1 // From http://mkweb.bcgsc.ca/circos/guide/tables/
 2 var chord = d3.layout.chord()
 3   .padding(.05)
 4   .sortSubgroups(d3.descending)
 5   .matrix([
 6     [11975,  5871, 8916, 2868],
 7     [ 1951, 10048, 2060, 6171],
 8     [ 8010, 16145, 8090, 8045],
 9     [ 1013,   990,  940, 6907]
10   ]);
11 
12 var w = 600,
13     h = 600,
14     r0 = Math.min(w, h) * .41,
15     r1 = r0 * 1.1;
16 
17 var fill = d3.scale.ordinal()
18     .domain(d3.range(4))
19     .range(["#000000", "#FFDD89", "#957244", "#F26223"]);
20 
21 var svg = d3.select("#chart")
22   .append("svg:svg")
23     .attr("width", w)
24     .attr("height", h)
25   .append("svg:g")
26     .attr("transform", "translate(" + w / 2 + "," + h / 2 + ")");
27 
28 svg.append("svg:g")
29   .selectAll("path")
30     .data(chord.groups)
31   .enter().append("svg:path")
32     .style("fill", function(d) { return fill(d.index); })
33     .style("stroke", function(d) { return fill(d.index); })
34     .attr("d", d3.svg.arc().innerRadius(r0).outerRadius(r1))
35     .on("mouseover", fade(.1))
36     .on("mouseout", fade(1));
37 
38 var ticks = svg.append("svg:g")
39   .selectAll("g")
40     .data(chord.groups)
41   .enter().append("svg:g")
42   .selectAll("g")
43     .data(groupTicks)
44   .enter().append("svg:g")
45     .attr("transform", function(d) {
46       return "rotate(" + (d.angle * 180 / Math.PI - 90) + ")"
47           + "translate(" + r1 + ",0)";
48     });
49 
50 ticks.append("svg:line")
51     .attr("x1", 1)
52     .attr("y1", 0)
53     .attr("x2", 5)
54     .attr("y2", 0)
55     .style("stroke", "#000");
56 
57 ticks.append("svg:text")
58     .attr("x", 8)
59     .attr("dy", ".35em")
60     .attr("text-anchor", function(d) {
61       return d.angle > Math.PI ? "end" : null;
62     })
63     .attr("transform", function(d) {
64       return d.angle > Math.PI ? "rotate(180)translate(-16)" : null;
65     })
66     .text(function(d) { return d.label; });
67 
68 svg.append("svg:g")
69     .attr("class", "chord")
70   .selectAll("path")
71     .data(chord.chords)
72   .enter().append("svg:path")
73     .style("fill", function(d) { return fill(d.target.index); })
74     .attr("d", d3.svg.chord().radius(r0))
75     .style("opacity", 1);
76 
77 /** Returns an array of tick angles and labels, given a group. */
78 function groupTicks(d) {
79   var k = (d.endAngle - d.startAngle) / d.value;
80   return d3.range(0, d.value, 1000).map(function(v, i) {
81     return {
82       angle: v * k + d.startAngle,
83       label: i % 5 ? null : v / 1000 + "k"
84     };
85   });
86 }
87 
88 /** Returns an event handler for fading a given chord group. */
89 function fade(opacity) {
90   return function(g, i) {
91     svg.selectAll("g.chord path")
92         .filter(function(d) {
93           return d.source.index != i && d.target.index != i;
94         })
95       .transition()
96         .style("opacity", opacity);
97   };
98 }