Thank you Jim for the feedback. I actually implemented it the way I describe it in my first email and it seems fast enough for me.
Just to give a bit of context I will need it at some point in package kit. I also implemented subset by row which I actually need more as I am working on a faster version of the unique and duplicated function. The function unique is particularly slow for data.frame. So far I got a 100x speedup. Best regards Morgan On Tue, 23 Jun 2020, 21:11 Jim Hester, <james.f.hes...@gmail.com> wrote: > It looks to me like internally .subset2 uses `get1index()`, but this > function is declared in Defn.h, which AFAIK is not part of the exported R > API. > > Looking at the code for `get1index()` it looks like it just loops over > the (translated) names, so I guess I just do that [0]. > > [0]: > https://github.com/r-devel/r-svn/blob/1ff1d4197495a6ee1e1d88348a03ff841fd27608/src/main/subscript.c#L226-L235 > > On Wed, Jun 17, 2020 at 6:11 AM Morgan Morgan <morgan.email...@gmail.com> > wrote: > >> Hi, >> >> Hope you are well. >> >> I was wondering if there is a function at C level that is equivalent to >> mtcars$carb or .subset2(mtcars, "carb"). >> >> If I have the index of the column then the answer would be VECTOR_ELT(df, >> asInteger(idx)) but I was wondering if there is a way to do it directly >> from the name of the column without having to loop over columns names to >> find the index? >> >> Thank you >> Best regards >> Morgan >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel >> > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
