It would be easier to diagnose the problem if you included an example illustrating exactly what you did. I'll guess:
> a <- list(3,4,5) > mean(a) [1] NA Warning message: In mean.default(a) : argument is not numeric or logical: returning NA > mean(as.numeric(a)) [1] 4 But that's just a guess, as I don't know the actual contents of your list! albyn On Fri, Aug 30, 2013 at 5:18 AM, agnes69 <fes...@gredeg.cnrs.fr> wrote: > When I try to apply mean to a list, I get the answer : > > argument is not numeric or logical: returning NA > > Could you help me? > > (I am a very beginner) > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/mean-tp4674999.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > [[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.