thanks for your effort. to be more precise:
ID , OS, time and many more are the columns. each entry is a row. when I do: x <- unique(dataset$ID) It just gives me a list of all IDs (levels). I want to get a dataframe where just one entry (row) for each ID is included... like: userA , Win, 12:22 userA, OSX, 23:22 userB, Win, 04:44 should only give me row 1 and row 3... -- View this message in context: http://r.789695.n4.nabble.com/Delete-rows-with-duplicate-field-tp2123939p2123974.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.