time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (2190B)

      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 abs = require( '@stdlib/math/base/special/abs' );
     25 
     26 
     27 // MAIN //
     28 
     29 /**
     30 * Computes the cumulative maximum absolute value of a strided array.
     31 *
     32 * @param {PositiveInteger} N - number of indexed elements
     33 * @param {NumericArray} x - input array
     34 * @param {integer} strideX - `x` stride length
     35 * @param {NonNegativeInteger} offsetX - starting index for `x`
     36 * @param {NumericArray} y - output array
     37 * @param {integer} strideY - `y` stride length
     38 * @param {NonNegativeInteger} offsetY - starting index for `y`
     39 * @returns {NumericArray} output array
     40 *
     41 * @example
     42 * var floor = require( '@stdlib/math/base/special/floor' );
     43 *
     44 * var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ];
     45 * var y = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
     46 * var N = floor( x.length / 2 );
     47 *
     48 * var v = cumaxabs( N, x, 2, 1, y, 1, 0 );
     49 * // returns [ 1.0, 2.0, 2.0, 4.0, 0.0, 0.0, 0.0, 0.0 ]
     50 */
     51 function cumaxabs( N, x, strideX, offsetX, y, strideY, offsetY ) {
     52 	var max;
     53 	var ix;
     54 	var iy;
     55 	var v;
     56 	var i;
     57 
     58 	if ( N <= 0 ) {
     59 		return y;
     60 	}
     61 	ix = offsetX;
     62 	iy = offsetY;
     63 
     64 	max = abs( x[ ix ] );
     65 	y[ iy ] = max;
     66 
     67 	iy += strideY;
     68 	i = 1;
     69 	if ( isnan( max ) === false ) {
     70 		for ( i; i < N; i++ ) {
     71 			ix += strideX;
     72 			v = abs( x[ ix ] );
     73 			if ( isnan( v ) ) {
     74 				max = v;
     75 				break;
     76 			}
     77 			if ( v > max ) {
     78 				max = v;
     79 			}
     80 			y[ iy ] = max;
     81 			iy += strideY;
     82 		}
     83 	}
     84 	if ( isnan( max ) ) {
     85 		for ( i; i < N; i++ ) {
     86 			y[ iy ] = max;
     87 			iy += strideY;
     88 		}
     89 	}
     90 	return y;
     91 }
     92 
     93 
     94 // EXPORTS //
     95 
     96 module.exports = cumaxabs;