[R] ave and grouping
Dieter Menne
dieter.menne at menne-biomed.de
Mon Mar 2 14:01:04 CET 2009
Patrick Hausmann <Patrick.Hausmann <at> uni-bremen.de> writes:
> # 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$gr <- with(sleep, ave(extra, group, FUN = function(x) x[ b[1] ]))
> sleep
Nice example, but I don't fully understand what you want.
sleep$b[1]
8
Or could it be that you got into the factor-trap? Try
R-FAQ How-do-I-convert-factors-to-numeric_003f
Dieter
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