b = {
const t0 = performance.now();
const W = 1200;
const data = new Float64Array(W * W);
for (const p of points) data[Math.floor(p[0]) + W * Math.floor(W - p[1])]++;
d3.blur2({ data, width: W }, bandwidth);
const canvas = heatmap(data, {
width: W,
upscale: (width / 2 - 10) / W,
color
});
const time = performance.now() - t0;
return Object.assign(canvas, { time });
}