[Rd] specials and ::

[Therneau, Terry M., Ph.D.]

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
therneau using mayo.edu

"TERR-ree THUR-noh"

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