Auto-generated commit

README.md

@@ -963,6 +963,47 @@ idx = arr.indexOf( new Complex64( 1.0, -1.0 ), 1 );
 // returns -1
 ```
 
+<a name="method-lastIndexOf"></a>
+
+#### Complex64Array.prototype.lastIndexOf( searchElement\[, fromIndex] )
+
+Returns the last index at which a given element can be found.
+
+```javascript
+var Complex64 = require( '@stdlib/complex-float32' );
+
+var arr = new Complex64Array( 10 );
+
+arr.set( [ 1.0, -1.0 ], 0 );
+arr.set( [ 2.0, -2.0 ], 1 );
+arr.set( [ 3.0, -3.0 ], 2 );
+arr.set( [ 4.0, -4.0 ], 3 );
+arr.set( [ 2.0, -2.0 ], 4 );
+
+var idx = arr.lastIndexOf( new Complex64( 3.0, -3.0 ) );
+// returns 2
+
+idx = arr.lastIndexOf( new Complex64( 2.0, -2.0 ), 2 );
+// returns 1
+```
+
+If `searchElement` is not present in the array, the method returns `-1`.
+
+```javascript
+var Complex64 = require( '@stdlib/complex-float32' );
+
+var arr = new Complex64Array( 10 );
+
+arr.set( [ 1.0, -1.0 ], 0 );
+arr.set( [ 2.0, -2.0 ], 1 );
+
+var idx = arr.lastIndexOf( new Complex64( 3.0, -3.0 ) );
+// returns -1
+
+idx = arr.lastIndexOf( new Complex64( 2.0, -2.0 ), 0 );
+// returns -1
+```
+
 <a name="method-set"></a>
 
 #### Complex64Array.prototype.set( z\[, i] )

benchmark/benchmark.last_index_of.js

@@ -0,0 +1,59 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2023 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-harness' );
+var Complex64 = require( '@stdlib/complex-float32' );
+var isInteger = require('@stdlib/assert-is-integer' ).isPrimitive;
+var pkg = require( './../package.json' ).name;
+var Complex64Array = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg+':lastIndexOf', function benchmark( b ) {
+	var arr;
+	var idx;
+	var v;
+	var i;
+
+	arr = [];
+	for ( i = 0; i < 10; i++ ) {
+		arr.push( new Complex64( i, i ) );
+	}
+	arr = new Complex64Array( arr );
+
+	v = new Complex64( 10.0, 10.0 );
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		idx = arr.lastIndexOf( v, 9 );
+		if ( typeof idx !== 'number' ) {
+			b.fail( 'should return an integer' );
+		}
+	}
+	b.toc();
+	if ( !isInteger( idx ) ) {
+		b.fail( 'should return an integer' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

benchmark/benchmark.last_index_of.length.js

@@ -0,0 +1,106 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2023 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-harness' );
+var pow = require( '@stdlib/math-base-special-pow' );
+var Complex64 = require( '@stdlib/complex-float32' );
+var isInteger = require('@stdlib/assert-is-integer' ).isPrimitive;
+var pkg = require( './../package.json' ).name;
+var Complex64Array = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var arr;
+	var i;
+
+	arr = [];
+	for ( i = 0; i < len; i++ ) {
+		arr.push( new Complex64( i, -i ) );
+	}
+	arr = new Complex64Array( arr );
+
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var idx;
+		var v;
+		var i;
+
+		v = new Complex64( 0, 0 );
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			idx = arr.lastIndexOf( v );
+			if ( typeof idx !== 'number' ) {
+				b.fail( 'should return an integer' );
+			}
+		}
+		b.toc();
+		if ( !isInteger( idx ) ) {
+			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( pkg+':lastIndexOf:len='+len, f );
+	}
+}
+
+main();

docs/types/index.d.ts

@@ -386,6 +386,35 @@ declare class Complex64Array implements Complex64ArrayInterface {
 	*/
 	indexOf( searchElement: ComplexLike, fromIndex?: number ): number;
 
+	/**
+	* Returns the last index at which a given element can be found.
