As footnote, the error in survival:::untangle.specials is that it assumed that if attr(myterms, 'specials')[['strata']] was = to 4, then one could use myterms[-4] to remove the strata term. Not so. In the model y ~ x1 + x2 + strata(x3) the attritube will be 4 -- the response counts --- but to remove it I need to use [-3] since the response does not count in [.terms or drop.terms.
Is this an inconsistency that should be documented and/or repaired? What would break if we did? I don't know. By chance, all the usages in the survival package happened after a call to delete.response so it would be immune to such a change. Terry T. [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel