Coloring spaces between lines in xyplot

Seth W Bigelow wrote:

Ok, thanks to Carl Witthoft I now know that to color spaces between  and
below a pair of lines in xyplot, I will need to redefine the lines as
polygons, and use the lpolygon panel function, as in the following

library(lattice)
p <- c(1,10,10,1)       #  vector of x values
q <- c(4,29.2,16,2.5)          # vector of y values for upper polygon
r <- c(2.5,16,0,0)                    # vector of y values for lower
polygon

xyplot(
  q + r ~ p,
  panel = lpolygon,
  col = c("red","green")
  )

But, having spent several hours arriving at this increment of knowlege, I
find myself stumped at how to assign different colors to the two 
polygons!
the above "col" line did not do the job.

  

Hi Seth,
Maybe you could use the stackpoly function in the plotrix package:

x<-matrix(x,nrow=10)
y<-matrix(y,nrow=10)
stackpoly(x,y,stack=TRUE)

Jim