Probably the first thing to do is supply some sample data See https://github.com/hadley/devtools/wiki/Reproducibility for some suggestions.
However you may want to take a look at http://stackoverflow.com/questions/13279582/select-only-the-first-rows-for-each-unique-value-of-a-column-in-r particularly at answer number 3 which uses the data.table package and which looks like it may do what you want. John Kane Kingston ON Canada > -----Original Message----- > From: jsdroys...@bellsouth.net > Sent: Fri, 15 Mar 2013 12:06:05 -0400 > To: r-help@r-project.org > 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. ____________________________________________________________ FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop! ______________________________________________ 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.
