diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/README.md b/lib/node_modules/@stdlib/ndarray/diagonal/README.md
new file mode 100644
index 000000000000..1497cb977139
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/README.md
@@ -0,0 +1,182 @@
+
+
+# diagonal
+
+> Return a **read-only** view of the diagonal of a matrix (or stack of matrices).
+
+
+
+
+
+For an `M`-by-`N` matrix `A`, the `k`-th diagonal is defined as
+
+
+
+```math
+D_k = \{\, A_{i,j} : j - i = k \,\}
+```
+
+
+
+
+
+where `k = 0` corresponds to the main diagonal, `k > 0` corresponds to the super-diagonals (above the main diagonal), and `k < 0` corresponds to the sub-diagonals (below the main diagonal). For example, given the matrix
+
+
+
+```math
+A = \begin{bmatrix} a_{0,0} & a_{0,1} & a_{0,2} \\ a_{1,0} & a_{1,1} & a_{1,2} \\ a_{2,0} & a_{2,1} & a_{2,2} \end{bmatrix}
+```
+
+
+
+
+
+the main diagonal is `[ a_{0,0}, a_{1,1}, a_{2,2} ]`, the super-diagonal `k = 1` is `[ a_{0,1}, a_{1,2} ]`, and the sub-diagonal `k = -1` is `[ a_{1,0}, a_{2,1} ]`.
+
+
+
+
+
+
+
+
+
+## Usage
+
+```javascript
+var diagonal = require( '@stdlib/ndarray/diagonal' );
+```
+
+#### diagonal( x\[, options] )
+
+Returns a read-only view of the diagonal of a matrix (or stack of matrices).
+
+```javascript
+var array = require( '@stdlib/ndarray/array' );
+
+var x = array( [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ] );
+// returns [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ]
+
+var y = diagonal( x );
+// returns [ 1.0, 5.0, 9.0 ]
+```
+
+The function accepts the following arguments:
+
+- **x**: input [`ndarray`][@stdlib/ndarray/ctor].
+- **options**: function options.
+
+The function accepts the following options:
+
+- **k**: diagonal offset. The diagonal offset is interpreted as `column - row`. Accordingly, when `k = 0`, the function returns the main diagonal; when `k > 0`, the function returns the diagonal above the main diagonal; and when `k < 0`, the function returns the diagonal below the main diagonal. Default: `0`.
+- **dims**: dimension indices defining the plane from which to extract the diagonal. Must contain exactly two unique dimension indices. The first element specifies the row-like dimension. The second element specifies the column-like dimension. 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`. Default: `[-2, -1]`.
+
+
+
+
+
+
+
+
+
+## Notes
+
+- The order of the dimension indices contained in `options.dims` matters. The first element specifies the row-like dimension. The second element specifies the column-like dimension.
+- Each provided dimension index must reside on the interval `[-ndims, ndims-1]`.
