FWIW I have wanted to do this many times and it seems natural.
I had guessed that the reason it wasn't implemented was that it requires
the under operation to maintain state in some sense (the shape of the
original input before flattening) out of curiosity, are there any other
verbs that do th
I feel similar feature is covered by @ (At) from Dyalog APL,
as I can think of the definition for monadic "structural
under" using APL could roughly be
r←(f sunder g)y;i
i←,g⍳⍴y
r←(f@i)y
(⌽sunder,) 3 3⍴⍳9
9 8 7
6 5 4
3 2 1
ldbeth
> In
> Henry Rich wrote:
Henry> This seem
This seems like a useful feature and not difficult to implement. We can
discuss here what should be supported.
Morten's reservations (in the cited article) are reasonable. I note that J
has semiduals, and that it would make sense to support structural under for
dyads using semiduals.
Henry Rich
> In
> "'Viktor Grigorov' via Programming" wrote:
> Why does
> (|. &. ,) i.3 3
> result in a domain error (likewise with &.:), while
> ($ $ (|. @ ,) ) i.3 3
> doesn't?
The domain error is raised by ,^:_1 and as in J and APL
the inverse of ravel is not defined in present time.
T
I guess it's true that the obverse of ravel hasn't changed:
,inv i.9
|domain error
| ,inv i.9
JVERSION
Installer: j602a_win64.exe
Engine: j602/2008-03-03/16:45
Library: 6.02.071
--
Raul
On Fri, Oct 13, 2023 at 2:38 PM 'Viktor Grigorov' via Programming
wrote:
>
> Hey,
>
> While work
