[Jprogramming] Classification problem

[Roger Hui]

http://www.vector.org.uk/?vol=24&no=3&art=hui
Bring Something Beautiful



----- Original Message -----
From: Devon McCormick <devonmcc at gmail.com>
Date: Thursday, September 23, 2010 7:59
Subject: Re: [Jprogramming] Classification problem
To: Programming forum <programming at jsoftware.com>

> I agree with you in general but sometimes elegance and 
> correctness are foes
> - but that's often only because the problem is "ugly" - see
> http://www.paulgraham.com/taste.html .
> 
> On Thu, Sep 23, 2010 at 9:55 AM, Robert Raschke 
> <rtrlists at googlemail.com>wrote:
> > I disagree, first comes elegance and correctness, and these 
> tend to go hand
> > in hand if you are concentrating on elegance. I quite strongly 
> believe a
> > human reader is way more important than any machine.
> >
> > Robby
> >
> > On Thu, Sep 23, 2010 at 2:24 PM, R.E. Boss 
> <r.e.boss at planet.nl> wrote:
> >
> > > I agree. First comes correctness, then performance, then elegance.
> > >
> > >
> > > R.E. Boss
> > >
> > >
> > > > -----Oorspronkelijk bericht-----
> > > > Van: programming-bounces at jsoftware.com [mailto:programming-
> > > > bounces at 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.boss at 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-bounces at jsoftware.com 
> [mailto:programming-
> > > > >> bounces at 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-bounces at jsoftware.com [programming-
> > > > >> bounces at jsoftware.com] On Behalf Of Raul Miller [
> > > rauldmiller at 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.