time-to-botec

Benchmark sampling in different programming languages
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assign.js (2291B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2018 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 // FUNCTIONS //
     22 
     23 /**
     24 * Generates a stride array from an array shape (row-major).
     25 *
     26 * @private
     27 * @param {NonNegativeIntegerArray} shape - array shape
     28 * @param {(Array|TypedArray|Object)} out - output object
     29 * @returns {(Array|TypedArray|Object)} array strides
     30 */
     31 function rowmajor( shape, out ) {
     32 	var ndims;
     33 	var s;
     34 	var i;
     35 
     36 	ndims = shape.length;
     37 	s = 1;
     38 	for ( i = ndims-1; i >= 0; i-- ) {
     39 		out[ i ] = s;
     40 		s *= shape[ i ];
     41 	}
     42 	return out;
     43 }
     44 
     45 /**
     46 * Generates a stride array from an array shape (column-major).
     47 *
     48 * @private
     49 * @param {NonNegativeIntegerArray} shape - array shape
     50 * @param {(Array|TypedArray|Object)} out - output object
     51 * @returns {(Array|TypedArray|Object)} array strides
     52 */
     53 function columnmajor( shape, out ) {
     54 	var s;
     55 	var i;
     56 
     57 	s = 1;
     58 	for ( i = 0; i < shape.length; i++ ) {
     59 		out[ i ] = s;
     60 		s *= shape[ i ];
     61 	}
     62 	return out;
     63 }
     64 
     65 
     66 // MAIN //
     67 
     68 /**
     69 * Generates a stride array from an array shape.
     70 *
     71 * @param {NonNegativeIntegerArray} shape - array shape
     72 * @param {string} order - specifies whether an array is row-major (C-style) or column-major (Fortran-style)
     73 * @param {(Array|TypedArray|Object)} out - output object
     74 * @returns {(Array|TypedArray|Object)} array strides
     75 *
     76 * @example
     77 * var strides = [ 0, 0 ];
     78 *
     79 * var out = shape2strides( [ 3, 2 ], 'row-major', strides );
     80 * // returns [ 2, 1 ]
     81 *
     82 * var bool = ( out === strides );
     83 * // returns true
     84 *
     85 * out = shape2strides( [ 3, 2 ], 'column-major', strides );
     86 * // returns [ 1, 3 ]
     87 */
     88 function shape2strides( shape, order, out ) {
     89 	if ( order === 'column-major' ) {
     90 		return columnmajor( shape, out );
     91 	}
     92 	return rowmajor( shape, out );
     93 }
     94 
     95 
     96 // EXPORTS //
     97 
     98 module.exports = shape2strides;