D3 Sankey 链接缩放问题

d3.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 = d3.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(
        d3.sum(node.sourceLinks, value),
        d3.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 = d3.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 = d3.nest()
      .key(function(d) {
        return d.x;
      })
      .sortKeys(d3.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 = d3.min(nodesByBreadth, function(nodes) {
        return (size[1] - (nodes.length - 1) * nodePadding) / d3.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, breadth) {
        nodes.forEach(function(node) {
          if (node.targetLinks.length) {
            var y = d3.sum(node.targetLinks, weightedSource) / d3.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 = d3.sum(node.sourceLinks, weightedTarget) / d3.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(function(a, b) {
          return a.value > b.value ? -1 : a.value < b.value ? 1 : 0;
        });
        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;
};


/* ------------------- our code ------------------------ */

var units = "Widgets";

var linkData = [{
  "source": 7,
  "target": 6,
  "productIdx": "8350",
  "qty": 27200,
  "mv": 3054016,
  "matrixCost": 300,
  "sourceNodeName": "G",
  "targetNodeName": "L",
  "value": 27200
}, {
  "source": 7,
  "target": 11,
  "productIdx": "8350",
  "qty": 196599,
  "mv": 22074135.72,
  "matrixCost": 5000,
  "sourceNodeName": "G",
  "targetNodeName": "K",
  "value": 196599
}, {
  "source": 9,
  "target": 11,
  "productIdx": "8350",
  "qty": 113401,
  "mv": 12732664.28,
  "matrixCost": 5020,
  "sourceNodeName": "I",
  "targetNodeName": "K",
  "value": 113401
}, {
  "source": 2,
  "target": 10,
  "productIdx": "8350",
  "qty": 0,
  "mv": 0,
  "matrixCost": 100015,
  "sourceNodeName": "C",
  "targetNodeName": "J",
  "value": 0
}, {
  "source": 0,
  "target": 10,
  "productIdx": "8350",
  "qty": 2500000,
  "mv": 280700000,
  "matrixCost": 100033,
  "sourceNodeName": "A",
  "targetNodeName": "J",
  "value": 2500000
}, {
  "source": 9,
  "target": 5,
  "productIdx": "8350",
  "qty": 0,
  "mv": 0,
  "matrixCost": 240048,
  "sourceNodeName": "I",
  "targetNodeName": "F",
  "value": 0
}, {
  "source": 9,
  "target": 3,
  "productIdx": "8350",
  "qty": 1309599,
  "mv": 147041775.72,
  "matrixCost": 240048,
  "sourceNodeName": "I",
  "targetNodeName": "D",
  "value": 1309599
}, {
  "source": 0,
  "target": 5,
  "productIdx": "8350",
  "qty": 0,
  "mv": 0,
  "matrixCost": 240048,
  "sourceNodeName": "A",
  "targetNodeName": "F",
  "value": 0
}, {
  "source": 2,
  "target": 5,
  "productIdx": "8350",
  "qty": 0,
  "mv": 0,
  "matrixCost": 240048,
  "sourceNodeName": "C",
  "targetNodeName": "F",
  "value": 0
}, {
  "source": 2,
  "target": 3,
  "productIdx": "8350",
  "qty": 3250408,
  "mv": 364955810.24,
  "matrixCost": 240048,
  "sourceNodeName": "C",
  "targetNodeName": "D",
  "value": 3250408
}, {
  "source": 8,
  "target": 1,
  "productIdx": "8350",
  "qty": 0,
  "mv": 0,
  "matrixCost": 240048,
  "sourceNodeName": "H",
  "targetNodeName": "B",
  "value": 0
}, {
  "source": 4,
  "target": 1,
  "productIdx": "8350",
  "qty": 10,
  "mv": 1122.8,
  "matrixCost": 240048,
  "sourceNodeName": "E",
  "targetNodeName": "B",
  "value": 10
}]

