Re: Unexpected result with inner product

[Christian Robert]

On NARS2000.64 it gives:

    ⎕fmt (A≠0) +.Q B
┌2───────┐
3┌0─┐┌0─┐│
││ 0││ 0││
│└~─┘└~─┘│
│        │
│┌0─┐┌0─┐│
││ 0││ 0││
│└~─┘└~─┘│
│        │
│┌0─┐┌0─┐│
││ 0││ 0││
│└~─┘└~─┘2
└∊───────┘

so, the same thing as gnu-apl

Xtian.

On 2022-01-25 23:25, Elias Mårtenson wrote:
> Consider the following code:
> *
> *
> *    A←3 4⍴1 3 2 0 2 1 0 1 4 0 0 2
>      B←4 2⍴4 1 0 3 0 2 2 0
>      Q←{⍺/⍵}
>      (A≠0) +.Q B*
>
> My reading (and implementation) of the ISO spec suggests the output should be 
> the following:
>
> ┏━━━┓
> ┃4 6┃
> ┃6 4┃
> ┃6 1┃
> ┗━━━┛
>
> However, in GNU APL I get this:
>
> ┏→━━━━━━┓
> ↓┏⊖┓ ┏⊖┓┃
> ┃┃0┃ ┃0┃┃
> ┃┗━┛ ┗━┛┃
> ┃┏⊖┓ ┏⊖┓┃
> ┃┃0┃ ┃0┃┃
> ┃┗━┛ ┗━┛┃
> ┃┏⊖┓ ┏⊖┓┃
> ┃┃0┃ ┃0┃┃
> ┃┗━┛ ┗━┛┃
> ┗∊━━━━━━┛
>
> Which one is correct?
>
> Regards,
> Elias