ndarray.js (2323B)
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 25 26 // MAIN // 27 28 /** 29 * Computes the sum of double-precision floating-point strided array elements, ignoring `NaN` values and using ordinary recursive summation. 30 * 31 * @param {PositiveInteger} N - number of indexed elements 32 * @param {Float64Array} x - input array 33 * @param {integer} strideX - `x` stride length 34 * @param {NonNegativeInteger} offsetX - `x` starting index 35 * @param {Float64Array} out - output array 36 * @param {integer} strideOut - `out` stride length 37 * @param {NonNegativeInteger} offsetOut - `out` starting index 38 * @returns {Float64Array} output array 39 * 40 * @example 41 * var Float64Array = require( '@stdlib/array/float64' ); 42 * var floor = require( '@stdlib/math/base/special/floor' ); 43 * 44 * var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] ); 45 * var out = new Float64Array( 2 ); 46 * 47 * var N = floor( x.length / 2 ); 48 * 49 * var v = dnannsumors( N, x, 2, 1, out, 1, 0 ); 50 * // returns <Float64Array>[ 5.0, 4 ] 51 */ 52 function dnannsumors( N, x, strideX, offsetX, out, strideOut, offsetOut ) { 53 var sum; 54 var ix; 55 var io; 56 var n; 57 var i; 58 59 ix = offsetX; 60 io = offsetOut; 61 62 sum = 0.0; 63 if ( N <= 0 ) { 64 out[ io ] = sum; 65 out[ io+strideOut ] = 0; 66 return out; 67 } 68 if ( N === 1 || strideX === 0 ) { 69 if ( isnan( x[ ix ] ) ) { 70 out[ io ] = sum; 71 out[ io+strideOut ] = 0; 72 return out; 73 } 74 out[ io ] = x[ ix ]; 75 out[ io+strideOut ] = 1; 76 return out; 77 } 78 n = 0; 79 for ( i = 0; i < N; i++ ) { 80 if ( isnan( x[ ix ] ) === false ) { 81 sum += x[ ix ]; 82 n += 1; 83 } 84 ix += strideX; 85 } 86 out[ io ] = sum; 87 out[ io+strideOut ] = n; 88 return out; 89 } 90 91 92 // EXPORTS // 93 94 module.exports = dnannsumors;