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force-multi-foci with convex hulls

I have modified the force-multi-foci example to add a convex hull around each cluster of nodes.

I achieved this by using d3.nest() to create a new dataset of clusters containing the nodes in each cluster. Then in the tick() method I create and update the path element for each cluster in this dataset.

<!DOCTYPE html>
<html>
<head>
<title>Force-Directed Layout with Convex Hull</title>
<script src="http://mbostock.github.com/d3/d3.js?2.9.2"></script>
</head>
<body>
<div id="chart"></div>
<script type="text/javascript">
var w = 960,
h = 500,
fill = d3.scale.category10(),
nodes = d3.range(100).map(Object);
var groups = d3.nest().key(function(d) { return d & 3; }).entries(nodes);
var groupPath = function(d) {
return "M" +
d3.geom.hull(d.values.map(function(i) { return [i.x, i.y]; }))
.join("L")
+ "Z";
};
var groupFill = function(d, i) { return fill(i & 3); };
var vis = d3.select("#chart").append("svg")
.attr("width", w)
.attr("height", h);
var force = d3.layout.force()
.nodes(nodes)
.links([])
.size([w, h])
.start();
var node = vis.selectAll("circle.node")
.data(nodes)
.enter().append("circle")
.attr("class", "node")
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; })
.attr("r", 8)
.style("fill", function(d, i) { return fill(i & 3); })
.style("stroke", function(d, i) { return d3.rgb(fill(i & 3)).darker(2); })
.style("stroke-width", 1.5)
.call(force.drag);
vis.style("opacity", 1e-6)
.transition()
.duration(1000)
.style("opacity", 1);
force.on("tick", function(e) {
// Push different nodes in different directions for clustering.
var k = 6 * e.alpha;
nodes.forEach(function(o, i) {
o.x += i & 2 ? k : -k;
o.y += i & 1 ? k : -k;
});
node.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
vis.selectAll("path")
.data(groups)
.attr("d", groupPath)
.enter().insert("path", "circle")
.style("fill", groupFill)
.style("stroke", groupFill)
.style("stroke-width", 40)
.style("stroke-linejoin", "round")
.style("opacity", .2)
.attr("d", groupPath);
});
d3.select("body").on("click", function() {
nodes.forEach(function(o, i) {
o.x += (Math.random() - .5) * 40;
o.y += (Math.random() - .5) * 40;
});
force.resume();
});
</script>
</body>
</html>
@aziele
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aziele commented Dec 22, 2013

Great example! Any chance I can provide, as input, custom nodes and links, the way Force-Directed Graph works with miserables.json file?

@mshankr
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mshankr commented Jul 27, 2017

THIS IS A SUPER AWESOME EXAMPLE OF CONVEX HULL ON D3 FORCE LAYOUT!!! GREAT JOB & THANK YOU!!!!

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