ndarray.js (2054B)
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 float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' ); 24 25 26 // MAIN // 27 28 /** 29 * Computes the cumulative sum of single-precision floating-point strided array elements using ordinary recursive summation. 30 * 31 * @param {PositiveInteger} N - number of indexed elements 32 * @param {number} sum - initial sum 33 * @param {Float32Array} x - input array 34 * @param {integer} strideX - `x` stride length 35 * @param {NonNegativeInteger} offsetX - starting index for `x` 36 * @param {Float32Array} y - output array 37 * @param {integer} strideY - `y` stride length 38 * @param {NonNegativeInteger} offsetY - starting index for `y` 39 * @returns {Float32Array} output array 40 * 41 * @example 42 * var Float32Array = require( '@stdlib/array/float32' ); 43 * var floor = require( '@stdlib/math/base/special/floor' ); 44 * 45 * var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] ); 46 * var y = new Float32Array( x.length ); 47 * var N = floor( x.length / 2 ); 48 * 49 * var v = scusumors( N, 0.0, x, 2, 1, y, 1, 0 ); 50 * // returns <Float32Array>[ 1.0, -1.0, 1.0, 5.0, 0.0, 0.0, 0.0, 0.0 ] 51 */ 52 function scusumors( N, sum, x, strideX, offsetX, y, strideY, offsetY ) { 53 var ix; 54 var iy; 55 var i; 56 57 if ( N <= 0 ) { 58 return y; 59 } 60 ix = offsetX; 61 iy = offsetY; 62 for ( i = 0; i < N; i++ ) { 63 sum = float64ToFloat32( sum + x[ ix ] ); 64 y[ iy ] = sum; 65 ix += strideX; 66 iy += strideY; 67 } 68 return y; 69 } 70 71 72 // EXPORTS // 73 74 module.exports = scusumors;