Poisson density functions. More...

#include "statsLib.h"

Functions
dvariable	dpois (const double &k, const prevariable &lambda)
dvariable	dpois (const prevariable &k, const prevariable &lambda)
dvariable	dpois (const dvector &k, const dvar_vector &lambda)

Detailed Description

Poisson density functions.

Author:: Steven Martell

Date:: 24/06/2011

This file contains the negative loglikelihood functions for the Poisson distribution. The function dpois is overloaded to accommodate variable and data objects.

The negative log likelihood function is implemented as:

$-k \ln( \lambda ) - \lambda + \ln(k!)$

where $p$ is the probability and $n$ number of trials, and $x$ is the number of successes.

Definition in file dpois.cpp.

Function Documentation

dvariable dpois	(	const double &	k,
		const prevariable &	lambda
	)

Author:: Steven James Dean Martell UBC Fisheries Centre

Date:: 2011-06-24

Parameters:

k	observed number
lambda	epected mean of the distribution

Returns:: returns the negative loglikelihood $-k \ln( \lambda ) - \lambda + \ln(k)!$

See also:

Definition at line 35 of file dpois.cpp.

dvariable dpois	(	const prevariable &	k,
		const prevariable &	lambda
	)

Author:: Steven James Dean Martell UBC Fisheries Centre

Date:: 2011-06-24

Parameters:

k	observed number
lambda	epected mean of the distribution

Returns:: returns the negative loglikelihood $-k \ln( \lambda ) - \lambda + \ln(k!)$

See also:

Definition at line 51 of file dpois.cpp.

dvariable dpois	(	const dvector &	k,
		const dvar_vector &	lambda
	)

Author:: Steven James Dean Martell UBC Fisheries Centre

Date:: 2011-06-24

Parameters:

k	vector of observed numbers
lambda	vector of epected means of the distribution

Returns:: returns the negative loglikelihood $\sum_i -k_i \ln( \lambda_i ) - \lambda_i + \ln(k_i!)$

See also:

Definition at line 67 of file dpois.cpp.

Functions

Detailed Description

Function Documentation