Very nice Ben, your TT is “hard coded to rank 3”, so fails on other than rank 3.
I “tinkered” by replacing 0 1 2 with i. $ $, and converted to tacit using 13 :
which worked, but less readable...
]a=:i.2 3 4
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
16 17 18 19
20 21 22 23
]b=:i.2 2
0 1
2 3
T=:{{((i. $ $ y)-.x) |: y}} NB. Generalised 0 1 2 to (i. Rank y)
0 1{1 T a
0 1 2 3
12 13 14 15
4 5 6 7
16 17 18 19
0 1{1 T b NB. Your original function failed here
on rank 2
0 2
1 3
TT=:13 : '((i. $ $ y)-.x) |: y’
TT
] |:~ [ -.~ [: i. [: # [: $ ]
0 1{1 TT a
0 1 2 3
12 13 14 15
4 5 6 7
16 17 18 19
0 1{1 TT b
0 2
1 3
Impressive solution Ben (strong scent of APL in there !)… well done.
Piet does this do what you want ?
Best, Rob
> On 7 Sep 2023, at 10:22 am, Ben Gorte <[email protected]> wrote:
>
> Still not quite sure what you mean, but how about:
>
> ]n =: i.2 3 4
>
> 0 1 2 3
>
> 4 5 6 7
>
> 8 9 10 11
>
>
> 12 13 14 15
>
> 16 17 18 19
>
> 20 21 22 23
>
>
> 1{0 T n NB. -: 1{n
>
> 12 13 14 15
>
> 16 17 18 19
>
> 20 21 22 23
>
>
> 1{1 T n
>
> 4 5 6 7
>
> 16 17 18 19
>
>
> 1{2 T n
>
> 1 5 9
>
> 13 17 21
>
> If that's the one, then T would be:
>
> T =: {{ (0 1 2-.x) |: y }}
>
>
> (sorry, not tacit)
>
>
> Ben
>
> On Thu, 7 Sept 2023 at 09:58, Piet de Jong <[email protected]> wrote:
>
>> This works!
>> Except the ordering of the axes is slightly unusual to my way of thinking.
>> For example suppose m=.i.3 3 3 is the “cube" be sliced and v is your verb.
>> Then the items of (0 v m) has successive items “going back” into the cube.
>> The items (1 v m) are the horizontal slices.
>> The items of (2 v m) are the vertical slices.
>>
>> The order of the last two appear "unnatural". (To my way of thinking at
>> least)
>> This seems to beg the question what is the natural order when slicing.
>>
>>> On 7 Sep 2023, at 08:32, Henry Rich <[email protected]> wrote:
>>>
>>> Since you want all the slices, what you are looking for is a transpose.
>>>
>>> Maybe
>>>
>>> ~.@(, i.@#) |: ]
>>>
>>> Untested.
>>>
>>> Henry Rich
>>>
>>> On Wed, Sep 6, 2023, 6:10 PM Piet de Jong <[email protected]> wrote:
>>>
>>>> Here is my “wish"
>>>>
>>>> A dyadic (tacit) verb such that x v y gives all the slices of y along
>>>> dimension x, where x is integer. That is to say
>>>>
>>>> i{ x v y
>>>>
>>>> is slice i of the array y along dimension x.
>>>>
>>>> Thanks for all your help!
>>>>
>>>>> On 7 Sep 2023, at 08:04, 'robert therriault' via Programming <
>>>> [email protected]> wrote:
>>>>>
>>>>> Or something like this?
>>>>>
>>>>> [n =. i. 2 2 2
>>>>> 0 1
>>>>> 2 3
>>>>>
>>>>> 4 5
>>>>> 6 7
>>>>> ,./ n
>>>>> 0 1 4 5
>>>>> 2 3 6 7
>>>>> ($ $ (,@,./)) n
>>>>> 0 1
>>>>> 4 5
>>>>>
>>>>> 2 3
>>>>> 6 7
>>>>>
>>>>> Cheers, bob
>>>>>
>>>>>
>>>>>> On Sep 6, 2023, at 14:49, 'robert therriault' via Programming <
>>>> [email protected]> wrote:
>>>>>>
>>>>>> Hi Piet,
>>>>>>
>>>>>> Maybe show us what you would want to do with higher dimensions? Or a
>>>> less symmetric 2 dimensional shape?
>>>>>>
>>>>>> For shape 2 2, I would use the even simpler
>>>>>>
>>>>>> |: m
>>>>>> 0 2
>>>>>> 1 3
>>>>>>
>>>>>> Hope this helps.
>>>>>>
>>>>>> Cheers, bob
>>>>>>
>>>>>>> On Sep 6, 2023, at 14:26, Brian Schott <[email protected]>
>> wrote:
>>>>>>>
>>>>>>> ,./0 1 {"1 m
>>>>>>
>>>>>> ----------------------------------------------------------------------
>>>>>> 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
