ndarray.js (2032B)
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 // VARIABLES // 22 23 var M = 8; 24 25 26 // MAIN // 27 28 /** 29 * Fills a double-precision floating-point strided array with a specified scalar constant. 30 * 31 * @param {PositiveInteger} N - number of indexed elements 32 * @param {number} alpha - scalar 33 * @param {Float64Array} x - input array 34 * @param {integer} stride - index increment 35 * @param {NonNegativeInteger} offset - starting index 36 * @returns {Float64Array} input array 37 * 38 * @example 39 * var Float64Array = require( '@stdlib/array/float64' ); 40 * 41 * var x = new Float64Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] ); 42 * 43 * dfill( 3, 5.0, x, 1, x.length-3 ); 44 * // x => <Float64Array>[ 1.0, -2.0, 3.0, 5.0, 5.0, 5.0 ] 45 */ 46 function dfill( N, alpha, x, stride, offset ) { 47 var ix; 48 var m; 49 var i; 50 51 if ( N <= 0 ) { 52 return x; 53 } 54 ix = offset; 55 56 // Use loop unrolling if the stride is equal to `1`... 57 if ( stride === 1 ) { 58 m = N % M; 59 60 // If we have a remainder, run a clean-up loop... 61 if ( m > 0 ) { 62 for ( i = 0; i < m; i++ ) { 63 x[ ix ] = alpha; 64 ix += stride; 65 } 66 } 67 if ( N < M ) { 68 return x; 69 } 70 for ( i = m; i < N; i += M ) { 71 x[ ix ] = alpha; 72 x[ ix+1 ] = alpha; 73 x[ ix+2 ] = alpha; 74 x[ ix+3 ] = alpha; 75 x[ ix+4 ] = alpha; 76 x[ ix+5 ] = alpha; 77 x[ ix+6 ] = alpha; 78 x[ ix+7 ] = alpha; 79 ix += M; 80 } 81 return x; 82 } 83 for ( i = 0; i < N; i++ ) { 84 x[ ix ] = alpha; 85 ix += stride; 86 } 87 return x; 88 } 89 90 91 // EXPORTS // 92 93 module.exports = dfill;