Re: [Bug-apl] Supporting negative ranks for ⍤ operator

[Elias Mårtenson]

In GNU APL, the following two expressions yield the same result:

      (+/⍤1) 3 4⍴⍳100

┏→━━━━━━━┓

┃10 26 42┃

┗━━━━━━━━┛

And:

      (+/⍤¯1) 3 4⍴⍳100

┏→━━━━━━━┓

┃10 26 42┃

┗━━━━━━━━┛

I would expect the latter to yield the following (which is what I believe Dyalog does):

┏→━━━━━━━━━━┓

┃15 18 21 24┃

┗━━━━━━━━━━━┛

Regards,

Elias

On 6 May 2016 at 21:22, Jay Foad <address@hidden> wrote:

On 6 May 2016 at 13:52, Juergen Sauermann <address@hidden> wrote:
> Except maybe for the Dyalog ¯1 case (primarily because I don't know what
> "major cells" are).

Dyalog treats ¯1 the same as the ISO standard (and therefore also GNU
APL). "Major cell" is explained on page 14 of:
http://docs.dyalog.com/14.1/Dyalog%20APL%20Programmer's%20Guide.pdf

Jay.