f=: 13 :'0=?~ x#y'
f
0 = [: ?~ #
Maybe someday I'll just write expressions like yours easily..... The idea
seems so simple now.
However, I discovered this oddity:
3 3 3 +/ 4 4 4 4
7 7 7 7
7 7 7 7
7 7 7 7
3 3 3 ?/ 4 4 4 4
3 2 1
1 3 0
2 3 1
3 2 1
2 3 1
2 1 3
1 3 0
1 0 2
2 0 3
0 3 1
0 1 3
2 3 1
This seems odd:
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Bo Jacoby
Sent: Thursday, November 08, 2012 4:46 AM
sTo: [email protected]
Subject: Re: [Jprogramming] Arc consistency in J
Linda, stick to integer arithmetic:
5 (0=[:?~#) 8
0 0 0 0 0 0 1 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 0 0 1 0 0
- Bo
>________________________________
> Fra: Linda Alvord <[email protected]>
>Til: [email protected]
>Sendt: 10:10 torsdag den 8. november 2012
>Emne: Re: [Jprogramming] Arc consistency in J
>
> 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: [email protected]
>[mailto:[email protected]] 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.
<[email protected]>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 <[email protected]>
>> 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.
>> > <[email protected]
>> > >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
>----------------------------------------------------------------------
>For information about J forums see http://www.jsoftware.com/forums.htm
>
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>For information about J forums see http://www.jsoftware.com/forums.htm
>
>
>
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