beta.binomial: Beta-Binomial Prior Distribution for Models
Description
Creates an object representing the prior distribution on models for BAS.
Usage
beta.binomial(alpha = 1, beta = 1)
Arguments
alpha
parameter in the beta prior distribution
beta
parameter in the beta prior distribution
Value
returns an object of class "prior", with the family and
hyperparameters.
Details
The beta-binomial distribution on model size is obtained by assigning each
variable inclusion indicator independent Bernoulli distributions with
probability w, and then giving w a beta(alpha,beta) distribution.
Marginalizing over w leads to the distribution on model size having the
beta-binomial distribution. The default hyperparameters lead to a uniform
distribution over model size.