+
+
+
+
+
+
+
+
+
+## Examples
+
+
+
+```javascript
+var uniform = require( '@stdlib/random/uniform' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var diagonal = require( '@stdlib/ndarray/diagonal' );
+
+// Create a stack of matrices:
+var x = uniform( [ 2, 3, 3 ], -10.0, 10.0 );
+console.log( ndarray2array( x ) );
+
+// Extract the main diagonals from the stack:
+var y = diagonal( x );
+console.log( ndarray2array( y ) );
+
+// Extract super-diagonals from the stack:
+y = diagonal( x, {
+ 'k': 1
+});
+console.log( ndarray2array( y ) );
+
+// Extract sub-diagonals from the stack:
+y = diagonal( x, {
+ 'k': -1
+});
+console.log( ndarray2array( y ) );
+```
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/ctor
+
+
+
+
+
+
+
+
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/benchmark/benchmark.js b/lib/node_modules/@stdlib/ndarray/diagonal/benchmark/benchmark.js
new file mode 100644
index 000000000000..a98591399199
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/benchmark/benchmark.js
@@ -0,0 +1,196 @@
+/**
+* @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 diagonal = require( './../lib' );
+
+
+// MAIN //
+
+bench( format( '%s: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 = diagonal( values[ i%values.length ] );
+ 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', 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 = diagonal( values[ i%values.length ] );
+ 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 opts;
+ 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 */
+
+ opts = {
+ 'dims': [ 0, 2 ]
+ };
+
+ b.tic();
+ for ( i = 0; i < b.iterations; i++ ) {
+ v = diagonal( values[ i%values.length ], opts );
+ 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=4', 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, 2 ], { 'dtype': 'float64' } ),
+ empty( [ 2, 2, 2, 2 ], { 'dtype': 'float32' } ),
+ empty( [ 2, 2, 2, 2 ], { 'dtype': 'int32' } ),
+ empty( [ 2, 2, 2, 2 ], { 'dtype': 'complex128' } ),
+ empty( [ 2, 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 = diagonal( values[ i%values.length ] );
+ 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=5', 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, 2, 2 ], { 'dtype': 'float64' } ),
+ empty( [ 2, 2, 2, 2, 2 ], { 'dtype': 'float32' } ),
+ empty( [ 2, 2, 2, 2, 2 ], { 'dtype': 'int32' } ),
+ empty( [ 2, 2, 2, 2, 2 ], { 'dtype': 'complex128' } ),
+ empty( [ 2, 2, 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 = diagonal( values[ i%values.length ] );
+ 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();
+});
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/docs/repl.txt b/lib/node_modules/@stdlib/ndarray/diagonal/docs/repl.txt
new file mode 100644
index 000000000000..cec5eec794ce
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/docs/repl.txt
@@ -0,0 +1,50 @@
+
+{{alias}}( x[, options] )
+ Returns a read-only view of the diagonal of a matrix (or stack of
+ matrices).
+
+ The order of the dimension indices contained in `options.dims` matters.
+ The first element specifies the row-like dimension. The second element
+ specifies the column-like dimension.
+
+ Each provided dimension index must reside on the interval [-ndims, ndims-1].
+
+ Parameters
+ ----------
+ x: ndarray
+ Input array.
+
+ options: Object (optional)
+ Function options.
+
+ options.k: integer (optional)
+ Diagonal offset. The diagonal offset is interpreted as `column - row`.
+ Accordingly, when equal to zero, the function returns the main diagonal.
+ When greater than zero, the function returns the diagonal above the main
+ diagonal. When less than zero, the function returns the diagonal below
+ the main diagonal. Default: 0.
+
+ options.dims: ArrayLikeObject (optional)
+ Dimension indices defining the plane from which to extract the
+ diagonal. The first element specifies the row-like dimension. The
+ second element specifies the column-like dimension. Must contain
+ exactly two unique dimension indices. If less than zero, an index is
+ resolved relative to the last dimension, with the last dimension
+ corresponding to the value `-1`. Default: [ -2, -1 ].
+
+ Returns
+ -------
+ out: ndarray
+ Output array view.
+
+ Examples
+ --------
+ > var x = {{alias:@stdlib/ndarray/array}}( [ [ 1, 2 ], [ 3, 4 ] ] )
+ [ [ 1, 2 ], [ 3, 4 ] ]
+ > var y = {{alias}}( x )
+ [ 1, 4 ]
+ > y = {{alias}}( x, { 'k': 1 } )
+ [ 2 ]
+
+ See Also
+ --------
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/docs/types/index.d.ts b/lib/node_modules/@stdlib/ndarray/diagonal/docs/types/index.d.ts
new file mode 100644
index 000000000000..0bfbcf915d56
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/docs/types/index.d.ts
@@ -0,0 +1,70 @@
+/*
+* @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.
+*/
+
+// TypeScript Version: 4.1
+
+///
+
+import { ndarray } from '@stdlib/types/ndarray';
+import { Collection } from '@stdlib/types/array';
+
+/**
+* Interface defining function options.
