HI, Try this: ke$b<-ave(ke$a,ke$patid,FUN=max) ke # patid a b #1 1 1 2 #2 1 2 2 #3 1 2 2 #4 2 1 1 #5 3 1 2 #6 3 2 2 A.K.
----- Original Message ----- From: Kemi Racheal <kemiadeboye2...@yahoo.com> To: R-help@r-project.org Cc: Sent: Saturday, November 17, 2012 3:56 AM Subject: [R] manipulating longitudinal data in r 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. Oluwakemi [[alternative HTML version deleted]] ______________________________________________ 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. ______________________________________________ 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.
