The R Project SVN R

\name{plot.default}

\alias{plot.default}

\title{The Default Scatterplot Function}

\description{

  Draw a scatter plot with \dQuote{decorations} such as axes and titles

  in the active graphics window.

}

\usage{

\method{plot}{default}(x, y = NULL, type = "p",  xlim = NULL, ylim = NULL,

     log = "", main = NULL, sub = NULL, xlab = NULL, ylab = NULL,

     ann = par("ann"), axes = TRUE, frame.plot = axes,

     panel.first = NULL, panel.last = NULL, asp = NA, \dots)

}

\arguments{

  \item{x, y}{the \code{x} and \code{y} arguments provide the x and y

    coordinates for the plot.  Any reasonable way of defining the

    coordinates is acceptable.  See the function \code{\link{xy.coords}}

    for details.}

  \item{type}{1-character string giving the type of plot desired.  The

    following values are possible, for details, see \code{\link{plot}}:

    \code{"p"} for points, \code{"l"} for lines,

    \code{"o"} for overplotted points and lines,

    \code{"b"}, \code{"c"}) for (empty if \code{"c"}) points joined by lines,

    \code{"s"} and \code{"S"} for stair steps and

    \code{"h"} for histogram-like vertical lines.  Finally,

    \code{"n"} does not produce any points or lines.}

  \item{xlim}{the x limits (x1, x2) of the plot.  Note that \code{x1 > x2}

    is allowed and leads to a \dQuote{reversed axis}.}

  \item{ylim}{the y limits of the plot.}

  \item{log}{a character string which contains \code{"x"} if the x axis

    is to be logarithmic, \code{"y"} if the y axis is to be logarithmic

    and \code{"xy"} or \code{"yx"} if both axes are to be logarithmic.}

  \item{main}{a main title for the plot, see also \code{\link{title}}.}

  \item{sub}{a sub title for the plot.}

  \item{xlab}{a label for the x axis, defaults to a description of \code{x}.}

  \item{ylab}{a label for the y axis, defaults to a description of \code{y}.}

  \item{ann}{a logical value indicating whether the default annotation

    (title and x and y axis labels) should appear on the plot.}

  \item{axes}{a logical value indicating whether both axes should be drawn on

    the plot.  Use graphical parameter \code{"xaxt"} or \code{"yaxt"}

    to suppress just one of the axes.}

  \item{frame.plot}{a logical indicating whether a box should be drawn

    around the plot.}

  \item{panel.first}{an expression to be evaluated after the plot axes

    are set up but before any plotting takes place.  This can be useful

    for drawing background grids or scatterplot smooths.}

  \item{panel.last}{an expression to be evaluated after plotting has

    taken place.}

  \item{asp}{the \eqn{y/x} aspect ratio, see \code{\link{plot.window}}.}

  \item{\dots}{other graphical parameters (see \code{\link{par}} and

    section \sQuote{Details} below).}

}

\details{

  Commonly used graphical parameters are:

  \describe{

    \item{\code{col}}{The colors for lines and points.  Multiple colors can be

      specified so that each point can be given its own color.  If there

      are fewer colors than points they are recycled in the standard

      fashion.  Lines will all be plotted in the first colour specified.}

    \item{\code{bg}}{a vector of background colors for open plot symbols, see

      \code{\link{points}}.  Note: this is \bold{not} the same setting

      as \code{\link{par}("bg")}.}

    \item{\code{pch}}{a vector of plotting characters or symbols:

      see \code{\link{points}}.}

    \item{\code{cex}}{a numerical vector giving the amount by which

      plotting text and symbols should be scaled relative to the

      default.  This works as a multiple of \code{\link{par}("cex")}.

      \code{NULL} and \code{NA} are equivalent to \code{1.0}.}

    \item{\code{lty}}{the line type, see \code{\link{par}}.}

    \item{\code{cex.main, col.lab, font.sub}, etc}{settings for main- and

      sub-title and axis annotation, see \code{\link{title}} and

      \code{\link{par}}.}

    \item{\code{lwd}}{the line width, see \code{\link{par}}.}

  }

}

\references{

  Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)

  \emph{The New S Language}.

  Wadsworth \& Brooks/Cole.

  Cleveland, W. S. (1985)

  \emph{The Elements of Graphing Data.}

  Monterey, CA: Wadsworth.

  Murrell, P. (2005) \emph{R Graphics}. Chapman & Hall/CRC Press.

}

\seealso{

  \code{\link{plot}}, \code{\link{plot.window}}, \code{\link{xy.coords}}.

}

\examples{

Speed <- cars$speed

Distance <- cars$dist

plot(Speed, Distance, panel.first = grid(8,8),

     pch = 0, cex = 1.2, col = "blue")

plot(Speed, Distance,

     panel.first = lines(stats::lowess(Speed, Distance), lty = "dashed"),

     pch = 0, cex = 1.2, col = "blue")

## Show the different plot types

x <- 0:12

y <- sin(pi/5 * x)

op <- par(mfrow = c(3,3), mar = .1+ c(2,2,3,1))

for (tp in c("p","l","b",  "c","o","h",  "s","S","n")) {

   plot(y ~ x, type = tp,

        main = paste("plot(*, type = \"",tp,"\")",sep=""))

   if(tp == "S") {

      lines(x,y, type = "s", col = "red", lty = 2)

      mtext("lines(*, type = \"s\", ...)", col = "red", cex=.8)

   }

}

par(op)

##--- Log-Log Plot  with  custom axes

lx <- seq(1,5, length=41)

yl <- expression(e^{-frac(1,2) * {log[10](x)}^2})

y <- exp(-.5*lx^2)

op <- par(mfrow=c(2,1), mar=par("mar")+c(0,1,0,0))

plot(10^lx, y, log="xy", type="l", col="purple",

     main="Log-Log plot", ylab=yl, xlab="x")

plot(10^lx, y, log="xy", type="o", pch='.', col="forestgreen",

     main="Log-Log plot with custom axes", ylab=yl, xlab="x",

     axes = FALSE, frame.plot = TRUE)

my.at <- 10^(1:5)

axis(1, at = my.at, labels = formatC(my.at, format="fg"))

at.y <- 10^(-5:-1)

axis(2, at = at.y, labels = formatC(at.y, format="fg"), col.axis="red")

par(op)

}

\keyword{hplot}