gradient.rect {plotrix}R Documentation

Display a rectangle filled with an arbitrary color gradient.

Description

gradient.rect draws a rectangle consisting of nslices subrectangles, each of the color specified by the respective triplet in reds, greens and blues. The rectangle is 'sliced' in the direction specified by gradient.

Usage

 gradient.rect(xleft,ybottom,xright,ytop,reds,greens,blues,nslices=50,
  gradient="x")

Arguments

xleft,xright,ybottom,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.
nslices The number of sub-rectangles that will be drawn.
gradient whether the gradient should be horizontal (x) or vertical.

Value

the vector of hexadecimal color values

Author(s)

Jim Lemon

Examples

 # get an empty box
 plot(0:10,type="n",axes=FALSE)
 # first try a "rainbow"
 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")
 # finally a real mess
 gradient.rect(7,0,9,6,reds=c(1,0),
  greens=rescale(rnorm(20),c(0,1)),blues=c(1,0),
  gradient="y")

[Package plotrix version 1.41 Index]