dmeanstdevpn.js (1803B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2020 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 dmeanvarpn = require( './../../../base/dmeanvarpn' ); 24 var sqrt = require( '@stdlib/math/base/special/sqrt' ); 25 26 27 // MAIN // 28 29 /** 30 * Computes the mean and standard deviation of a double-precision floating-point strided array using a two-pass algorithm. 31 * 32 * @param {PositiveInteger} N - number of indexed elements 33 * @param {number} correction - degrees of freedom adjustment 34 * @param {Float64Array} x - input array 35 * @param {integer} strideX - `x` stride length 36 * @param {Float64Array} out - output array 37 * @param {integer} strideOut - `out` stride length 38 * @returns {Float64Array} output array 39 * 40 * @example 41 * var Float64Array = require( '@stdlib/array/float64' ); 42 * 43 * var x = new Float64Array( [ 1.0, -2.0, 2.0 ] ); 44 * var out = new Float64Array( 2 ); 45 * 46 * var v = dmeanstdevpn( x.length, 1, x, 1, out, 1 ); 47 * // returns <Float64Array>[ ~0.3333, ~2.0817 ] 48 */ 49 function dmeanstdevpn( N, correction, x, strideX, out, strideOut ) { 50 var io; 51 52 dmeanvarpn( N, correction, x, strideX, out, strideOut ); 53 if ( strideOut < 0 ) { 54 io = 0; 55 } else { 56 io = strideOut; 57 } 58 out[ io ] = sqrt( out[ io ] ); 59 return out; 60 } 61 62 63 // EXPORTS // 64 65 module.exports = dmeanstdevpn;