gplots (version 3.1.0)

colorpanel: Generate a smoothly varying set of colors

Description

colorpanel generate a set of colors that varies smoothly. redgreen, greenred, bluered, and redblue generate red-black-green, green-black-red, red-white-blue, and blue-white-red colorbars, respectively. colors

Usage

colorpanel(n, low, mid, high)
redgreen(n)
greenred(n)
bluered(n)
redblue(n)

Arguments

n

Desired number of color elements in the panel.

low, mid, high

Colors to use for the Lowest, middle, and highest values. mid may be ommited.

Value

Vector of HTML-style RGB colors.

Details

The values for low, mid, high can be given as color names ('red'), plot color index (2=red), and HTML-style RGB, ("\#FF0000"=red).

If mid is supplied, then the returned color panel will consist of n - floor(n/2) HTML-style RGB elements which vary smoothly between low and mid, then between mid and high. Note that if n is even, the color mid will occur twice at the center of the sequence.

If mid is omitted, the color panel will vary smoothly beween low and high.

See Also

colors

Examples

# NOT RUN {
showpanel <- function(col)
{
  image(z=matrix(1:100, ncol=1), col=col, xaxt="n", yaxt="n" )
}

par(mfrow=c(3,3))

# two colors only:
showpanel(colorpanel(8,low="red",high="green"))

# three colors
showpanel(colorpanel(8,"red","black","green"))
# note the duplicatation of black at the center, using an odd
# number of elements resolves this:
showpanel(colorpanel(9,"red","black","green"))

showpanel(greenred(64))
showpanel(redgreen(64))
showpanel(bluered(64))
showpanel(redblue(64))

# }