negbin1: Family Functions for Negative Binomial 1 Models
In addreg: Additive Regression for Discrete Data

Description Usage Arguments Details Value Author(s)

Specifies the information required to fit a negative binomial 1 (NB1) model.

1	negbin1(link, phi = stop("'phi' must be given"))

`link`	included for compatibility with `family`. For `addreg` models, this will always be `"identity"`.
`phi`	the value of the scale parameter of the NB1 distribution (see "Details"). This can be set to `NA` for initialisation, but during estimation the family should be updated with the current estimate, and must be strictly positive.

The NB1 distribution can be parameterised in terms of a mean μ and scale parameter φ (the phi argument of this function), such that if Y \sim NB1(μ, φ), then E(Y) = μ and Var(Y) = (1+φ)μ.

These can be related to the size and prob arguments of the NegBinomial functions by size = μ / φ and prob = 1 / (1 + φ).

An object of class "family": see family for full details. Note that when the estimate of phi is updated in a model, this family object must be reloaded using the new estimate.

Mark W. Donoghoe markdonoghoe@gmail.com

addreg documentation built on May 2, 2019, 9:38 a.m.