\HeaderA{panel.smooth}{Simple Panel Plot}{panel.smooth}
\keyword{hplot}{panel.smooth}
\keyword{dplot}{panel.smooth}
\begin{Description}\relax
An example of a simple useful \code{panel} function to be used as
argument in e.g., \code{\LinkA{coplot}{coplot}} or \code{\LinkA{pairs}{pairs}}.
\end{Description}
\begin{Usage}
\begin{verbatim}
panel.smooth(x, y, col = par("col"), bg = NA, pch = par("pch"),
             cex = 1, col.smooth = "red", span = 2/3, iter = 3,
             ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x, y}] numeric vectors of the same length
\item[\code{col, bg, pch, cex}] numeric or character codes for the color(s),
point type and size of \code{\LinkA{points}{points}}; see also
\code{\LinkA{par}{par}}.
\item[\code{col.smooth}] color to be used by \code{lines} for drawing the
smooths.
\item[\code{span}] smoothing parameter \code{f} for \code{\LinkA{lowess}{lowess}}, see
there.
\item[\code{iter}] number of robustness iterations for \code{\LinkA{lowess}{lowess}}.
\item[\code{...}] further arguments to \code{\LinkA{lines}{lines}}.
\end{ldescription}
\end{Arguments}
\begin{SeeAlso}\relax
\code{\LinkA{coplot}{coplot}} and \code{\LinkA{pairs}{pairs}} where \code{panel.smooth}
is typically used;
\code{\LinkA{lowess}{lowess}} which does the smoothing.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
pairs(swiss, panel = panel.smooth, pch = ".")# emphasize the smooths
pairs(swiss, panel = panel.smooth, lwd = 2, cex= 1.5, col="blue")# hmm...
\end{ExampleCode}
\end{Examples}

