mean.js (1011B)
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 /** 22 * Computes the arithmetic mean of a numeric array. 23 * 24 * @private 25 * @param {NumericArray} arr - input array 26 * @returns {number} arithmetic mean 27 */ 28 function mean( arr ) { 29 var delta; 30 var len; 31 var mu; 32 var i; 33 34 mu = 0.0; 35 len = arr.length; 36 for ( i = 0; i < len; i++ ) { 37 delta = arr[ i ] - mu; 38 mu += delta / (i+1); 39 } 40 return mu; 41 } 42 43 44 // EXPORTS // 45 46 module.exports = mean;