Hello List, I would like to simplify a data.frame like this
columnA columnB user10 proj12 user10 proj19 user10 proj12 into something like: columnA columnB columnC user10 proj12 2 user10 proj19 1 I know unique() can simplify the data.frame, but how to count and store the duplicates? thanks in advance for any help. best regards, Simone ______________________________________________ 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.