var nodes = [{
  "nodeId": 0,
  "nodeName": "A",
  "entityCd": "16G"
}, {
  "nodeId": 1,
  "nodeName": "B",
  "entityCd": "161"
}, {
  "nodeId": 2,
  "nodeName": "C",
  "entityCd": "16G"
}, {
  "nodeId": 3,
  "nodeName": "D",
  "entityCd": "XX"
}, {
  "nodeId": 4,
  "nodeName": "E",
  "entityCd": "XX"
}, {
  "nodeId": 5,
  "nodeName": "F",
  "entityCd": "XX"
}, {
  "nodeId": 6,
  "nodeName": "L",
  "entityCd": "16G",
  "bucketCd": "LoantoCoverDublinPBCustShort",
  "bucketName": "Loan to Cover Dublin PB Cust Short",
  "bucketType": "U"
}, {
  "nodeId": 7,
  "nodeName": "G",
  "entityCd": "16G"
}, {
  "nodeId": 8,
  "nodeName": "H",
  "entityCd": "XX"
}, {
  "nodeId": 9,
  "nodeName": "I",
  "entityCd": "16G"
}, {
  "nodeId": 10,
  "nodeName": "J",
  "entityCd": "16G"
}, {
  "nodeId": 11,
  "nodeName": "K",
  "entityCd": "16G"
}]
var formatNumber = d3.format(",.0f"), // zero decimal places
  format = function(d) {
    return formatNumber(d)
  };

// append the svg object to the body of the page
var svg = d3.select("#" + "chart"),
  width = +svg.attr("width"),
  height = +svg.attr("height");


var sankey = d3.sankey()
  .nodeWidth(10)
  .nodePadding(10)
  .size([width - 1, height - 6]);

var path = sankey.link();

d3.selectAll('.tooltip-sankey').style("visibility", "hidden");
var tooltip = d3.select("body")
  .append("div")
  .attr("class", "tooltip-sankey")
  .style("position", "absolute")
  .style("z-index", "10")
  .style("visibility", "hidden");

// load the data

sankey
  .nodes(nodes)
  .links(linkData)
  .layout(32);

//node scale
var maxVal_node = d3.max(nodes.map(m => m.value));
var minVal_node = d3.min(nodes.map(m => m.value));
var nodeScale = d3.scaleLinear().domain([minVal_node, maxVal_node])
  .range([10, 120]);

// add in the links
var link = svg.append("g").selectAll(".link")
  .data(linkData)
  .enter().append("path")
  .attr("class", "link-sankey")
  .attr("d", path)
  .style('stroke', function(d) {
    return d.color;
  }).style("stroke-width", function(d) {
    return Math.max(1, d.dy)
  })
  .sort(function(a, b) {
    return b.dy - a.dy;
  })

  .on("mouseover", function(d) {
    var sourceId, targetId;
    for (var item in d.source.sourceLinks)
      if (d.value === d.source.sourceLinks[item].value) sourceId = item;
    for (var item in d.target.targetLinks)
      if (d.value === d.target.targetLinks[item].value) targetId = item;
    var source = d3.select("#inner-rect-" + d.source.id + "-" + sourceId);
    var target = d3.select("#inner-rect-" + d.target.id + "-" + targetId);
    source.style("stroke-opacity", 1).style("fill", "#1f77b4");
    target.style("stroke-opacity", 1).style("fill", "#1f77b4");

    //update text - one line
    var sourceText = d3.select("#text-" + d.source.id);
    sourceText.text(d.source.nodeName + ' : ' + d.value);
    var targetText = d3.select("#text-" + d.target.id);
    targetText.text(d.target.nodeName + ' : ' + d.value);

    tooltip.html("Source: <b>" + d.source.nodeName + "</b><br/>Target: <b>" + d.target.nodeName + "</b><br/>Identifier: <b>" + +"</b>" + "</b><br/>Qty: <b>" + format(d.value) + "</b>" + "</b><br/>Mv($): <b>" + format(d.mv) + "</b>");
    return tooltip.style("visibility", "visible");
  })
  .on("mousemove", function() {
    var tooltipWidth = parseInt(tooltip.style("width"));
    if (window.innerWidth - d3.event.pageX < tooltipWidth) return tooltip.style("top", (d3.event.pageY - 10) + "px").style("left", (d3.event.pageX - tooltipWidth) + "px");
    return tooltip.style("top", (d3.event.pageY - 10) + "px").style("left", (d3.event.pageX + 10) + "px");
  })
  .on("mouseout", function(d) {
    var sourceId, targetId;
    for (var item in d.source.sourceLinks)
      if (d.value === d.source.sourceLinks[item].value) sourceId = item;
    for (var item in d.target.targetLinks)
      if (d.value === d.target.targetLinks[item].value) targetId = item;

