feat: add blas/ext/base/ndarray/dlast-index-equal

lib/node_modules/@stdlib/blas/ext/base/ndarray/dlast-index-equal/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.
+
+-->
+
+# dlastIndexEqual
+
+> Return the index of the last element in a one-dimensional double-precision floating-point ndarray equal to a corresponding element in another one-dimensional double-precision floating-point ndarray.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var dlastIndexEqual = require( '@stdlib/blas/ext/base/ndarray/dlast-index-equal' );
+```
+
+#### dlastIndexEqual( arrays )
+
+Returns the index of the last element in a one-dimensional double-precision floating-point ndarray equal to a corresponding element in another one-dimensional double-precision floating-point ndarray.
+
+```javascript
+var Float64Vector = require( '@stdlib/ndarray/vector/float64' );
+
+var x = new Float64Vector( [ 1.0, 2.0, 3.0, 4.0 ] );
+var y = new Float64Vector( [ 0.0, 0.0, 3.0, 0.0 ] );
+
+var idx = dlastIndexEqual( [ x, y ] );
+// returns 2
+```
+
+The function has the following parameters:
+
+-   **arrays**: array-like object containing the following ndarrays:
+
+    -   first one-dimensional input ndarray.
+    -   second one-dimensional input ndarray.
+
+If the function is unable to find matching elements, the function returns `-1`.
+
+```javascript
+var Float64Vector = require( '@stdlib/ndarray/vector/float64' );
+
+var x = new Float64Vector( [ 1.0, 2.0, 3.0, 4.0 ] );
+var y = new Float64Vector( [ 5.0, 6.0, 7.0, 8.0 ] );
+
+var idx = dlastIndexEqual( [ x, y ] );
+// returns -1
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   When comparing elements, the function checks for equality using the strict equality operator `===`. As a consequence, `NaN` values are considered distinct, and `-0` and `+0` are considered the same.
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var discreteUniform = require( '@stdlib/random/discrete-uniform' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var dlastIndexEqual = require( '@stdlib/blas/ext/base/ndarray/dlast-index-equal' );
+
+var opts = {
+    'dtype': 'float64'
+};
+var x = discreteUniform( [ 10 ], 0, 10, opts );
+console.log( ndarray2array( x ) );
+
+var y = discreteUniform( [ 10 ], 0, 10, opts );
+console.log( ndarray2array( y ) );
+
+var idx = dlastIndexEqual( [ x, y ] );
+console.log( idx );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- 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">
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/blas/ext/base/ndarray/dlast-index-equal/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 isInteger = require( '@stdlib/assert/is-integer' ).isPrimitive;
+var pow = require( '@stdlib/math/base/special/pow' );
+var Float64Vector = require( '@stdlib/ndarray/vector/float64' );
+var ones = require( '@stdlib/array/ones' );
+var zeros = require( '@stdlib/array/zeros' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var dlastIndexEqual = require( './../lib' );
+
+
+// VARIABLES //
+
+var options = {
+	'dtype': 'float64'
+};
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var x = new Float64Vector( ones( len, options.dtype ) );
+	var y = new Float64Vector( zeros( len, options.dtype ) );
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var out;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			out = dlastIndexEqual( [ x, y ] );
+			if ( out !== out ) {
+				b.fail( 'should return an integer' );
+			}
+		}
+		b.toc();
+		if ( !isInteger( out ) ) {
+			b.fail( 'should return an integer' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var f;
+	var i;
+
+	min = 1; // 10^min
+	max = 6; // 10^max
+
+	for ( i = min; i <= max; i++ ) {
+		len = pow( 10, i );
+		f = createBenchmark( len );
+		bench( format( '%s:len=%d', pkg, len ), f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/blas/ext/base/ndarray/dlast-index-equal/docs/repl.txt

