Hi all, I have a dataframe with survey data. Now I want to calculate means from several but not all columns (e.g. a1, a2, a3) and save them in a new separate column (e.g. a).
Like: a = mean(a1, a2, a3) Can someone help me or give me the right key word to look for? Thanks [[alternative HTML version deleted]] ______________________________________________ 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.