diff -r efd9c589177a -r c0b4a8b5a012 toolkit/exemples/couple/javascript/d3/examples/qq/stats.js --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolkit/exemples/couple/javascript/d3/examples/qq/stats.js Thu Apr 10 14:20:23 2014 +0200 @@ -0,0 +1,28 @@ +// Sample from a normal distribution with mean 0, stddev 1. +function normal() { + var x = 0, y = 0, rds, c; + do { + x = Math.random() * 2 - 1; + y = Math.random() * 2 - 1; + rds = x * x + y * y; + } while (rds == 0 || rds > 1); + c = Math.sqrt(-2 * Math.log(rds) / rds); // Box-Muller transform + return x * c; // throw away extra sample y * c +} + +// Simple 1D Gaussian (normal) distribution +function normal1(mean, deviation) { + return function() { + return mean + deviation * normal(); + }; +} + +// Gaussian Mixture Model (k=3) fit using E-M algorithm +function normal3(dd) { + return function() { + var r = Math.random(), + i = r < dd[0][2] ? 0 : r < dd[0][2] + dd[1][2] ? 1 : 2, + d = dd[i]; + return d[0] + Math.sqrt(d[1]) * normal(); + } +}