shancarter · February 8, 2018 21:13
diff --git a/index.html b/index.html
 <!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>
	<!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>