R: Draw One or More Rectangles

rect {graphics}

R Documentation

Draw One or More Rectangles

Description

rect draws a rectangle (or sequence of rectangles) with the given coordinates, fill and border colors.

Usage

rect(xleft, ybottom, xright, ytop, density = NULL, angle = 45,
     col = NA, border = NULL, lty = par("lty"), lwd = par("lwd"),
     ...)

Arguments

`xleft`	a vector (or scalar) of left x positions.
`ybottom`	a vector (or scalar) of bottom y positions.
`xright`	a vector (or scalar) of right x positions.
`ytop`	a vector (or scalar) of top y positions.
`density`	the density of shading lines, in lines per inch. The default value of `NULL` means that no shading lines are drawn. A zero value of `density` means no shading lines whereas negative values (and `NA`) suppress shading (and so allow color filling).
`angle`	angle (in degrees) of the shading lines.
`col`	color(s) to fill or shade the rectangle(s) with. The default `NA` (or also `NULL`) means do not fill, i.e., draw transparent rectangles, unless `density` is specified.
`border`	color for rectangle border(s). The default means `par("fg")`. Use `border = NA` to omit borders. If there are shading lines, `border = TRUE` means use the same colour for the border as for the shading lines.
`lty`	line type for borders and shading; defaults to `"solid"`.
`lwd`	line width for borders and shading. Note that the use of `lwd = 0` (as in the examples) is device-dependent.
`...`	graphical parameters such as `xpd`, `lend`, `ljoin` and `lmitre` can be given as arguments.

Details

The positions supplied, i.e., xleft, ..., are relative to the current plotting region. If the x-axis goes from 100 to 200 then xleft must be larger than 100 and 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 hist, barplot, legend, etc.

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=.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\"))")

## 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)