ndarray.js (2309B)
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 isnan = require( '@stdlib/math/base/assert/is-nan' ); 24 var abs = require( '@stdlib/math/base/special/abs' ); 25 26 27 // MAIN // 28 29 /** 30 * Computes the cumulative minimum absolute value of double-precision floating-point strided array elements. 31 * 32 * @param {PositiveInteger} N - number of indexed elements 33 * @param {Float64Array} x - input array 34 * @param {integer} strideX - `x` stride length 35 * @param {NonNegativeInteger} offsetX - starting index for `x` 36 * @param {Float64Array} y - output array 37 * @param {integer} strideY - `y` stride length 38 * @param {NonNegativeInteger} offsetY - starting index for `y` 39 * @returns {Float64Array} output array 40 * 41 * @example 42 * var Float64Array = require( '@stdlib/array/float64' ); 43 * var floor = require( '@stdlib/math/base/special/floor' ); 44 * 45 * var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] ); 46 * var y = new Float64Array( x.length ); 47 * var N = floor( x.length / 2 ); 48 * 49 * var v = dcuminabs( N, x, 2, 1, y, 1, 0 ); 50 * // returns <Float64Array>[ 1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0 ] 51 */ 52 function dcuminabs( N, x, strideX, offsetX, y, strideY, offsetY ) { 53 var min; 54 var ix; 55 var iy; 56 var v; 57 var i; 58 59 if ( N <= 0 ) { 60 return y; 61 } 62 ix = offsetX; 63 iy = offsetY; 64 65 min = abs( x[ ix ] ); 66 y[ iy ] = min; 67 68 iy += strideY; 69 i = 1; 70 if ( isnan( min ) === false ) { 71 for ( i; i < N; i++ ) { 72 ix += strideX; 73 v = abs( x[ ix ] ); 74 if ( isnan( v ) ) { 75 min = v; 76 break; 77 } 78 if ( v < min ) { 79 min = v; 80 } 81 y[ iy ] = min; 82 iy += strideY; 83 } 84 } 85 if ( isnan( min ) ) { 86 for ( i; i < N; i++ ) { 87 y[ iy ] = min; 88 iy += strideY; 89 } 90 } 91 return y; 92 } 93 94 95 // EXPORTS // 96 97 module.exports = dcuminabs;