+*/
+interface Options {
+ /**
+ * Diagonal offset (default: 0).
+ */
+ k?: number;
+
+ /**
+ * Dimension indices defining the plane from which to extract the diagonal (default: [-2, -1]).
+ */
+ dims?: Collection;
+}
+
+/**
+* Returns a read-only view of the diagonal of a matrix (or stack of matrices).
+*
+* ## Notes
+*
+* - The order of the dimension indices contained in `options.dims` matters. The first element specifies the row-like dimension. The second element specifies the column-like dimension.
+* - Each provided dimension index must reside on the interval `[-ndims, ndims-1]`.
+* - The diagonal offset `options.k` is interpreted as `column - row`. Accordingly, when `options.k = 0`, the function returns the main diagonal; when `options.k > 0`, the function returns the diagonal above the main diagonal; and when `options.k < 0`, the function returns the diagonal below the main diagonal.
+*
+* @param x - input array
+* @param options - function options
+* @param options.k - diagonal offset (default: 0)
+* @param options.dims - dimension indices defining the plane from which to extract the diagonal (default: [-2, -1])
+* @returns output array
+*
+* @example
+* var array = require( '@stdlib/ndarray/array' );
+*
+* var x = array( [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ] );
+* // returns [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ]
+*
+* var y = diagonal( x );
+* // returns [ 1.0, 5.0, 9.0 ]
+*/
+declare function diagonal( x: T, options?: Options ): T;
+
+
+// EXPORTS //
+
+export = diagonal;
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/docs/types/test.ts b/lib/node_modules/@stdlib/ndarray/diagonal/docs/types/test.ts
new file mode 100644
index 000000000000..d7671d4cbc9f
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/docs/types/test.ts
@@ -0,0 +1,93 @@
+/*
+* @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.
+*/
+
+/* eslint-disable space-in-parens */
+
+import zeros = require( '@stdlib/ndarray/zeros' );
+import diagonal = require( './index' );
+
+
+// TESTS //
+
+// The function returns an ndarray...
+{
+ diagonal( zeros( [ 2, 2 ] ) ); // $ExpectType float64ndarray
+ diagonal( zeros( [ 2, 2 ] ), {} ); // $ExpectType float64ndarray
+ diagonal( zeros( [ 2, 2 ] ), { 'k': 1 } ); // $ExpectType float64ndarray
+ diagonal( zeros( [ 2, 2 ] ), { 'dims': [ 0, 1 ] } ); // $ExpectType float64ndarray
+ diagonal( zeros( [ 2, 2 ] ), { 'k': 1, 'dims': [ 0, 1 ] } ); // $ExpectType float64ndarray
+}
+
+// The compiler throws an error if the function is provided a first argument which is not an ndarray...
+{
+ diagonal( '10' ); // $ExpectError
+ diagonal( 10 ); // $ExpectError
+ diagonal( false ); // $ExpectError
+ diagonal( true ); // $ExpectError
+ diagonal( null ); // $ExpectError
+ diagonal( void 0 ); // $ExpectError
+ diagonal( [] ); // $ExpectError
+ diagonal( {} ); // $ExpectError
+ diagonal( ( x: number ): number => x ); // $ExpectError
+}
+
+// The compiler throws an error if the function is provided a second argument which is not an object...
+{
+ const x = zeros( [ 2, 2 ] );
+
+ diagonal( x, '10' ); // $ExpectError
+ diagonal( x, 10 ); // $ExpectError
+ diagonal( x, false ); // $ExpectError
+ diagonal( x, true ); // $ExpectError
+ diagonal( x, null ); // $ExpectError
+ diagonal( x, [] ); // $ExpectError
+ diagonal( x, ( x: number ): number => x ); // $ExpectError
+}
+
+// The compiler throws an error if the function is provided a `k` option which is not a number...
