\Header{vcov}{Calculate Variance-Covariance Matrix for a Fitted Model Object}
\methalias{vcov.coxph}{vcov}
\methalias{vcov.glm}{vcov}
\methalias{vcov.gls}{vcov}
\methalias{vcov.lm}{vcov}
\methalias{vcov.lme}{vcov}
\methalias{vcov.survreg}{vcov}
\keyword{models}{vcov}
\keyword{nonlinear}{vcov}
\begin{Description}\relax
Returns the variance-covariance matrix of the main parameters of
a fitted model object.
\end{Description}
\begin{Usage}
\begin{verbatim}
vcov(object, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] a fitted model object.

\item[\code{...}] additional arguments for method functions.  For the
\code{\Link{glm}} method this can be used to pass a
\code{dispersion} parameter.

\end{ldescription}
\end{Arguments}
\begin{Details}\relax
This is a generic function.
Functions with names beginning in \code{vcov.} will be
methods for this function.
Classes with methods for this function include:
\code{lm}, \code{glm}, \code{nls}, \code{lme}, \code{gls}, \code{coxph}
and \code{survreg}
\end{Details}
\begin{Value}
A matrix of the estimated covariances between the parameter estimates
in the linear or non-linear predictor of the model.
\end{Value}

