Hey, I've got a data set (e.g. named Data) which contains a lot of variables, for example: s1, s2, ..., s50
My first question is: It is possible to do this: Data$s1 But is it also possible to do something like this: Data$s1:s50 (I've tried a lot of versions of those without a result) My second question: I want to do a stepwise logistic regression. For this purpose I use the following procedures: result<-glm(...) step(result, direction="forward) Now the problem I have, is, that I have to include all my 50 variables (s1-s50), but I don't want to write them all down like y~s1+s2+s3+s4... (furthermore it has to be implemented in a loop, so I really need it). I've tried do store the 50 variables in a list (e.g. list[[1]]) and tried this: result<-glm(y ~ list[[1]], ...) This works! But if I try to do it stepwise result2<-step(result) I always get the same results as from glm without a stepwise approach. So obviously R can't handle this if you put a list in. How can I make this work? Thanks in advance, Anna -- View this message in context: http://www.nabble.com/Handle-lot-of-variables---Regression-tp25889056p25889056.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.