ndarray.js (1912B)
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 * @param {NonNegativeInteger} offset - starting index 36 * @returns {number} sum 37 * 38 * @example 39 * var Float32Array = require( '@stdlib/array/float32' ); 40 * var floor = require( '@stdlib/math/base/special/floor' ); 41 * 42 * var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] ); 43 * var N = floor( x.length / 2 ); 44 * 45 * var v = snansumors( N, x, 2, 1 ); 46 * // returns 5.0 47 */ 48 function snansumors( N, x, stride, offset ) { 49 var sum; 50 var ix; 51 var i; 52 53 sum = 0.0; 54 if ( N <= 0 ) { 55 return sum; 56 } 57 if ( N === 1 || stride === 0 ) { 58 if ( isnanf( x[ offset ] ) ) { 59 return sum; 60 } 61 return x[ offset ]; 62 } 63 ix = offset; 64 for ( i = 0; i < N; i++ ) { 65 if ( isnanf( x[ ix ] ) === false ) { 66 sum = float64ToFloat32( sum + x[ ix ] ); 67 } 68 ix += stride; 69 } 70 return sum; 71 } 72 73 74 // EXPORTS // 75 76 module.exports = snansumors;