The R Project SVN R

% File src/library/graphics/man/rect.Rd

% Part of the R package, https://www.R-project.org

% Copyright 1995-2012 R Core Team

% Distributed under GPL 2 or later

\name{rect}

\title{Draw One or More Rectangles}

\usage{

rect(xleft, ybottom, xright, ytop, density = NULL, angle = 45,

     col = NA, border = NULL, lty = par("lty"), lwd = par("lwd"),

     \dots)

}

\alias{rect}

\arguments{

  \item{xleft}{a vector (or scalar) of left x positions.}

  \item{ybottom}{a vector (or scalar) of bottom y positions.}

  \item{xright}{a vector (or scalar) of right x positions.}

  \item{ytop}{a vector (or scalar) of top y positions.}

  \item{density}{the density of shading lines, in lines per inch.

    The default value of \code{NULL} means that no shading lines are drawn.

    A zero value of \code{density} means no shading lines whereas

    negative values (and \code{NA}) suppress shading (and so allow

    color filling).}

  \item{angle}{angle (in degrees) of the shading lines.}

  \item{col}{color(s) to fill or shade the rectangle(s) with.

    The default \code{NA} (or also \code{NULL}) means do not fill,

    i.e., draw transparent rectangles, unless \code{density} is specified.}

  \item{border}{color for rectangle border(s).  The default means

    \code{par("fg")}.  Use \code{border = NA} to omit borders.

    If there are shading

    lines, \code{border = TRUE} means use the same colour for

    the border as for the shading lines.}

  \item{lty}{line type for borders and shading; defaults to \code{"solid"}.}

  \item{lwd}{line width for borders and shading.  Note that the use of

    \code{lwd = 0} (as in the examples) is device-dependent.}

  \item{\dots}{\link{graphical parameters} such as \code{xpd}, \code{lend},

    \code{ljoin} and \code{lmitre} can be given as

    arguments.}

}

\description{

  \code{rect} draws a rectangle (or sequence of rectangles) with the

  given coordinates, fill and border colors.

}

\details{

  The positions supplied, i.e., \code{xleft, \dots},

  are relative to the current plotting region.  If the x-axis goes from

  100 to 200 then \code{xleft} must be larger than 100 and \code{xright}

  must be less than 200.  The position vectors will be recycled to the

  length of the longest.

  It is a graphics primitive used in \code{\link{hist}},

  \code{\link{barplot}}, \code{\link{legend}}, etc.

}

\seealso{

  \code{\link{box}} for the standard box around the plot;

  \code{\link{polygon}} and \code{\link{segments}} for flexible line

  drawing.

  \code{\link{par}} for how to specify colors.

}

\examples{

require(grDevices)

## set up the plot region:

op <- par(bg = "thistle")

plot(c(100, 250), c(300, 450), type = "n", xlab = "", ylab = "",

     main = "2 x 11 rectangles; 'rect(100+i,300+i,  150+i,380+i)'")

i <- 4*(0:10)

## draw rectangles with bottom left (100, 300)+i

## and top right (150, 380)+i

rect(100+i, 300+i, 150+i, 380+i, col = rainbow(11, start = 0.7, end = 0.1))

rect(240-i, 320+i, 250-i, 410+i, col = heat.colors(11), lwd = i/5)

## Background alternating  ( transparent / "bg" ) :

j <- 10*(0:5)

rect(125+j, 360+j,   141+j, 405+j/2, col = c(NA,0),

     border = "gold", lwd = 2)

rect(125+j, 296+j/2, 141+j, 331+j/5, col = c(NA,"midnightblue"))

mtext("+  2 x 6 rect(*, col = c(NA,0)) and  col = c(NA,\"m..blue\")")

## an example showing colouring and shading

plot(c(100, 200), c(300, 450), type= "n", xlab = "", ylab = "")

rect(100, 300, 125, 350) # transparent

rect(100, 400, 125, 450, col = "green", border = "blue") # coloured

rect(115, 375, 150, 425, col = par("bg"), border = "transparent")

rect(150, 300, 175, 350, density = 10, border = "red")

rect(150, 400, 175, 450, density = 30, col = "blue",

     angle = -30, border = "transparent")

legend(180, 450, legend = 1:4, fill = c(NA, "green", par("fg"), "blue"),

       density = c(NA, NA, 10, 30), angle = c(NA, NA, 30, -30))

par(op)

}

\keyword{aplot}