[Jprogramming] Outer product (APL)

[Mike Day]

Do these examples help?

    a (<@,/  )b        NB. your original, but boxed
+-------------+
|0 1 2 0 1 2 3|
+-------------+

    a (<@,"0/  )b     NB. what you're seeking?
+---+---+---+---+
|0 0|0 1|0 2|0 3|
+---+---+---+---+
|1 0|1 1|1 2|1 3|
+---+---+---+---+
|2 0|2 1|2 2|2 3|
+---+---+---+---+

    3 (<@,"0/ &i. )4   NB. can embed the iota
+---+---+---+---+
|0 0|0 1|0 2|0 3|
+---+---+---+---+
|1 0|1 1|1 2|1 3|
+---+---+---+---+
|2 0|2 1|2 2|2 3|
+---+---+---+---+

Apologies if these don't display well - they look
ok in draft.

Mike

On 02/04/2016 08:11, Gian Medri wrote:
> Hi !
>
> In J the outer product  has the form:    a foo/ b.
> It doesn't  work for comma.
> Example
> a=: i. 3
> b=: i.4
> [  a ,/ b
> 0 1 2 0 1 2 3
> APL
>   a °. , b
>   0 0  0 1  0 2  0 3
>   1 0  1 1  1 2  1 3
>   2 0  2 1  2 2  2 3
>
> 3 x 4 boxed result
>
> Can I have the same result  in J as easily as in APL?
> Best regards
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus