D3 visualization combining techniques from clustered force layouts and convex polygons as a form of pseudo elasticity. Also experimented with using non-rendering nodes to aid in generating and updating the shapes.
See Clustered Force Layout III, Convex Hull, and D3.js and Canvas.
forked from thordav‘s block: Elastic Bubbles
<!DOCTYPE html>
<meta charset="utf-8">
<script src="//d3js.org/d3.v3.min.js"></script>
<body>
Drag the bubbles using your mouse (or finger).
</body>
<script>
var width = 960,
height = 500,
padding = 10, // separation between same-color circles
maxRadius = 5,
clusterPadding = 25; // separation between different-color circles
var n =50, // total number of circles
m = 5; // number of distinct clusters
//container
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
var allChartBg_vorinoi = svg.append("g");
var allChartBg_group = svg.append("g");
//*******************************************************
//*******************************************************
//function variables
//*******************************************************
//color generator
var color = d3.scale.category10().domain(d3.range(m));
//custom drag
var drag = d3.behavior.drag()
.origin(function(d) { return d; })
.on("dragstart", dragstarted)
.on("drag", dragged)
.on("dragend", dragended);
//path generator
var groupFunction = d3.svg.line()
.interpolate("basis-closed")
.tension(0.0)
.x(function(d) { return d[0]; })
.y(function(d) { return d[1]; });
//*******************************************************
//*******************************************************
//node generator
//*******************************************************
// The largest node for each cluster.
var clusters = new Array(m);
var nodes = d3.range(n).map(function() {
var i = Math.floor(Math.random() * m),
r = Math.sqrt((i + 1) / m * -Math.log(Math.random())) * maxRadius,
d = {cluster: i, radius: r};
if (!clusters[i] || (r > clusters[i].radius)) clusters[i] = d;
return d;
});
//*******************************************************
//*******************************************************
//elements
//*******************************************************
//hidden circles
var circle = svg.selectAll("custom.circle").data(nodes);
circle.enter().append("custom")
.classed("circle", true)
.attr("id", function(d, i) { return (clusters[d.cluster] === d) ? "cluster_" + d.cluster : "circle_" + i; })
.attr("r", function(d) { return d.radius; });
//grouping bubble
var groupPath;
var groups = d3.nest().key(function (d) { return d.cluster + ""; }).entries(nodes);
groups.forEach(function(n) {
n.strokeWidth = d3.max(n.values, function(d) { return d.radius; });
});
groupPath = allChartBg_group.selectAll(".groupPath").data(groups);
groupPath.enter().append("path")
.attr("class", "groupPath")
.style("opacity", 1)
.style("fill", function(d) { return color(d.key); })
.style("stroke", function(d) { return color(d.key); })
.style("stroke-linejoin", "round")
.style("stroke-width", function(d) { return d.strokeWidth * 3; })
.on("mousedown", function(d) {
selectedCluster = d.key;
})
.call(drag);
groupPath.exit().remove();
//*******************************************************
//*******************************************************
//animation
//*******************************************************
var force = d3.layout.force()
.nodes(nodes)
.size([width, height])
.gravity(0)
.charge(0)
.on("tick", tick)
.start();
function tick(e) {
circle
.each(cluster(10 * e.alpha * e.alpha))
.each(collide(.25))
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
//grouping bubble
groupPath.attr("d", function(d) { return groupFunction(d3.geom.hull(d.values.map(function (i) { return [i.x, i.y]; }))); });
}
//*******************************************************
//*******************************************************
// clustering function
//*******************************************************
// Move d to be adjacent to the cluster node.
function cluster(alpha) {
return function(d) {
var cluster = clusters[d.cluster],
k = 1;
// For cluster nodes, apply custom gravity.
if (cluster === d) {
cluster.x = (cluster.x === undefined) ? width /2 : cluster.x;
cluster.y = (cluster.y === undefined) ? height /2 : cluster.y;
cluster = {x: width / 2, y: height / 2, radius: -d.radius};
//cluster.radius = (cluster.radius === undefined) ? d.radius : cluster.radius;
k = .1 * Math.sqrt(d.radius);
}
var x = d.x - cluster.x,
y = d.y - cluster.y,
l = Math.sqrt(x * x + y * y),
r = d.radius + cluster.radius;
if (l != r) {
l = (l - r) / l * alpha * k;
d.x -= x *= l;
d.y -= y *= l;
cluster.x += x;
cluster.y += y;
}
};
}
//*******************************************************
//*******************************************************
// collision handler
//*******************************************************
// Resolves collisions between d and all other circles.
function collide(alpha) {
var quadtree = d3.geom.quadtree(nodes);
return function(d) {
var r = d.radius + 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.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.cluster === quad.point.cluster ? padding : clusterPadding);
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;
});
};
}
//*******************************************************
//*******************************************************
//custom drag functions
//*******************************************************
function dragstarted(d) {
d3.select(this).classed("dragging", true);
}
function dragged(d) {
d3.select("#cluster_" + selectedCluster)
.attr("cx", function(c) {
c.x = d3.event.sourceEvent.x;
return d3.event.sourceEvent.x;
})
.attr("cy", function(c) {
c.y = d3.event.sourceEvent.y;
return d3.event.sourceEvent.y;
});
force.start();
}
function dragended(d) {
d3.select(this).classed("dragging", false);
}
//*******************************************************
</script>