ummm... ?duplicates -- Bert
On Wed, Jul 25, 2012 at 1:22 PM, David L Carlson <dcarl...@tamu.edu> wrote: > duplicate <- ifelse(c(0, a$col[-length(a$col)])==c(a$col), 1, 0) > > ---------------------------------------------- > David L Carlson > Associate Professor of Anthropology > Texas A&M University > College Station, TX 77843-4352 > > >> -----Original Message----- >> From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- >> project.org] On Behalf Of Jeff >> Sent: Wednesday, July 25, 2012 3:06 PM >> To: r-help@r-project.org >> Subject: [R] Simple question on finding duplicates >> >> >> I'm trying to find duplicate values in a column of a data frame. >> For >> example, dataframe (a) below has two 3's. I would like to mark each >> value of >> each row as either not being a duplicate of the one before (0), or >> as a >> duplicate (1) - for example, as in dataframe (b). In SPSS, I would >> simply >> compare each value to it's "lagged" value, but I can't figure out >> how to do >> this with R. >> Can someone point me in the right direction? >> Thanks >> a <- data.frame( col1 = c(1,2,3,3,4)) >> b <- data.frame( col1 = c(1,2,3,3,4), duplicate = c(0,0,0,1,0)) >> ______________________________________________ >> 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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.