time-to-botec

Benchmark sampling in different programming languages
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snanrange.js (1969B)

      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 isnanf = require( '@stdlib/math/base/assert/is-nanf' );
     24 var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' );
     25 
     26 
     27 // MAIN //
     28 
     29 /**
     30 * Computes the range of a single-precision floating-point strided array, ignoring `NaN` values.
     31 *
     32 * @param {PositiveInteger} N - number of indexed elements
     33 * @param {Float32Array} x - input array
     34 * @param {integer} stride - stride length
     35 * @returns {number} range
     36 *
     37 * @example
     38 * var Float32Array = require( '@stdlib/array/float32' );
     39 *
     40 * var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] );
     41 * var N = x.length;
     42 *
     43 * var v = snanrange( N, x, 1 );
     44 * // returns 4.0
     45 */
     46 function snanrange( N, x, stride ) {
     47 	var max;
     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 		if ( isnanf( x[ 0 ] ) ) {
     58 			return NaN;
     59 		}
     60 		return 0.0;
     61 	}
     62 	if ( stride < 0 ) {
     63 		ix = (1-N) * stride;
     64 	} else {
     65 		ix = 0;
     66 	}
     67 	for ( i = 0; i < N; i++ ) {
     68 		v = x[ ix ];
     69 		if ( v === v ) {
     70 			break;
     71 		}
     72 		ix += stride;
     73 	}
     74 	if ( i === N ) {
     75 		return NaN;
     76 	}
     77 	min = v;
     78 	max = min;
     79 	i += 1;
     80 	for ( i; i < N; i++ ) {
     81 		ix += stride;
     82 		v = x[ ix ];
     83 		if ( isnanf( v ) ) {
     84 			continue;
     85 		}
     86 		if ( v < min ) {
     87 			min = v;
     88 		} else if ( v > max ) {
     89 			max = v;
     90 		}
     91 	}
     92 	return float64ToFloat32( max - min );
     93 }
     94 
     95 
     96 // EXPORTS //
     97 
     98 module.exports = snanrange;