Try this: dat$sequence <- as.vector(unlist(lapply( aggregate(dat$ID, by=list(x), FUN=length)$x, FUN=function(x){seq(1, x)))) dat0 <- dat[dat$sequence==1, ]
HTH, X On Sat, Feb 23, 2013 at 1:07 PM, Rui Barradas <ruipbarra...@sapo.pt> wrote: > Hello, > > You can use ?aggregate and ?head to do what you want. Try the following. > > > > dat <- read.table(text=" > > ID COMPL SEX HEREDITY > 1 0 1 2 > 1 0 1 2 > 1 3 1 2 > 2 0 0 1 > 2 1 0 1 > 2 2 0 1 > 2 2 0 1 > 3 0 0 1 > 3 0 0 1 > 3 0 0 1 > 3 0 0 1 > 3 2 0 1 > 4 0 1 2 > 4 0 1 2 > ", header = TRUE) > > aggregate(. ~ ID, data = subset(dat, COMPL != 0), head, 1) > > > Hope this helps, > > Rui Barradas > > Em 23-02-2013 14:28, Tasnuva Tabassum escreveu: > > I have a longitudinal competing risk data of the form: >> >> ID COMPL SEX HEREDITY >> 1 0 1 2 >> 1 0 1 2 >> 1 3 1 2 >> 2 0 0 1 >> 2 1 0 1 >> 2 2 0 1 >> 2 2 0 1 >> 3 0 0 1 >> 3 0 0 1 >> 3 0 0 1 >> 3 0 0 1 >> 3 2 0 1 >> 4 0 1 2 >> 4 0 1 2. >> >> Where, COMPL= health complication of diabetic patients which has value >> labels as 0= no complication,1=coronary heart disease, 2=retinopathy, >> 3= >> nephropathy. >> >> >> I want to select only the first complication that occurred to each >> patient. >> What R function can I use? >> >> [[alternative HTML version deleted]] >> >> ______________________________**________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> >> PLEASE do read the posting guide http://www.R-project.org/** >> posting-guide.html <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<https://stat.ethz.ch/mailman/listinfo/r-help> > PLEASE do read the posting guide http://www.R-project.org/** > posting-guide.html <http://www.R-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > -- ============================== Xiaogang Su, Ph.D. Associate Professor & Statistician School of Nursing, University of Alabama Birmingham, AL 35294-1210 (205) 934-2355 [Office] x...@uab.edu xiaogan...@gmail.com https://sites.google.com/site/xgsu00/ [[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.