chart = {
const zoom = d3.zoom()
.scaleExtent([1, 40])
.on("zoom", zoomed);
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);
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 clicked(event, [x, y]) {
event.stopPropagation();
svg.transition().duration(750).call(
zoom.transform,
d3.zoomIdentity.translate(width / 2, height / 2).scale(40).translate(-x, -y),
d3.pointer(event)
);
}
function zoomed({transform}) {
g.attr("transform", 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
});
}