feat: add hypergeometric-entropy

lib/node_modules/@stdlib/stats/base/dists/hypergeometric/entropy/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.
+
+-->
+
+# Entropy
+
+> [Hypergeometric][hypergeometric-distribution] distribution [differential entropy][entropy].
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+The [differential entropy][entropy] for a [hypergeometric][hypergeometric-distribution] random variable is given by
+
+<!-- <equation class="equation" label="eq:hypergeometric_entropy" align="center" raw="H(X) = - \sum P(k) \ln(P(k))" alt="Differential entropy for a hypergeometric distribution."> -->
+
+```math
+H(X) = - \sum_{k=\max(0, n+K-N)}^{\min(n, K)} P(X=k) \ln(P(X=k))
+```
+
+<!-- <div class="equation" align="center" data-raw-text="H(X) = - \sum P(k) \ln(P(k))" data-equation="eq:hypergeometric_entropy">
+    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@51534079fef45e990850102147e8945fb023d1d0/lib/node_modules/@stdlib/stats/base/dists/hypergeometric/entropy/docs/img/equation_hypergeometric_entropy.svg" alt="Differential entropy for a hypergeometric distribution.">
+    <br>
+</div> -->
+
+<!-- </equation> -->
+
+where `N` is the population size, `K` is the subpopulation size, and `n` is the number of draws.
+
+</section>
+
+<!-- /.intro -->
+
+<!-- Package usage documentation. -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var entropy = require( '@stdlib/stats/base/dists/hypergeometric/entropy' );
+```
+
+#### entropy( N, K, n )
+
+Returns the [differential entropy][entropy] for a [hypergeometric][hypergeometric-distribution] distribution with population size `N`, subpopulation size `K`, and number of draws `n` (in [nats][nats]).
+
+```javascript
+var y = entropy( 16, 11, 4 );
+// returns ~1.22
+
+y = entropy( 2, 1, 1 );
+// returns ~0.693
+```
+
+If provided `NaN` as any argument, the function returns `NaN`.
+
+```javascript
+var y = entropy( NaN, 10, 4 );
+// returns NaN
+
+y = entropy( 20, NaN, 4 );
+// returns NaN
+
+y = entropy( 20, 10, NaN );
+// returns NaN
+```
+
+If provided a population size `N`, subpopulation size `K` or draws `n` which is not a nonnegative integer, the function returns `NaN`.
+
+```javascript
+var y = entropy( 10.5, 4, 2 );
+// returns NaN
+
+y = entropy( 10, 1.5, 2 );
+// returns NaN
+
+y = entropy( 10, 5, -2.0 );
+// returns NaN
+```
+
+If the number of draws `n` or subpopulation size `K` exceeds population size `N`, the function returns `NaN`.
+
+```javascript
+var y = entropy( 10, 11, 4 );
+// returns NaN
+
+y = entropy( 10, 5, 12 );
+// returns NaN
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var randu = require( '@stdlib/random/base/randu' );
+var round = require( '@stdlib/math/base/special/round' );
+var entropy = require( '@stdlib/stats/base/dists/hypergeometric/entropy' );
+
+var i;
+var N;
+var K;
+var n;
+var y;
+
+for ( i = 0; i < 10; i++ ) {
+    N = round( randu() * 20.0 );
+    K = round( randu() * N );
+    n = round( randu() * N );
+    y = entropy( N, K, n );
+    console.log( 'N: %d, K: %d, n: %d, H(X;N,K,n): %d', N, K, n, y.toFixed( 4 ) );
+}
+```
+
+</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">
+
+[hypergeometric-distribution]: https://en.wikipedia.org/wiki/Hypergeometric_distribution
+
+[entropy]: https://en.wikipedia.org/wiki/Entropy_%28information_theory%29
+
+[nats]: https://en.wikipedia.org/wiki/Nat_%28unit%29
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/stats/base/dists/hypergeometric/entropy/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 Float64Array = require( '@stdlib/array/float64' );
+var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pkg = require( './../package.json' ).name;
+var entropy = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var len;
+	var N;
+	var K;
+	var n;
+	var y;
+	var i;
+
+	len = 100;
+	N = new Float64Array( len );
+	K = new Float64Array( len );
+	n = new Float64Array( len );
+	for ( i = 0; i < len; i++ ) {
+		N[ i ] = discreteUniform( 1, 100 );
+		K[ i ] = discreteUniform( 1, N[ i ] );
+		n[ i ] = discreteUniform( 1, N[ i ] );
+	}
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		y = entropy( N[ i % len ], K[ i % len ], n[ i % len ] );
+		if ( isnan( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnan( y ) ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/stats/base/dists/hypergeometric/entropy/docs/repl.txt

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+
+{{alias}}( N, K, n )
+    Returns the differential entropy of a hypergeometric distribution.
+
+    If provided `NaN` as any argument, the function returns `NaN`.
+
+    If provided a population size `N`, subpopulation size `K` or draws `n` which
+    is not a nonnegative integer, the function returns `NaN`.
+
+    If the number of draws `n` or the subpopulation size `K` exceed population
+    size `N`, the function returns `NaN`.
+
+    Parameters
+    ----------
+    N: integer
+        Population size.
+
+    K: integer
+        Subpopulation size.
+
+    n: integer
+        Number of draws.
+
+    Returns
+    -------
+    out: number
+        Entropy.
+
+    Examples
+    --------
+    > var v = {{alias}}( 16, 11, 4 )
+    ~1.22
+    > v = {{alias}}( 2, 1, 1 )
+    ~0.693
+
+    > v = {{alias}}( 10, 5, 12 )
+    NaN
+    > v = {{alias}}( 10.3, 10, 4 )
+    NaN
+    > v = {{alias}}( 10, 5.5, 4 )
+    NaN
+    > v = {{alias}}( 10, 5, 4.5 )
+    NaN
+
+    > v = {{alias}}( NaN, 10, 4 )
+    NaN
+    > v = {{alias}}( 20, NaN, 4 )
+    NaN
+    > v = {{alias}}( 20, 10, NaN )
+    NaN
+
+    See Also
+    --------
+

lib/node_modules/@stdlib/stats/base/dists/hypergeometric/entropy/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
+
+/**
+* Returns the differential entropy of a hypergeometric distribution.
+*
+* ## Notes
+*
+* -   If provided a population size `N`, subpopulation size `K` or draws `n` which is not a nonnegative integer, the function returns `NaN`.
+* -   If the number of draws `n` or subpopulation size `K` exceed population size `N`, the function returns `NaN`.
+*
+* @param N - population size
+* @param K - subpopulation size
+* @param n - number of draws
+* @returns entropy
+*
+* @example
+* var v = entropy( 16, 11, 4 );
+* // returns ~1.22
+*
+* @example
+* var v = entropy( 2, 1, 1 );
+* // returns ~0.693
+*
+* @example
+* var v = entropy( 10, 5, 12 );
+* // returns NaN
+*
+* @example
+* var v = entropy( 10.3, 10, 4 );
+* // returns NaN
+*
+* @example
+* var v = entropy( 10, 5.5, 4 );
+* // returns NaN
+*
+* @example
+* var v = entropy( 10, 5, 4.5 );
+* // returns NaN
+*
+* @example
+* var v = entropy( NaN, 10, 4 );
+* // returns NaN
+*
+* @example
+* var v = entropy( 20, NaN, 4 );
+* // returns NaN
+*
+* @example
+* var v = entropy( 20, 10, NaN );
+* // returns NaN
+*/
+declare function entropy( N: number, K: number, n: number ): number;
+
+
+// EXPORTS //
+
+export = entropy;