeftToRight(alpha) {
        nodesByBreadth.forEach(function(nodes) {
          nodes.forEach(function(node) {
            if (node.targetLinks.length) {
              var y = d3Array.sum(node.targetLinks, weightedSource) / d3Array.sum(node.targetLinks, value);
              node.y += (y - center(node)) * alpha;
            }
          });
        });
  
        function weightedSource(link) {
          return center(link.source) * link.value;
        }
      }
  
      function relaxRightToLeft(alpha) {
        nodesByBreadth.slice().reverse().forEach(function(nodes) {
          nodes.forEach(function(node) {
            if (node.sourceLinks.length) {
              var y = d3Array.sum(node.sourceLinks, weightedTarget) / d3Array.sum(node.sourceLinks, value);
              node.y += (y - center(node)) * alpha;
            }
          });
        });
  
        function weightedTarget(link) {
          return center(link.target) * link.value;
        }
      }
  
      function resolveCollisions() {
        nodesByBreadth.forEach(function(nodes) {
          var node,
              dy,
              y0 = 0,
              n = nodes.length,
              i;
  
          // Push any overlapping nodes down.
          nodes.sort(ascendingDepth);
          for (i = 0; i < n; ++i) {
            node = nodes[i];
            dy = y0 - node.y;
            if (dy > 0) node.y += dy;
            y0 = node.y + node.dy + nodePadding;
          }
  
          // If the bottommost node goes outside the bounds, push it back up.
          dy = y0 - nodePadding - size[1];
          if (dy > 0) {
            y0 = node.y -= dy;
  
            // Push any overlapping nodes back up.
            for (i = n - 2; i >= 0; --i) {
              node = nodes[i];
              dy = node.y + node.dy + nodePadding - y0;
              if (dy > 0) node.y -= dy;
              y0 = node.y;
            }
          }
        });
      }
  
      function ascendingDepth(a, b) {
        return a.y - b.y;
      }
    }
  
    function computeLinkDepths() {
      nodes.forEach(function(node) {
        node.sourceLinks.sort(ascendingTargetDepth);
        node.targetLinks.sort(ascendingSourceDepth);
      });
      nodes.forEach(function(node) {
        var sy = 0, ty = 0;
        node.sourceLinks.forEach(function(link) {
          link.sy = sy;
          sy += link.dy;
        });
        node.targetLinks.forEach(function(link) {
          link.ty = ty;
          ty += link.dy;
        });
      });
  
      function ascendingSourceDepth(a, b) {
        return a.source.y - b.source.y;
      }
  
      function ascendingTargetDepth(a, b) {
        return a.target.y - b.target.y;
      }
    }
  
    function center(node) {
      return node.y + node.dy / 2;
    }
  
    function value(link) {
      return link.value;
    }
  
    return sankey;
  };
  
  exports.sankey = sankey;
  
  Object.defineProperty(exports, '__esModule', { value: true });
  
  })));