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@bstaats
Created September 28, 2011 23:19
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Force Layouts - Multiple Foci Collision
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
<title>Force Layouts - Multiple Foci Collision</title>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.js"></script>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.geom.js"></script>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.layout.js"></script>
<style type="text/css">
rect{
fill: white;
}
circle {
stroke: #000;
stroke-opacity: .5;
}
</style>
</head>
<body>
<div id="body">
<div id="chart"></div>
</div>
<script type="text/javascript">
var w = 960,
h = 500;
var nodes = d3.range(5).map(function(i) {
return {type: Math.random() * 5 | 0,
radius: 30,
fixed:true,
type:i,
x: (i+1) * (w / 6),
y: h / 2};
}),
color = d3.scale.category10();
var force = d3.layout.force()
.gravity(0)
.charge(0)
.nodes(nodes)
.size([w, h]);
force.start();
var svg = d3.select("#chart").append("svg:svg")
.attr("width", w)
.attr("height", h);
svg.append("svg:rect")
.attr("width", w)
.attr("height", h);
svg.selectAll("circle")
.data(nodes)
.enter().append("svg:circle")
.attr("r", function(d) { return d.radius - 2; })
.style("fill", function(d, i) { return color(d.type); });
force.on("tick", function(e) {
var q = d3.geom.quadtree(nodes),
k = e.alpha * .1,
i = 0,
n = nodes.length,
o;
while (++i < n) {
o = nodes[i];
if (o.fixed) continue;
c = nodes[o.type];
o.x += (c.x - o.x) * k;
o.y += (c.y - o.y) * k;
q.visit(collide(o));
}
svg.selectAll("circle")
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
});
var p0;
svg.on("mousemove", function() {
var p1 = d3.svg.mouse(this),
node = {radius:Math.random() * 12 + 4, type: Math.random() * 5 | 0, x: p1[0], y: p1[1], px: (p0 || (p0 = p1))[0], py: p0[1]};
p0 = p1;
svg.append("svg:circle")
.data([node])
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; })
.attr("r", function(d) { return d.radius - 2; })
.style("fill", function(d) {return color(d.type);})
.transition()
.delay(3000)
.attr("r", 1e-6)
.each("end", function() { nodes.splice(6, 1); })
.remove();
nodes.push(node);
force.resume();
});
function collide(node) {
var r = node.radius + 16,
nx1 = node.x - r,
nx2 = node.x + r,
ny1 = node.y - r,
ny2 = node.y + r;
return function(quad, x1, y1, x2, y2) {
if (quad.point && (quad.point !== node)) {
var x = node.x - quad.point.x,
y = node.y - quad.point.y,
l = Math.sqrt(x * x + y * y),
r = node.radius + quad.point.radius;
if (l < r) {
l = (l - r) / l * .5;
node.px += x * l;
node.py += y * l;
}
}
return x1 > nx2
|| x2 < nx1
|| y1 > ny2
|| y2 < ny1;
};
}
</script>
</body>
</html>
@johan
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johan commented Oct 23, 2011

Thanks for this tidy example! I've had so much fun forking and tinkering with it :-) (http://bl.ocks.org/1306938)

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