time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (1896B)

      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 isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' );
     25 
     26 
     27 // MAIN //
     28 
     29 /**
     30 * Computes the maximum value of a strided array, ignoring `NaN` values.
     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} maximum 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, NaN, NaN ];
     42 * var N = floor( x.length / 2 );
     43 *
     44 * var v = nanmax( N, x, 2, 1 );
     45 * // returns 4.0
     46 */
     47 function nanmax( N, x, stride, offset ) {
     48 	var max;
     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 	for ( i = 0; i < N; i++ ) {
     61 		v = x[ ix ];
     62 		if ( v === v ) {
     63 			break;
     64 		}
     65 		ix += stride;
     66 	}
     67 	if ( i === N ) {
     68 		return NaN;
     69 	}
     70 	max = v;
     71 	i += 1;
     72 	for ( i; i < N; i++ ) {
     73 		ix += stride;
     74 		v = x[ ix ];
     75 		if ( isnan( v ) ) {
     76 			continue;
     77 		}
     78 		if ( v > max || ( v === max && isPositiveZero( v ) ) ) {
     79 			max = v;
     80 		}
     81 	}
     82 	return max;
     83 }
     84 
     85 
     86 // EXPORTS //
     87 
     88 module.exports = nanmax;