gradient.rect {plotrix} | R Documentation |
Display a rectangle filled with an arbitrary color gradient
Description
‘gradient.rect’ draws a rectangle consisting of ‘nslices’ subrectangles of the colors in ‘col’ or those returned by ‘color.gradient’ if ‘col’ is NULL. The rectangle is 'sliced' in the direction specified by ‘gradient’.
Usage
gradient.rect(xleft,ybottom,xright,ytop,reds,greens,blues,col=NULL,
nslices=50,gradient="x",border=par("fg"))
Arguments
xleft , ybottom , xright , ytop |
Positions of the relevant corners of the desired rectangle, as in ‘rect’. |
reds , greens , blues |
vectors of the values of the color components either as 0 to 1 or ,if any value is greater than 1, 0 to 255. |
col |
Vector of colors. If supplied, this takes precedence over ‘reds, greens, blues’ and ‘nslices’ will be set to its length. |
nslices |
The number of sub-rectangles that will be drawn. |
gradient |
whether the gradient should be horizontal (x) or vertical. |
border |
The color of the border around the rectangle (NA for none). |
Value
the vector of hexadecimal color values from ‘color.gradient’ or ‘col’.
Author(s)
Jim Lemon
Examples
# get an empty box
plot(0:10,type="n",axes=FALSE)
# run across the three primaries
gradient.rect(1,0,3,6,reds=c(1,0),
greens=c(seq(0,1,length=10),seq(1,0,length=10)),
blues=c(0,1),gradient="y")
# now a "danger gradient"
gradient.rect(4,0,6,6,c(seq(0,1,length=10),rep(1,10)),
c(rep(1,10),seq(1,0,length=10)),c(0,0),gradient="y")
# now just a smooth gradient across the bar
gradient.rect(7,0,9,6,col=smoothColors("red",38,"blue"),border=NA)