It will not work because the presence of the first row means that all the variables are read in as factors, not numeric. You must convert numeric variables to numeric **after** eliminating the first row, or read the data in using read.table(..., head=TRUE). See ?read.table for details.
**After** the above changes, perhaps with(Daten, boxplot(Gewicht ~ interaction(Dosis,Geshlecht, drop=TRUE)) ) will work if you read in column names properly. Otherwise, V2 ~interaction(V1,V3, drop=TRUE) if you do the conversions to numeric. Please read *An Introduction to R" or other online R tutorial before posting further here. You need to understand basic R data handling before you proceed. At present, you do not. -- Bert On Sat, May 11, 2013 at 8:40 AM, maggy yan <kiot...@gmail.com> wrote: > my dataset looked like this in the beginning: > >>Daten > V1 V2 V3 > 1 Dosis Gewicht Geschlecht > 2 0 6.62 m > 3 0 6.65 m > 4 0 5.78 m > 5 0 5.63 m > > I need box plots for V2 with all combination of V1 and V3, so I deleted the > first row, and tried this: > boxplot(Daten$V2[Daten$V3=="m"]) > but it does not work and I have no clue what I did wrong. > I'm thankful for any help! > > [[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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.
