Question

我是d3js的新手，正在尝试构建sankey图。除了两个连接的D-> K和F-> M之外，所有链接都是彩色的。由于节点是可拖动的，因此，如果将D节点向下移动一点，则可以看到链接出现。对于F同样，但方向相反。

有人可以帮助我，以便链接显示在前面，而不会移动。

<!DOCTYPE html>
<meta charset='utf-8'>
<title>Sankey</title>
<script src='https://cdnjs.cloudflare.com/ajax/libs/d3/4.4.0/d3.min.js'></script>
<script>
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 && x < nodes.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(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;
};
</script>
<style>
.node rect {
  cursor: move;
  fill-opacity: .9;
  shape-rendering: crispEdges;
}
 
.node text {
  pointer-events: none;
  font-family: Helvetica;
  font-size: 12px;
}
</style>
<body>
<div id='chart'>
<script>
const units = '';
const margin = {top: 10, right: 10, bottom: 10, left: 10};
const width = 660 - margin.left - margin.right;
const height = 300 - margin.top - margin.bottom;

// zero decimal places
const formatNumber = d3.format(',.0f');

const format = d => `${formatNumber(d)} ${units}`;

d3.select('#chart')
  .style('visibility', 'visible');

// append the svg canvas to the page
const svg = d3.select('#chart').append('svg')
  .attr('width', width + margin.left + margin.right)
  .attr('height', height + margin.top + margin.bottom)
  .append('g')
    .attr('transform', `translate(${margin.left},${margin.top})`);

// set the sankey diagram properties
const sankey = d3.sankey()
  .nodeWidth(12)
  .nodePadding(10)
  .size([width, height]);

const path = sankey.link();

// append a defs (for definition) element to your SVG
const defs = svg.append('defs');

// load the data
var graph = { "nodes": [ { "node": 0, "name": "A" }, { "node": 1, "name": "B" }, { "node": 2, "name": "C" }, { "node": 3, "name": "D" }, { "node": 4, "name": "E" }, { "node": 5, "name": "F" }, { "node": 6, "name": "G" }, { "node": 7, "name": "H" }, { "node": 8, "name": "I" }, { "node": 9, "name": "J" }, { "node": 10, "name": "K" }, { "node": 11, "name": "L" }, { "node": 12, "name": "M" } ], "links": [ { "source": 0, "target": 3, "value": 17740 }, { "source": 0, "target": 4, "value": 8680 }, { "source": 0, "target": 5, "value": 2735 }, { "source": 0, "target": 6, "value": 4964 }, { "source": 0, "target": 7, "value": 3520 }, { "source": 1, "target": 3, "value": 6865 }, { "source": 1, "target": 4, "value": 8476 }, { "source": 1, "target": 5, "value": 2215 }, { "source": 1, "target": 6, "value": 4805 }, { "source": 1, "target": 7, "value": 4187 }, { "source": 2, "target": 3, "value": 7573 }, { "source": 2, "target": 4, "value": 2709 }, { "source": 2, "target": 5, "value": 803 }, { "source": 2, "target": 6, "value": 2208 }, { "source": 2, "target": 7, "value": 1066 }, { "source": 3, "target": 8, "value": 708 }, { "source": 3, "target": 9, "value": 6609 }, { "source": 3, "target": 10, "value": 26808 }, { "source": 3, "target": 11, "value": 190 }, { "source": 3, "target": 12, "value": 188 }, { "source": 4, "target": 8, "value": 642 }, { "source": 4, "target": 9, "value": 4219 }, { "source": 4, "target": 10, "value": 17101 }, { "source": 4, "target": 11, "value": 104 }, { "source": 4, "target": 12, "value": 223 }, { "source": 5, "target": 8, "value": 106 }, { "source": 5, "target": 9, "value": 934 }, { "source": 5, "target": 10, "value": 5731 }, { "source": 5, "target": 11, "value": 14 }, { "source": 5, "target": 12, "value": 24 }, { "source": 6, "target": 8, "value": 282 }, { "source": 6, "target": 9, "value": 2214 }, { "source": 6, "target": 10, "value": 10908 }, { "source": 6, "target": 11, "value": 104 }, { "source": 6, "target": 12, "value": 172 }, { "source": 7, "target": 8, "value": 86 }, { "source": 7, "target": 9, "value": 293 }, { "source": 7, "target": 10, "value": 10449 }, { "source": 7, "target": 11, "value": 10 }, { "source": 7, "target": 12, "value": 12 } ] };

  sankey
    .nodes(graph.nodes)
    .links(graph.links)
    .layout(13); // any value > 13 breaks the link gradient
 
  // add in the links
  const link = svg.append('g').selectAll('.link')
    .data(graph.links)
    .enter().append('path')
      .attr('class', 'link')
      .attr('d', path)
      .style('stroke-width', d => Math.max(1, d.dy))
      .style('fill', 'none')
      .style('stroke-opacity', 0.18)
      .sort((a, b) => b.dy - a.dy)
      .on('mouseover', function() {
        d3.select(this).style('stroke-opacity', 0.5);
      })
      .on('mouseout', function() {
        d3.select(this).style('stroke-opacity', 0.2);
      });
 
  // add the link titles
  link.append('title')
    .text(d => `${d.source.name} → ${d.target.name}\n${format(d.value)}`);
 
  // add in the nodes
  const node = svg.append('g').selectAll('.node')
    .data(graph.nodes)
    .enter().append('g')
      .attr('class', 'node')
      .attr('transform', d => `translate(${d.x},${d.y})`)
      .call(d3.drag()
        .subject(d => d)
        .on('start', function() { 
          this.parentNode.appendChild(this); })
        .on('drag', dragmove));
 
  // add the rectangles for the nodes
  node.append('rect')
    .attr('height', d => d.dy)
    .attr('width', sankey.nodeWidth())
    .style('fill', '#000')
    .append('title')
      .text(d => `${d.name}\n${format(d.value)}`);
 
  // add in the title for the nodes
  node.append('text')
    .attr('x', -6)
    .attr('y', d => d.dy / 2)
    .attr('dy', '.35em')
    .attr('text-anchor', 'end')
    .attr('transform', null)
    .text(d => d.name)
    .filter(d => d.x < width / 2)
      .attr('x', 6 + sankey.nodeWidth())
      .attr('text-anchor', 'start');

  // add gradient to links
  link.style('stroke', (d, i) => {
    console.log('d from gradient stroke func', d);

    // make unique gradient ids  
    const gradientID = `gradient${i}`;

    const startColor = d.source.color;
    const stopColor = d.target.color;

    console.log('startColor', startColor);
    console.log('stopColor', stopColor);

    const linearGradient = defs.append('linearGradient')
        .attr('id', gradientID);

    linearGradient.selectAll('stop') 
      .data([                             
          {offset: '10%', color: startColor },      
          {offset: '90%', color: stopColor }    
        ])                  
      .enter().append('stop')
      .attr('offset', d => {
        console.log('d.offset', d.offset);
        return d.offset; 
      })   
      .attr('stop-color', d => {
        //console.log('d.color', d.color);
        return d.color;
      });

    return `url(#${gradientID})`;
  })
 
// the function for moving the nodes
  function dragmove(d) {
    d3.select(this).attr('transform', 
      `translate(${d.x = Math.max(0, Math.min(width - d.dx, d3.event.x))},${d.y = Math.max(0, Math.min(height - d.dy, d3.event.y))})`);
    sankey.relayout();
    link.attr('d', path);
  }

</script>
</body>
</html>

d3js sankey链接未显示

0 个答案: