VarCorr.brmsfit.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/brmsfit-methods.R
\name{VarCorr.brmsfit}
\alias{VarCorr.brmsfit}
\alias{VarCorr}
\title{Extract Variance and Correlation Components}
\usage{
\method{VarCorr}{brmsfit}(
  x,
  sigma = 1,
  summary = TRUE,
  robust = FALSE,
  probs = c(0.025, 0.975),
  ...
)
}
\arguments{
\item{x}{An object of class \code{brmsfit}.}

\item{sigma}{Ignored (included for compatibility with
\code{\link[nlme:VarCorr]{VarCorr}}).}

\item{summary}{Should summary statistics be returned
instead of the raw values? Default is \code{TRUE}.}

\item{robust}{If \code{FALSE} (the default) the mean is used as
the measure of central tendency and the standard deviation as
the measure of variability. If \code{TRUE}, the median and the
median absolute deviation (MAD) are applied instead.
Only used if \code{summary} is \code{TRUE}.}

\item{probs}{The percentiles to be computed by the \code{quantile}
function. Only used if \code{summary} is \code{TRUE}.}

\item{...}{Currently ignored.}
}
\value{
A list of lists (one per grouping factor), each with
three elements: a matrix containing the standard deviations,
an array containing the correlation matrix, and an array
containing the covariance matrix with variances on the diagonal.
}
\description{
This function calculates the estimated standard deviations,
correlations and covariances of the group-level terms
in a multilevel model of class \code{brmsfit}.
For linear models, the residual standard deviations,
correlations and covariances are also returned.
}
\examples{
\dontrun{
fit <- brm(count ~ zAge + zBase * Trt + (1+Trt|visit),
           data = epilepsy, family = gaussian(), chains = 2)
VarCorr(fit)
}

}