The survival package makes significant use of the "specials" argument of terms(), before calling model.frame; it is part of nearly every modeling function. The reason is that strata argments simply have to be handled differently than other things on the right hand side. Likewise for tt() and cluster(), though those are much less frequent.
I now get "bug reports" from the growing segment that believes one should put packagename:: in front of every single instance. For instance fit <- survival::survdiff( survival::Surv(time, status) ~ ph.karno + survival::strata(inst), data= survival::lung) This fails to give the correct answer because it fools terms(formula, specials= "strata"). I've stood firm in my response of "that's your bug, not mine", but I begin to believe I am swimming uphill. One person responded that it was company policy to qualify everything. I don't see an easy way to fix survival, and even if I did it would be a tremendous amout of work. What are other's thoughts? Terry -- Terry M Therneau, PhD Department of Quantitative Health Sciences Mayo Clinic thern...@mayo.edu "TERR-ree THUR-noh" [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel