On Mon, Apr 13, 2009 at 4:15 AM, Peter Dalgaard <p.dalga...@biostat.ku.dk> wrote: > Stavros Macrakis wrote: > >> It would of course be nice if the existing difftime class could be fit >> into this, as it is currently pretty much a second-class citizen. For >> example, c of two time differences is currently a numeric vector, >> losing its units (hours, days, etc.) completely. > > That's actually a generic feature/issue of c(). We also have > >> c(factor(1),factor(3)) > [1] 1 1 >> library(survival) > Loading required package: splines >> c(Surv(1,T),Surv(2,F)) > [1] 1 1 2 0 > > and similar issues apply to rbind() of data frames, > >> rbind(data.frame(s=Surv(1,T)),data.frame(s=Surv(2,F))) > s.time s.status > 1 1 1 > 2 2 0 > > There is some potential for redesigning this, using a concat() generic which > should do the Right Thing for all classed vector-like objects. (There is > such a function in Splus, but I don't their data frame code is using it.)
It would also be nice to have a strip_attr function for those times you want to be explicit about using c to remove attributes. Hadley -- http://had.co.nz/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
