>>>>> "GaGr" == Gabor Grothendieck <[EMAIL PROTECTED]> >>>>> on Wed, 23 May 2007 08:56:50 -0400 writes:
GaGr> On 5/23/07, Seth Falcon <[EMAIL PROTECTED]> wrote: >> Andrew Clausen <[EMAIL PROTECTED]> writes: >> >> > Hi Seth, >> > >> > On Mon, May 21, 2007 at 05:15:10PM -0700, Seth Falcon wrote: >> >> I will also add that the notion of a default argument on a generic >> >> function seems a bit odd to me. If an argument is available for >> >> dispatch, I just don't see what sense it makes to have a default. In >> >> those cases, the default should be handled by the method that has a >> >> signature with said argument matching the "missing" class. >> >> >> >> What often does make sense is to define a generic function where some >> >> argument are not available for dispatch. For example: >> >> >> >> setGeneric("foo", signature="flesh", >> >> function(flesh, skeleton=attr(flesh, "skeleton") >> >> standardGeneric("foo"))) >> > >> > That's an excellent suggestion. Thanks! However, I had to set the signature >> > to c("numeric", "missing") rather than just "numeric". >> > >> > I have uploaded a new version here: >> > >> > http://www.econ.upenn.edu/~clausen/computing/relist.R >> >> I misunderstood. You aren't using S4 classes/methods at all >> and so I don't actually see how my comments could have been helpful in >> any way. relist seems like a really odd solution to me, but based on >> the discussion I guess it has its use cases. GaGr> You didn't misunderstand but there was an offline GaGr> discussion pointing out that one primary use is in the GaGr> inner loop of an optimization so it should be made as GaGr> efficient as possible and it was changed with that in GaGr> mind. Thank you Gabor for that explanation. (I had wondered, too, and was glad that Andrew had dropped S4 generics seemingly "by himself" ;-)) Re your proposal of mixing this into reshape(): I think it's a nice and didactly helpful idea to point out the similarity in concepts between reshape() and relist(). However, I wouldn't like to make reshape() generic in this sense: As Andrew has mentioned as well, I think the two topics of data.frame (/matrix) reshaping and list <-> vector transformation seem too much different... Martin ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel