ndarray.js (1725B)
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 isNegativeZero = require( '@stdlib/math/base/assert/is-negative-zero' ); 25 26 27 // MAIN // 28 29 /** 30 * Computes the minimum value of a strided array. 31 * 32 * @param {PositiveInteger} N - number of indexed elements 33 * @param {NumericArray} x - input array 34 * @param {integer} stride - stride length 35 * @param {NonNegativeInteger} offset - starting index 36 * @returns {number} minimum value 37 * 38 * @example 39 * var floor = require( '@stdlib/math/base/special/floor' ); 40 * 41 * var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ]; 42 * var N = floor( x.length / 2 ); 43 * 44 * var v = min( N, x, 2, 1 ); 45 * // returns -2.0 46 */ 47 function min( N, x, stride, offset ) { 48 var min; 49 var ix; 50 var v; 51 var i; 52 53 if ( N <= 0 ) { 54 return NaN; 55 } 56 if ( N === 1 || stride === 0 ) { 57 return x[ offset ]; 58 } 59 ix = offset; 60 min = x[ ix ]; 61 for ( i = 1; i < N; i++ ) { 62 ix += stride; 63 v = x[ ix ]; 64 if ( isnan( v ) ) { 65 return v; 66 } 67 if ( v < min || ( v === min && isNegativeZero( v ) ) ) { 68 min = v; 69 } 70 } 71 return min; 72 } 73 74 75 // EXPORTS // 76 77 module.exports = min;