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@shancarter
Last active February 8, 2018 21:13
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Clustered Force Layout 4.0
<!doctype html>
<meta charset="utf-8">
<body>
<script src="//d3js.org/d3.v4.min.js"></script>
<script>
let margin = {top: 100, right: 100, bottom: 100, left: 100};
let width = 960,
height = 500,
padding = 1.5, // separation between same-color circles
clusterPadding = 6, // separation between different-color circles
maxRadius = 12;
let n = 200, // total number of nodes
m = 10, // number of distinct clusters
z = d3.scaleOrdinal(d3.schemeCategory20),
clusters = new Array(m);
let svg = d3.select('body')
.append('svg')
.attr('height', height)
.attr('width', width)
.append('g').attr('transform', 'translate(' + width / 2 + ',' + height / 2 + ')');
let nodes = d3.range(200).map(() => {
let i = Math.floor(Math.random() * m),
radius = Math.sqrt((i + 1) / m * -Math.log(Math.random())) * maxRadius,
d = {cluster: i, r: radius};
if (!clusters[i] || (radius > clusters[i].r)) clusters[i] = d;
return d;
});
let circles = svg.append('g')
.datum(nodes)
.selectAll('.circle')
.data(d => d)
.enter().append('circle')
.attr('r', (d) => d.r)
.attr('fill', (d) => z(d.cluster))
.attr('stroke', 'black')
.attr('stroke-width', 1);
let simulation = d3.forceSimulation(nodes)
.velocityDecay(0.2)
.force("x", d3.forceX().strength(.0005))
.force("y", d3.forceY().strength(.0005))
.force("collide", collide)
.force("cluster", clustering)
.on("tick", ticked);
function ticked() {
circles
.attr('cx', (d) => d.x)
.attr('cy', (d) => d.y);
}
// These are implementations of the custom forces.
function clustering(alpha) {
nodes.forEach(function(d) {
var cluster = clusters[d.cluster];
if (cluster === d) return;
var x = d.x - cluster.x,
y = d.y - cluster.y,
l = Math.sqrt(x * x + y * y),
r = d.r + cluster.r;
if (l !== r) {
l = (l - r) / l * alpha;
d.x -= x *= l;
d.y -= y *= l;
cluster.x += x;
cluster.y += y;
}
});
}
function collide(alpha) {
var quadtree = d3.quadtree()
.x((d) => d.x)
.y((d) => d.y)
.addAll(nodes);
nodes.forEach(function(d) {
var r = d.r + maxRadius + Math.max(padding, clusterPadding),
nx1 = d.x - r,
nx2 = d.x + r,
ny1 = d.y - r,
ny2 = d.y + r;
quadtree.visit(function(quad, x1, y1, x2, y2) {
if (quad.data && (quad.data !== d)) {
var x = d.x - quad.data.x,
y = d.y - quad.data.y,
l = Math.sqrt(x * x + y * y),
r = d.r + quad.data.r + (d.cluster === quad.data.cluster ? padding : clusterPadding);
if (l < r) {
l = (l - r) / l * alpha;
d.x -= x *= l;
d.y -= y *= l;
quad.data.x += x;
quad.data.y += y;
}
}
return x1 > nx2 || x2 < nx1 || y1 > ny2 || y2 < ny1;
});
});
}
</script>
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