+{
+ const x = zeros( [ 2, 2 ] );
+
+ diagonal( x, { 'k': '10' } ); // $ExpectError
+ diagonal( x, { 'k': false } ); // $ExpectError
+ diagonal( x, { 'k': true } ); // $ExpectError
+ diagonal( x, { 'k': null } ); // $ExpectError
+ diagonal( x, { 'k': [] } ); // $ExpectError
+ diagonal( x, { 'k': {} } ); // $ExpectError
+ diagonal( x, { 'k': ( x: number ): number => x } ); // $ExpectError
+}
+
+// The compiler throws an error if the function is provided a `dims` option which is not a collection of numbers...
+{
+ const x = zeros( [ 2, 2 ] );
+
+ diagonal( x, { 'dims': '10' } ); // $ExpectError
+ diagonal( x, { 'dims': 10 } ); // $ExpectError
+ diagonal( x, { 'dims': false } ); // $ExpectError
+ diagonal( x, { 'dims': true } ); // $ExpectError
+ diagonal( x, { 'dims': null } ); // $ExpectError
+ diagonal( x, { 'dims': {} } ); // $ExpectError
+ diagonal( x, { 'dims': [ '0', '1' ] } ); // $ExpectError
+ diagonal( x, { 'dims': ( x: number ): number => x } ); // $ExpectError
+}
+
+// The compiler throws an error if the function is provided an unsupported number of arguments...
+{
+ diagonal(); // $ExpectError
+ diagonal( zeros( [ 2, 2 ] ), {}, {} ); // $ExpectError
+}
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/examples/index.js b/lib/node_modules/@stdlib/ndarray/diagonal/examples/index.js
new file mode 100644
index 000000000000..9dda62a7d338
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/examples/index.js
@@ -0,0 +1,43 @@
+/**
+* @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';
+
+var uniform = require( '@stdlib/random/uniform' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var diagonal = require( './../lib' );
+
+// Create a stack of matrices:
+var x = uniform( [ 2, 3, 3 ], -10.0, 10.0 );
+console.log( ndarray2array( x ) );
+
+// Extract the main diagonals from the stack:
+var y = diagonal( x );
+console.log( ndarray2array( y ) );
+
+// Extract super-diagonals from the stack:
+y = diagonal( x, {
+ 'k': 1
+});
+console.log( ndarray2array( y ) );
+
+// Extract sub-diagonals from the stack:
+y = diagonal( x, {
+ 'k': -1
+});
+console.log( ndarray2array( y ) );
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/lib/index.js b/lib/node_modules/@stdlib/ndarray/diagonal/lib/index.js
new file mode 100644
index 000000000000..c6453b346908
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/lib/index.js
@@ -0,0 +1,44 @@
+/**
+* @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';
+
+/**
+* Return a read-only view of the diagonal of a matrix (or stack of matrices).
+*
+* @module @stdlib/ndarray/diagonal
+*
+* @example
+* var array = require( '@stdlib/ndarray/array' );
+* var diagonal = require( '@stdlib/ndarray/diagonal' );
+*
+* var x = array( [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ] );
+* // returns [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ]
+*
+* var y = diagonal( x );
+* // returns [ 1.0, 5.0, 9.0 ]
+*/
+
+// MODULES //
+
+var main = require( './main.js' );
+
+
+// EXPORTS //
+
+module.exports = main;
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/lib/main.js b/lib/node_modules/@stdlib/ndarray/diagonal/lib/main.js
new file mode 100644
index 000000000000..b978f08b56d3
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/lib/main.js
@@ -0,0 +1,98 @@
+/**
+* @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 isIntegerArray = require( '@stdlib/assert/is-integer-array' ).primitives;
+var isInteger = require( '@stdlib/assert/is-integer' ).isPrimitive;
+var isPlainObject = require( '@stdlib/assert/is-plain-object' );
+var isndarrayLike = require( '@stdlib/assert/is-ndarray-like' );
+var hasOwnProp = require( '@stdlib/assert/has-own-property' );
+var base = require( '@stdlib/ndarray/base/diagonal' );
+var format = require( '@stdlib/string/format' );
+
+
+// MAIN //
+
+/**
+* Returns a read-only view of the diagonal of a matrix (or stack of matrices).
