[I believe few users manipulate formulae and model frames like this, so I'm posting here instead of R-help.]
I just found out that model.frame() includes all terms, including those preceded by "-" in the formula, in its output (as mentioned on its help page). Is there a recommended way of excluding "negative" terms? My guess is that I can use info in the terms attribute to figure this out, but that doesn't seem very straightforward. Any pointer would be much appreciated. Best, Andy Andy Liaw, PhD Biometrics Research PO Box 2000 RY33-300 Merck Research Labs Rahway, NJ 07065 andy_liaw(a)merck.com 732-594-0820 ------------------------------------------------------------------------------ Notice: This e-mail message, together with any attachme...{{dropped:15}} ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel