time-to-botec

Benchmark sampling in different programming languages
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main.js (1926B)

      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 // MAIN //
     22 
     23 /**
     24 * Computes the minimum linear index in an underlying data buffer accessible to an array view.
     25 *
     26 * @param {NonNegativeIntegerArray} shape - array shape
     27 * @param {IntegerArray} strides - stride array
     28 * @param {NonNegativeInteger} offset - index offset
     29 * @returns {NonNegativeInteger} linear index
     30 *
     31 * @example
     32 * var shape = [ 10, 10 ];
     33 * var strides = [ 10, 1 ];
     34 * var offset = 10;
     35 *
     36 * var idx = minViewBufferIndex( shape, strides, offset );
     37 * // returns 10
     38 *
     39 * @example
     40 * var shape = [ 10, 10 ];
     41 * var strides = [ -10, -1 ];
     42 * var offset = 109;
     43 *
     44 * var idx = minViewBufferIndex( shape, strides, offset );
     45 * // returns 10
     46 *
     47 * @example
     48 * var shape = [ 10, 10 ];
     49 * var strides = [ 1, 10 ];
     50 * var offset = 10;
     51 *
     52 * var idx = minViewBufferIndex( shape, strides, offset );
     53 * // returns 10
     54 *
     55 * @example
     56 * var shape = [ 10, 10 ];
     57 * var strides = [ -1, -10 ];
     58 * var offset = 109;
     59 *
     60 * var idx = minViewBufferIndex( shape, strides, offset );
     61 * // returns 10
     62 */
     63 function minViewBufferIndex( shape, strides, offset ) {
     64 	var ndims;
     65 	var idx;
     66 	var i;
     67 
     68 	ndims = shape.length;
     69 	idx = offset;
     70 	for ( i = 0; i < ndims; i++ ) {
     71 		if ( strides[ i ] < 0 ) {
     72 			idx += strides[ i ] * (shape[ i ] - 1); // decrements the index
     73 		}
     74 	}
     75 	return idx;
     76 }
     77 
     78 
     79 // EXPORTS //
     80 
     81 module.exports = minViewBufferIndex;