\HeaderA{plot.factor}{Plotting Factor Variables}{plot.factor}
\keyword{hplot}{plot.factor}
\begin{Description}\relax
This functions implements a \dQuote{scatterplot} method for
\code{\LinkA{factor}{factor}} arguments of the \emph{generic}
\code{\LinkA{plot}{plot}} function.
Actually, \code{\LinkA{boxplot}{boxplot}} is used when \code{y} is numeric
and a \code{\LinkA{spineplot}{spineplot}} when \code{y} is a factor. For 
a single factor \code{x} (i.e., with \code{y} missing) a simple
\code{\LinkA{barplot}{barplot}} is produced.
\end{Description}
\begin{Usage}
\begin{verbatim}
## S3 method for class 'factor':
plot(x, y, legend.text = NULL, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x, y}] numeric or factor. \code{y} may be missing.
\item[\code{legend.text}] character vector for annotation of y axis,
defaults to \code{levels(y)}. Can be used instead of \code{yaxlabels}
(for backward compatibility).
\item[\code{...}] Further arguments to \code{\LinkA{plot}{plot}}, see also
\code{\LinkA{par}{par}}.
\end{ldescription}
\end{Arguments}
\begin{SeeAlso}\relax
\code{\LinkA{plot.default}{plot.default}}, \code{\LinkA{plot.formula}{plot.formula}},
\code{\LinkA{barplot}{barplot}}, \code{\LinkA{boxplot}{boxplot}}, \code{\LinkA{spineplot}{spineplot}}.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
plot(PlantGrowth)                                # -> plot.data.frame
plot(weight ~ group, data = PlantGrowth)         # numeric vector ~ factor
plot(cut(weight, 2) ~ group, data = PlantGrowth) # factor ~ factor
## passing "..." to spineplot() eventually:
plot(cut(weight, 3) ~ group, data = PlantGrowth,
     col = hcl(c(0, 120, 240), 50, 70))

plot(PlantGrowth$group, axes=FALSE, main="no axes")# extremely silly
\end{ExampleCode}
\end{Examples}

