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.
