feat: return index array as part of the results object

Author: kgryte

lib/node_modules/@stdlib/ndarray/base/unary-loop-interchange-order/README.md

@@ -64,6 +64,7 @@ The function returns an object having the following properties:
 -   **sh**: ordered dimensions.
 -   **sx**: input array strides sorted in loop order.
 -   **sy**: output array strides sorted in loop order.
+-   **idx**: dimension indices sorted in loop order.
 
 For all returned arrays, the first element corresponds to the innermost loop, and the last element corresponds to the outermost loop.
 

lib/node_modules/@stdlib/ndarray/base/unary-loop-interchange-order/docs/repl.txt

@@ -7,6 +7,7 @@
     - sh: ordered dimensions.
     - sx: input array strides sorted in loop order.
     - sy: output array strides sorted in loop order.
+    - idx: dimension indices sorted in loop order.
 
     For all returned arrays, the first element corresponds to the innermost
     loop, and the last element corresponds to the outermost loop.
@@ -39,6 +40,9 @@
     out.sy: Array<integer>
         Output array strides sorted in loop order.
 
+    out.idx: Array<integer>
+        Dimension indices sorted in loop order.
+
     Examples
     --------
     > var x = {{alias:@stdlib/ndarray/array}}( [ [ 1, 2 ], [ 3, 4 ] ] );

lib/node_modules/@stdlib/ndarray/base/unary-loop-interchange-order/docs/types/index.d.ts

@@ -40,6 +40,11 @@ interface LoopOrderObject {
 	* Output array strides sorted in loop order.
 	*/
 	sy: Array<number>;
+
+	/**
+	* Dimension indices sorted in loop order.
+	*/
+	idx: Array<number>;
 }
 
 /**
@@ -52,6 +57,7 @@ interface LoopOrderObject {
 *     -   **sh**: dimensions sorted in loop order.
 *     -   **sx**: input ndarray strides sorted in loop order.
 *     -   **sy**: output ndarray strides sorted in loop order.
+*     -   **idx**: dimension indices sorted in loop order.
 *
 * -   When iterating over the elements of a multi-dimensional array, accessing elements which are closer in memory can improve performance. To this end, loop interchange is a technique used in loop nest optimization to improve locality of reference and take advantage of CPU cache.
 *
@@ -83,6 +89,9 @@ interface LoopOrderObject {
 *
 * var ssy = o.sy;
 * // returns [ 6, -2, 1 ]
+*
+* var idx = o.idx;
+* // returns [ 2, 1, 0 ]
 */
 declare function unaryLoopOrder( shape: ArrayLike<number>, stridesX: ArrayLike<number>, stridesY: ArrayLike<number> ): LoopOrderObject;
 

lib/node_modules/@stdlib/ndarray/base/unary-loop-interchange-order/lib/index.js

@@ -42,6 +42,9 @@
 *
 * var ssy = o.sy;
 * // returns [ 6, -2, 1 ]
+*
+* var idx = o.idx;
+* // returns [ 2, 1, 0 ]
 */
 
 // MODULES //

lib/node_modules/@stdlib/ndarray/base/unary-loop-interchange-order/lib/main.js

@@ -38,6 +38,7 @@ var sort2ins = require( './sort2ins.js' );
 *     -   **sh**: dimensions sorted in loop order.
 *     -   **sx**: input ndarray strides sorted in loop order.
 *     -   **sy**: output ndarray strides sorted in loop order.
+*     -   **idx**: dimension indices sorted in loop order.
 *
 * @param {NonNegativeIntegerArray} sh - array dimensions
 * @param {IntegerArray} sx - input array stride lengths
@@ -61,6 +62,9 @@ var sort2ins = require( './sort2ins.js' );
 *
 * var ssy = o.sy;
 * // returns [ 6, -2, 1 ]
+*
+* var idx = o.idx;
+* // returns [ 2, 1, 0 ]
 */
 function loopOrder( sh, sx, sy ) {
 	var idx;
@@ -79,7 +83,8 @@ function loopOrder( sh, sx, sy ) {
 	return {
 		'sh': sh,
 		'sx': sx,
-		'sy': sy
+		'sy': sy,
+		'idx': idx
 	};
 }
 

lib/node_modules/@stdlib/ndarray/base/unary-loop-interchange-order/test/test.js

@@ -57,6 +57,9 @@ tape( 'the function returns loop interchange data (row-major)', function test( t
 	t.strictEqual( isArray( o.sy ), true, 'returns expected value' );
 	t.deepEqual( o.sy, [ 1, 2, -4 ], 'returns expected value' );
 
+	t.strictEqual( isArray( o.idx ), true, 'returns expected value' );
+	t.deepEqual( o.idx, [ 2, 1, 0 ], 'returns expected value' );
+
 	t.end();
 });
 
@@ -84,6 +87,9 @@ tape( 'the function returns loop interchange data (column-major)', function test
 	t.strictEqual( isArray( o.sy ), true, 'returns expected value' );
 	t.deepEqual( o.sy, [ -1, 4, 8 ], 'returns expected value' );
 
+	t.strictEqual( isArray( o.idx ), true, 'returns expected value' );
+	t.deepEqual( o.idx, [ 0, 1, 2 ], 'returns expected value' );
+
 	t.end();
 });
 
@@ -111,6 +117,9 @@ tape( 'the function returns loop interchange data (mixed order)', function test(
 	t.strictEqual( isArray( o.sy ), true, 'returns expected value' );
 	t.deepEqual( o.sy, [ -8, -4, 1 ], 'returns expected value' );
 
+	t.strictEqual( isArray( o.idx ), true, 'returns expected value' );
+	t.deepEqual( o.idx, [ 2, 1, 0 ], 'returns expected value' );
+
 	t.end();
 });
 
@@ -119,5 +128,6 @@ tape( 'if provided empty arrays, the function returns empty arrays', function te
 	t.deepEqual( o.sh, [], 'returns expected value' );
 	t.deepEqual( o.sx, [], 'returns expected value' );
 	t.deepEqual( o.sy, [], 'returns expected value' );
+	t.deepEqual( o.idx, [], 'returns expected value' );
 	t.end();
 });