ee=:(]%2) > ?~@$
ee
0.5 > ?~@$
ff=: 13 :'0.5 > ?~x$y'
ff
0.5 > [: ?~ $
5 ff 8
0 0 0 0 1 0 0 0
0 0 0 0 0 0 0 1
0 0 0 0 1 0 0 0
0 1 0 0 0 0 0 0
0 0 1 0 0 0 0 0
J is so smart, it eliminate the need for *
hh=: 13 :' ?~x$y'
hh
[: ?~ $
]A=:5 hh 8
4 7 1 6 0 5 3 2
4 2 3 1 5 7 0 6
7 3 5 4 1 2 6 0
5 3 2 4 1 7 6 0
2 5 4 0 3 6 7 1
0.5 > A
0 0 0 0 1 0 0 0
0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 1
0 0 0 1 0 0 0 0
Mind boggling!
Linda
-----Original Message-----
From: programming-boun...@forums.jsoftware.com
[mailto:programming-boun...@forums.jsoftware.com] On Behalf Of Devon
McCormick
Sent: Wednesday, November 07, 2012 12:56 PM
To: J-programming forum
Subject: Re: [Jprogramming] Arc consistency in J
At first glance, I thought the right tine of this fork
(2 %~ ]) > [: (? ]) $
could be replaced by an idiom I frequently use
(?@$)
but then realized that what we need is
(?~@$)
so "dd" can be written as
(]%2) > ?~@$
On Wed, Nov 7, 2012 at 1:31 AM, Michal D. <michal.dobrog...@gmail.com>wrote:
> Thanks Roger, that makes sense now. The history of J is one of it`s
> intriguing aspects for sure.
>
> Re: Linda: I would call it a v(erb) as opposed to a N(oun). But what
> do I know? ;-)
>
> Mike
>
> On Tue, Nov 6, 2012 at 8:53 AM, Roger Hui <rogerhui.can...@gmail.com>
> wrote:
>
> > 'noun verb verb' is a fork and is interpreted as 'noun"_ verb verb'
> (noun"_
> > is a constant verb whose result is noun).
> > http://keiapl.org/anec/#nvv
> >
> > 'verb verb noun' can not be made into a fork because 'verb noun'
> > already has an interpretation (*viz*., apply verb to noun).
> >
> >
> > On Tue, Nov 6, 2012 at 8:47 AM, Michal D.
> > <michal.dobrog...@gmail.com
> > >wrote:
> >
> > > > Change from a Noun to a verb, view its tacit version and apply
> > > > it to
> > > data:
> > > >
> > > > dd=: 13 :'(y%2) > (?]) x$y'
> > > >
> > > > dd
> > > > (2 %~ ]) > [: (? ]) $
> > > >
> > >
> > > That is quite cool. I'm surprised that you can automatically get
> > > the
> > tacit
> > > definition. Does this work for any explicitly defined verb?
> > >
> > > I'm also surprised at the way %~ came out. Do left hand arguments
> > > not require a & to bind the argument? It is strange to me that
> > > (1) works
> but
> > > (2) does not. It seems to me that (3) is the logical way to
> > > phrase
> > either
> > > of them (ie. a fork with a constant right / left side). To
> > > reiterate,
> > why
> > > does (1) work?
> > >
> > > (1) (2 %~ ]) > [: (? ]) $
> > > (2) (] % 2) > [: (? ]) $
> > > (3a) (2: %~ ]) > [: (? ]) $
> > > (3b) (] %~ 2:) > [: (? ]) $
> > > (4a) (%&2 ]) > [: (? ]) $ NB. incorrect (hook caught me out
> > again)!
> > > (4b) ([: %&2 ]) > [: (? ]) $ NB. correct
> > >
> > > Cheers,
> > >
> > > Mike
> > > ------------------------------------------------------------------
> > > ---- 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
>
--
Devon McCormick, CFA
^me^ at acm.
org is my
preferred e-mail
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