Hi, If you can dput() a small part of your dataset e.g. dput(head(yourdataset),20)), it would be helpful.
Otherwise, dat1<- data.frame(ID=rep(1:3,times=c(3,4,2)),col2=rnorm(9)) aggregate(.~ID,data=dat1,head,1) # ID col2 #1 1 -0.0637622 #2 2 1.1782429 #3 3 0.4670021 A.K. ----- Original Message ----- From: Julie Royster <jsdroys...@bellsouth.net> To: r-help@r-project.org Cc: Sent: Friday, March 15, 2013 12:06 PM Subject: [R] seeking tip to keep first of multiple observations per ID Dear R community, I am a neophyte and I cannot figure out how to accomplish keeping only the first record for each ID in a data.frame that has assorted numbers of records per ID. I studied and found references to packages plyr and sql for R, and I fear the documentation for those was over my head and I could not identify what may be there to reach my goal. If someone could point me toward a method I will gladly study documentation, or if there is an example posted someplace I will follow it. THANKS! Julie [[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.
