Skip to content
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
126 changes: 126 additions & 0 deletions lib/node_modules/@stdlib/ndarray/reverse-dimensions/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,126 @@
<!--

@license Apache-2.0

Copyright (c) 2026 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.

-->

# reverseDimensions

> Return a **read-only** view of an input [`ndarray`][@stdlib/ndarray/ctor] in which the order of elements along specified dimensions is reversed.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro section element. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="usage">

## Usage

```javascript
var reverseDimensions = require( '@stdlib/ndarray/reverse-dimensions' );
```

#### reverseDimensions( x, dims )

Returns a read-only view of an input [`ndarray`][@stdlib/ndarray/ctor] in which the order of elements along specified dimensions is reversed.

```javascript
var array = require( '@stdlib/ndarray/array' );

var x = array( [ [ 1.0, 2.0 ], [ 3.0, 4.0 ], [ 5.0, 6.0 ] ] );
// returns <ndarray>[ [ 1.0, 2.0 ], [ 3.0, 4.0 ], [ 5.0, 6.0 ] ]

var y = reverseDimensions( x, [ 0, 1 ] );
// returns <ndarray>[ [ 6.0, 5.0 ], [ 4.0, 3.0 ], [ 2.0, 1.0 ] ]
```

The function accepts the following arguments:

- **x**: input ndarray.
- **dims**: indices of dimensions along which to reverse elements. If a dimension index is provided as an integer less than zero, the dimension index is resolved relative to the last dimension, with the last dimension corresponding to the value `-1`.

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var uniform = require( '@stdlib/random/uniform' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var reverseDimensions = require( '@stdlib/ndarray/reverse-dimensions' );

var x = uniform( [ 3, 3, 3 ], -10.0, 10.0 );
console.log( ndarray2array( x ) );

