Hi all I have a very basic question, yet i have not found how to do it. Suppose my dataset looks like this:
Year Area value 1 a 20 1 a 25 1 a 28 1 a 31 1 a 23 1 b 25 1 b 28 1 b 23 1 b 19 2 a 25 2 a 23 2 a 24 2 a 26 2 b 27 2 b 28 2 b 20 2 b 25 2 b 28 Now, i want to calculate a MEAN per year per area. How do i do that? With mean(value) i calculate the mean of all values of course. I just need to know how to group year and area correctly. I assume that i can use this grouping in other calculations too, right? Cheers, Luc -- View this message in context: http://www.nabble.com/calculating-means-per-group-tp19271479p19271479.html Sent from the R devel mailing list archive at Nabble.com. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
