\HeaderA{vignette}{View or List Vignettes}{vignette}
\keyword{documentation}{vignette}
\begin{Description}\relax
View a specified vignette, or list the available ones.
\end{Description}
\begin{Usage}
\begin{verbatim}
vignette(topic, package = NULL, lib.loc = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{topic}] a character string giving the (base) name of the vignette
to view.
\item[\code{package}] a character vector with the names of packages to
search through, or \code{NULL} in which case \emph{all} available
packages in the library trees specified by \code{lib.loc} are
searched.
\item[\code{lib.loc}] a character vector of directory names of \R{} libraries,
or \code{NULL}.  The default value of \code{NULL} corresponds to all
libraries currently known.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
Currently, only PDF versions of vignettes can be viewed.
The program specified by the \code{pdfviewer} option is used for this.
If several vignettes have PDF versions with base name identical to
\code{topic}, the first one found is used for viewing.

If no topics are given, the available vignettes are listed.  The
corresponding information is returned in an object of class
\code{"packageIQR"}.  The structure of this class is experimental.
\end{Details}
\begin{Examples}
\begin{ExampleCode}
## List vignettes in all attached packages
vignette()
## List vignettes in all available packages
vignette(package = .packages(all.available = TRUE))
\end{ExampleCode}
\end{Examples}

