react-native-macos/packager/src/worker-farm/examples/pi/calc.js

A framework for building native macOS apps using React

/**
 * Copyright (c) 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

/* eslint-disable */
/* A simple PI 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) {
  var inside = 0
    , i = points

  while (i--)
    if (Math.pow(Math.random(), 2) + Math.pow(Math.random(), 2) <= 1)
      inside++

  callback(null, (inside / points) * 4)
}