+*
+* ## Notes
+*
+* - The order of the dimension indices contained in `options.dims` matters. The first element specifies the row-like dimension. The second element specifies the column-like dimension.
+* - Each provided dimension index must reside on the interval `[-ndims, ndims-1]`.
+* - The diagonal offset `options.k` is interpreted as `column - row`. Accordingly, when `options.k = 0`, the function returns the main diagonal; when `options.k > 0`, the function returns the diagonal above the main diagonal; and when `options.k < 0`, the function returns the diagonal below the main diagonal.
+*
+* @param {ndarray} x - input array
+* @param {Options} [options] - function options
+* @param {integer} [options.k=0] - diagonal offset
+* @param {IntegerArray} [options.dims=[-2,-1]] - dimension indices defining the plane from which to extract the diagonal
+* @throws {TypeError} first argument must be an ndarray
+* @throws {TypeError} options argument must be an object
+* @throws {TypeError} `k` option must be an integer
+* @throws {TypeError} `dims` option must be an array of integers
+* @throws {RangeError} must provide exactly two dimension indices
+* @throws {RangeError} input ndarray must have at least two dimensions
+* @throws {RangeError} must provide valid dimension indices
+* @throws {Error} must provide unique dimension indices
+* @returns {ndarray} ndarray view
+*
+* @example
+* var array = require( '@stdlib/ndarray/array' );
+*
+* var x = array( [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ] );
+* // returns [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ], [ 7.0, 8.0, 9.0 ] ]
+*
+* var y = diagonal( x );
+* // returns [ 1.0, 5.0, 9.0 ]
+*/
+function diagonal( x, options ) {
+ var dims;
+ var k;
+
+ if ( !isndarrayLike( x ) ) {
+ throw new TypeError( format( 'invalid argument. First argument must be an ndarray. Value: `%s`.', x ) );
+ }
+ dims = [ -2, -1 ];
+ k = 0;
+ if ( arguments.length > 1 ) {
+ if ( !isPlainObject( options ) ) {
+ throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
+ }
+ if ( hasOwnProp( options, 'k' ) ) {
+ if ( !isInteger( options.k ) ) {
+ throw new TypeError( format( 'invalid option. `%s` option must be an integer. Option: `%s`.', 'k', options.k ) );
+ }
+ k = options.k;
+ }
+ if ( hasOwnProp( options, 'dims' ) ) {
+ if ( !isIntegerArray( options.dims ) ) {
+ throw new TypeError( format( 'invalid option. `%s` option must be an array of integers. Option: `%s`.', 'dims', options.dims ) );
+ }
+ dims = options.dims;
+ }
+ }
+ return base( x, dims, k, false );
+}
+
+
+// EXPORTS //
+
+module.exports = diagonal;
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/package.json b/lib/node_modules/@stdlib/ndarray/diagonal/package.json
new file mode 100644
index 000000000000..4a52d2b2dc40
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/package.json
@@ -0,0 +1,63 @@
+{
+ "name": "@stdlib/ndarray/diagonal",
+ "version": "0.0.0",
+ "description": "Return a read-only view of the diagonal of a matrix (or stack of matrices).",
+ "license": "Apache-2.0",
+ "author": {
+ "name": "The Stdlib Authors",
+ "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
+ },
+ "contributors": [
+ {
+ "name": "The Stdlib Authors",
+ "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
+ }
+ ],
+ "main": "./lib",
+ "directories": {
+ "benchmark": "./benchmark",
+ "doc": "./docs",
+ "example": "./examples",
+ "lib": "./lib",
+ "test": "./test"
+ },
+ "types": "./docs/types",
+ "scripts": {},
+ "homepage": "https://github.com/stdlib-js/stdlib",
+ "repository": {
+ "type": "git",
+ "url": "git://github.com/stdlib-js/stdlib.git"
+ },
+ "bugs": {
+ "url": "https://github.com/stdlib-js/stdlib/issues"
+ },
+ "dependencies": {},
+ "devDependencies": {},
+ "engines": {
+ "node": ">=0.10.0",
+ "npm": ">2.7.0"
+ },
+ "os": [
+ "aix",
+ "darwin",
+ "freebsd",
+ "linux",
+ "macos",
+ "openbsd",
+ "sunos",
+ "win32",
+ "windows"
+ ],
+ "keywords": [
+ "stdlib",
+ "stdtypes",
+ "types",
+ "data",
+ "structure",
+ "ndarray",
