Published unlisted
Edited
Jul 12, 2020
1 fork
chart = {
let focussed;
const zoom = d3
.zoom()
.scaleExtent([1, 40])
.on("zoom", zoomed)
.filter(function() {
// this is all very hacky
const _event = d3.event;
const point = d3.zoomTransform(this).apply(focussed);
d3.event = {
clientX: point[0] + this.getBoundingClientRect().x,
clientY: point[1] + this.getBoundingClientRect().y,
preventDefault: () => _event.preventDefault(),
stopImmediatePropagation: () => _event.stopImmediatePropagation(),
deltaY: _event.deltaY,
deltaMode: _event.deltaMode
};
return true;
});
const svg = d3
.create("svg")
.attr("viewBox", [0, 0, width, height])
.on("click", reset);
const g = svg.append("g");
g.selectAll("circle")
.data(data)
.join("circle")
.attr("cx", ([x]) => x)
.attr("cy", ([, y]) => y)
.attr("r", radius)
.attr("fill", (d, i) => d3.interpolateRainbow(i / 360))
.on("click", clicked);
svg.call(zoom).on("mousemove", mousemove);
function random() {
const [x, y] = data[Math.floor(Math.random() * data.length)];
svg
.transition()
.duration(2500)
.call(
zoom.transform,
d3.zoomIdentity
.translate(width / 2, height / 2)
.scale(40)
.translate(-x, -y)
);
}
function reset() {
svg
.transition()
.duration(750)
.call(
zoom.transform,
d3.zoomIdentity,
d3.zoomTransform(svg.node()).invert([width / 2, height / 2])
);
}
function mousemove() {
const p = d3.zoomTransform(this).invert(d3.mouse(this));
focussed = quadtree.find(p[0], p[1]);
// used to be zoom.center(q)
g.selectAll("circle").attr("r", p => (p == focussed ? radius + 3 : radius));
}
function clicked([x, y]) {
d3.event.stopPropagation();
svg
.transition()
.duration(750)
.call(
zoom.transform,
d3.zoomIdentity
.translate(width / 2, height / 2)
.scale(40)
.translate(-x, -y),
d3.mouse(svg.node())
);
}
function zoomed() {
g.attr("transform", d3.event.transform);
}
return Object.assign(svg.node(), {
zoomIn: () => svg.transition().call(zoom.scaleBy, 2),
zoomOut: () => svg.transition().call(zoom.scaleBy, 0.5),
zoomRandom: random,
zoomReset: reset
});
}
height = 500
radius = 6
step = radius * 5
quadtree = d3.quadtree()
.addAll(data)
data = Array.from({length: 1000}, (_, i) => {
const radius = step * Math.sqrt(i += 0.5), a = theta * i;
return [
width / 2 + radius * Math.cos(a),
height / 2 + radius * Math.sin(a)
];
})
theta = Math.PI * (3 - Math.sqrt(5))
d3 = require("d3@5")
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.
