color.scale {plotrix} | R Documentation |
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.
color.scale(x,redrange,greenrange,bluerange)
x |
a numeric vector |
redrange,greenrange,bluerange |
{color ranges into which to scale the numeric vector x
}
A vector of hexadecimal color values as used by col
.
Jim Lemon
# 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))