See also: http://www.jsoftware.com/jwiki/Essays/Index_in_Nub
----- Original Message ----- From: Oleg Kobchenko <[EMAIL PROTECTED]> Date: Thursday, September 18, 2008 23:42 Subject: Re: [Jprogramming] Verb Sequence or Ranking problem? To: Programming forum <[email protected]> > There is one important use of Reflexive (i.~) unnamed > on that page (although used in other examples). > Applied with Key (/.) it is also unmentioned on > http://www.jsoftware.com/jwiki/Essays/Key > > i.~ Self-Index is the simplest equivalent for > the x argument "key" of dyadic (/.); > > Self-Classify is invariant under self-index > > A=. ?.10000 5$3 NB. > complex key > #~.A > 243 > I=. > i.~A NB. simplest equivalent > I -:&= > A NB. same self-classify > 1 > > B=: > ?.10000$0 NB. grouped values > ts'A (+//.,(+/%#)/.,<.//.,>.//.,:#/.) B' > 0.00653044 266624 > ts'I (+//.,(+/%#)/.,<.//.,>.//.,:#/.) B' > 0.000493079 53504 > 0.00653044 266624%0.000493079 53504 > 13.2442 4.98325 > NB. 13x time and 5x space > 10 ts'(i.~A) (+//.,(+/%#)/.,<.//.,>.//.,:#/.) B' > 0.00174575 201216 > 0.00646434 266624 % 0.00174575 201216 > 3.7029 1.32506 > > See more at Aggregation model in JDB > http://www.jsoftware.com/jwiki/JDB/Aggregation/Formal > > > > ----- Original Message ---- > > From: Roger Hui <[EMAIL PROTECTED]> > > To: Programming forum <[email protected]> > > Sent: Friday, September 19, 2008 1:30:31 AM > > Subject: Re: [Jprogramming] Verb Sequence or Ranking problem? > > > > See http://www.jsoftware.com/jwiki/Essays/Reflexive > > for useful examples of x f x . > > > > See http://www.jsoftware.com/help/dictionary/special.htm > > under /. (about mid-way down the page) for other uses > > of f/. > > > > > > > > ----- Original Message ----- > > From: Alex Rufon > > Date: Thursday, September 18, 2008 22:08 > > Subject: RE: [Jprogramming] Verb Sequence or Ranking problem? > > To: Programming forum > > > > > Oh. > > > > > > I know about the reflexive primitive. But I always thought > that you > > > always need both left and right parameters to switch. This > > > confused me > > > because what I understood was that the code was to be run as: > > > a #/. > > > |syntax error > > > | a#/. > > > > > > So basically, this is a shortcut/trick where the noun is > used as both > > > left and right parameters. Hmmmm. > > > > > > Thanks Rick. I appreciate it. > > > > > > r/Alex > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED] On Behalf Of > > > Sherlock, Ric > > > Sent: Friday, September 19, 2008 12:45 PM > > > To: Programming forum > > > Subject: RE: [Jprogramming] Verb Sequence or Ranking problem? > > > > > > ---Alex Rufon wrote: > > > > Can anybody elaborate on #/.~a > > > > > > > > I don't understand the presence of ~ in that sequence. Is > this > > > another> example of a fork/hook? > > > > > > This is not a tacit expression so it isn't a fork or hook. > > > See the dictionary page for Reflexive: > > > http://www.jsoftware.com/help/dictionary/d220v.htm > > > > > > #/.~ a > > > 2 2 1 3 > > > a #/. a > > > 2 2 1 3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
