Thanks for your answer. It is intended, that the variables are treated as class factor, because these are binary variables with, for example, the presence or the absence of a plant organ. As far as I understood, I have to treat them for other calculations as factor. Therefore I classified these variables as factors in my original dataframe.
If I do what you suggested, I have to change the classes of all my variables. Is there a possibility to do something similar without changing the classes? B. Eik Vettorazzi wrote: > > First of all your construction of ABC leads to a structure with 3 factor > variables due to the way cbind processes the input variables - which is > not intended I think. > > You can do sth like > > ABC<-data.frame(A,B,C) > aggregate(ABC[,2:3],by=list(A),sum) > > hth. > > Birgitle schrieb: >> Hello R-Users! >> >> I need a little help to build up a contingency table out of several >> variables. >> >> A<-c("F","M","M","F","F","F","F","M","F","M","F","F") >> B<-c(0,0,0,0,0,0,1,1,1,1,0,1) >> C<-c(0,1,1,1,1,1,1,1,1,0,0,0) >> >> ABC<-as.data.frame(cbind(A,B,C)) >> >> ABC >> >> A B C >> 1 F 0 0 >> 2 M 0 1 >> 3 M 0 1 >> 4 F 0 1 >> 5 F 0 1 >> 6 F 0 1 >> 7 F 1 1 >> 8 M 1 1 >> 9 F 1 1 >> 10 M 1 0 >> 11 F 0 0 >> 12 F 1 0 >> >> I would like to count in each variable B and C the frequencies for M and >> F >> (variable A) and finally get the following table: >> >> B C >> F 3 5 >> >> M 2 3 >> >> Is there a function that can do that in one step? >> Tried ?structable, ?ftable, ?xtabs, ?table but could not get what I would >> like to have. >> >> Maybe I did not use the tried functions in the right way. >> >> Many thanks in advance for any help. >> >> B. >> >> >> >> ----- >> The art of living is more like wrestling than dancing. >> (Marcus Aurelius) >> > > -- > Eik Vettorazzi > Institut für Medizinische Biometrie und Epidemiologie > Universitätsklinikum Hamburg-Eppendorf > > Martinistr. 52 > 20246 Hamburg > > T ++49/40/42803-8243 > F ++49/40/42803-7790 > > ______________________________________________ > 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. > > ----- The art of living is more like wrestling than dancing. (Marcus Aurelius) -- View this message in context: http://www.nabble.com/contingency-table%2C-several-variables-from-dataframe-tp19775083p19777611.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.