Perhaps first the question could be answered why "reversing y along each axis" was introduced in defining ;.0
R.E. Boss > -----Oorspronkelijk bericht----- > Van: [EMAIL PROTECTED] [mailto:programming- > [EMAIL PROTECTED] Namens Dan Bron > Verzonden: vrijdag 20 juni 2008 20:23 > Aan: Programming forum > Onderwerp: Re: [Jprogramming] Apply to all axis > > June Kim wrote: > > I think "apply to all axis" is sometimes useful in some cases such as: > > reversing on all axis: > > I responded: > >The most fun way to do this is: > > > > ];.0 y > > Currently, u;.0 y means "apply u to y after reversing y along > each axis; it is equivalent to (0 _1 */$y) u;.0 y ". This and related > threads suggest a better definition. What do Jers think about the > following proposal? > > Let u;.0 y be changed to mean "apply u along each axis of y". That > is, let it solve the problem which is the topic of this and related > threads (the question is raised often enough that it is almost a FAQ). > > Formally, let > > u;.0 y <==> 0&|:@:u^:(#@:$) y > > I doubt the monad u;.0 finds much use in the wild; for the few > exceptions, converting from the old definition to the new will be > painless. Anyone who currently uses the current definition of u;.0 y > can simply replace the expression with u |.;.0 y or (0 _1 */$y) u;.0 > y after the change. Verb definitions with the monad u;.0 embedded may > simply subsitute @:(|.;.0) for ;.0 . > > Objections? Seconds? Comments? > > -Dan > > PS: If adopted, the proposal would save me having to complete my Essay. > Which I may never do anyway. In which case the adoption would ease my > guilt :) > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
