time-to-botec

Benchmark sampling in different programming languages
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smskrange.js (2289B)

      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 range of a single-precision floating-point strided array according to a mask.
     31 *
     32 * @param {PositiveInteger} N - number of indexed elements
     33 * @param {Float32Array} x - input array
     34 * @param {integer} strideX - `x` stride length
     35 * @param {Uint8Array} mask - mask array
     36 * @param {integer} strideMask - `mask` stride length
     37 * @returns {number} range
     38 *
     39 * @example
     40 * var Float32Array = require( '@stdlib/array/float32' );
     41 * var Uint8Array = require( '@stdlib/array/uint8' );
     42 *
     43 * var x = new Float32Array( [ 1.0, -2.0, 4.0, 2.0 ] );
     44 * var mask = new Uint8Array( [ 0, 0, 1, 0 ] );
     45 *
     46 * var v = smskrange( x.length, x, 1, mask, 1 );
     47 * // returns 4.0
     48 */
     49 function smskrange( N, x, strideX, mask, strideMask ) {
     50 	var max;
     51 	var min;
     52 	var ix;
     53 	var im;
     54 	var v;
     55 	var i;
     56 
     57 	if ( N <= 0 ) {
     58 		return NaN;
     59 	}
     60 	if ( strideX < 0 ) {
     61 		ix = (1-N) * strideX;
     62 	} else {
     63 		ix = 0;
     64 	}
     65 	if ( strideMask < 0 ) {
     66 		im = (1-N) * strideMask;
     67 	} else {
     68 		im = 0;
     69 	}
     70 	for ( i = 0; i < N; i++ ) {
     71 		if ( mask[ im ] === 0 ) {
     72 			break;
     73 		}
     74 		ix += strideX;
     75 		im += strideMask;
     76 	}
     77 	if ( i === N ) {
     78 		return NaN;
     79 	}
     80 	min = x[ ix ];
     81 	if ( isnanf( min ) ) {
     82 		return min;
     83 	}
     84 	max = min;
     85 	i += 1;
     86 	for ( i; i < N; i++ ) {
     87 		ix += strideX;
     88 		im += strideMask;
     89 		if ( mask[ im ] ) {
     90 			continue;
     91 		}
     92 		v = x[ ix ];
     93 		if ( isnanf( v ) ) {
     94 			return v;
     95 		}
     96 		if ( v < min ) {
     97 			min = v;
     98 		} else if ( v > max ) {
     99 			max = v;
    100 		}
    101 	}
    102 	return float64ToFloat32( max - min );
    103 }
    104 
    105 
    106 // EXPORTS //
    107 
    108 module.exports = smskrange;