[R] R stepping through multiplie interactions

[ppeetteerr]

I have a lm in R in the form
model <- lm( Z ~ A*B*C*D,data=mydata)
I want to run the model and include all interactions expect the 4 way
(A:B:C:D) is there an easy way of doing this? I then want to step down the
model eliminating the non-significant terms I understand step() does this
but how would I do it by hand?
-- 
View this message in context: http://www.nabble.com/R-stepping-through-multiplie-interactions-tp21629339p21629339.html
Sent from the R help mailing list archive at Nabble.com.