Sweave driver extension
On Tue, Jan 31, 2012 at 7:18 AM, Terry Therneau <therneau at mayo.edu> wrote:
Three thinngs - ? My original questions to R-help was "who do I talk to". ?That was answered by Brian R, and the discussion of how to change Sweave moved offline. ?FYI, I have a recode in hand that allows arbitrary reordering of chunks; but changes to code used by hundreds need to be approached cautiously. ?Like the witch says in Wizard of Oz: "... But that's not what's worrying me, it's how to do it. ?These things must be done delicately, or you hurt the spell." ? A few emails have made me aware of others who use noweb. ?Most of them, as I have, use the original Unix utility. ?But since survival is so interwoven with R I am trying to impliment that functionality entirely in R to make the code self contained. ?Just working out how to best do so. ?Yihui: with respect to the note below, I don't see why you want to add new syntax. ?Why add "run_chunk(a)" when it is a synonym for <<a>>?
A short answer is it is easy to implement, because run_chunk() uses eval() which naturally supports recursion (you can eval(parse(text = "eval(parse(text = ...))"))). I think I will add <<>> in the next few days too. There have been quite a few features like this one that I did not plan to do because I do not use them at all, but I added them to knitr one by one anyway when I saw convincing reasons (function overhead problems in this case). So I really appreciate these discussions. I feel r-devel is not a good place for me to chime in, so I will turn the discussion irrelevant to r-devel offline later.
Terry T.
Regards, Yihui -- Yihui Xie <xieyihui at gmail.com> Phone: 515-294-2465 Web: http://yihui.name Department of Statistics, Iowa State University 2215 Snedecor Hall, Ames, IA