\Header{rect}{Draw a Rectangle}
\keyword{aplot}{rect}
\begin{Description}\relax
\code{rect} draws a rectangle (or sequence of rectangles) with the
given coordinates, fill and border colors.\end{Description}
\begin{Usage}
\begin{verbatim}
rect(xleft, ybottom, xright, ytop, density = NULL, angle = 45,
     col = NULL, border = NULL, lty = NULL, lwd = par("lwd"), xpd = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{xleft}] a vector (or scalar) of left x positions.
\item[\code{ybottom}] a vector (or scalar) of bottom y positions.
\item[\code{xright}] a vector (or scalar) of right x positions.
\item[\code{ytop}] a vector (or scalar) of top y positions.
\item[\code{density}] the density of shading lines, in lines per inch.
The default value of \code{NULL} means that no shading lines are drawn.
Non-positive values of \code{density} also inhibit the drawing
of shading lines.
\item[\code{angle}] angle (in degrees) of the shading lines.
\item[\code{col}] color(s) to fill or shade the rectangle(s) with.
The default \code{NULL}, or also \code{\Link{NA}} do not fill,
i.e., draw transparent rectangles.
\item[\code{border}] color for rectangle border(s).
\item[\code{lty}] line type for borders; defaults to \code{"solid"}.
\item[\code{lwd}] width for borders.
\item[\code{xpd}] logical (``e\bold{xp}an\bold{d}''); defaults to
\code{par("xpd")}.  See \code{\Link{par}(xpd= )}.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The positions supplied, i.e., \code{xleft, ...},
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.

It is a primitive function used in \code{\Link{hist}},
\code{\Link{barplot}}, \code{\Link{legend}}, etc.\end{Details}
\begin{SeeAlso}\relax
\code{\Link{box}} for the ``standard'' box around the plot;
\code{\Link{polygon}} and \code{\Link{segments}} for flexible line
drawing.\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
## set up the plot region:
op <- par(bg = "thistle")
plot(c(100, 250), c(300, 450), type = "n", xlab="",
     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=.7,end=.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\"))")
par(op)
\end{ExampleCode}
\end{Examples}

