Simple question on finding duplicates
ummm... ?duplicates -- Bert
On Wed, Jul 25, 2012 at 1:22 PM, David L Carlson <dcarlson at 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-bounces at r-project.org [mailto:r-help-bounces at r- project.org] On Behalf Of Jeff Sent: Wednesday, July 25, 2012 3:06 PM To: r-help at 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))
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______________________________________________ R-help at 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