{
const height = 500;
const context = DOM.context2d(width, height);
const canvas = context.canvas;
const radius = 20;
const circles = d3.range(324).map((i) => ({
x: (i % 25) * (radius + 1) * 2,
y: Math.floor(i / 25) * (radius + 1) * 2
}));
const simulation = d3.forceSimulation(circles)
.force("collide", d3.forceCollide(radius + 1).iterations(4))
.on("tick", drawCircles);
d3.select(canvas)
.call(d3.drag()
.subject(subject)
.on("start", started)
.on("drag", dragged)
.on("end", ended));
function drawCircles() {
context.clearRect(0, 0, width, height);
context.save();
circles.forEach(drawCircle);
context.strokeStyle = "#fff";
context.stroke();
}
function drawCircle(d) {
context.beginPath();
context.fillStyle = d.type;
context.moveTo(d.x + radius, d.y);
context.arc(d.x, d.y, radius, 0, 2 * Math.PI);
context.fill();
}
function subject(event) {
return simulation.find(event.x, event.y, radius);
}
function started(event) {
if (!event.active) simulation.alphaTarget(0.3).restart();
event.subject.fx = event.subject.x;
event.subject.fy = event.subject.y;
}
function dragged(event) {
event.subject.fx = event.x;
event.subject.fy = event.y;
}
function ended(event) {
if (!event.active) simulation.alphaTarget(0);
event.subject.fx = null;
event.subject.fy = null;
}
return canvas;
}
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.