+ "diagonal",
+ "matrix",
+ "stack",
+ "view"
+ ]
+}
diff --git a/lib/node_modules/@stdlib/ndarray/diagonal/test/test.js b/lib/node_modules/@stdlib/ndarray/diagonal/test/test.js
new file mode 100644
index 000000000000..59de2800faaa
--- /dev/null
+++ b/lib/node_modules/@stdlib/ndarray/diagonal/test/test.js
@@ -0,0 +1,656 @@
+/**
+* @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 tape = require( 'tape' );
+var Float64Array = require( '@stdlib/array/float64' );
+var isndarrayLike = require( '@stdlib/assert/is-ndarray-like' );
+var isReadOnly = require( '@stdlib/ndarray/base/assert/is-read-only' );
+var isEqualDataType = require( '@stdlib/ndarray/base/assert/is-equal-data-type' );
+var ndarray = require( '@stdlib/ndarray/ctor' );
+var array = require( '@stdlib/ndarray/array' );
+var zeroTo = require( '@stdlib/blas/ext/zero-to' );
+var getShape = require( '@stdlib/ndarray/shape' );
+var getData = require( '@stdlib/ndarray/data-buffer' );
+var getDType = require( '@stdlib/ndarray/dtype' );
+var getOrder = require( '@stdlib/ndarray/order' );
+var scalar2ndarray = require( '@stdlib/ndarray/from-scalar' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var diagonal = require( './../lib' );
+
+
+// TESTS //
+
+tape( 'main export is a function', function test( t ) {
+ t.ok( true, __filename );
+ t.strictEqual( typeof diagonal, 'function', 'main export is a function' );
+ t.end();
+});
+
+tape( 'the function throws an error if provided a first argument which is not an ndarray', function test( t ) {
+ var values;
+ var i;
+
+ values = [
+ '5',
+ 5,
+ NaN,
+ true,
+ false,
+ null,
+ void 0,
+ [],
+ {},
+ function noop() {}
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), TypeError, 'throws an error when provided ' + values[ i ] );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( value );
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a second argument which is not an object', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ '5',
+ 5,
+ NaN,
+ true,
+ false,
+ null,
+ void 0,
+ [],
+ function noop() {}
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), TypeError, 'throws an error when provided ' + values[ i ] );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, value );
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a `k` option which is not an integer', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ '5',
+ 3.14,
+ NaN,
+ true,
+ false,
+ null,
+ void 0,
+ [],
+ {},
+ function noop() {}
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), TypeError, 'throws an error when provided ' + values[ i ] );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, {
+ 'k': value
+ });
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a `dims` option which is not an array-like object', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ 5,
+ 3.14,
+ NaN,
+ true,
+ false,
+ null,
+ void 0,
+ {},
+ function noop() {}
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), TypeError, 'throws an error when provided ' + values[ i ] );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, {
+ 'dims': value
+ });
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a `dims` option which is not an array of integers', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ [ '0', '1' ],
+ [ 0.5, 1.5 ],
+ [ NaN, NaN ],
+ [ null, null ],
+ [ true, false ],
+ [ {}, {} ]
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), TypeError, 'throws an error when provided [' + values[ i ] + ']' );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, {
+ 'dims': value
+ });
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a `dims` option which does not contain exactly two dimension indices', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ [ 0 ],
+ [ 0, 1, 0 ]
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), RangeError, 'throws an error when provided dimension indices [' + values[ i ] + ']' );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, {
+ 'dims': value
+ });
