Hi together, below is a small example which produces outcome I do not understand, namely that the median function works fine on a data.frame without negative numbers, but doesn't work on a data.frame with one negative number. I'm sure there is a reasonable explanation for that or better, that I'm doing something wrong and someone could guide me how to solve it. I tried googling it, but couldn't find a solution:
> #Set up data frame > df <- data.frame(V1=c(1,2,3,4),V2=c(2,3,4,5)) > #Both work fine > mean(df) V1 V2 2.5 3.5 > median(df) [1] 2.5 3.5 > > #Now, I just make one number negative in the data.frame > df <- data.frame(V1=c(1,2,3,-4),V2=c(2,3,4,5)) > mean(df)#Works fine V1 V2 0.5 3.5 > median(df)#Why do I get that error? [1] NA 0.5 Warnmeldung: In mean.default(X[[1L]], ...) : argument is not numeric or logical: returning NA > #It works fine on both columns seperately > median(df$V1) [1] 1.5 > median(df$V2) [1] 3.5 > > sessionInfo() R version 2.13.0 (2011-04-13) Platform: x86_64-pc-mingw32/x64 (64-bit) locale: [1] C attached base packages: [1] graphics grDevices datasets stats utils methods base other attached packages: [1] urca_1.2-5 zoo_1.6-5 svSocket_0.9-51 loaded via a namespace (and not attached): [1] grid_2.13.0 lattice_0.19-23 svMisc_0.9-61 tcltk_2.13.0 tools_2.13.0 Thanks Christoph -- -------------------------------------------------------------------------------------------------------------------------------------------------------------------- Christoph Jäckel (Dipl.-Kfm.) -------------------------------------------------------------------------------------------------------------------------------------------------------------------- Research Assistant Chair for Financial Management and Capital Markets | Lehrstuhl für Finanzmanagement und Kapitalmärkte TUM School of Management | Technische Universität München Arcisstr. 21 | D-80333 München | Germany ______________________________________________ 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.
