@stdlib/stats-base-dists-poisson-entropy NPM

Entropy

Poisson distribution entropy.

The entropy (in nats) for a Poisson random variable is

where λ is the mean parameter.

Installation

npm install @stdlib/stats-base-dists-poisson-entropy

Usage

var entropy = require( '@stdlib/stats-base-dists-poisson-entropy' );

entropy( lambda )

Returns the entropy of a Poisson distribution with mean parameter lambda (in nats).

var v = entropy( 9.0 );
// returns ~2.508

v = entropy( 0.5 );
// returns ~0.928

If provided lambda < 0, the function returns NaN.

var v = entropy( -1.0 );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var entropy = require( '@stdlib/stats-base-dists-poisson-entropy' );

var lambda;
var v;
var i;

for ( i = 0; i < 10; i++ ) {
    lambda = randu() * 20.0;
    v = entropy( lambda );
    console.log( 'λ: %d, H(X;λ): %d', lambda.toFixed( 4 ), v.toFixed( 4 ) );
}

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.