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@max-mapper
Forked from mbostock/.block
Created February 6, 2012 17:24
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Clustered Force Layout + Custom Gravity
<!DOCTYPE html>
<meta charset="utf-8">
<style>
circle {
stroke: #fff;
}
</style>
<body>
<script src="http://mbostock.github.com/d3/d3.js?2.7.4"></script>
<script src="http://mbostock.github.com/d3/d3.geom.js?2.7.4"></script>
<script src="http://mbostock.github.com/d3/d3.layout.js?2.7.4"></script>
<script>
var margin = {top: 0, right: 0, bottom: 0, left: 0},
width = 640 - margin.left - margin.right,
height = 320 - margin.top - margin.bottom;
var n = 10,
m = 10,
padding = 6,
radius = d3.scale.sqrt().range([0, 50]),
color = d3.scale.category10().domain(d3.range(m));
var nodes = d3.range(n).map(function() {
var i = Math.floor(Math.random() * m),
v = (i + 1) / m * -Math.log(Math.random());
return {
radius: radius(v),
color: color(i)
};
});
var force = d3.layout.force()
.nodes(nodes)
.size([width, height])
.gravity(0)
.charge(0)
.on("tick", tick)
.start();
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var circle = svg.selectAll("circle")
.data(nodes)
.enter().append("circle")
.attr("r", function(d) { return d.radius; })
.style("fill", function(d) { return d.color; })
.call(force.drag);
function tick(e) {
circle
.each(cluster(10 * e.alpha * e.alpha))
.each(collide(.5))
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
}
// Move d to be adjacent to the cluster node.
function cluster(alpha) {
var max = {};
// Find the largest node for each cluster.
nodes.forEach(function(d) {
if (!(d.color in max) || (d.radius > max[d.color].radius)) {
max[d.color] = d;
}
});
return function(d) {
var node = max[d.color],
l,
r,
x,
y,
k = 1,
i = -1;
// For cluster nodes, apply custom gravity.
if (node == d) {
node = {x: width / 2, y: height / 2, radius: -d.radius};
k = .1 * Math.sqrt(d.radius);
}
x = d.x - node.x;
y = d.y - node.y;
l = Math.sqrt(x * x + y * y);
r = d.radius + node.radius;
if (l != r) {
l = (l - r) / l * alpha * k;
d.x -= x *= l;
d.y -= y *= l;
node.x += x;
node.y += y;
}
};
}
// Resolves collisions between d and all other circles.
function collide(alpha) {
var quadtree = d3.geom.quadtree(nodes);
return function(d) {
var r = d.radius + radius.domain()[1] + padding,
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.point && (quad.point !== d)) {
var x = d.x - quad.point.x,
y = d.y - quad.point.y,
l = Math.sqrt(x * x + y * y),
r = d.radius + quad.point.radius + (d.color !== quad.point.color) * padding;
if (l < r) {
l = (l - r) / l * alpha;
d.x -= x *= l;
d.y -= y *= l;
quad.point.x += x;
quad.point.y += y;
}
}
return x1 > nx2
|| x2 < nx1
|| y1 > ny2
|| y2 < ny1;
});
};
}
</script>
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