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+
+{{alias}}( arrays )
+    Returns the index of the last element in a one-dimensional double-
+    precision floating-point ndarray equal to a corresponding element in
+    another one-dimensional double-precision floating-point ndarray.
+
+    When comparing elements, the function checks for equality using the strict
+    equality operator `===`. As a consequence, `NaN` values are considered
+    distinct, and `-0` and `+0` are considered the same.
+
+    Parameters
+    ----------
+    arrays: ArrayLikeObject<ndarray>
+        Array-like object containing the following ndarrays:
+
+        - first one-dimensional input ndarray.
+        - second one-dimensional input ndarray.
+
+    Returns
+    -------
+    out: integer
+        Index.
+
+    Examples
+    --------
+    > var x = new {{alias:@stdlib/ndarray/vector/float64}}( [ 1.0, 2.0, 3.0, 4.0 ] );
+    > var y = new {{alias:@stdlib/ndarray/vector/float64}}( [ 0.0, 0.0, 3.0, 0.0 ] );
+    > {{alias}}( [ x, y ] )
+    2
+
+    See Also
+    --------

lib/node_modules/@stdlib/blas/ext/base/ndarray/dlast-index-equal/docs/types/index.d.ts

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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.
+*/
+
+// TypeScript Version: 4.1
+
+/// <reference types="@stdlib/types"/>
+
+import { float64ndarray } from '@stdlib/types/ndarray';
+
+/**
+* Returns the index of the last element in a one-dimensional double-precision floating-point ndarray equal to a corresponding element in another one-dimensional double-precision floating-point ndarray.
+*
+* ## Notes
+*
+* -   The function expects the following ndarrays:
+*
+*     -   first one-dimensional input ndarray.
+*     -   second one-dimensional input ndarray.
+*
+* -   When comparing elements, the function checks for equality using the strict equality operator `===`. As a consequence, `NaN` values are considered distinct, and `-0` and `+0` are considered the same.
+*
+* @param arrays - array-like object containing ndarrays
+* @returns index
+*
+* @example
+* var Float64Vector = require( '@stdlib/ndarray/vector/float64' );
+*
+* var x = new Float64Vector( [ 1.0, 2.0, 3.0, 4.0 ] );
+* var y = new Float64Vector( [ 0.0, 0.0, 3.0, 0.0 ] );
+*
+* var idx = dlastIndexEqual( [ x, y ] );
+* // returns 2
+*/
+declare function dlastIndexEqual( arrays: [ float64ndarray, float64ndarray ] ): number;
+
+
+// EXPORTS //
+
+export = dlastIndexEqual;

lib/node_modules/@stdlib/blas/ext/base/ndarray/dlast-index-equal/docs/types/test.ts

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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.
+*/
+
+/* eslint-disable space-in-parens */
+
+import zeros = require( '@stdlib/ndarray/zeros' );
+import dlastIndexEqual = require( './index' );
+
+
+// TESTS //
+
+// The function returns a number...
+{
+	const x = zeros( [ 10 ], {
+		'dtype': 'float64'
+	});
+	const y = zeros( [ 10 ], {
+		'dtype': 'float64'
+	});
+
+	dlastIndexEqual( [ x, y ] ); // $ExpectType number
+}
+
+// The compiler throws an error if the function is provided a first argument which is not an array of ndarrays...
+{
+	dlastIndexEqual( '10' ); // $ExpectError
+	dlastIndexEqual( 10 ); // $ExpectError
+	dlastIndexEqual( true ); // $ExpectError
+	dlastIndexEqual( false ); // $ExpectError
+	dlastIndexEqual( null ); // $ExpectError
+	dlastIndexEqual( undefined ); // $ExpectError
+	dlastIndexEqual( [] ); // $ExpectError
+	dlastIndexEqual( {} ); // $ExpectError
+	dlastIndexEqual( ( x: number ): number => x ); // $ExpectError
+}
+
+// The compiler throws an error if the function is provided an unsupported number of arguments...
+{
+	const x = zeros( [ 10 ], {
+		'dtype': 'float64'
+	});
+	const y = zeros( [ 10 ], {
+		'dtype': 'float64'
+	});
+
+	dlastIndexEqual(); // $ExpectError
+	dlastIndexEqual( [ x, y ], {} ); // $ExpectError
+}