\Header{lset}{Simple Interfaces to modify Trellis Settings}
\alias{col.whitebg}{lset}
\keyword{utilities}{lset}
\begin{Description}\relax
A (hopefully) simpler alternative interface to
\code{trellis.par.get/set}. NOT S compatible
\end{Description}
\begin{Usage}
\begin{verbatim}
lset(theme = col.whitebg())
col.whitebg()
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{theme}] a list decribing how to change the settings of the
current active device. Valid components are those in the list
returned by \code{trellis.par.get()}. Each component must itself be
a list, with one or more of the appropriate components (need not
have all components). Changes are made to the settings for the
currently active device only.

\end{ldescription}
\end{Arguments}
\begin{Details}\relax
\code{lset} is a wrapper to \code{trellis.par.set} that allows setting
more than one parameter at a time, and only the components that are to
be changed need be specified.

This function is expected to be used in conjunction with functions
that return `themes', i.e., lists which when supplied to \code{lset}
change the overall look and feel of the display.

\code{col.whitebg} is one such function, which returns a list which
when supplied to \code{lset} changes the background to transparent and
the other colors to something suitable. Contributions of more such
`themes' are welcome. 

\code{lset} is used to modify the settings on a one-time basis. It is
also possible to make persistent changes in the default theme used via
a user-settable option, see \code{\Link{trellis.device}} for details.
\end{Details}
\begin{Author}\relax
Deepayan Sarkar \email{deepayan@stat.wisc.edu}
\end{Author}
\begin{SeeAlso}\relax
\code{\Link{lattice.theme}}, \code{\Link{trellis.device}},
\code{\Link{show.settings}}, \code{\Link{Lattice}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
show.settings(col.whitebg())
# The following reproduces S-PLUS Unix black and white pch:
#lset(list(superpose.symbol=list(pch=c("o","+",">","s","w","#","{"))))
\end{ExampleCode}
\end{Examples}

