time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (2098B)

      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 * @param {NonNegativeInteger} offset - starting index
     36 * @returns {number} range
     37 *
     38 * @example
     39 * var Float32Array = require( '@stdlib/array/float32' );
     40 * var floor = require( '@stdlib/math/base/special/floor' );
     41 *
     42 * var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] );
     43 * var N = floor( x.length / 2 );
     44 *
     45 * var v = snanrange( N, x, 2, 1 );
     46 * // returns 6.0
     47 */
     48 function snanrange( N, x, stride, offset ) {
     49 	var max;
     50 	var min;
     51 	var ix;
     52 	var v;
     53 	var i;
     54 
     55 	if ( N <= 0 ) {
     56 		return NaN;
     57 	}
     58 	if ( N === 1 || stride === 0 ) {
     59 		if ( isnanf( x[ offset ] ) ) {
     60 			return x[ offset ];
     61 		}
     62 		return 0.0;
     63 	}
     64 	ix = offset;
     65 	for ( i = 0; i < N; i++ ) {
     66 		v = x[ ix ];
     67 		if ( v === v ) {
     68 			break;
     69 		}
     70 		ix += stride;
     71 	}
     72 	if ( i === N ) {
     73 		return NaN;
     74 	}
     75 	min = v;
     76 	max = min;
     77 	i += 1;
     78 	for ( i; i < N; i++ ) {
     79 		ix += stride;
     80 		v = x[ ix ];
     81 		if ( isnanf( v ) ) {
     82 			continue;
     83 		}
     84 		if ( v < min ) {
     85 			min = v;
     86 		} else if ( v > max ) {
     87 			max = v;
     88 		}
     89 	}
     90 	return float64ToFloat32( max - min );
     91 }
     92 
     93 
     94 // EXPORTS //
     95 
     96 module.exports = snanrange;