\HeaderA{panel.levelplot}{Default Panel Function for levelplot}{panel.levelplot}
\aliasA{panel.contourplot}{panel.levelplot}{panel.contourplot}
\keyword{dplot}{panel.levelplot}
\begin{Description}\relax
This is the default panel function for \code{levelplot}.
\end{Description}
\begin{Usage}
\begin{verbatim}
panel.levelplot(x, y, z, 
                subscripts,
                at = pretty(z),
                shrink,
                labels = NULL,
                label.style = c("mixed", "flat", "align"),
                contour = FALSE,
                region = TRUE,
                col = add.line$col,
                lty = add.line$lty,
                lwd = add.line$lwd,
                cex = add.text$cex,
                font = add.text$font,
                fontfamily = add.text$fontfamily,
                fontface = add.text$fontface,
                col.text = add.text$col,
                ...,
                col.regions = regions$col,
                alpha.regions = regions$alpha)
panel.contourplot(...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x, y, z}] variables defining the plot 
\item[\code{subscripts}] integer vector indicating what subset of \code{x}, \code{y} and
\code{z} to draw

\item[\code{at}] numeric vector specifying breakpoints for change in colors

\item[\code{shrink}] either a numeric vector of length 2 (meant to work as both x and y
components), or a list with components x and y which are numeric
vectors of length 2.  This allows the rectangles to be scaled
proportional to the z-value. The specification can be made
separately for widths (x) and heights (y).  The elements of the
length 2 numeric vector gives the minimum and maximum proportion of
shrinkage (corresponding to min and max of z).

\item[\code{labels}] contour labels
\item[\code{label.style}] controls choice of how label positions are determined.

\item[\code{contour}] logical, specifying whether contour lines should be
drawn

\item[\code{region}] logical, specifying whether inter-contour regions should be filled
with the appropriate color

\item[\code{col, lty, lwd}] graphical parameters for contour lines
\item[\code{cex, col.text, font, fontfamily, fontface}] graphical parameters for contour labels
\item[\code{...}] extra parameters 
\item[\code{col.regions}] a vector of colors used if \code{region=TRUE}.  Usually a subset of
the colors are used, the exact number being one more than the length
of \code{at}.  These are chosen to be roughly equally spaced along
\code{col.regions}.  In the unusual case when \code{col.regions} is
not longer than \code{at}, it is repeated to be as long as
necessary.

\item[\code{alpha.regions}] numeric scalar controlling transparency of facets

\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The same function is used for both \code{levelplot} and
\code{contourplot} (which differ only in default values of some
arguments). \code{panel.contourplot} is a simple wrapper to
\code{panel.levelplot}.

When \code{contour=TRUE}, the \code{contourLines} function is used to
calculate the contour lines.
\end{Details}
\begin{Author}\relax
Deepayan Sarkar \email{Deepayan.Sarkar@R-project.org}
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{levelplot}{levelplot}}, \code{\LinkA{contourLines}{contourLines}}
\end{SeeAlso}

