time-to-botec/squiggle/node_modules/@stdlib/stats/base/dists/poisson/README.md

Poisson

Poisson distribution.

Usage

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

poisson

Poisson distribution.

var dist = poisson;
// returns {...}

The namespace contains the following distribution functions:

• cdf( x, lambda ): Poisson distribution cumulative distribution function.
• logpmf( x, lambda ): evaluate the natural logarithm of the probability mass function (PMF) for a Poisson distribution.
• mgf( t, lambda ): Poisson distribution moment-generating function (MGF).
• pmf( x, lambda ): Poisson distribution probability mass function (PMF).
• quantile( p, lambda ): Poisson distribution quantile function.

The namespace contains the following functions for calculating distribution properties:

• kurtosis( lambda ): Poisson distribution excess kurtosis.
• mean( lambda ): Poisson distribution expected value.
• median( lambda ): Poisson distribution median.
• mode( lambda ): Poisson distribution mode.
• skewness( lambda ): Poisson distribution skewness.
• stdev( lambda ): Poisson distribution standard deviation.
• variance( lambda ): Poisson distribution variance.

The namespace contains a constructor function for creating a Poisson distribution object.

• Poisson( [lambda] ): Poisson distribution constructor.

var Poisson = require( '@stdlib/stats/base/dists/poisson' ).Poisson;

var dist = new Poisson( 2.0 );

var y = dist.pmf( 3.0 );
// returns ~0.18

y = dist.pmf( 2.3 );
// returns 0.0

Examples

var objectKeys = require( '@stdlib/utils/keys' );
var poisson = require( '@stdlib/stats/base/dists/poisson' );

console.log( objectKeys( poisson ) );