[R] contingency table, several variables from dataframe

2008-10-02 Thread Birgitle
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

Re: [R] contingency table, several variables from dataframe

2008-10-02 Thread Eik Vettorazzi
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

Re: [R] contingency table, several variables from dataframe

2008-10-02 Thread Birgitle
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

Re: [R] contingency table, several variables from dataframe

2008-10-02 Thread Eik Vettorazzi
Ok, then treat them as factors - but if they are really binary and coded 0 and 1, which kind of calculation would lead to different results for a factor instead of a numeric variable? Anyway, ABC-as.data.frame(cbind(A,B,C)) aggregate(ABC[,2:3],by=list(A),FUN=function(x)sum(x=='1')) # '1' is

Re: [R] contingency table, several variables from dataframe

2008-10-02 Thread Birgitle
I think it makes a difference if I want to use a classification method like rpart () or if I use a modelling approach like glm(). Many thanks for the kind and fast help. I am still very untrained and it is difficult for me to create such codes. B. Eik Vettorazzi wrote: Ok, then treat them