sd_to_prec {mcp}

Transform a prior from SD to precision.

Description

JAGS uses precision rather than SD. This function converts dnorm(4.2, 1.3) into dnorm(4.2, 1/1.3^2). It allows users to specify priors using SD and then it's transformed for the JAGS code. It works for the following distributions: dnorm|dt|dcauchy|ddexp|dlogis|dlnorm. In all of these, tau/sd is the second parameter.

Usage

sd_to_prec(prior_str)

Arguments

prior_str

String. A JAGS prior. Can be truncated, e.g. ⁠dt(3, 2, 1) T(my_var, )⁠.

Value

A string

Author(s)

Jonas Kristoffer Lindeløv [e-mail]