R: The Beta-binomial Distribution

BetaBinomial {brms} | R Documentation

## The Beta-binomial Distribution

### Description

Cumulative density & mass functions, and random number generation for the Beta-binomial distribution using the following re-parameterisation of the Stan Beta-binomial definition:

- `mu = alpha * beta` mean probability of trial success.

- `phi = (1 - mu) * beta` precision or over-dispersion, component.

### Usage

    dbeta_binomial(x, size, mu, phi, log = FALSE)

    pbeta_binomial(q, size, mu, phi, lower.tail = TRUE, log.p = FALSE)

    rbeta_binomial(n, size, mu, phi)

### Arguments

`x, q` | Vector of quantiles.
`size` | Vector of number of trials (zero or more).
`mu` | Vector of means.
`phi` | Vector of precisions.
`log` | Logical; If `TRUE`, values are returned on the log scale.
`lower.tail` | Logical; If `TRUE` (default), return P(X <= x). Else, return P(X > x) .
`log.p` | Logical; If `TRUE`, values are returned on the log scale.
`n` | Number of draws to sample from the distribution.

[Package brms version 2.17.0 Index]