time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (2428B)

      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 double-precision floating-point strided array according to a mask.
     31 *
     32 * @param {PositiveInteger} N - number of indexed elements
     33 * @param {Float64Array} x - input array
     34 * @param {integer} strideX - `x` stride length
     35 * @param {NonNegativeInteger} offsetX - `x` starting index
     36 * @param {Uint8Array} mask - mask array
     37 * @param {integer} strideMask - `mask` stride length
     38 * @param {NonNegativeInteger} offsetMask - `mask` starting index
     39 * @returns {number} minimum value
     40 *
     41 * @example
     42 * var Float64Array = require( '@stdlib/array/float64' );
     43 * var Uint8Array = require( '@stdlib/array/uint8' );
     44 * var floor = require( '@stdlib/math/base/special/floor' );
     45 *
     46 * var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, -5.0, -6.0 ] );
     47 * var mask = new Uint8Array( [ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1 ] );
     48 * var N = floor( x.length / 2 );
     49 *
     50 * var v = dmskmin( N, x, 2, 1, mask, 2, 1 );
     51 * // returns -2.0
     52 */
     53 function dmskmin( N, x, strideX, offsetX, mask, strideMask, offsetMask ) {
     54 	var min;
     55 	var ix;
     56 	var im;
     57 	var v;
     58 	var i;
     59 
     60 	if ( N <= 0 ) {
     61 		return NaN;
     62 	}
     63 	ix = offsetX;
     64 	im = offsetMask;
     65 	for ( i = 0; i < N; i++ ) {
     66 		if ( mask[ im ] === 0 ) {
     67 			break;
     68 		}
     69 		ix += strideX;
     70 		im += strideMask;
     71 	}
     72 	if ( i === N ) {
     73 		return NaN;
     74 	}
     75 	min = x[ ix ];
     76 	if ( isnan( min ) ) {
     77 		return min;
     78 	}
     79 	i += 1;
     80 	for ( i; i < N; i++ ) {
     81 		ix += strideX;
     82 		im += strideMask;
     83 		if ( mask[ im ] ) {
     84 			continue;
     85 		}
     86 		v = x[ ix ];
     87 		if ( isnan( v ) ) {
     88 			return v;
     89 		}
     90 		if ( v < min || ( v === min && isNegativeZero( v ) ) ) {
     91 			min = v;
     92 		}
     93 	}
     94 	return min;
     95 }
     96 
     97 
     98 // EXPORTS //
     99 
    100 module.exports = dmskmin;