I think that your 'C' column is a factor(or character), because the character used(comma).
One option: dat$C <- as.numeric(gsub(",", ".", as.character(dat$C))) library(doBy) summaryBy(C ~ B, data=dat, FUN=c(median, var), na.rm = T) On 09/03/2008, Agrarimmobilien <[EMAIL PROTECTED]> wrote: > Hello, > > I try to transform a data frame like > > A B C > > 1 1 2,5 > 2 2 NA > 3 1 1,0 > 4 1 56 > 5 2 23 > 6 1 NA > 7 2 46 > > to the following dataframe, calculating the variance and median of the > C-column, group by B, so the result will be: > > B C(median) D (var) > 1 19,83 9 > 2 34,5 21 > > > Doing this, I got problems with the NAs in column C. > I tried to combine the aggregate - function > aggregate(C, list(B), FUN=(mean, var)) > > with the following functions > > var(C, use="complete.obs") > median(C, rm.na=TRUE) > > but it doesn't work as I want. Has anybody an idea how to do this work? > > thank you > Iksmax > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.