javascript - 如何在 D3.js 的 Hierarchical Edge Bundling 中控制组节点距离

Question

这是 D3 中 HEB 可视化示例的链接。

http://mbostock.github.io/d3/talk/20111116/bundle.html

我注意到在可视化中，组之间有一个明显的距离(或所谓的空间)，显然这个组之间的距离大于同一组内节点之间的距离。但是我并没有真正得到代码的哪一部分控制了这个距离。任何人都知道这里是如何控制距离的？我想在我自己的 HEB 中使用此功能。

Answer 1

组间距离由D3集群布局决定。默认行为是在组之间留出一个节点大小的空白空间。

这可以通过向集群布局提供自定义 separation() 函数来修改。要添加的关键行是:

    .separation(function(a, b) { return (a.parent == b.parent ? 1 : 5 ) })

这会将组距离增加到五个节点宽度。

通过选择其他值代替5可以得到:

这是完整的例子:

var diameter = 300,
    radius = diameter / 2,
    innerRadius = radius - 80;

var cluster = d3.layout.cluster()
    .separation(function(a, b) { return (a.parent == b.parent ? 1 : 5 ) })
    .size([360, innerRadius])
    .sort(null)
    .value(function(d) { return d.size; });

var bundle = d3.layout.bundle();

var line = d3.svg.line.radial()
    .interpolate("bundle")
    .tension(.85)
    .radius(function(d) { return d.y; })
    .angle(function(d) { return d.x / 180 * Math.PI; });

var svg = d3.select("body").append("svg")
    .attr("width", diameter)
    .attr("height", diameter)
    .append("g")
    .attr("transform", "translate(" + radius + "," + radius + ")");

var classes = getData();

var nodes = cluster.nodes(packageHierarchy(classes)),
    links = packageImports(nodes);

svg.selectAll(".link")
    .data(bundle(links))
   .enter()
    .append("path")
    .attr("class", "link")
    .attr("d", line);

svg.selectAll(".node")
    .data(nodes.filter(function(n) { return !n.children; }))
   .enter()
    .append("g")
    .attr("class", "node")
    .attr("transform", function(d) {
        return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")";
    })
    .append("text")
    .attr("dx", function(d) { return d.x < 180 ? 8 : -8; })
    .attr("dy", ".31em")
    .attr("text-anchor", function(d) { return d.x < 180 ? "start" : "end"; })
    .attr("transform", function(d) { return d.x < 180 ? null : "rotate(180)"; })
    .text(function(d) { return d.key; });

d3.select(self.frameElement).style("height", diameter + "px");

// Lazily construct the package hierarchy from class names.
function packageHierarchy(classes) {
  var map = {};

  function find(name, data) {
    var node = map[name], i;
    if (!node) {
      node = map[name] = data || {name: name, children: []};
      if (name.length) {
        node.parent = find(name.substring(0, i = name.lastIndexOf(".")));
        node.parent.children.push(node);
        node.key = name.substring(i + 1);
      }
    }
    return node;
  }

  classes.forEach(function(d) {
    find(d.name, d);
  });

  return map[""];
}

// Return a list of imports for the given array of nodes.
function packageImports(nodes) {
  var map = {},
      imports = [];

  // Compute a map from name to node.
  nodes.forEach(function(d) {
    map[d.name] = d;
  });

  // For each import, construct a link from the source to target node.
  nodes.forEach(function(d) {
    if (d.imports) d.imports.forEach(function(i) {
      imports.push({source: map[d.name], target: map[i]});
    });
  });

  return imports;
}

function getData() {
    return [
        {"name":"Female.Ann",     "imports":["Male.Andrew"]},
        {"name":"Female.Brenda",  "imports":["Male.Bill"]},
        {"name":"Female.Claudia", "imports":["Male.Andrew"]},
        {"name":"Female.Claudia", "imports":["Male.Bill"]},
        {"name":"Female.Deborah", "imports":["Male.Darryl"]},
        {"name":"Female.Emily",   "imports":["Male.Andrew"]},
        {"name":"Female.Flora",   "imports":["Male.Darryl"]},
        {"name":"Female.Gia",     "imports":["Male.Darryl"]},
        {"name":"Female.Hannah",  "imports":["Male.Curtis"]},
        {"name":"Female.Irene",   "imports":["Male.Hugh"]},
        {"name":"Male.Andrew",    "imports":["Female.Emily"]},
        {"name":"Male.Bill",      "imports":["Female.Emily"]},
        {"name":"Male.Curtis",    "imports":["Female.Emily"]},
        {"name":"Male.Darryl",    "imports":["Female.Claudia"]},
        {"name":"Male.Edgar",     "imports":["Female.Claudia"]},
        {"name":"Male.Franklin",  "imports":["Female.Claudia"]},
        {"name":"Male.George",    "imports":["Female.Claudia"]},
        {"name":"Male.Hugh",      "imports":["Female.Claudia"]},
    ];
};

.node {
  font: 11px "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.link {
  stroke: steelblue;
  stroke-opacity: .4;
  fill: none;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>