Software Engineer
Published
Edited
Feb 22, 2022
1 fork
1 star
md`# Clustering Circles`
chart = {
const nodes = pack().leaves()
console.log(nodes)
const simulation = d3.forceSimulation(nodes)
.force("x", d3.forceX(width / 7).strength(0.005))
.force("y", d3.forceY(width / 7).strength(0.005))
.force("cluster", forceCluster())
.force("collision", forceCollide())
const svg = d3.select(DOM.svg(width, height));
const node = svg.append("g")
.selectAll("circle")
.data(nodes)
.join("circle")
.attr("cx", d => d.x)
.attr("cy", d => d.y)
.attr("fill", d => color(d.data.group))
.call(drag(simulation));
node.transition()
.delay((d, i) => Math.random() * 500)
.duration(750)
.attrTween("r", d => {
const i = d3.interpolate(0, d.r);
return t => d.r = i(t);
});
simulation.on("tick", () => {
node
.attr("cx", d => d.x)
.attr("cy", d => d.y);
});
invalidation.then(() => simulation.stop());
return svg.node();
}
pack = () => d3.pack()
.size([width, height])
.padding(1)
(d3.hierarchy(data)
.sum(d => d.value))
function forceCluster() {
const strength = 0.05;
let nodes;
function force(alpha){
const centroids = d3.rollup(nodes, centroid, d => d.data.group)
const l = alpha * strength;
for (const d of nodes) {
const {x: cx, y: cy} = centroids.get(d.data.group);
d.vx-= ( d.x - cx)*l
d.vy-= ( d.y - cy)*l
}
}
force.initialize = _ => nodes = _;
return force;
}
function forceCollide() {
const alpha = 0.5; // fixed for greater rigidity!
const padding1 = 2; // separation between same-color nodes
const padding2 = 8; // separation between different-color nodes
let nodes;
let maxRadius;
function force() {
const quadtree = d3.quadtree(nodes, d => d.x, d => d.y);
console.log(quadtree)
for (const d of nodes) {
const r = d.r + maxRadius;
const nx1 = d.x - r, ny1 = d.y - r;
const nx2 = d.x + r, ny2 = d.y + r;
quadtree.visit((q, x1, y1, x2, y2) => {
if (!q.length) do {
if (q.data !== d) {
const r = d.r + q.data.r + (d.data.group === q.data.data.group ? padding1 : padding2);
let x = d.x - q.data.x, y = d.y - q.data.y, l = Math.hypot(x, y);
if (l < r) {
l = (l - r) / l * alpha;
d.x -= x *= l, d.y -= y *= l;
q.data.x += x, q.data.y += y;
}
}
} while (q = q.next);
return x1 > nx2 || x2 < nx1 || y1 > ny2 || y2 < ny1;
});
}
}
force.initialize = _ => maxRadius = d3.max(nodes = _, d => d.r) + Math.max(padding1, padding2);
return force;
}
data = ({children:Array.from( d3.group(
Array.from({length: n}, () => ({
group: Math.random() * m | 0,
value: -Math.log(Math.random())
})),
d => d.group
), ([,children]) => ({children}))})
function centroid(nodes) {
let x = 0;
let y = 0;
let z = 0;
for (const d of nodes) {
let k = d.r ** 2;
x += d.x * k;
y += d.y * k;
z += k;
}
return {x: x / z, y: y / z};
}
drag = simulation => {
function dragstarted(d) {
if (!d3.event.active) simulation.alphaTarget(0.3).restart();
d.fx = d.x;
d.fy = d.y;
}
function dragged(d) {
d.fx = d3.event.x;
d.fy = d3.event.y;
}
function dragended(d) {
if (!d3.event.active) simulation.alphaTarget(0);
d.fx = null;
d.fy = null;
}
return d3.drag()
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended);
}
color = d3.scaleOrdinal(d3.range(m),d3.schemeCategory10)
n = 500
m = 10
height = 500
d3 = require("d3@5", "d3-array@2")
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
