I agree. First comes correctness, then performance, then elegance.
R.E. Boss > -----Oorspronkelijk bericht----- > Van: programming-boun...@jsoftware.com [mailto:programming- > boun...@jsoftware.com] Namens Brian Schott > Verzonden: donderdag 23 september 2010 14:41 > Aan: Programming forum > Onderwerp: Re: [Jprogramming] Classification problem > > I agree that this solution is elegant, but for a large data set I > assume that Raul's idea of prepending and then dropping 3 elements > would be more efficient. Don't you, too? > > (<@}./.~ *) _1 0 1,data > > On Thu, Sep 23, 2010 at 8:26 AM, R.E. Boss <r.e.b...@planet.nl> wrote: > > One of the more elegant solutions is > > > > ((/:&(* </. ])) *) data > > +---------------+---+-----+ > > |_3 _1 _10 _2 _4|0 0|1 1 6| > > +---------------+---+-----+ > > > > > > R.E. Boss > > > > > >> -----Oorspronkelijk bericht----- > >> Van: programming-boun...@jsoftware.com [mailto:programming- > >> boun...@jsoftware.com] Namens Marshall Lochbaum > >> Verzonden: woensdag 22 september 2010 23:57 > >> Aan: Programming forum > >> Onderwerp: Re: [Jprogramming] Classification problem > >> > >> It looks to me like the most terse way is > >> ((</. /: ~...@[)~ f) data > >> > >> Although this computes the nub twice, unlike some earlier solutions. > >> > >> Marshall > >> > >> ________________________________________ > >> From: programming-boun...@jsoftware.com [programming- > >> boun...@jsoftware.com] On Behalf Of Raul Miller [rauldmil...@gmail.com] > >> Sent: Wednesday, September 22, 2010 3:29 PM > >> To: Programming forum > >> Subject: Re: [Jprogramming] Classification problem > >> > >> Note, if * is the universe of interesting > >> functions (if it does not need to be generic) then > >> I would be tempted to use a variation on Dan's > >> second suggestion: > >> > >> (<@}./.~ *) _1 0 1,data > >> > >> Note that this also preserves the relative > >> ordering of the data items. > >> > >> -- > >> Raul > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > (B=) <-----my sig > Brian Schott > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
