main.js (2073B)
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 // MAIN // 22 23 /** 24 * Applies a unary callback to elements in a strided input array and assigns results to elements in a strided output array. 25 * 26 * @param {ArrayLikeObject<Collection>} arrays - array-like object containing one input array and one output array 27 * @param {NonNegativeIntegerArray} shape - array-like object containing a single element, the number of indexed elements 28 * @param {IntegerArray} strides - array-like object containing the stride lengths for the input and output arrays 29 * @param {Callback} fcn - unary callback 30 * @returns {void} 31 * 32 * @example 33 * var Float64Array = require( '@stdlib/array/float64' ); 34 * 35 * function scale( x ) { 36 * return x * 10.0; 37 * } 38 * 39 * var x = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0 ] ); 40 * var y = new Float64Array( x.length ); 41 * 42 * var shape = [ x.length ]; 43 * var strides = [ 1, 1 ]; 44 * 45 * unary( [ x, y ], shape, strides, scale ); 46 * 47 * console.log( y ); 48 * // => <Float64Array>[ 10.0, 20.0, 30.0, 40.0, 50.0 ] 49 */ 50 function unary( arrays, shape, strides, fcn ) { 51 var sx; 52 var sy; 53 var ix; 54 var iy; 55 var x; 56 var y; 57 var N; 58 var i; 59 60 N = shape[ 0 ]; 61 if ( N <= 0 ) { 62 return; 63 } 64 sx = strides[ 0 ]; 65 sy = strides[ 1 ]; 66 if ( sx < 0 ) { 67 ix = (1-N) * sx; 68 } else { 69 ix = 0; 70 } 71 if ( sy < 0 ) { 72 iy = (1-N) * sy; 73 } else { 74 iy = 0; 75 } 76 x = arrays[ 0 ]; 77 y = arrays[ 1 ]; 78 for ( i = 0; i < N; i++ ) { 79 y[ iy ] = fcn( x[ ix ] ); 80 ix += sx; 81 iy += sy; 82 } 83 } 84 85 86 // EXPORTS // 87 88 module.exports = unary;