for want of a better verb name.
Here's a long winded way of conditionally converting 0$0 to 0 0$0.
empty=:(<'') = [: < [
reempty2=:13 : '>(empty x){x;0 0$0' f.
reempty3=:13 : '>(empty x){x;0 0 0$0' f.
On 14 January 2013 09:38, Steven Taylor <tayl...@gmail.com> wrote:
> thanks for the 0 0$0 comment idea.
>
> the bit that caught me was where an empty take comes back as 0 $ 0 from
> take. The sequence was a little like this.
>
> (i.2 2),~ 0$0{i.6 2
> 0 0
> 0 1
> 2 3
>
> Just trying to keep it as tacit as possible. i.e. 0$0 could be a list of
> zero or more indices.
>
>
> On 13 January 2013 21:23, Raul Miller <rauldmil...@gmail.com> wrote:
>
>> Note that (0 0$0), i. 2 2 would also work. The trailing dimension
>> gets expanded, just like in your original case, so the net result is
>> equivalent to (0 2$0,i. 2 2 which is to say nothing happens.
>>
>> But, depending on your situation, 0 0 $ 0 might be more generally
>> useful than 0 2 $ 0.
>>
>> FYI,
>>
>> --
>> Raul
>>
>> p.s. sorry about the hijacking
>>
>> On Sun, Jan 13, 2013 at 4:05 PM, Steven Taylor <tayl...@gmail.com> wrote:
>> > I think the email thread got hijacked... but a follow up to the original
>> > join question...
>> >
>> > Roger pointed out that I wasn't being logical (i.e. appending rank 1 to
>> > rank 2 doesn't make sense).
>> >
>> > ... and if I do this, I now get back what I expected to see.
>> >
>> > (0 2$0), i.2 2
>> > 0 1
>> > 2 3
>> >
>> > So... I borrowed the idea of q's "reshape" and implemented it in J as a
>> > helper verb. So far, it seems to be doing the trick.
>> >
>> > thanks for the comments and help.
>> >
>> >
>> > On 13 January 2013 02:19, Raul Miller <rauldmil...@gmail.com> wrote:
>> >
>> >> On Sat, Jan 12, 2013 at 8:50 PM, Linda Alvord <lindaalv...@verizon.net
>> >
>> >> wrote:
>> >> > As long as the ranks agree, u&v y -> u v y
>> >> >
>> >> > Would this be useful as a definition of compose?
>> >>
>> >> That is the definition for the monadic case but is incomplete since it
>> >> does not mention the dyadic case.
>> >>
>> >> But note also that the dictionary's vocabulary is a reference work and
>> >> it has already stated that the ranks must agree. Keep in mind that
>> >> the dictionary also includes material such as
>> >> http://www.jsoftware.com/help/dictionary/samp13.htm
>> >>
>> >> FYI,
>> >>
>> >> --
>> >> Raul
>> >> ----------------------------------------------------------------------
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>> >>
>> > ----------------------------------------------------------------------
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>> ----------------------------------------------------------------------
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>>
>
>
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