# DoublePoisson: Double Poisson Distribution In rmutil: Utilities for Nonlinear Regression and Repeated Measurements Models

## Description

These functions provide information about the double Poisson distribution with parameters `m` and `s`: density, cumulative distribution, quantiles, and random generation.

The double Poisson distribution with `mu` = m has density

p(y) = c(m,s) s^(y/m) (m/y)^(y log(s)) y^(y-1) / y!

for y = 0, …, where c(.) is a normalizing constant.

## Usage

 ```1 2 3 4``` ```ddoublepois(y, m, s, log=FALSE) pdoublepois(q, m, s) qdoublepois(p, m, s) rdoublepois(n, m, s) ```

## Arguments

 `y` vector of counts `q` vector of quantiles `p` vector of probabilities `n` number of values to generate `m` vector of means `s` vector of overdispersion parameters `log` if TRUE, log probabilities are supplied.

`dpois` for the Poisson, `dconsul` for the Consul generalized Poisson, `dgammacount` for the gamma count, `dmultpois` for the multiplicative Poisson, `dpvfpois` for the power variance function Poisson, and `dnbinom` for the negative binomial distribution.
 ```1 2 3 4``` ```ddoublepois(5,10,0.9) pdoublepois(5,10,0.9) qdoublepois(0.08,10,0.9) rdoublepois(10,10,0.9) ```