Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 24x 24x 6x 6x 6x 6x 18x 18x 6x 6x 6x 2x 2x 6x 1x 1x 1x 1x 1x 1x 1x 4x 3x 3x 3x 9x 9x 4x 4x 4x 9x 3x 3x 3x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 18x 18x 6x 6x 1x 1x 1x 1x 1x | /**
* @license Apache-2.0
*
* Copyright (c) 2025 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
// MODULES //
var zeroTo = require( '@stdlib/array/base/zero-to' );
var copy = require( '@stdlib/array/base/copy-indexed' );
var take = require( '@stdlib/array/base/take-indexed' );
var strides2order = require( '@stdlib/ndarray/base/strides2order' );
var sort2ins = require( './sort2ins.js' );
// MAIN //
/**
* Reorders ndarray dimensions and associated strides for loop interchange.
*
* ## Notes
*
* - The returned array has the following elements:
*
* ```text
* [ <shape>, ...<strides> ]
* ```
*
* where
*
* - **shape**: dimensions sorted in loop order.
* - **...strides**: strides for each respective ndarray sorted in loop order.
*
* @param {NonNegativeIntegerArray} shape - array dimensions
* @param {ArrayLikeObject<ArrayLikeObject<integer>>} strides - list of stride arrays containing the stride lengths for each input and output ndarray
* @returns {Array<Array>} loop interchange data
*
* @example
* var sh = [ 2, 3, 4 ];
*
* var sx = [ 12, 4, 1 ]; // row-major
* var sy = [ 24, 8, 1 ]; // row-major
* var sz = [ 1, -2, 6 ]; // column-major
*
* var o = loopOrder( sh, [ sx, sy, sz ] );
* // returns [...]
*
* var ssh = o[ 0 ];
* // returns [ 4, 3, 2 ]
*
* var ssx = o[ 1 ];
* // returns [ 1, 4, 12 ]
*
* var ssy = o[ 2 ];
* // returns [ 1, 8, 24 ]
*
* var ssz = o[ 3 ];
* // returns [ 6, -2, 1 ]
*/
function loopOrder( shape, strides ) {
var idx;
var tmp;
var max;
var len;
var out;
var st;
var N;
var M;
var i;
var j;
N = strides.length;
// Initialize an array for grouping stride arrays according to memory layout:
tmp = [];
for ( i = 0; i < 4; i++ ) { // note: `4` corresponds to the number of possible return values from `strides2order`
tmp.push( [] );
}
M = tmp.length;
// Group stride arrays according to memory layout:
for ( i = 0; i < N; i++ ) {
tmp[ strides2order( strides[ i ] ) ].push( strides[ i ] );
}
// Determine which array should be used to generate the loop order:
max = tmp[ 0 ].length;
if ( max === N ) {
// If all arrays are "disorganized", then just use the first array, as, generally, each array is likely to be as un-ideal as every other:
st = strides[ 0 ];
} else if ( max === N-1 ) {
// If all but one array is "disorganized", find the "organized" array...
for ( i = 1; i < M; i++ ) {
if ( tmp[ i ].length ) {
st = tmp[ i ][ 0 ];
break;
}
}
} else {
// Find the layout which is most common...
j = 0;
for ( i = 1; i < M; i++ ) {
len = tmp[ i ].length;
if ( len >= max ) {
max = len;
j = i;
}
}
// Use the strides of the first array having the most common layout:
st = tmp[ j ][ 0 ];
}
// Initialize a loop interchange index array for generating a loop order permutation:
idx = zeroTo( shape.length );
// Sort strides in increasing order of magnitude:
sort2ins( copy( st ), idx );
// Permute the shape based on the sorted strides:
out = [ take( shape, idx ) ];
// Permute each stride array based on the sorted strides:
for ( i = 0; i < N; i++ ) {
out.push( take( strides[ i ], idx ) );
}
return out;
}
// EXPORTS //
module.exports = loopOrder;
|