% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/priors.R
\name{prior_exponential}
\alias{prior_exponential}
\title{Specify an exponential prior}
\usage{
prior_exponential(rate = 1)
}
\arguments{
\item{rate}{Rate parameter (default 1). Larger \code{rate} = tighter prior
concentrated near zero.}
}
\value{
A list with components \code{distribution = "exponential"}, \code{rate},
and placeholders (\code{mean = 0}, \code{sd = 1 / rate}) so the same
Stan-field translation works.
}
\description{
Exponential prior on a positive scalar. Currently supported for
\code{\link[=mlumr]{prior_sigma}} (normal-family residual SD) only; rejected for
unconstrained intercepts and regression coefficients.
\code{prior_exponential(rate = 1)} has mean 1 and is a reasonable
weakly-informative choice when the outcome is standardized.
}
\examples{
prior_exponential(rate = 1)
}
