Re: [Rd] relist, an inverse operator to unlist

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Tue, 22 May 2007 19:36:56 -0400

One additional idea.

I wonder if reshape might be promoted to a generic and relist made into methods for it. The unlisted version of an object would be the "long" version and the original version of the list would be the "wide" version.

This would consolidate the two concepts together and make it easier to use since the user could leverage his knowledge of how reshape works to lists where it would work analogously.

Essentially reshape(myList, direction = "long") would be similar to unlist but would add the attributes need to reverse the procedure and reshape(myList, direction = "wide") would perform the inversion.

I am not sure if the reshape package has any bearing here as well.

On 5/22/07, Andrew Clausen <clausen_at_econ.upenn.edu> wrote:
> 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
>
> Cheers,
> Andrew
>
> ______________________________________________
> R-devel_at_r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>



R-devel_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel Received on Tue 22 May 2007 - 23:40:21 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Wed 23 May 2007 - 12:33:41 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-devel. Please read the posting guide before posting to the list.