I am new to d3 was trying to make a chord diagram.
But I am able to make it with four arrays only, how can I make it for 10? I was going through another example for d3 but I was still not able to understand it.
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
font: 10px sans-serif;
}
.chord path {
fill-opacity: .67;
stroke: #000;
stroke-width: .5px;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
// From http://mkweb.bcgsc.ca/circos/guide/tables/
var matrix = [
[11975, 5871, 8916, 2868],
[ 1951, 10048, 2060, 6171],
[ 8010, 16145, 8090, 8045],
[ 1013, 990, 940, 6907]
];
var chord = d3.layout.chord()
.padding(.05)
.sortSubgroups(d3.descending)
.matrix(matrix);
var width = 960,
height = 500,
innerRadius = Math.min(width, height) * .41,
outerRadius = innerRadius * 1.1;
var fill = d3.scale.ordinal()
.domain(d3.range(4))
.range(["#000000", "#FFDD89", "#957244", "#F26223"]);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
svg.append("g").selectAll("path")
.data(chord.groups)
.enter().append("path")
.style("fill", function(d) { return fill(d.index); })
.style("stroke", function(d) { return fill(d.index); })
.attr("d", d3.svg.arc().innerRadius(innerRadius).outerRadius(outerRadius))
.on("mouseover", fade(.1))
.on("mouseout", fade(1));
var ticks = svg.append("g").selectAll("g")
.data(chord.groups)
.enter().append("g").selectAll("g")
.data(groupTicks)
.enter().append("g")
.attr("transform", function(d) {
return "rotate(" + (d.angle * 180 / Math.PI - 90) + ")"
+ "translate(" + outerRadius + ",0)";
});
ticks.append("line")
.attr("x1", 1)
.attr("y1", 0)
.attr("x2", 5)
.attr("y2", 0)
.style("stroke", "#000");
ticks.append("text")
.attr("x", 8)
.attr("dy", ".35em")
.attr("transform", function(d) { return d.angle > Math.PI ? "rotate(180)translate(-16)" : null; })
.style("text-anchor", function(d) { return d.angle > Math.PI ? "end" : null; })
.text(function(d) { return d.label; });
svg.append("g")
.attr("class", "chord")
.selectAll("path")
.data(chord.chords)
.enter().append("path")
.attr("d", d3.svg.chord().radius(innerRadius))
.style("fill", function(d) { return fill(d.target.index); })
.style("opacity", 1);
// Returns an array of tick angles and labels, given a group.
function groupTicks(d) {
var k = (d.endAngle - d.startAngle) / d.value;
return d3.range(0, d.value, 1000).map(function(v, i) {
return {
angle: v * k + d.startAngle,
label: i % 5 ? null : v / 1000 + "k"
};
});
}
// Returns an event handler for fading a given chord group.
function fade(opacity) {
return function(g, i) {
svg.selectAll(".chord path")
.filter(function(d) { return d.source.index != i && d.target.index != i; })
.transition()
.style("opacity", opacity);
};
}
</script>`
Can you explain how does the map function work?
The matrix you specify needs to be a square matrix to designate the flow between elements. That is, each array must be as long as there are arrays. Here is an example with a 10x10 matrix.