pc.ddof {INLA} | R Documentation

## PC-prior for dof in a standarized Student-t

### Description

A function to evaluate the PC-prior for the degrees of freedom in a standarized Student-t distribution

### Usage

         inla.pc.ddof(dof, lambda, u, alpha, log=FALSE)

### Arguments

`dof` | Degrees of freedom
`log` | Logical. Return the density or the log-density
`lambda` | The optional value of `lambda`, instead of defining it implicitely through `u` and `alpha`
`u` | The upper value of dof used to elicitate `lambda`, `Prob(dof < u) = alpha`
`alpha` | The probability `alpha` used to elicitate `lambda`

### Details

These functions implements the PC-prior for the dof in a standarized Student-t distribution (ie. with unit variance and `dof` > 2). Either `lambda`, or `u` AND `alpha` must be given. Due the internal tabulation, `dof` must be larger than 2.0025.

### Value

`inla.pc.ddof` returns the prior density for given `dof`.

### Author(s)

Havard Rue hrue@r-inla.org

[Package INLA version 18.07.12 Index]