feat: add ndarray/base/rot90

lib/node_modules/@stdlib/ndarray/base/rot90/README.md

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+<!--
+
+@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.
+
+-->
+
+# rot90
+
+> Rotate an ndarray 90 degrees in a specified plane.
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- Package usage documentation. -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var rot90 = require( '@stdlib/ndarray/base/rot90' );
+```
+
+#### rot90( x, dims, k, writable )
+
+Rotates an ndarray 90 degrees in the plane specified by two dimension indices.
+
+```javascript
+var array = require( '@stdlib/ndarray/array' );
+
+var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
+// returns <ndarray>[ [ 1, 2 ], [ 3, 4 ] ]
+
+var y = rot90( x, [ 0, 1 ], 1, false );
+// returns <ndarray>[ [ 2, 4 ], [ 1, 3 ] ]
+```
+
+The function accepts the following arguments:
+
+-   **x**: input ndarray.
+-   **dims**: dimension indices defining the plane of rotation. Must contain exactly two unique dimension indices. 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`.
+-   **k**: number of times to rotate by 90 degrees. Positive values rotate counterclockwise. Negative values rotate clockwise.
+-   **writable**: boolean indicating whether a returned ndarray should be writable.
+
+</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">
+
+## Notes
+
+-   If `k > 0`, the function rotates the plane from the first specified dimension toward the second specified dimension. This means that, for a two-dimensional ndarray and `dims = [0, 1]`, the function rotates the plane counterclockwise.
+-   If `k < 0`, the function rotates the plane from the second specified dimension toward the first specified dimension. This means that, for a two-dimensional ndarray and `dims = [1, 0]`, the function rotates the plane clockwise.
+-   Each provided dimension index must reside on the interval `[-ndims, ndims-1]`.
+-   The `writable` parameter **only** applies to ndarray constructors supporting **read-only** instances.
+-   The returned ndarray is a **view** of the input ndarray. Accordingly, writing to the original ndarray will **mutate** the returned ndarray and vice versa.
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var array = require( '@stdlib/ndarray/array' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var rot90 = require( '@stdlib/ndarray/base/rot90' );
+
+// Create a 2x3 matrix:
+var x = array( [ [ 1, 2, 3 ], [ 4, 5, 6 ] ] );
+
+// Rotate 90 degrees counterclockwise in the (0,1) plane:
+var y = rot90( x, [ 0, 1 ], 1, false );
+var arr = ndarray2array( y );
+// returns [ [ 3, 6 ], [ 2, 5 ], [ 1, 4 ] ]
+
+// Rotate 180 degrees:
+y = rot90( x, [ 0, 1 ], 2, false );
+arr = ndarray2array( y );
+// returns [ [ 6, 5, 4 ], [ 3, 2, 1 ] ]
+
+// Rotate 270 degrees counterclockwise (equivalent to k=-1):
+y = rot90( x, [ 0, 1 ], 3, false );
+arr = ndarray2array( y );
+// returns [ [ 4, 1 ], [ 5, 2 ], [ 6, 3 ] ]
+
+// Rotate 360 degrees (equivalent to no rotation):
+y = rot90( x, [ 0, 1 ], 4, false );
+arr = ndarray2array( y );
+// returns [ [ 1, 2, 3 ], [ 4, 5, 6 ] ]
+
+// Rotate 90 degrees clockwise (equivalent to k=3):
+y = rot90( x, [ 0, 1 ], -1, false );
+arr = ndarray2array( y );
+// returns [ [ 4, 1 ], [ 5, 2 ], [ 6, 3 ] ]
+
+// Supports negative dimension indices:
+y = rot90( x, [ -2, -1 ], 1, false );
+arr = ndarray2array( y );
+// returns [ [ 3, 6 ], [ 2, 5 ], [ 1, 4 ] ]
+```
+
+</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">
+
+<!-- <related-links> -->
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/ndarray/base/rot90/benchmark/benchmark.js

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+/**
+* @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 baseEmpty = require( '@stdlib/ndarray/base/empty' );
+var empty = require( '@stdlib/ndarray/empty' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var rot90 = require( './../lib' );
+
+
+// MAIN //
+
+bench( format( '%s::base:ndims=2', pkg ), function benchmark( b ) {
+	var values;
+	var v;
+	var i;
+
+	values = [
+		baseEmpty( 'float64', [ 2, 2 ], 'row-major' ),
+		baseEmpty( 'float32', [ 2, 2 ], 'row-major' ),
+		baseEmpty( 'int32', [ 2, 2 ], 'row-major' ),
+		baseEmpty( 'complex128', [ 2, 2 ], 'row-major' ),
+		baseEmpty( 'generic', [ 2, 2 ], 'row-major' )
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = rot90( values[ i%values.length ], [ 0, 1 ], 1, false );
+		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::non-base:ndims=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 ], { '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 = rot90( values[ i%values.length ], [ 0, 1 ], 1, false );
+		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::base:ndims=3,dims=[1,2]', pkg ), function benchmark( b ) {
+	var values;
+	var v;
+	var i;
+
+	values = [
+		baseEmpty( 'float64', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'float32', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'int32', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'complex128', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'generic', [ 2, 2, 2 ], 'row-major' )
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = rot90( values[ i%values.length ], [ 1, 2 ], 1, false );
+		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::base:ndims=3,dims=[0,2]', pkg ), function benchmark( b ) {
+	var values;
+	var v;
+	var i;
+
+	values = [
+		baseEmpty( 'float64', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'float32', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'int32', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'complex128', [ 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'generic', [ 2, 2, 2 ], 'row-major' )
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = rot90( values[ i%values.length ], [ 0, 2 ], 1, false );
+		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::base:ndims=4', pkg ), function benchmark( b ) {
+	var values;
+	var v;
+	var i;
+
+	values = [
+		baseEmpty( 'float64', [ 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'float32', [ 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'int32', [ 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'complex128', [ 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'generic', [ 2, 2, 2, 2 ], 'row-major' )
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = rot90( values[ i%values.length ], [ 2, 3 ], 1, false );
+		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::base:ndims=5', pkg ), function benchmark( b ) {
+	var values;
+	var v;
+	var i;
+
+	values = [
+		baseEmpty( 'float64', [ 2, 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'float32', [ 2, 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'int32', [ 2, 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'complex128', [ 2, 2, 2, 2, 2 ], 'row-major' ),
+		baseEmpty( 'generic', [ 2, 2, 2, 2, 2 ], 'row-major' )
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = rot90( values[ i%values.length ], [ 3, 4 ], 1, false );
+		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();
+});