calc.js
683 Bytes
'use strict'
/* A simple π estimation function using a Monte Carlo method
* For 0 to `points`, take 2 random numbers < 1, square and add them to
* find the area under that point in a 1x1 square. If that area is <= 1
* then it's *within* a quarter-circle, otherwise it's outside.
* Take the number of points <= 1 and multiply it by 4 and you have an
* estimate!
* Do this across multiple processes and average the results to
* increase accuracy.
*/
module.exports = function (points, callback) {
let inside = 0
, i = points
while (i--)
if (Math.pow(Math.random(), 2) + Math.pow(Math.random(), 2) <= 1)
inside++
callback(null, (inside / points) * 4)
}