snansumors.js (1786B)
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 var isnanf = require( '@stdlib/math/base/assert/is-nanf' ); 25 26 27 // MAIN // 28 29 /** 30 * Computes the sum of single-precision floating-point strided array elements, ignoring `NaN` values and using ordinary recursive summation. 31 * 32 * @param {PositiveInteger} N - number of indexed elements 33 * @param {Float32Array} x - input array 34 * @param {integer} stride - stride length 35 * @returns {number} sum 36 * 37 * @example 38 * var Float32Array = require( '@stdlib/array/float32' ); 39 * 40 * var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] ); 41 * var N = x.length; 42 * 43 * var v = snansumors( N, x, 1 ); 44 * // returns 1.0 45 */ 46 function snansumors( N, x, stride ) { 47 var sum; 48 var ix; 49 var i; 50 51 sum = 0.0; 52 if ( N <= 0 ) { 53 return sum; 54 } 55 if ( N === 1 || stride === 0 ) { 56 if ( isnanf( x[ 0 ] ) ) { 57 return sum; 58 } 59 return x[ 0 ]; 60 } 61 if ( stride < 0 ) { 62 ix = (1-N) * stride; 63 } else { 64 ix = 0; 65 } 66 for ( i = 0; i < N; i++ ) { 67 if ( isnanf( x[ ix ] ) === false ) { 68 sum = float64ToFloat32( sum + x[ ix ] ); 69 } 70 ix += stride; 71 } 72 return sum; 73 } 74 75 76 // EXPORTS // 77 78 module.exports = snansumors;