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a `dims` option having out-of-bounds dimension indices', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ [ 0, 2 ],
+ [ 2, 0 ],
+ [ -3, 0 ],
+ [ 0, -3 ]
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), RangeError, 'throws an error when provided dimension indices [' + values[ i ] + ']' );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, {
+ 'dims': value
+ });
+ };
+ }
+});
+
+tape( 'the function throws an error if provided a `dims` option having duplicate dimension indices', function test( t ) {
+ var values;
+ var x;
+ var i;
+
+ x = zeroTo( [ 2, 2 ] );
+
+ values = [
+ [ 0, 0 ],
+ [ 1, 1 ],
+ [ 0, -2 ],
+ [ -1, 1 ]
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), Error, 'throws an error when provided dimension indices [' + values[ i ] + ']' );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ diagonal( x, {
+ 'dims': value
+ });
+ };
+ }
+});
+
+tape( 'the function throws an error if provided an input ndarray having fewer than two dimensions', function test( t ) {
+ var values;
+ var i;
+
+ values = [
+ scalar2ndarray( 5.0 ),
+ array( [ 1.0, 2.0, 3.0 ] )
+ ];
+
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[ i ] ), RangeError, 'throws an error when provided an ndarray having ' + values[ i ].ndims + ' dimensions' );
+ }
+ t.end();
+
+ function badValue( x ) {
+ return function badValue() {
+ diagonal( x );
+ };
+ }
+});
+
+tape( 'the function returns a read-only view of the main diagonal of a square matrix', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x );
+ expected = [ 0, 4, 8 ];
+
+ t.notEqual( actual, x, 'returns expected value' );
+ t.strictEqual( isndarrayLike( actual ), true, 'returns expected value' );
+ t.strictEqual( isReadOnly( actual ), true, 'returns expected value' );
+ t.strictEqual( getData( actual ), getData( x ), 'returns expected value' );
+ t.strictEqual( isEqualDataType( getDType( actual ), getDType( x ) ), true, 'returns expected value' );
+ t.deepEqual( getShape( actual ), [ 3 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function returns a read-only view of a super-diagonal (k>0)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x, {
+ 'k': 1
+ });
+ expected = [ 1, 5 ];
+ t.strictEqual( isReadOnly( actual ), true, 'returns expected value' );
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': 2
+ });
+ expected = [ 2 ];
+ t.deepEqual( getShape( actual ), [ 1 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function returns a read-only view of a sub-diagonal (k<0)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x, {
+ 'k': -1
+ });
+ expected = [ 3, 7 ];
+ t.strictEqual( isReadOnly( actual ), true, 'returns expected value' );
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': -2
+ });
+ expected = [ 6 ];
+ t.deepEqual( getShape( actual ), [ 1 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function returns an empty view when the diagonal offset is out-of-bounds', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x, {
+ 'k': 3
+ });
+ expected = [];
+ t.deepEqual( getShape( actual ), [ 0 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': -3
+ });
+ t.deepEqual( getShape( actual ), [ 0 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function returns a view of a non-square matrix (M < N)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 2, 4 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x );
+ expected = [ 0, 5 ];
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': 2
+ });
+ expected = [ 2, 7 ];
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function returns a view of a non-square matrix (M > N)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 4, 2 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x );
+ expected = [ 0, 3 ];
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': -2
+ });
+ expected = [ 4, 7 ];
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function supports negative dimension indices (default `dims=[-2,-1]`)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x, {
