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     .separation(function(a, b) { return (a.parent == b.parent ? 1 : 2) / a.depth; });
 6 
 7 var diagonal = d3.svg.diagonal.radial()
 8     .projection(function(d) { return [d.y, d.x / 180 * Math.PI]; });
 9 
10 var vis = d3.select("#chart").append("svg:svg")
11     .attr("width", r * 2)
12     .attr("height", r * 2 - 150)
13   .append("svg:g")
14     .attr("transform", "translate(" + r + "," + r + ")");
15 
16 d3.json("../data/flare.json", function(json) {
17   var nodes = tree.nodes(json);
18 
19   var link = vis.selectAll("path.link")
20       .data(tree.links(nodes))
21     .enter().append("svg:path")
22       .attr("class", "link")
23       .attr("d", diagonal);
24 
25   var node = vis.selectAll("g.node")
26       .data(nodes)
27     .enter().append("svg:g")
28       .attr("class", "node")
29       .attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
30 
31   node.append("svg:circle")
32       .attr("r", 4.5);
33 
34   node.append("svg:text")
35       .attr("dx", function(d) { return d.x < 180 ? 8 : -8; })
36       .attr("dy", ".31em")
37       .attr("text-anchor", function(d) { return d.x < 180 ? "start" : "end"; })
38       .attr("transform", function(d) { return d.x < 180 ? null : "rotate(180)"; })
39       .text(function(d) { return d.name; });
40 });