feat: add stats/array/max-by

lib/node_modules/@stdlib/stats/array/max-by/README.md

@@ -0,0 +1,155 @@
+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# maxBy
+
+> Calculate the maximum value of an array via a callback function.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var maxBy = require( '@stdlib/stats/array/max-by' );
+```
+
+#### maxBy( x, clbk\[, thisArg] )
+
+Computes the maximum value of an array via a callback function.
+
+```javascript
+function accessor( v ) {
+    return v * 2.0;
+}
+
+var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ];
+
+var v = maxBy( x, accessor );
+// returns 8.0
+```
+
+The function has the following parameters:
+
+-   **x**: input array.
+-   **clbk**: callback function.
+-   **thisArg**: execution context (_optional_).
+
+The invoked callback is provided four arguments:
+
+-   **value**: array element.
+-   **aidx**: array index.
+-   **sidx**: strided index (`offset + aidx*stride`).
+-   **array**: input array/collection.
+
+To set the callback execution context, provide a `thisArg`.
+
+```javascript
+function accessor( v ) {
+    this.count += 1;
+    return v * 2.0;
+}
+
+var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ];
+
+var context = {
+    'count': 0
+};
+
+var v = maxBy( x, accessor, context );
+// returns 8.0
+
+var cnt = context.count;
+// returns 8
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   If provided an empty array, the function returns `NaN`.
+-   A provided callback function should return a numeric value.
+-   If a provided callback function does not return any value (or equivalently, explicitly returns `undefined`), the value is **ignored**.
+-   The function supports array-like objects having getter and setter accessors for array element access (e.g., [`@stdlib/array/base/accessor`][@stdlib/array/base/accessor]).
+-   When possible, prefer using [`dmax`][@stdlib/stats/array/dmax], [`smax`][@stdlib/stats/array/smax], and/or [`max`][@stdlib/stats/array/max], as, depending on the environment, these interfaces are likely to be significantly more performant.
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var maxBy = require( '@stdlib/stats/array/max-by' );
+
+function accessor( v ) {
+    return v * 2.0;
+}
+
+var x = discreteUniform( 10, -50, 50, {
+    'dtype': 'float64'
+});
+console.log( x );
+
+var v = maxBy( x, accessor );
+console.log( v );
+```
+
+</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/array/base/accessor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/base/accessor
+
+[@stdlib/stats/array/dmax]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/array/dmax
+
+[@stdlib/stats/array/max]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/array/max
+
+[@stdlib/stats/array/smax]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/array/smax
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/stats/array/max-by/benchmark/benchmark.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 uniform = require( '@stdlib/random/array/uniform' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var pkg = require( './../package.json' ).name;
+var maxBy = require( './../lib' );
+
+
+// VARIABLES //
+
+var options = {
+	'dtype': 'generic'
+};
+
+
+// FUNCTIONS //
+
+/**
+* Accessor function.
+*
+* @private
+* @param {number} value - array element
+* @returns {number} accessed value
+*/
+function accessor( value ) {
+	return value * 2.0;
+}
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var x = uniform( len, -10, 10, options );
+	return benchmark;
+
+	function benchmark( b ) {
+		var v;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			v = maxBy( x, accessor );
+			if ( isnan( v ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( isnan( v ) ) {
+			b.fail( 'should not return NaN' );
+		}
+		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+':len='+len, f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/stats/array/max-by/docs/repl.txt

@@ -0,0 +1,44 @@
+
+{{alias}}( x )
+    Computes the maximum value of an array via a callback function.
+
+    If provided an empty array, the function returns `NaN`.
+
+    The callback function is provided three arguments:
+
+    - value: array element.
+    - aidx: array index.
+    - sidx: strided index (offset + aidx*stride).
+    - array: the input array.
+
+    The callback function should return a numeric value.
+
+    If the callback function does not return any value (or equivalently,
+    explicitly returns `undefined`), the value is ignored.
+
+    Parameters
+    ----------
+    x: Array<number>|TypedArray
+        Input array.
+
+    clbk: Function
+        Callback function.
+
+    thisArg: any (optional)
+        Execution context.
+
+    Returns
+    -------
+    out: number
+        Maximum value.
+
+    Examples
+    --------
+    > function accessor( v ) { return v * 2.0; };
+    > var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ];
+    > {{alias}}( x, accessor )
+    8.0
+
+    See Also
+    --------
+