At 08:56 17/11/2012, Kemi Racheal wrote:
Dear list member,
I have the following data example
ke <- data.frame(patid=c(1,1,1,2,3,3),a=c(1,2,2,1,1,2))
I want to add another variable b, such that the max of 'a' by id is returned
i.e data ke becomes
ke <- data.frame(patid=c(1,1,1,2,3,3),a=c(1,2,2,1,1,2),b=c(2,2,2,1,2,2))
Any help will be appreciated.
Dear Kemi
It is often easier to do some sorts of manipulations on the wide
format of the data. I appreciate that you can always do it both ways.
Oluwakemi
[[alternative HTML version deleted]]
Michael Dewey
i...@aghmed.fsnet.co.uk
http://www.aghmed.fsnet.co.uk/home.html
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