chart = {
const context = DOM.context2d(width, height),
path = d3
.geoPath(projection)
.context(context);
yield context.canvas;
while (animate) {
const rotate = projection.rotate();
rotate[0] += 0.3;
projection.rotate(rotate);
render(context, path);
yield context.canvas;
}
const sel = d3.select(context.canvas).style("cursor", "grab");
d3.geoInertiaDrag(sel, () => render(context, path), projection);
invalidation.then(() => sel.on(".drag", null));
render(context, path);
}
function render(context, path) {
// dark blue sphere
context.fillStyle = "#000";
context.fillRect(0, 0, width, height);
context.beginPath();
path({ type: "Sphere" });
context.fillStyle = "#003";
context.fill();
const clipAngle = projection.clipAngle();
context.globalAlpha = 0.3;
projection.clipAngle(180);
draw(context, path.pointRadius(0.7));
// front globe
context.globalAlpha = 1;
projection.clipAngle(clipAngle);
draw(context, path.pointRadius(1.5));
}
function draw(context, path) {
for (const [value, points] of groups) {
context.beginPath();
path({
type: "MultiPoint",
coordinates: points.map(p => [p.lon, p.lat])
});
context.fillStyle = value === "NA" ? "#666" : color(value);
context.fill();
}
}
mapped = {
var m = d3.range(-90,91).map(x => d3.range(-180,181).map(y => undefined));
for (var datum of data){m[90+(+datum.lat)][180+(+datum.lon)] = datum.change}
return m;
}
// See https://www.dynamicmath.xyz/sketches/sunflowerSphere/
function sphericalPhyllotaxis(n) {
const g = 1.61803398875;
const degrees = 180 / Math.PI;
return Array.from({ length: n }, (_, i) => {
const z = 1 - (2 * i + 1) / n;
const a = Math.PI * 2 * g * i;
const b = Math.sin(Math.acos(1 - (2 * i + 1) / n));
const x = Math.cos(a) * b;
const y = Math.sin(a) * b;
return [Math.atan2(y, x) * degrees, Math.asin(z) * degrees];
});
}
phyllo = sphericalPhyllotaxis(nPoints)
.map(([lon, lat]) => ({ lon, lat, change: mapped[Math.round(lat)+90][Math.round(lon)+180]}))
.filter(({change}) => change !== undefined)
height = Math.min(550, width)
d3 = require("d3@6", "d3-inertia@0.2", "d3-geo-projection@2")
import { Toggle, Range } from "@observablehq/inputs"
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.