ave and grouping
Try performing ave over the indexes rather than over extra itself: sleep$newcol <- with(sleep, ave(1:nrow(sleep), group, FUN = function(ix) extra[b[ix][1]])) On Mon, Mar 2, 2009 at 4:28 AM, Patrick Hausmann
<Patrick.Hausmann at uni-bremen.de> wrote:
Dear list, # I have a DF like this: sleep$b ? <- c(rep(8,10), rep(9,10)) sleep$me ?<- with(sleep, ave(extra, group, FUN = mean)) sleep # I would like to create a new variable # holding the b-th value of group 1 and 2. # This is not what I want, it takes always the '8' from group '1' # and not the '9' sleep$gr ?<- with(sleep, ave(extra, group, FUN = function(x) x[ b[1] ])) sleep Thanks for any help! Patrick
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