time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (1998B)

      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 * @param {NonNegativeInteger} offset - starting index
     35 * @returns {number} range
     36 *
     37 * @example
     38 * var Float64Array = require( '@stdlib/array/float64' );
     39 * var floor = require( '@stdlib/math/base/special/floor' );
     40 *
     41 * var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] );
     42 * var N = floor( x.length / 2 );
     43 *
     44 * var v = dnanrange( N, x, 2, 1 );
     45 * // returns 6.0
     46 */
     47 function dnanrange( N, x, stride, offset ) {
     48 	var max;
     49 	var min;
     50 	var ix;
     51 	var v;
     52 	var i;
     53 
     54 	if ( N <= 0 ) {
     55 		return NaN;
     56 	}
     57 	if ( N === 1 || stride === 0 ) {
     58 		if ( isnan( x[ offset ] ) ) {
     59 			return x[ offset ];
     60 		}
     61 		return 0.0;
     62 	}
     63 	ix = offset;
     64 	for ( i = 0; i < N; i++ ) {
     65 		v = x[ ix ];
     66 		if ( v === v ) {
     67 			break;
     68 		}
     69 		ix += stride;
     70 	}
     71 	if ( i === N ) {
     72 		return NaN;
     73 	}
     74 	min = v;
     75 	max = min;
     76 	i += 1;
     77 	for ( i; i < N; i++ ) {
     78 		ix += stride;
     79 		v = x[ ix ];
     80 		if ( isnan( v ) ) {
     81 			continue;
     82 		}
     83 		if ( v < min ) {
     84 			min = v;
     85 		} else if ( v > max ) {
     86 			max = v;
     87 		}
     88 	}
     89 	return max - min;
     90 }
     91 
     92 
     93 // EXPORTS //
     94 
     95 module.exports = dnanrange;