From: Rolf Turner In response to my question Andy Liaw wrote:
Here's one way:
<snip>
dat$rank <- with(dat, ave(x, f, FUN=rank))
<snip>
Don't know how this rates on the slick-quick-sexy scale...
Thanks Andy. That's definitely a 10 on the slick-quick-sexy scale. I (blush!) didn't know about ``ave()''.
All credits should go to the author of ave(). I didn't know about it either until I saw it on R-help a while ago. Cheers, Andy
cheers, Rolf