time-to-botec

Benchmark sampling in different programming languages
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dnanrange.js (1869B)

      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 
     25 
     26 // MAIN //
     27 
     28 /**
     29 * Computes the range of a double-precision floating-point strided array, ignoring `NaN` values.
     30 *
     31 * @param {PositiveInteger} N - number of indexed elements
     32 * @param {Float64Array} x - input array
     33 * @param {integer} stride - stride length
     34 * @returns {number} range
     35 *
     36 * @example
     37 * var Float64Array = require( '@stdlib/array/float64' );
     38 *
     39 * var x = new Float64Array( [ 1.0, -2.0, NaN, 2.0 ] );
     40 * var N = x.length;
     41 *
     42 * var v = dnanrange( N, x, 1 );
     43 * // returns 4.0
     44 */
     45 function dnanrange( N, x, stride ) {
     46 	var max;
     47 	var min;
     48 	var ix;
     49 	var v;
     50 	var i;
     51 
     52 	if ( N <= 0 ) {
     53 		return NaN;
     54 	}
     55 	if ( N === 1 || stride === 0 ) {
     56 		if ( isnan( x[ 0 ] ) ) {
     57 			return NaN;
     58 		}
     59 		return 0.0;
     60 	}
     61 	if ( stride < 0 ) {
     62 		ix = (1-N) * stride;
     63 	} else {
     64 		ix = 0;
     65 	}
     66 	for ( i = 0; i < N; i++ ) {
     67 		v = x[ ix ];
     68 		if ( v === v ) {
     69 			break;
     70 		}
     71 		ix += stride;
     72 	}
     73 	if ( i === N ) {
     74 		return NaN;
     75 	}
     76 	min = v;
     77 	max = min;
     78 	i += 1;
     79 	for ( i; i < N; i++ ) {
     80 		ix += stride;
     81 		v = x[ ix ];
     82 		if ( isnan( v ) ) {
     83 			continue;
     84 		}
     85 		if ( v < min ) {
     86 			min = v;
     87 		} else if ( v > max ) {
     88 			max = v;
     89 		}
     90 	}
     91 	return max - min;
     92 }
     93 
     94 
     95 // EXPORTS //
     96 
     97 module.exports = dnanrange;