+	*
+	* @param searchElement - element to find
+	* @param fromIndex - index at which to start searching backward (inclusive)
+	* @returns index or -1
+	*
+	* @example
+	* var Complex64 = require( '@stdlib/complex-float32' );
+	*
+	* var arr = new Complex64Array( 5 );
+	*
+	* arr.set( [ 1.0, -1.0 ], 0 );
+	* arr.set( [ 2.0, -2.0 ], 1 );
+	* arr.set( [ 3.0, -3.0 ], 2 );
+	* arr.set( [ 4.0, -4.0 ], 3 );
+	* arr.set( [ 3.0, -3.0 ], 4 );
+	*
+	* var idx = arr.lastIndexOf( new Complex64( 3.0, -3.0 ) );
+	* // returns 4
+	*
+	* idx = arr.lastIndexOf( new Complex64( 3.0, -3.0 ), 3 );
+	* // returns 2
+	*
+	* idx = arr.lastIndexOf( new Complex64( 5.0, -5.0 ), 3 );
+	* // returns -1
+	*/
+	lastIndexOf( searchElement: ComplexLike, fromIndex?: number ): number;
+
 	/**
 	* Sets an array element.
 	*

lib/main.js

@@ -1032,6 +1032,73 @@ setReadOnly( Complex64Array.prototype, 'indexOf', function indexOf( searchElemen
 	return -1;
 });
 
+/**
+* Returns the last index at which a given element can be found.
+*
+* @name lastIndexOf
+* @memberof Complex64Array.prototype
+* @type {Function}
+* @param {Complex64} searchElement - element to find
+* @param {integer} [fromIndex] - index at which to start searching backward (inclusive)
+* @throws {TypeError} `this` must be a complex number array
+* @throws {TypeError} first argument must be a complex number
+* @throws {TypeError} second argument must be an nonnegative integer
+* @returns {integer} index or -1
+*
+* @example
+* var Complex64 = require( '@stdlib/complex-float32' );
+*
+* var arr = new Complex64Array( 5 );
+*
+* arr.set( [ 1.0, -1.0 ], 0 );
+* arr.set( [ 2.0, -2.0 ], 1 );
+* arr.set( [ 3.0, -3.0 ], 2 );
+* arr.set( [ 4.0, -4.0 ], 3 );
+* arr.set( [ 3.0, -3.0 ], 4 );
+*
+* var idx = arr.lastIndexOf( new Complex64( 3.0, -3.0 ) );
+* // returns 4
+*
+* idx = arr.lastIndexOf( new Complex64( 3.0, -3.0 ), 3 );
+* // returns 2
+*
+* idx = arr.lastIndexOf( new Complex64( 5.0, -5.0 ), 3 );
+* // returns -1
+*/
+setReadOnly( Complex64Array.prototype, 'lastIndexOf', function lastIndexOf( searchElement, fromIndex ) {
+	var buf;
+	var idx;
+	var re;
+	var im;
+	var i;
+	if ( !isComplexArray( this ) ) {
+		throw new TypeError( 'invalid invocation. `this` is not a complex number array.' );
+	}
+	if ( !isComplexLike( searchElement ) ) {
+		throw new TypeError( format( 'invalid argument. First argument must be a complex number. Value: `%s`.', searchElement ) );
+	}
+	if ( arguments.length > 1 ) {
+		if ( !isNonNegativeInteger( fromIndex ) ) {
+			throw new TypeError( format( 'invalid argument. Second argument must be a nonnegative integer. Value: `%s`.', fromIndex ) );
+		}
+		if ( fromIndex >= this._length ) {
+			fromIndex = this._length - 1;
+		}
+	} else {
+		fromIndex = this._length - 1;
+	}
+	re = realf( searchElement );
+	im = imagf( searchElement );
+	buf = this._buffer;
+	for ( i = fromIndex; i >= 0; i-- ) {
+		idx = 2 * i;
+		if ( re === buf[ idx ] && im === buf[ idx+1 ] ) {
+			return i;
+		}
+	}
+	return -1;
+});
+
 /**
 * Number of array elements.
 *