<!DOCTYPE html>
<html>
<head>
<title>Donut Chart</title>
<script type="text/javascript" src="../../d3.js"></script>
<script type="text/javascript" src="../../d3.layout.js"></script>
<style type="text/css">
body {
font: 10px sans-serif;
}
</style>
</head>
<body>
<script type="text/javascript">
var w = 400,
h = 400,
r1 = Math.min(w, h) / 2,
r0 = r1 * .6,
n = 10,
q = 0,
data0 = d3.range(n).map(Math.random),
data1 = d3.range(n).map(Math.random),
data,
color = d3.scale.category20(),
arc = d3.svg.arc(),
donut = d3.layout.pie().sort(null);
var vis = d3.select("body")
.append("svg:svg")
.attr("width", w)
.attr("height", h);
vis.selectAll("g.arc")
.data(arcs(data0, data1))
.enter().append("svg:g")
.attr("class", "arc")
.attr("transform", "translate(" + r1 + "," + r1 + ")")
.append("svg:path")
.attr("fill", function(d, i) { return color(i); })
.attr("d", arc);
window.addEventListener("keypress", swap, false);
function arcs(data0, data1) {
var arcs0 = donut(data0),
arcs1 = donut(data1),
i = -1,
arc;
while (++i < n) {
arc = arcs0[i];
arc.innerRadius = r0;
arc.outerRadius = r1;
arc.next = arcs1[i];
}
return arcs0;
}
function swap() {
d3.selectAll("g.arc > path")
.data(++q & 1 ? arcs(data0, data1) : arcs(data1, data0))
.each(transitionSplit);
}
// 1. Wedges split into two rings.
function transitionSplit(d, i) {
d3.select(this)
.transition().duration(1000)
.attrTween("d", tweenArc({
innerRadius: i & 1 ? r0 : (r0 + r1) / 2,
outerRadius: i & 1 ? (r0 + r1) / 2 : r1
}))
.each("end", transitionRotate);
}
// 2. Wedges translate to be centered on their final position.
function transitionRotate(d, i) {
var a0 = d.next.startAngle + d.next.endAngle,
a1 = d.startAngle - d.endAngle;
d3.select(this)
.transition().duration(1000)
.attrTween("d", tweenArc({
startAngle: (a0 + a1) / 2,
endAngle: (a0 - a1) / 2
}))
.each("end", transitionResize);
}
// 3. Wedges then update their values, changing size.
function transitionResize(d, i) {
d3.select(this)
.transition().duration(1000)
.attrTween("d", tweenArc({
startAngle: d.next.startAngle,
endAngle: d.next.endAngle
}))
.each("end", transitionUnite);
}
// 4. Wedges reunite into a single ring.
function transitionUnite(d, i) {
d3.select(this)
.transition().duration(1000)
.attrTween("d", tweenArc({
innerRadius: r0,
outerRadius: r1
}));
}
function tweenArc(b) {
return function(a) {
var i = d3.interpolate(a, b);
for (var key in b) a[key] = b[key]; // update data
return function(t) {
return arc(i(t));
};
};
}
</script>
</body>
</html>