Visualization toolmaker. Founder @observablehq. Creator @d3. Former @nytgraphics. Pronounced BOSS-tock.
Raft Consensus SimulatorJulia sets and the Mandelbrot setHow a power law emerges from aggregationLambert's Cosine LawSorting AlgorithmsFaceted SnowPeriodic Planar Three-Body OrbitsBicycle Drivetrain AnalyzerIntroduction to Linear RegressionKaplan-Meier CurvesBaseline GridHow Raymarching Works?Cell SettlingAn Easier-to-Use Sine BarInferring chart type from autocorrelation and other evilsVariable Thickness BandHyperbolic planeTorus KnotsLet’s Try t-SNE!Routes to chaosHow to build a Teachable Machine with TensorFlow.jsBoba ScienceBoidsPredator and PreyDe Casteljau’s AlgorithmCenterline labelingA visually more appealing fisheye functionFederal Budget in a Bottle2D point in triangle testBMI CalculatorSoundsThere’s Plenty of Room in the Cornerst-SNE explained in plain javascriptCircles, Spirals and SunflowersMini de Jong Attractor
Beta-Distributed Random Values
function randb(alpha, beta) {
const u = randg(alpha);
return u / (u + randg(beta));
}
// Returns a gamma deviate by the method of Marsaglia and Tsang.
function randg(shape) {
let oalph = shape, a1, a2, u, v, x, mat;
if (!shape) shape = 1;
if (shape < 1) shape += 1;
a1 = shape - 1 / 3;
a2 = 1 / Math.sqrt(9 * a1);
do {
do {
x = randn();
v = 1 + a2 * x;
} while (v <= 0);
v = v * v * v;
u = Math.random();
} while (
u > 1 - 0.331 * Math.pow(x, 4) &&
Math.log(u) > 0.5 * x * x + a1 * (1 - v + Math.log(v))
);
if (shape === oalph) return a1 * v; // alpha > 1
do u = Math.random(); while (u === 0); // alpha < 1
return Math.pow(u, 1 / oalph) * a1 * v;
}
// Returns a normal deviate (mu=0, sigma=1).
function randn() {
let u, v, x, y, q;
do {
u = Math.random();
v = 1.7156 * (Math.random() - 0.5);
x = u - 0.449871;
y = Math.abs(v) + 0.386595;
q = x * x + y * (0.19600 * y - 0.25472 * x);
} while (q > 0.27597 && (q > 0.27846 || v * v > -4 * Math.log(u) * u * u));
return v / u;
}
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.