var y = reverseDimensions( x, [ 0, 2 ] );
console.log( ndarray2array( y ) );
```

</section>

<!-- /.examples -->

<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="references">

</section>

<!-- /.references -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/ctor

<!-- <related-links> -->

<!-- </related-links> -->

</section>

<!-- /.links -->
Original file line number Diff line number Diff line change
@@ -0,0 +1,223 @@
/**
* @license Apache-2.0
*
* Copyright (c) 2026 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 bench = require( '@stdlib/bench' );
var isndarrayLike = require( '@stdlib/assert/is-ndarray-like' );
var empty = require( '@stdlib/ndarray/empty' );
var format = require( '@stdlib/string/format' );
var pkg = require( './../package.json' ).name;
var reverseDimensions = require( './../lib' );


// MAIN //

bench( format( '%s:ndims=1,dims=[0]', pkg ), function benchmark( b ) {
var values;
var v;
var i;

/* eslint-disable object-curly-newline, stdlib/line-closing-bracket-spacing */

values = [
empty( [ 2 ], { 'dtype': 'float64' } ),
empty( [ 2 ], { 'dtype': 'float32' } ),
empty( [ 2 ], { 'dtype': 'int32' } ),
empty( [ 2 ], { 'dtype': 'complex128' } ),
empty( [ 2 ], { 'dtype': 'generic' } )
];

/* eslint-enable object-curly-newline, stdlib/line-closing-bracket-spacing */

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = reverseDimensions( values[ i%values.length ], [ 0 ] );
if ( typeof v !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( !isndarrayLike( v ) ) {
b.fail( 'should return an ndarray' );
}
b.pass( 'benchmark finished' );
b.end();
});

bench( format( '%s:ndims=2,dims=[0]', pkg ), function benchmark( b ) {
var values;
var v;
var i;

/* eslint-disable object-curly-newline, stdlib/line-closing-bracket-spacing */

values = [
empty( [ 2, 2 ], { 'dtype': 'float64' } ),
empty( [ 2, 2 ], { 'dtype': 'float32' } ),
empty( [ 2, 2 ], { 'dtype': 'int32' } ),
empty( [ 2, 2 ], { 'dtype': 'complex128' } ),
empty( [ 2, 2 ], { 'dtype': 'generic' } )
];

/* eslint-enable object-curly-newline, stdlib/line-closing-bracket-spacing */

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = reverseDimensions( values[ i%values.length ], [ 0 ] );
if ( typeof v !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( !isndarrayLike( v ) ) {
b.fail( 'should return an ndarray' );
}
b.pass( 'benchmark finished' );
b.end();
});

bench( format( '%s:ndims=2,dims=[0,1]', pkg ), function benchmark( b ) {
var values;
var v;
var i;

/* eslint-disable object-curly-newline, stdlib/line-closing-bracket-spacing */

values = [
empty( [ 2, 2 ], { 'dtype': 'float64' } ),
empty( [ 2, 2 ], { 'dtype': 'float32' } ),
empty( [ 2, 2 ], { 'dtype': 'int32' } ),
empty( [ 2, 2 ], { 'dtype': 'complex128' } ),
empty( [ 2, 2 ], { 'dtype': 'generic' } )
];

/* eslint-enable object-curly-newline, stdlib/line-closing-bracket-spacing */

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = reverseDimensions( values[ i%values.length ], [ 0, 1 ] );
if ( typeof v !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( !isndarrayLike( v ) ) {
b.fail( 'should return an ndarray' );
}
b.pass( 'benchmark finished' );
b.end();
});

bench( format( '%s:ndims=3,dims=[0]', pkg ), function benchmark( b ) {
var values;
var v;
var i;

/* eslint-disable object-curly-newline, stdlib/line-closing-bracket-spacing */

values = [
empty( [ 2, 2, 2 ], { 'dtype': 'float64' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'float32' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'int32' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'complex128' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'generic' } )
];

/* eslint-enable object-curly-newline, stdlib/line-closing-bracket-spacing */

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = reverseDimensions( values[ i%values.length ], [ 0 ] );
if ( typeof v !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( !isndarrayLike( v ) ) {
b.fail( 'should return an ndarray' );
}
b.pass( 'benchmark finished' );
b.end();
});

bench( format( '%s:ndims=3,dims=[0,2]', pkg ), function benchmark( b ) {
var values;
var v;
var i;

/* eslint-disable object-curly-newline, stdlib/line-closing-bracket-spacing */

values = [
empty( [ 2, 2, 2 ], { 'dtype': 'float64' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'float32' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'int32' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'complex128' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'generic' } )
];

/* eslint-enable object-curly-newline, stdlib/line-closing-bracket-spacing */

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = reverseDimensions( values[ i%values.length ], [ 0, 2 ] );
if ( typeof v !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( !isndarrayLike( v ) ) {
b.fail( 'should return an ndarray' );
}
b.pass( 'benchmark finished' );
b.end();
});

bench( format( '%s:ndims=3,dims=[0,1,2]', pkg ), function benchmark( b ) {
var values;
var v;
var i;

/* eslint-disable object-curly-newline, stdlib/line-closing-bracket-spacing */

values = [
empty( [ 2, 2, 2 ], { 'dtype': 'float64' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'float32' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'int32' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'complex128' } ),
empty( [ 2, 2, 2 ], { 'dtype': 'generic' } )
];

/* eslint-enable object-curly-newline, stdlib/line-closing-bracket-spacing */

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = reverseDimensions( values[ i%values.length ], [ 0, 1, 2 ] );
if ( typeof v !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( !isndarrayLike( v ) ) {
b.fail( 'should return an ndarray' );
}
b.pass( 'benchmark finished' );
b.end();
});
30 changes: 30 additions & 0 deletions lib/node_modules/@stdlib/ndarray/reverse-dimensions/docs/repl.txt
Original file line number Diff line number Diff line change
@@ -0,0 +1,30 @@

{{alias}}( x, dims )
Returns a read-only view of an input ndarray in which the order of elements
along specified dimensions is reversed.

Parameters
----------
x: ndarray
Input array.

dims: ArrayLike<integer>
Indices of dimensions to reverse. If a dimension index is provided as an
integer less than zero, the dimension index is resolved relative to the
last dimension, with the last dimension corresponding to the value `-1`.

Returns
-------
out: ndarray
A read-only view of an input ndarray in which the order of elements
along specified dimensions is reversed.

Examples
--------
> var x = {{alias:@stdlib/ndarray/array}}( [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ] )
<ndarray>[ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]
> var y = {{alias}}( x, [ 0, 1 ] )
<ndarray>[ [ 4.0, 3.0 ], [ 2.0, 1.0 ] ]

See Also
--------
Loading