    //update text - one line
    var sourceText = d3.select("#text-" + d.source.id);
    sourceText.text(d.source.nodeName + ' : ' + d.source.value);
    var targetText = d3.select("#text-" + d.target.id);
    targetText.text(d.target.nodeName + ' : ' + d.target.value);

    return tooltip.style("visibility", "hidden");
  });

// add in the nodes
var node = svg.append("g").selectAll(".node")
  .data(nodes)
  .enter().append("g")
  .on("click", showConnections)
  .on("mouseover", function(d) {
    if (d.totalPledge == 0 || d.totalBorrow == 0) {
      tooltip.html("Name: <b>" + d.nodeName + "</b><br/>Total Qty: <b>" + format(d.value) + "</b>");
    } else {
      tooltip.html("Name: <b>" + d.nodeName + "</b><br/>Total Qty: <b>" + format(d.value) + "</b>");
    }
    return tooltip.style("visibility", "visible");
  })
  .on("mousemove", function() {
    var tooltipWidth = parseInt(tooltip.style("width"));
    if (window.innerWidth - d3.event.pageX < tooltipWidth) return tooltip.style("top", (d3.event.pageY - 10) + "px").style("left", (d3.event.pageX - tooltipWidth) + "px");
    return tooltip.style("top", (d3.event.pageY - 10) + "px").style("left", (d3.event.pageX + 10) + "px");
  })
  .on("mouseout", function() {
    return tooltip.style("visibility", "hidden");
  })
  .attr("class", "node")
  .attr("transform", function(d) {
    return "translate(" + d.x + "," + d.y + ")";
  })
  .on("click", showConnections);

// add the rectangles for the nodes
node.append("rect")
  .attr("height", function(d) {
    return nodeScale(d.value);
  })
  .attr("width", sankey.nodeWidth())
  .style("fill", function() {
    return "#605f66"
  })
  .style("stroke", function(d) {
    return d3.rgb(d.color).darker(2);
  })
  .on("click", showConnections)


// add in the title for the nodes
node.append("text")
  .attr("x", -6)
  .attr("y", function(d) {
    return nodeScale(d.value) / 2
  })
  .attr("dy", ".15em")
  .attr("text-anchor", "end")
  //.style("font-size", "10px")
  .attr("transform", null)
  .attr("class", "nodeText")
  .text(function(d) {
    return d.nodeName;
  })
  .filter(function(d) {
    return d.x < width / 2;
  })
  .attr("x", 6 + sankey.nodeWidth())
  .attr("text-anchor", "start");

function showConnections(d) {
  if (!d3.select(this).classed("selected")) {
    d3.select(this).classed("selected", true);
    d3.select(this).style("stroke", "black")
      .style("stroke-opacity", 0.2);
    //If this link is connected to the node
    link.style("stroke-opacity", function(l) {
      if (l.source.nodeName == d.nodeName || l.target.nodeName == d.nodeName) {
        return 0.6;
      } else
        return 0.2;
    });
  } else {
    d3.select(this).classed("selected", false);
    d3.select(this).style("stroke", "black")
      .style("stroke-opacity", 0.2)
    link.style("stroke-opacity", function() {
      return 0.2;
    });
  }
}

.node rect {
  cursor: move;
}

.link {
  fill: none;
  stroke: #000;
  stroke-opacity: .2;
}

.link:hover {
  stroke-opacity: .5;
}

* {
  font: 11px sans-serif;
}

.linkLabel {
  z-index: 10;
}

svg line.links {
  stroke: #999999;
  stroke-opacity: 0.6;
  stroke-width: 1px;
}

.link-sankey {
  fill: none;
  stroke: #1f77b4;
  stroke-opacity: .2;
}

.link-sankey:hover {
  stroke-opacity: .5 !important;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.13.0/d3.min.js"></script>
<svg width="550" height="400" id="chart"></svg>