Thanks for your help, put I've tried that and it still gives me back the mean when I use it within tapply for some reason
On Tue, Jun 25, 2013 at 12:17 PM, Rui Barradas <ruipbarra...@sapo.pt> wrote: > Hello, > > You can write a function gmean and tapply it to your data. > > > gmean <- function(x, na.rm = FALSE){ > if(na.rm) x <- x[!is.na(x)] > n <- length(x) > prod(x)^(1/n) > } > > tapply(data$value, data$group, gmean) > > > Hope this helps, > > Rui Barradas > > Em 25-06-2013 11:58, Shane Carey escreveu: > > Hi, >> >> I am trying to calculate the geometric mean with tapply. This is the >> formula I am using: >> >> exp(tapply(log(data$value), data$group, mean)) >> >> >> However, it returns the arithmetic mean. Any ideas? >> >> >> Thanks >> >> >> -- Shane [[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.