Sorry, my fault. a problem with the data I was working with. Whoopsadaisey. Thanks all.
Cheers On Tue, Jun 25, 2013 at 1:50 PM, PIKAL Petr <petr.pi...@precheza.cz> wrote: > Hm > > > > -----Original Message----- > > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > > project.org] On Behalf Of Shane Carey > > Sent: Tuesday, June 25, 2013 1:25 PM > > To: Rui Barradas > > Cc: r-help@r-project.org > > Subject: Re: [R] Calculate geometric mean with tapply > > > > 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 > > can we believe it? Data, code please > > > set.seed(111) > > x<-rnorm(10) > > mean(x) > [1] -0.6690135 > > gmean(x) > [1] 0.4985282 > > tapply(vysled$gamapoml, vysled$vzorek, mean) > vz2 vz4 vz6 > 341.0 343.0 332.4 > > tapply(vysled$gamapoml, vysled$vzorek, gmean) > vz2 vz4 vz6 > 340.5418 342.6154 332.2701 > > > > I get different result for mean and gmean within tapply my data. > > Regards > Petr > > > > > > 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. > -- 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.
