tr.poisson: Truncated Poisson Prior Distribution for Models
Description
Creates an object representing the prior distribution on models for BAS
using a truncated Poisson Distribution on the Model Size
Usage
tr.poisson(lambda, trunc)
Value
returns an object of class "prior", with the family and
hyperparameters.
Arguments
lambda
parameter in the Poisson distribution representing expected
model size with infinite predictors
trunc
parameter that determines truncation in the distribution i.e.
P(M; lambda, trunc) = 0 if M > trunc
Author
Merlise Clyde
Details
The Poisson prior distribution on model size is obtained by assigning each
variable inclusion indicator independent Bernoulli distributions with
probability w, and then taking a limit as p goes to infinity and w goes to
zero, such that p*w converges to lambda. The Truncated version assigns zero
probability to all models of size M > trunc.
See Also
bas.lm, Bernoulli,uniform
Other priors modelpriors:
Bernoulli(),
Bernoulli.heredity(),
beta.binomial(),
tr.beta.binomial(),
tr.power.prior(),
uniform()