> Is there a way to do this modification in rpart or is there any other > function I could use that would consider interdependence in the > response variable?
This feature already exists: the "xval" option can be a vector of integers that defines the "left out" groups. First all the 1's are left out, then the 2s, then the 3s, etc. Unfortunately this was overlooked in the documentation for rpart.control; it's in the documentation for xpred.rpart though. I'll fix this soon as part of some other updates. Terry Therneau ______________________________________________ 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.