all=:([:<([: (([ (,^:A) 6:) ) g) f."0 _)"0 _
On Wed, Apr 17, 2013 at 3:58 AM, Linda Alvord <[email protected]>wrote:
> I'm trying to write this in simple J.
>
> T =: 2 2 $ +/`|:`|.`(-/ .*)
> g=:[ , [: < [ ('0';]) ]
> A=:0:`(<'`:')
> all=:([:<([:(,^:A)&6 g) f."0 _)"0 _
> T all i.2 2
> ----T---┐
> │2 4│0 2│
> │ │1 3│
> +---+---+
> │2 3│_2 │
> │0 1│ │
> L---+----
> NB. u&n y is defined as y u n
>
> Can you write 'all' without using & in the function?
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Jose Mario
> Quintana
> Sent: Tuesday, April 16, 2013 5:42 PM
> To: [email protected]
> Subject: Re: [Jprogramming] Table of Verbs
>
> I am referring to the verbs produced by ( u=. 2 2 $ +/ ; |: ; |. ; -/ . *
> ),
> ( w=. tf T ) and ( v=. T(4 :'<y`:0 x'"_ 0&) ). Although (v) and (w) are
> equivalent in the sense that they should produce the same results when
> given
> the same argument they are not the same in the following sense: ( tf T )
> resolves into a verb defined exactly as (u), namely ( 2 2 $ +/ ; |: ;
> |. ; -/ . * ), whereas ( T(4 :'<y`:0 x'"_ 0&) ) resolves into an
> |equivalent
> verb with a different definition, namely ( 4 : '<y`:0 x'"_ 0&(2
> 2$(<(<,'/'),<,<,'+'),(<'|:'),(<'|.'),<(<,'.'),<(<(<,'/'),<,<,'-'),<,'*') ).
>
> Moreover, since the verbs (u) and (w) are, in the end, defined exactly in
> the same manner, their atomic representations are also the same,
>
> ar=. 5!:1@<
>
> (ar'u') -: (ar'w')
> 1
> In contrast, the verb (v) has a different atomic representation,
>
> (ar'u') -: (ar'v')
> 0
> That was the intended significance of,
>
> (tf T) `'' -: u f.`'' NB. (tf T) is (2 2 $ +/ ; |: ; |. ; -/ . *)
> 1
> in my original post.
>
> I hope this helps.
>
> On Tue, Apr 16, 2013 at 9:48 AM, Raul Miller <[email protected]>
> wrote:
>
> > Now I'm thinking you want a nice display using the built-in display
> > mechanisms for the result (to be distinguished from the code which
> > generates that result). In other words (except you would not do it
> > this way), something like:
> >
> > (3 :'(($y)$(4 :''(x`:6;y`:6)`''''''''''/,y)`:6)`'''''T)`:6
> >
> > I could make that prettier, of course, but single line execution is
> > nice enough for discussion purposes.
> >
> > (Here, also, the shape has been factored out of the computation, and
> > is applied as a final step. But I am currently thinking that that's a
> > means to the end, rather than the end itself.)
> >
> >
> > On Tue, Apr 16, 2013 at 9:00 AM, Jose Mario Quintana
> > <[email protected]> wrote:
> > > "Would you consider Tfixed`:0 as being U?"
> > >
> > > No. Maybe the following can clarify what I tried to convey:
> > >
> > > u=. 2 2 $ +/ ; |: ; |. ; -/ . *
> > > v=. T(4 :'<y`:0 x'"_ 0&)
> > > w=. tf T
> > >
> > > u
> > > 2 2 $ +/ ; |: ; |. ; -/ .*
> > >
> > > v
> > > 4 : '<y`:0 x'"_ 0&(2
> > > 2$(<(<,'/'),<,<,'+'),(<'|:'),(<'|.'),<(<,'.'),<(<(<,'/'),<,<,'-'),<,
> > > '*')
> > >
> > > w
> > > 2 2 $ +/ ; |: ; |. ; -/ .*
> > >
> > >
> > >
> > >
> > > On Tue, Apr 16, 2013 at 12:14 AM, Raul Miller
> > > <[email protected]>
> > wrote:
> > >
> > >> On Mon, Apr 15, 2013 at 8:28 PM, Jose Mario Quintana
> > >> <[email protected]> wrote:
> > >> > So far no solution is transforming T into U and perhaps emulating
> > >> > U is
> > >> what
> > >> > was meant, as in
> > >> > Raul's solution T(4 :'<y`:0 x'"_ 0&).
> > >>
> > >> I don't understand what you mean here.
> > >>
> > >> How was my solution "not U"?
> > >>
> > >> What is the difference between being U and emulating U?
> > >>
> > >> I think the distinction you are drawing here has to do with
> > >> replicating some functionality in each cell of the table of verbs,
> > >> but if that's the case I don't know why it's important. Those
> > >> approaches take more code to implement and also result in a table
> > >> with different cells.
> > >>
> > >> Put differently, `:0 was the probably the right approach - the
> > >> problem was that the verbs were not conformable. Fixing the
> > >> "problem" means changing the verbs or changing the environment in
> which
> they operate.
> > >> If you're going to change the verbs, I'd change them from the
> > >> start, or I'd use something like:
> > >>
> > >> T =: 2 2 $ +/`|:`|.`(-/ .*)
> > >> Tfixed=: 3 :'{.''''`(<@(y`:0))'"0 T
> > >>
> > >> Tfixed`:0 i. 2 2
> > >> +---+---+
> > >> |2 4|0 2|
> > >> | |1 3|
> > >> +---+---+
> > >> |2 3|_2 |
> > >> |0 1| |
> > >> +---+---+
> > >>
> > >> So...
> > >>
> > >> Would you consider Tfixed`:0 as being U?
> > >>
> > >> Thanks,
> > >>
> > >> --
> > >> 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
> >
> ----------------------------------------------------------------------
> 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
