| license: mit |
Built with blockbuilder.org
forked from ericsoco's block: cluster force
Moving toward a v4 modular version of Mike Bostock's Clustered Force Layout III.
There are two things worth mentioning here:
forceSimulation()cluster force, offering an API similar to other core d3-force modules like, e.g., the positioning forces.This version ramps up collision strength using a d3.timer, to move toward the jitter-reduction effect in the original block.
Next: Cluster Force III
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <body> | |
| <script src="//d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var width = 960, | |
| height = 500, | |
| padding = 1.5, // separation between same-color nodes | |
| clusterPadding = 6, // separation between different-color nodes | |
| maxRadius = 12; | |
| var n = 200, // total number of nodes | |
| m = 10; // number of distinct clusters | |
| var color = d3.scaleSequential(d3.interpolateRainbow) | |
| .domain(d3.range(m)); | |
| // 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, | |
| x: Math.cos(i / m * 2 * Math.PI) * 100 + width / 2 + Math.random(), | |
| y: Math.sin(i / m * 2 * Math.PI) * 100 + height / 2 + Math.random() | |
| }; | |
| if (!clusters[i] || (r > clusters[i].radius)) clusters[i] = d; | |
| return d; | |
| }); | |
| var force = d3.forceSimulation() | |
| // keep entire simulation balanced around screen center | |
| .force('center', d3.forceCenter(width/2, height/2)) | |
| // cluster by section | |
| .force('cluster', cluster() | |
| .strength(0.2)) | |
| // apply collision with padding | |
| .force('collide', d3.forceCollide(d => d.radius + padding) | |
| .strength(0)) | |
| .on('tick', layoutTick) | |
| .nodes(nodes); | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width) | |
| .attr("height", height); | |
| var node = svg.selectAll("circle") | |
| .data(nodes) | |
| .enter().append("circle") | |
| .style("fill", function(d) { return color(d.cluster/10); }); | |
| // ramp up collision strength to provide smooth transition | |
| var transitionTime = 3000; | |
| var t = d3.timer(function (elapsed) { | |
| var dt = elapsed / transitionTime; | |
| force.force('collide').strength(Math.pow(dt, 2) * 0.7); | |
| if (dt >= 1.0) t.stop(); | |
| }); | |
| function layoutTick(e) { | |
| node | |
| .attr("cx", function(d) { return d.x; }) | |
| .attr("cy", function(d) { return d.y; }) | |
| .attr("r", function(d) { return d.radius; }); | |
| } | |
| // Move d to be adjacent to the cluster node. | |
| // from: https://bl.ocks.org/mbostock/7881887 | |
| function cluster () { | |
| var nodes, | |
| strength = 0.1; | |
| function force (alpha) { | |
| // scale + curve alpha value | |
| alpha *= strength * alpha; | |
| nodes.forEach(function(d) { | |
| var cluster = clusters[d.cluster]; | |
| if (cluster === d) return; | |
| let 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; | |
| d.x -= x *= l; | |
| d.y -= y *= l; | |
| cluster.x += x; | |
| cluster.y += y; | |
| } | |
| }); | |
| } | |
| force.initialize = function (_) { | |
| nodes = _; | |
| } | |
| force.strength = _ => { | |
| strength = _ == null ? strength : _; | |
| return force; | |
| }; | |
| return force; | |
| } | |
| </script> |