feat: add array/base/take-map

lib/node_modules/@stdlib/array/base/take-map/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2024 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.
+
+-->
+
+# takeMap
+
+> Take elements from an array and return a new array after applying a mapping function.
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var takeMap = require( '@stdlib/array/base/take-map' );
+```
+
+### takeMap( x, indices, mode, clbk )
+
+Takes elements from an array and returns a new array after applying a mapping function.
+
+```javascript
+var x = [ 1, 2, 3, 4 ];
+
+function customMapping( value ) {
+    return value * 2;
+}
+
+var y = takeMap( x, [ 1, 3 ], 'throw', customMapping );
+// returns [ 4, 8 ]
+```
+
+The function supports the following parameters:
+
+-   **x**: input array.
+-   **indices**: list of indices.
+-   **mode**: index [mode][@stdlib/ndarray/base/ind].
+-   **clbk**: function to apply.
+
+### takeMap.assign( x, indices, mode, out, stride, offset, clbk )
+
+> Takes elements from an array and assigns the values to elements in a provided output array.
+
+```javascript
+var x = [ 1, 2, 3, 4 ];
+
+var out = [ 0, 0, 0, 0, 0, 0 ];
+var indices = [ 0, 0, 1, 1, 3, 3 ];
+
+function clbk( val ) {
+    return val * 2;
+}
+
+var arr = takeMap.assign( x, indices, 'throw', out, -1, out.length-1, clbk );
+// returns [ 8, 8, 4, 4, 2, 2 ]
+
+var bool = ( arr === out );
+// returns true
+```
+
+The function supports the following parameters:
+
+-   **x**: input array.
+-   **indices**: list of indices.
+-   **mode**: index [mode][@stdlib/ndarray/base/ind].
+-   **out**: output array.
+-   **stride**: output array stride.
+-   **offset**: output array offset.
+-   **clbk**: callback function.
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var filledBy = require( '@stdlib/array/base/filled-by' );
+var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
+var linspace = require( '@stdlib/array/base/linspace' );
+var takeMap = require( '@stdlib/array/base/take-map' );
+
+// Generate a linearly spaced array:
+var x = linspace( 0, 100, 11 );
+console.log( x );
+
+// Generate an array of random indices:
+var N = discreteUniform( 5, 15 );
+var indices = filledBy( N, discreteUniform.factory( 0, x.length-1 ) );
+console.log( indices );
+
+// Define a mapping function (e.g., square the value):
+function square( val ) {
+    return val * val;
+}
+
+// Take a random sample of elements from `x` and apply the mapping function:
+var y = takeMap( x, indices, 'throw', square );
+console.log( y );
+```
+
+</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">
+
+[@stdlib/ndarray/base/ind]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/base/ind
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/array/base/take-map/benchmark/benchmark.assign.length.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2024 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 pow = require( '@stdlib/math/base/special/pow' );
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var zeros = require( '@stdlib/array/zeros' );
+var isArray = require( '@stdlib/assert/is-array' );
+var pkg = require( './../package.json' ).name;
+var takeMap = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var out;
+	var idx;
+
+	idx = discreteUniform( len, 0, 3, {
+		'dtype': 'generic'
+	});
+	out = zeros( len, 'generic' );
+
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var x;
+		var v;
+		var i;
+
+		x = [ 1, 2, 3, 4 ];
+		function clbk( val ) {
+			return val;
+		}
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			v = takeMap.assign( x, idx, 'throw', out, 1, 0, clbk );
+			if ( typeof v !== 'object' ) {
+				b.fail( 'should return an array' );
+			}
+		}
+		b.toc();
+		if ( !isArray( v ) ) {
+			b.fail( 'should return an array' );
+		}
+		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+':assign:len='+len, f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/array/base/take-map/benchmark/benchmark.js

@@ -0,0 +1,56 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2024 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 isArray = require( '@stdlib/assert/is-array' );
+var zeroTo = require( '@stdlib/array/base/zero-to' );
+var pkg = require( './../package.json' ).name;
+var takeMap = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg+'::copy:len=100', function benchmark( b ) {
+	var x;
+	var i;
+	var v;
+
+	x = zeroTo( 100 );
+
+	function clbk( val ) {
+		return val;
+	}
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = takeMap( x, x, 'throw', clbk );
+		if ( typeof v !== 'object' ) {
+			b.fail( 'should return an array' );
+		}
+	}
+	b.toc();
+	if ( !isArray( v ) ) {
+		b.fail( 'should return an array' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});