I understood what you were asking but R is an oo language so that's the model to use to do this sort of thing.
On Mon, May 18, 2009 at 5:48 PM, Stavros Macrakis <macra...@alum.mit.edu> wrote: > I guess I wasn't very clear. The goal is not to define diff on a different > object type, but to have a different 'subtraction' operator with the same > lag logic. An easy example would be quotient instead of subtraction. Of > course I could do that by simply cutting and pasting diff.default and > replacing '-'(a,b) with f(a,b), but it's cleaner to use a standard function > if there is one. > > -s > > On Mon, May 18, 2009 at 5:05 PM, Gabor Grothendieck > <ggrothendi...@gmail.com> wrote: >> >> You can define a new class for the object diff operates >> on and then define your own diff method for that. For >> some examples see: >> >> methods(diff) >> >> >> >> On Mon, May 18, 2009 at 4:24 PM, Stavros Macrakis <macra...@alum.mit.edu> >> wrote: >> > I would like to apply a function 'f' to the lagged version of a vector >> > and >> > the vector itself. >> > >> > This is easy to do explicitly: >> > >> > mapply( f, v[-1], v[-length(v)] ) >> > >> > or in the case of a pointwise vector function, simply >> > >> > f( v[-1], v[-length(v)] ) >> > >> > This is essentially the same as 'diff' but with an arbitrary function, >> > not >> > '-'. >> > >> > Is there a standard way to do this? Is there any particular reason that >> > 'diff' should not have an 'f' argument? >> > >> > -s >> > >> > [[alternative HTML version deleted]] >> > >> > ______________________________________________ >> > 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. >> > > > ______________________________________________ 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.
