time-to-botec

Benchmark sampling in different programming languages
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ndarray.js (2108B)

      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 * Calculates the range of a strided array via a callback function.
     30 *
     31 * @param {PositiveInteger} N - number of indexed elements
     32 * @param {Collection} x - input array/collection
     33 * @param {integer} stride - index increment
     34 * @param {NonNegativeInteger} offset - starting index
     35 * @param {Callback} clbk - callback
     36 * @param {*} [thisArg] - execution context
     37 * @returns {number} range
     38 *
     39 * @example
     40 * var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ];
     41 *
     42 * function accessor( v ) {
     43 *     return v * 2.0;
     44 * }
     45 *
     46 * var v = rangeBy( x.length, x, 1, 0, accessor );
     47 * // returns 18.0
     48 */
     49 function rangeBy( N, x, stride, offset, clbk, thisArg ) {
     50 	var max;
     51 	var min;
     52 	var ix;
     53 	var v;
     54 	var i;
     55 
     56 	if ( N <= 0 ) {
     57 		return NaN;
     58 	}
     59 	if ( N === 1 || stride === 0 ) {
     60 		v = clbk.call( thisArg, x[ 0 ], 0, 0, x );
     61 		if ( v === void 0 || isnan( v ) ) {
     62 			return NaN;
     63 		}
     64 		return 0.0;
     65 	}
     66 	ix = offset;
     67 	for ( i = 0; i < N; i++ ) {
     68 		min = clbk.call( thisArg, x[ ix ], i, ix, x );
     69 		if ( min !== void 0 ) {
     70 			break;
     71 		}
     72 		ix += stride;
     73 	}
     74 	if ( i === N ) {
     75 		return NaN;
     76 	}
     77 	max = min;
     78 	i += 1;
     79 	for ( i; i < N; i++ ) {
     80 		ix += stride;
     81 		v = clbk.call( thisArg, x[ ix ], i, ix, x );
     82 		if ( v === void 0 ) {
     83 			continue;
     84 		}
     85 		if ( isnan( v ) ) {
     86 			return v;
     87 		}
     88 		if ( v < min ) {
     89 			min = v;
     90 		} else if ( v > max ) {
     91 			max = v;
     92 		}
     93 	}
     94 	return max - min;
     95 }
     96 
     97 
     98 // EXPORTS //
     99 
    100 module.exports = rangeBy;