The operator %in% is very good! And that can be simpler like this: x %in% x[duplicated(x)] [1] FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE FALSE FALSE
On Thu, May 14, 2009 at 4:43 PM, Andrej Blejec <andrej.ble...@nib.si> wrote: > Try this > > x%in%x[which(y)] > > >From your example > >> x=c(1,2,3,4,4,5,6,7,8,9) >> y=duplicated(x) >> rbind(x,y) > [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] > x 1 2 3 4 4 5 6 7 8 9 > y 0 0 0 0 1 0 0 0 0 0 >> which(y) > [1] 5 >> x[which(y)] > [1] 4 >> x%in%x[which(y)] > [1] FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE FALSE FALSE > > Andrej > > -- > Andrej Blejec > National Institute of Biology > Vecna pot 111 POB 141 > SI-1000 Ljubljana > SLOVENIA > e-mail: andrej.ble...@nib.si > URL: http://ablejec.nib.si > tel: + 386 (0)59 232 789 > fax: + 386 1 241 29 80 > -------------------------- > Organizer of > Applied Statistics 2009 conference > http://conferences.nib.si/AS2009 > > >> -----Original Message----- >> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- >> project.org] On Behalf Of christiaan pauw >> Sent: Thursday, May 14, 2009 8:17 AM >> To: r-help@r-project.org >> Subject: [R] Duplicates and duplicated >> >> Hi everybody. >> I want to identify not only duplicate number but also the original >> number >> that has been duplicated. >> Example: >> x=c(1,2,3,4,4,5,6,7,8,9) >> y=duplicated(x) >> rbind(x,y) >> >> gives: >> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] >> x 1 2 3 4 4 5 6 7 8 9 >> y 0 0 0 0 1 0 0 0 0 0 >> >> i.e. the second 4 [,5] is a duplicate. >> >> What I want is the first and second 4. i.e [,4] and [,5] to be TRUE >> >> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] >> x 1 2 3 4 4 5 6 7 8 9 >> y 0 0 0 1 1 0 0 0 0 0 >> >> I assume it can be done by sorting the vector and then checking is the >> next >> or the previous entry matches using >> identical() . I am just unsure on how to write such a loop the logic > of >> which (I think) is as follows: >> >> sort x >> for every value of x check if the next value is identical and return >> TRUE >> (or 1) if it is and FALSE (or 0) if it is not >> AND >> check is the previous value is identical and return TRUE (or 1) if it >> is and >> FALSE (or 0) if it is not >> >> Im i thinking correct and can some help to write such a function >> >> regards >> Christiaan >> >> [[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. > ______________________________________________ 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.
