canvas = {
const context = DOM.context2d(width, height);
const canvas = context.canvas;
canvas.style.width = "100%";
canvas.style.maxWidth = "720px";
canvas.style.display = "block";
canvas.style.margin = "auto";
context.lineCap = "square";
context.fillStyle = "#fff";
while (true) {
const t = Date.now() / 20000;
context.save();
context.fillRect(0, 0, width, height);
context.translate(width / 2, height / 2 + 28);
knots(context, t, N * 2 / 9, N * 3 / 9, 0);
knots(context, t, N * 5 / 9, N * 6 / 9, 0);
knots(context, t, N * 8 / 9, N * 9 / 9, 0);
knots(context, t, N * 0 / 9, N * 1 / 9, 5);
knots(context, t, N * 3 / 9, N * 4 / 9, 5);
knots(context, t, N * 6 / 9, N * 7 / 9, 5);
knots(context, t, N * 0 / 9 - 1, N * 2 / 9 + 1, 0);
knots(context, t, N * 3 / 9 - 1, N * 5 / 9 + 1, 0);
knots(context, t, N * 6 / 9 - 1, N * 8 / 9 + 1, 0);
context.restore();
yield canvas;
}
}
function knots(context, t, i0, i1, wo) {
for (let a = -4; a < 5; ++a) {
context.strokeStyle = wo ? context.fillStyle : d3.interpolateRainbow((a + 5) * t);
knot(context, 15 * (a - 0.5), -(a + 5) * t, i0, i1, wo);
}
}
function knot(context, of, q, i0, i1, wo) {
const tau = 2 * Math.PI;
let theta = tau * i0 / N, w;
let vx0, vx1 = r * x(theta) + of * ypn(theta);
let vy0, vy1 = r * y(theta) + of * xpn(theta);
for (let i = i0 + 1; i < i1; ++i) {
theta = tau * i / N;
vx0 = vx1, vx1 = r * x(theta) + of * ypn(theta);
vy0 = vy1, vy1 = r * y(theta) + of * xpn(theta);
w = map(Math.cos(theta + tau * q), 1, -1, 0, 1);
w = lerp(2.5, 8.5, ease(Math.max(0, Math.min(1, 3.5 * w - 2.5)), 7)) + wo;
context.beginPath();
context.moveTo(vx0, vy0);
context.lineTo(vx1, vy1);
context.lineWidth = w;
context.stroke();
}
}
function x(q) {
return Math.sin(q) + 2 * Math.sin(2 * q);
}
function xp(q) {
return Math.cos(q) + 4 * Math.cos(2 * q);
}
function y(q) {
return Math.cos(q) - 2 * Math.cos(2 * q);
}
function yp(q) {
return -Math.sin(q) - 4 * Math.sin(2 * q);
}
function xpn(q) {
return xp(q) / dist(xp(q), yp(q), 0, 0);
}
function ypn(q) {
return yp(q) / dist(xp(q), yp(q), 0, 0);
}
function z(q) {
return Math.sin(3 * q);
}
function dist(x1, y1, x2, y2) {
return Math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2);
}
function map(value, start1, stop1, start2, stop2) {
return (value - start1)
/ (stop1 - start1)
* (stop2 - start2) + start2;
}
function lerp(start, stop, amt) {
return start + (stop - start) * amt;
}
function ease(p, g) {
return p < 0.5
? 0.5 * Math.pow(2 * p, g)
: 1 - 0.5 * Math.pow(2 * (1 - p), g);
}
d3 = require("d3-scale-chromatic@1.2.0/dist/d3-scale-chromatic.min.js")
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.