Visualization toolmaker. Founder @observablehq. Creator @d3. Former @nytgraphics. Pronounced BOSS-tock.
Guided Tour of an Infinite Sphere GridCreating a Canvas Noise Map for Generative Art012 Truchet tiles014 Joy Division016 Some TrianglesConnections 2Stacking Polygons In A CircleSplitting LinesBulge IllusionVoronoi Spirals IIPerlin Noise ContoursTruchet Tiles variant: Intertwined quarter circlesGetting Artsy With LloydUlam SpiralOil painting brushstrokesRotating VoronoiBridget Riley 3SphoiseTriangles And CirclesYvaral IITwo GridsRandomized Flood FillOrientedTrefoilsMeandering VoronoiVoronoi StipplingEyesSubstrateIncremental Drift (Rose Equation)Circles, Spirals and SunflowersVoronoi Stained Glass PortraitsYvaralMy first Observable Notebook - Art of πFitzHugh–Nagumo MazeBridget RileyStructure de QuadrilatèresFractal TreePencil TraceAltered World
Quadtree Art
graphic = {
replay;
const quads = new TinyQueue([new Quad(0, 0, width, width)], (a, b) => b.score - a.score);
const context = DOM.context2d(width, width);
context.canvas.style.width = "100%";
for (let i = 0; true; ++i) {
const q = quads.pop();
if (q === undefined || q.score < 50) break;
mutable score = q.score;
for (const s of q.split()) {
if (q.w >= 4) quads.push(s);
context.fillStyle = s.color;
context.fillRect(s.x, s.y, s.w, s.h);
context.strokeRect(s.x, s.y, s.w, s.h);
}
if (i % 15 === 0) yield context.canvas;
}
}
mutable score = null
width = 1024
area_power = 0.25
class Quad {
constructor(x, y, w, h) {
const [r, g, b, error] = colorFromHistogram(computeHistogram(x, y, w, h));
this.x = x, this.y = y, this.w = w, this.h = h;
this.color = `#${(0x1000000 + (r << 16) + (g << 8) + b).toString(16).substring(1)}`;
this.score = error * Math.pow(w * h, area_power);
}
split() {
const dx = this.w / 2, x1 = this.x, x2 = this.x + dx;
const dy = this.h / 2, y1 = this.y, y2 = this.y + dy;
return [
new Quad(x1, y1, dx, dy),
new Quad(x2, y1, dx, dy),
new Quad(x1, y2, dx, dy),
new Quad(x2, y2, dx, dy)
];
}
}
function computeHistogram(x, y, w, h) {
const {data} = imageContext.getImageData(x, y, w, h);
const histogram = new Uint32Array(1024);
for (let i = 0, n = data.length; i < n; i += 4) {
++histogram[0 * 256 + data[i + 0]];
++histogram[1 * 256 + data[i + 1]];
++histogram[2 * 256 + data[i + 2]];
++histogram[3 * 256 + data[i + 3]];
}
return histogram;
}
function weightedAverage(histogram) {
let total = 0;
let value = 0;
for (let i = 0; i < 256; ++i) total += histogram[i], value += histogram[i] * i;
value /= total;
let error = 0;
for (let i = 0; i < 256; ++i) error += (value - i) ** 2 * histogram[i];
return [value, Math.sqrt(error / total)];
}
function colorFromHistogram(histogram) {
const [r, re] = weightedAverage(histogram.subarray(0, 256));
const [g, ge] = weightedAverage(histogram.subarray(256, 512));
const [b, be] = weightedAverage(histogram.subarray(512, 768));
return [
Math.round(r),
Math.round(g),
Math.round(b),
re * 0.2989 + ge * 0.5870 + be * 0.1140
];
}
imageContext = FileAttachment("owl.jpg").image().then(image => {
const context = DOM.context2d(width, width, 1);
context.drawImage(image, 0, 0, width, width);
return context;
})
TinyQueue = require("tinyqueue@2")
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.
