time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (1878B)

      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 strided array, ignoring `NaN` values.
     30 *
     31 * @param {PositiveInteger} N - number of indexed elements
     32 * @param {NumericArray} x - input array
     33 * @param {integer} stride - stride length
     34 * @param {NonNegativeInteger} offset - starting index
     35 * @returns {number} range
     36 *
     37 * @example
     38 * var floor = require( '@stdlib/math/base/special/floor' );
     39 *
     40 * var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ];
     41 * var N = floor( x.length / 2 );
     42 *
     43 * var v = nanrange( N, x, 2, 1 );
     44 * // returns 6.0
     45 */
     46 function nanrange( N, x, stride, offset ) {
     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 ( isnan( x[ offset ] ) ) {
     58 			return NaN;
     59 		}
     60 		return 0.0;
     61 	}
     62 	ix = offset;
     63 	for ( i = 0; i < N; i++ ) {
     64 		v = x[ ix ];
     65 		if ( v === v ) {
     66 			break;
     67 		}
     68 		ix += stride;
     69 	}
     70 	if ( i === N ) {
     71 		return NaN;
     72 	}
     73 	min = v;
     74 	max = min;
     75 	i += 1;
     76 	for ( i; i < N; i++ ) {
     77 		ix += stride;
     78 		v = x[ ix ];
     79 		if ( isnan( v ) ) {
     80 			continue;
     81 		}
     82 		if ( v < min ) {
     83 			min = v;
     84 		} else if ( v > max ) {
     85 			max = v;
     86 		}
     87 	}
     88 	return max - min;
     89 }
     90 
     91 
     92 // EXPORTS //
     93 
     94 module.exports = nanrange;