ndarray.native.js (1690B)
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 Float32Array = require( '@stdlib/array/float32' ); 24 var addon = require( './sscal.native.js' ); 25 26 27 // MAIN // 28 29 /** 30 * Multiplies a vector `x` by a scalar `alpha`. 31 * 32 * @param {PositiveInteger} N - number of indexed elements 33 * @param {number} alpha - scalar 34 * @param {Float32Array} x - input array 35 * @param {integer} stride - index increment 36 * @param {NonNegativeInteger} offset - starting index 37 * @returns {Float32Array} input array 38 * 39 * @example 40 * var Float32Array = require( '@stdlib/array/float32' ); 41 * 42 * var x = new Float32Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] ); 43 * var alpha = 5.0; 44 * 45 * sscal( 3, alpha, x, 1, x.length-3 ); 46 * // x => <Float32Array>[ 1.0, -2.0, 3.0, -20.0, 25.0, -30.0 ] 47 */ 48 function sscal( N, alpha, x, stride, offset ) { 49 var view; 50 if ( stride < 0 ) { 51 stride *= -1; 52 offset -= (N-1) * stride; 53 } 54 view = new Float32Array( x.buffer, x.byteOffset+(x.BYTES_PER_ELEMENT*offset), x.length-offset ); // eslint-disable-line max-len 55 addon( N, alpha, view, stride ); 56 return x; 57 } 58 59 60 // EXPORTS // 61 62 module.exports = sscal;