plotrix (version 1.41)

color.scale: Linearly transform numeric values into colors.

Description

color.scale calculates a sequence of colors by a linear transformation of the numeric values supplied into the ranges for red, green and blue. If only one number is supplied for a color range, that color remains constant for all values of x. If more than two values are supplied, only the first two are used. Values for a color range must be between 0 and 1. The function is useful for highlighting a numeric dimension or adding an extra "dimension" to a plot.

Usage

color.scale(x,redrange,greenrange,bluerange)

Arguments

x

a numeric vector

redrange,greenrange,bluerange

Value

• A vector of hexadecimal color values as used by col.

See Also

rescale

Examples

# go from green to red with a constant blue value
 x<-rnorm(20)
 y<-rnorm(20)
 # use y for the color scale
 plot(x,y,col=color.scale(y,c(0,1),c(1,0),0.3))