Yes. Sorry for my typo, and lack of thought about it... Sent from my iCan't see what I'm typing (iPod) - excuse terseness and typos.
- joey On Dec 16, 2009, at 11:05, Roger Hui <[email protected]> wrote: > I don't see that the dyad I. (interval index) belongs with the others. > I assume you mean |. (rotate). > > { > {. > }. > |. > A. > > You can not have the new behaviour (boxed left arguments) > for {. }. |. and still be compatible. The left ranks are wrong. > > > > ----- Original Message ----- > From: Joey K Tuttle <[email protected]> > Date: Wednesday, December 16, 2009 10:57 > Subject: Re: [Jprogramming] Proposed extension to A. (incompatible) > To: Programming forum <[email protected]> > >> If such an extension was to be implemented I think it would make >> sense >> to have similar arguments work with I. {. {. as well. Current >> behavior >> could be left as a convenience/back compatibility. >> >> Sent from my iPod - excuse terseness and typos. >> >> - joey >> >> >> >> On Dec 16, 2009, at 10:41, Roger Hui <[email protected]> wrote: >> >>> The extension can be more readily accommodated (i.e., >>> with backward compatibility) if the left argument were boxed. >>> Likewise, if we were designing from scratch (which we are not), >>> we would be tempted to box the left arguments of the dyads >> |. {. }. . >>> >>> >>> >>> ----- Original Message ----- >>> From: Dan Bron <[email protected]> >>> Date: Wednesday, December 16, 2009 9:59 >>> Subject: [Jprogramming] Proposed extension to A. (incompatible) >>> To: 'Programming forum' <[email protected]> >>> >>>> I would like to propose an extension to dyad >>>> A. Specifically, I would like dyad A. to >>>> interpret left-arguments in a way similar >>>> to |. and {. , where each atom >>>> of x corresponds to an axis of >>>> y . For example, with the new >>>> definition, the phrase (0 >>>> _1 A. i. 4 5) would reverse the columns of y, yielding the >>>> same results as (_1 A.&.|: i. 4 5) does with the >>>> current definition. >>>> Similar statements apply to higher dimensions; I can post a >>>> model (using |:) if that's helpful. >>>> >>>> Of course, right now, the ranks of dyad A. are >>>> 0 _ . The new definition of >>>> A. would require them to be 1 >>>> _ , so >>>> extension is not backwards compatible. But because of the >>>> way A. is typically used, I doubt it would break >>>> much code in practice. >>>> Furthermore, the fix is trivial; substitute A."_ 0 >>>> _ for all uses of A. >>>> >>>> I believe the extension would be useful; more and more I find >>>> myself wanting direct access non-leading axes of an array, >> and I now >>>> make heavy use of (boxes <;.n y), (list {. y), >>>> (list |. y) etc. This extension to >>>> A. would make a nice companion to another >>>> proposal I made: >>>> >> http://www.jsoftware.com/jwiki/System/Interpreter/Requests#redefineu.3B.0y > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