+ 'dims': [ -2, -1 ]
+ });
+ expected = [ 0, 4, 8 ];
+ t.deepEqual( getShape( actual ), [ 3 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function swaps the row-like and column-like dimensions when `dims` is reversed', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ]
+ });
+
+ actual = diagonal( x, {
+ 'dims': [ 1, 0 ],
+ 'k': 1
+ });
+ expected = [ 3, 7 ];
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'dims': [ 1, 0 ],
+ 'k': -1
+ });
+ expected = [ 1, 5 ];
+ t.deepEqual( getShape( actual ), [ 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function supports a stack of matrices (ndims=3)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 2, 2, 2 ], {
+ 'dims': [ 0, 1, 2 ]
+ });
+
+ actual = diagonal( x );
+ expected = [ [ 0, 3 ], [ 4, 7 ] ];
+ t.strictEqual( isReadOnly( actual ), true, 'returns expected value' );
+ t.deepEqual( getShape( actual ), [ 2, 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': 1
+ });
+ expected = [ [ 1 ], [ 5 ] ];
+ t.deepEqual( getShape( actual ), [ 2, 1 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': -1
+ });
+ expected = [ [ 2 ], [ 6 ] ];
+ t.deepEqual( getShape( actual ), [ 2, 1 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function supports diagonals along arbitrary planes (ndims=3)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 2, 2, 3 ], {
+ 'dims': [ 0, 1, 2 ]
+ });
+
+ actual = diagonal( x, {
+ 'dims': [ 0, 2 ]
+ });
+ expected = [ [ 0, 7 ], [ 3, 10 ] ];
+ t.deepEqual( getShape( actual ), [ 2, 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function returns a column-major ndarray when the input ndarray is column-major', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ],
+ 'order': 'column-major'
+ });
+
+ actual = diagonal( x );
+ expected = [ 0, 4, 8 ];
+ t.strictEqual( getOrder( actual ), 'column-major', 'returns expected value' );
+ t.deepEqual( getShape( actual ), [ 3 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function supports input ndarrays having a non-zero buffer offset', function test( t ) {
+ var expected;
+ var actual;
+ var buf;
+ var x;
+
+ buf = new Float64Array( [ 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0 ] );
+ x = new ndarray( 'float64', buf, [ 3, 3 ], [ 3, 1 ], 1, 'row-major' );
+
+ actual = diagonal( x );
+ expected = [ 1.0, 5.0, 9.0 ];
+ t.deepEqual( getShape( actual ), [ 3 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+ t.strictEqual( getData( actual ), getData( x ), 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': 1
+ });
+ expected = [ 2.0, 6.0 ];
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': -1
+ });
+ expected = [ 4.0, 8.0 ];
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function supports a stack of non-square matrices (ndims=3)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 2, 2, 4 ], {
+ 'dims': [ 0, 1, 2 ]
+ });
+
+ actual = diagonal( x );
+ expected = [ [ 0, 5 ], [ 8, 13 ] ];
+ t.deepEqual( getShape( actual ), [ 2, 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': 2
+ });
+ expected = [ [ 2, 7 ], [ 10, 15 ] ];
+ t.deepEqual( getShape( actual ), [ 2, 2 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ actual = diagonal( x, {
+ 'k': -1
+ });
+ expected = [ [ 4 ], [ 12 ] ];
+ t.deepEqual( getShape( actual ), [ 2, 1 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});
+
+tape( 'the function preserves the input data type (dtype=int32)', function test( t ) {
+ var expected;
+ var actual;
+ var x;
+
+ x = zeroTo( [ 3, 3 ], {
+ 'dims': [ 0, 1 ],
+ 'dtype': 'int32'
+ });
+
+ actual = diagonal( x );
+ expected = [ 0, 4, 8 ];
+
+ t.strictEqual( isReadOnly( actual ), true, 'returns expected value' );
+ t.strictEqual( getData( actual ), getData( x ), 'returns expected value' );
+ t.strictEqual( isEqualDataType( getDType( actual ), getDType( x ) ), true, 'returns expected value' );
+ t.deepEqual( getShape( actual ), [ 3 ], 'returns expected value' );
+ t.deepEqual( ndarray2array( actual ), expected, 'returns expected value' );
+
+ t.end();
+});