min.js (1269B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var sqrt = require( '@stdlib/math/base/special/sqrt' ); 24 var ln = require( '@stdlib/math/base/special/ln' ); 25 var cos = require( '@stdlib/math/base/special/cos' ); 26 var PI = require( '@stdlib/constants/float64/pi' ); 27 28 29 // VARIABLES // 30 31 var COS_PI = cos( PI ); // -1 32 33 34 // MAIN // 35 36 /** 37 * Returns the minimum possible normally distributed pseudorandom number. 38 * 39 * @private 40 * @param {number} min - minimum possible uniformly distributed pseudorandom number 41 * @returns {number} minimum possible number 42 */ 43 function getMin( min ) { 44 var a = sqrt( -2.0 * ln( min ) ); 45 return a * COS_PI; 46 } 47 48 49 // EXPORTS // 50 51 module.exports = getMin;