>>>>> William Dunlap via R-devel
>>>>> on Thu, 20 Dec 2018 15:09:56 -0800 writes:
> When formula() is applied to the output of model.frame()
> it ignores the formula in the model.frame's 'terms'
> attribute:
>> d <- data.frame(A=log(1:6), B=LETTERS[rep(1:2,c(2,4))],
>> C=1/(1:6),
> D=rep(letters[25:26],c(4,2)), Y=1:6)
>> m0 <- model.frame(data=d, Y ~ A:B) formula(m0)
> Y ~ A + B
>> `attributes<-`(terms(m0), value=NULL)
> Y ~ A:B
> This is in part because model.frame()'s output has class
> "data.frame" instread of c("model.frame","data.frame"), as
> SV4 did, so there are no methods for model.frames.
> Is there a reason that model.frame() returns a data.frame
> with extra attributes but no special class or is it just
> an oversight?
May guess is "oversight" || "well let's keep it simple"
Do you (all readers) see situation where it could harm now (with
the 20'000 packages on CRAN+BIoc+...) to do as SV4 (S version 4) has been doing?
I'd be sympathetic to class()ing it.
Martin
> Bill Dunlap TIBCO Software wdunlap tibco.com
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
