On Jan 27, 2008 4:23 AM, Rainer M Krug <[EMAIL PROTECTED]> wrote: > Hi > > I want to highlight two panels in a grid created with facet_grid() by > putting a box around it or usiong another background colour. Is this > possible, and if yes, how?
It's possible, but not particularly easy. You could do something like: # Background colours background <- data.frame( cyl = c(4, 6, 8), fill = c(NA, alpha("red", 0.2), alpha("black", 0.3)) ) # Points defining square region for background square <- with(mtcars, data.frame( x = c(min(mpg), max(mpg), max(mpg), min(mpg)), y = c(min(wt), min(wt), max(wt), max(wt)) )) ggplot(mtcars, aes(x=mpg, y=wt)) + geom_polygon(aes(x=x,y=y, fill=fill), data=merge(background, square)) + geom_point() + scale_fill_identity() + facet_grid(. ~ cyl) Hadley -- http://had.co.nz/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.