The R Project SVN R

\name{boxplot}
\title{Box Plots}
\usage{
boxplot(\dots, range=1.5, width, varwidth=FALSE,
        notch=FALSE, names, data, plot=TRUE, col=NULL,
        border=par("fg"))
}
\alias{boxplot}
\arguments{
\item{\dots}{the data from which the boxplots are to be produced.
The data can be specified as separate vectors, each corresponding
to a component boxplot, or as a single list containing such vectors.
Alternatively a symbolic specification of the form
\code{x ~ g} can be given, indicating the the observations
in the vector \code{x} are to be grouped according to
the levels of the factor \code{g}.  In this case the argument
\code{data} can be used to provide values for the variables
in the specification.
\code{NA}s are allowed in the data.}
\item{range}{this determines how far the plot whiskers
extend out from the box.
If \code{range} is positive, 
the whiskers extend to the most extreme data point which
is no more than \code{range} times the interquartile range
from the box.
A value of zero causes the whiskers to extend to the data extremes.}
\item{width}{a vector giving the relative widths of the boxes
making up the plot.}
\item{varwidth}{if \code{varwidth} is \code{TRUE}, the boxes
are drawn with widths proportional to the square-roots
of the number of observations in the groups.}
\item{notch}{if \code{notch} is \code{TRUE}, a notch is drawn in each
side of the boxes.  If the notches of two plots do not
overlap then the medians are significantly different at the
5 percent level.}
\item{name}{group labels which while be printed under
each boxplot.}
\item{plot}{if \code{plot} is \code{TRUE} (the default) then
a boxplot is produced.
If not, the summaries which the boxplots are based on are
returned.}
\item{border}{an optional vector of colors for the outlines of
the boxplots.  The values in \code{border} are recycled if
the length of \code{border} is less than the number of plots.}
\item{col}{if \code{col} is non-null it is assumed to
contain colors to be used to col the bodies of the box plots.}
\item{\dots}{graphical parameters can also be passed as
arguments to \code{boxplot}.}
}
\value{
This function is usually invoked for its side effect
which is to produce box-and-whisker plots of the given values.
However, it also returns a list with one component corresponding
to each plot.  The components are themselves lists with named components
as follows: 
\item{stats}{a vector containing the extreme of the
lower whisker, the lower hinge, the median, the upper hinge
and the extreme of the upper whisker.}
\item{n}{the number of observations in the sample.}
\item{conf}{the lower and upper extremes of the notch.}
\item{out}{the values of any data points which lie beyond the
extremes of the whiskers.}
}
\seealso{
\code{\link{boxplot.stats}} which does the computation and
\code{\link{bxp}} for the plotting.
}
\examples{
data(insects)
boxplot(count~spray, data=insects, col="lightgray")
}