Will failed.3 have each id exactly once? Or could it have multiple lines for a given id?
-- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Linh Tran > Sent: Saturday, March 05, 2011 11:56 AM > To: r-help@r-project.org > Subject: [R] subsetting data by specified observation number > > Hi members, > > I'd like to thank you guys ahead of time for the help. I'm kind of > stuck. > > I have a data frame with ID and position numbers: > 1> head(failed.3) > id position > 1 10000997 2 > 4 1000RW_M 2 > 15 1006RW_G 2 > 24 1012RW_M 3 > 28 10160917 2 > 30 1016RW_M 13 > > I'd like to use this to subset out a large dataset and keep only the > observation number corresponding to the position number. So for > example, > ID 10000997 has 10 observations. I want to keep the 2nd one only. > > > Thanks, > > -linh > > ______________________________________________ > 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.
