Node-Link Tree
Implementation based on work by Jeff Heer and Jason Davies using Buchheim et al.’s linear-time variant of the Reingold-Tilford algorithm. Data shows the Flare class hierarchy, also courtesy Jeff Heer.
Source Code
1 var r = 960 / 2;
2
3 var tree = d3.layout.tree()
4 .size([360, r - 120])
5 .sort(null)
6 .children(function(d) { return isNaN(d.value) ? d3.entries(d.value) : null; })
7 .separation(function(a, b) { return (a.parent == b.parent ? 1 : 2) / a.depth; });
8
9 var diagonal = d3.svg.diagonal()
10 .projection(function(d) {
11 var r = d.y, a = (d.x - 90) / 180 * Math.PI;
12 return [r * Math.cos(a), r * Math.sin(a)];
13 });
14
15 var vis = d3.select("#chart").append("svg:svg")
16 .attr("width", r * 2)
17 .attr("height", r * 2 - 150)
18 .append("svg:g")
19 .attr("transform", "translate(" + r + "," + r + ")");
20
21 d3.json("flare.json", function(json) {
22 var nodes = tree(d3.entries(json)[0]);
23
24 var link = vis.selectAll("path.link")
25 .data(tree.links(nodes))
26 .enter().append("svg:path")
27 .attr("class", "link")
28 .attr("d", diagonal);
29
30 var node = vis.selectAll("g.node")
31 .data(nodes)
32 .enter().append("svg:g")
33 .attr("class", "node")
34 .attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
35
36 node.append("svg:circle")
37 .attr("r", 4.5);
38
39 node.append("svg:text")
40 .attr("dx", function(d) { return d.x < 180 ? 8 : -8; })
41 .attr("dy", ".31em")
42 .attr("text-anchor", function(d) { return d.x < 180 ? "start" : "end"; })
43 .attr("transform", function(d) { return d.x < 180 ? null : "rotate(180)"; })
44 .text(function(d) { return d.data.key; });
45 });