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
