R: Beta-binomial distribution

betabinomial {pomp}

R Documentation

Beta-binomial distribution

Description

Density and random generation for the Beta-binomial distribution with parameters size, mu, and theta.

Usage

rbetabinom(n = 1, size, prob, theta)

dbetabinom(x, size, prob, theta, log = FALSE)

Arguments

`n`	integer; number of random variates to generate.
`size`	`size` parameter of the binomial distribution
`prob`	mean of the Beta distribution
`theta`	Beta distribution dispersion parameter
`x`	vector of non-negative integer quantiles
`log`	logical; if TRUE, return logarithm(s) of probabilities.

Details

A variable X is Beta-binomially distributed if X\sim{\mathrm{Binomial}(n,P)} where P\sim{\mathrm{Beta}(\mu,\theta)}. Using the standard (a,b) parameterization, a=\mu\,\theta and b=(1-\mu)\,\theta.

Value

`rbetabinom`	Returns a vector of length `n` containing random variates drawn from the Beta-binomial distribution.
`dbetabinom`	Returns a vector (of length equal to the number of columns of `x`) containing the probabilities of observing each column of `x` given the specified parameters (`size`, `prob`, `theta`).

C API

An interface for C codes using these functions is provided by the package. Visit the package homepage to view the pomp C API document.