time-to-botec

Benchmark sampling in different programming languages
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copy_view.js (2551B)

      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 // MODULES //
     22 
     23 var bufferCtors = require( './../../base/buffer-ctors' );
     24 var allocUnsafe = require( '@stdlib/buffer/alloc-unsafe' );
     25 
     26 
     27 // FUNCTIONS //
     28 
     29 /**
     30 * Copies a "generic" ndarray view.
     31 *
     32 * @private
     33 * @param {ndarray} arr - input ndarray
     34 * @returns {Array} output data buffer
     35 */
     36 function generic( arr ) {
     37 	var len;
     38 	var out;
     39 	var i;
     40 
     41 	len = arr.length;
     42 	out = [];
     43 	for ( i = 0; i < len; i++ ) {
     44 		out.push( arr.get( i ) );
     45 	}
     46 	return out;
     47 }
     48 
     49 /**
     50 * Copies a "binary" ndarray view.
     51 *
     52 * @private
     53 * @param {ndarray} arr - input ndarray
     54 * @returns {Array} output data buffer
     55 */
     56 function binary( arr ) {
     57 	var len;
     58 	var out;
     59 	var i;
     60 
     61 	len = arr.length;
     62 	out = allocUnsafe( len );
     63 	for ( i = 0; i < len; i++ ) {
     64 		out[ i ] = arr.get( i );
     65 	}
     66 	return out;
     67 }
     68 
     69 /**
     70 * Copies a "typed" ndarray view.
     71 *
     72 * @private
     73 * @param {ndarray} arr - input ndarray
     74 * @param {string} dtype - data type
     75 * @returns {Array} output data buffer
     76 */
     77 function typed( arr, dtype ) {
     78 	var ctor;
     79 	var len;
     80 	var out;
     81 	var i;
     82 
     83 	ctor = bufferCtors( dtype );
     84 	len = arr.length;
     85 	out = new ctor( len );
     86 	for ( i = 0; i < len; i++ ) {
     87 		out[ i ] = arr.get( i );
     88 	}
     89 	return out;
     90 }
     91 
     92 
     93 // MAIN //
     94 
     95 /**
     96 * Copies an ndarray view to a data buffer.
     97 *
     98 * @private
     99 * @param {ndarray} arr - input ndarray
    100 * @param {string} dtype - data type
    101 * @returns {(Array|TypedArray|Buffer)} output data buffer
    102 *
    103 * @example
    104 * var ndarray = require( '@stdlib/ndarray/ctor' );
    105 *
    106 * var buffer = [ 1.0, 2.0, 3.0 ];
    107 * var shape = [ 3 ];
    108 * var strides = [ -1 ];
    109 * var vec = ndarray( 'generic', buffer, shape, strides, 2, 'row-major' );
    110 *
    111 * var b = copyView( vec, 'float64' );
    112 * // returns <Float64Array>[ 3.0, 2.0, 1.0 ]
    113 */
    114 function copyView( arr, dtype ) {
    115 	// TODO: handle complex number dtypes!!
    116 	if ( dtype === 'generic') {
    117 		return generic( arr );
    118 	}
    119 	if ( dtype === 'binary' ) {
    120 		return binary( arr );
    121 	}
    122 	return typed( arr, dtype );
    123 }
    124 
    125 
    126 // EXPORTS //
    127 
    128 module.exports = copyView;