Mike asked: "Bo: is it true that (3$3) is not a list of integers but (3#3) is?". No, I don't think so. My main point is that evaluating the expression 5(0.5>[:?~$)8 involves noninteger arithmetic while evaluating the equivalent simpler expression 5(0=[:?~$)8 does not.involve noninteger arithmetic. The matrix elements of 5([:?~$)8 are nonnegative integers, and a nonnegative integer less than a half equals zero. - Bo
>________________________________ > Fra: km <k...@math.uh.edu> >Til: "programm...@jsoftware.com" <programm...@jsoftware.com> >Sendt: 6:55 lørdag den 10. november 2012 >Emne: Re: [Jprogramming] Arc consistency in J > >About 3$3 and 3#3 I suggest you experiment. Type 3$3 then type 3#3 . Next >type $ 3$3 and $ 3#3 . What do you learn? The following will help you learn >about $ . > >http://www.jsoftware.com/docs/help701/dictionary/d210.htm > >Kip Murray > >Sent from my iPad > > >On Nov 9, 2012, at 11:21 PM, "Michal D." <michal.dobrog...@gmail.com> wrote: > >> Some nice things learned: ?~ instead of (?]). >> >> Bo: is it true that (3$3) is not a list of integers but (3#3) is? >> >> Fascinating discussion on ?/... so much intricatness. >> >> Mike >> >> On Thu, Nov 8, 2012 at 11:12 PM, Linda Alvord <lindaalv...@verizon.net>wrote: >> >>> The dawn finally broke. It's a deal! >>> >>> 3 10 4 ? 10 10 10 >>> 8 2 5 0 0 0 0 0 0 0 >>> 4 1 0 9 3 7 6 8 5 2 >>> 9 0 1 8 0 0 0 0 0 0 >>> >>> 3 10 4 ?/ 10 10 10 >>> 6 0 5 0 0 0 0 0 0 0 >>> 9 5 0 0 0 0 0 0 0 0 >>> 2 6 1 0 0 0 0 0 0 0 >>> >>> 8 4 9 5 6 1 3 0 2 7 >>> 9 3 5 8 0 6 4 7 1 2 >>> 1 6 8 0 4 2 5 3 9 7 >>> >>> 1 9 5 7 0 0 0 0 0 0 >>> 3 9 8 0 0 0 0 0 0 0 >>> 1 3 7 0 0 0 0 0 0 0 >>> >>> So: >>> >>> 8 8 8 8 8 ? 8 8 8 8 8 >>> 0 1 7 6 5 3 4 2 >>> 0 7 3 2 5 1 4 6 >>> 5 0 7 6 4 1 3 2 >>> 6 1 5 7 3 0 2 4 >>> 4 7 3 5 6 0 2 1 >>> >>> There is only one zero in each row. >>> >>> It is nice when the fog lifts. Thanks to everyone who helped me. >>> >>> f=:0 = # ? # >>> 5 f 8 >>> 0 0 0 0 0 1 0 0 >>> 0 0 0 0 0 0 1 0 >>> 0 0 1 0 0 0 0 0 >>> 0 0 0 0 0 0 0 1 >>> 0 0 0 0 0 1 0 0 >>> >>> 5!:4 <'f' >>> -- 0 >>> +- = >>> --+ -- # >>> L---+- ? >>> L- # >>> >>> >>> Quite a pretty picture. >>> >>> Linda >>> >>> >>> >>> -----Origineal Message----- >>> From: programming-boun...@forums.jsoftware.com >>> [mailto:programming-boune...@forums.jsoftware.com] On Behalf Of Peter B. >>> Kessler >>> Sent: Thursday, November 08, 2012 9:24 PM >>> To: programm...@jsoftware.comn >>> Subject: Re: [Jprogramming] Arc consistency in J >>> >>> The shape of the arguments to the verb that's being inserted is 3x4, so >>> when >>> that verb returns an atom, as dyadic + does, the shape of the result is >>> 3x4. >>> But dyadic ? (Deal[1]) doesn't return an atom: it returns a list of the >>> number of items of its left argument. So for each of the 3x4 applications >>> of dyadic ? returns a list of 3 elements, so the shape of the result is >>> 3x4x3. There's probably a more official way to say that, but that's my >>> model of J, so far. >>> >>> It might be slightly less confusing to use arguments that aren't also the >>> shapes of those arguments. E.g., >>> >>> The left argument is a list of length 2, and the right argument is a list >>> of >>> length 4, so there are 2x4 pairs between each of which is inserted a Deal. >>> Each Deal chooses 3 items from i. 6 without replacement. >>> >>> 3 3 ?/ 6 6 6 6 >>> 5 0 2 >>> 3 5 0 >>> 1 4 5 >>> 1 0 3 >>> >>> 0 3 2 >>> 0 5 2 >>> 1 2 4 >>> 3 0 1 >>> >>> so the shape of the result is 2x4x3. >>> >>> $ 3 3 ?/ 6 6 6 6 >>> 2 4 3 >>> >>> Does that seem less odd? >>> >>> ... peter >>> >>> [1] http://www.jsoftware.com/help/dictionary/d640.htm >>> >>> Linda Alvord wrote: >>>> 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: programming-boun...@forums.jsoftware.com >>>> [mailto:programming-boun...@forums.jsoftware.com] On Behalf Of Bo >>>> Jacoby >>>> Sent: Thursday, November 08, 2012 4:46 AM >>>> sTo: programm...@jsoftware.com >>>> 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 <lindaalv...@verizon.net> >>>>> Til: programm...@jsoftware.com >>>>> 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: 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 >>>>> --------------------------------------------------------------------- >>>>> - 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 >>>> >>>> ---------------------------------------------------------------------- >>>> 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 >> ---------------------------------------------------------------------- >> 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
