How is it possible to group rows of a matrix or a data frame by the same values of the first column? 1 14331 453452 653 3762 45
1 1433,453452 45, 653 376 Thanks Carol [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.