Skewness

Poisson distribution skewness.

The skewness for a Poisson random variable is

where λ is the mean parameter.

Installation

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

Usage

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

skewness( lambda )

Returns the skewness of a Poisson distribution with mean parameter lambda.

var v = skewness( 9.0 );
// returns ~0.333

v = skewness( 0.5 );
// returns ~1.414

If provided lambda <= 0, the function returns NaN.

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

Examples

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

var lambda;
var v;
var i;

for ( i = 0; i < 10; i++ ) {
    lambda = randu() * 20.0;
    v = skewness( lambda );
    console.log( 'λ: %d, skew(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.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.