Re: Index-of function with structured left-argument

From:

Dr . Jürgen Sauermann

Subject:

Date:

Tue, 14 Apr 2020 11:39:15 +0200

User-agent:

Mozilla/5.0 (X11; Linux i686; rv:60.0) Gecko/20100101 Thunderbird/60.6.1

Hi Elias,

my best guess is that this is a missing RANK ERROR somewhere.
I will look into it.

Best Regards,
Jürgen

On 4/14/20 10:15 AM, Elias Mårtenson wrote:

The ISO spec doesn't address what the index-of function should do when the left argument is not a scalar or a one-dimensional array.

GNU APL extends this, but I don't really understand in what way. How am I to interpret the output from this?

(2 2 ⍴ 104 105 106 107) ⍳ (3 4 ⍴ 100+⍳100)
┏→━━━━━━━━━━━━━━━━━━━━━━┓
↓┏⊖┓ ┏⊖┓ ┏⊖┓ ┏⊖┓ ┃
┃┃0┃ ┃0┃ ┃0┃ ┃0┃ ┃
┃┗━┛ ┗━┛ ┗━┛ ┗━┛ ┃
┃┏→━━┓ ┏→━━┓ ┏→━━┓ ┏→━━┓┃
┃┃0 0┃ ┃0 1┃ ┃1 0┃ ┃1 1┃┃
┃┗━━━┛ ┗━━━┛ ┗━━━┛ ┗━━━┛┃
┃┏⊖┓ ┏⊖┓ ┏⊖┓ ┏⊖┓ ┃
┃┃0┃ ┃0┃ ┃0┃ ┃0┃ ┃
┃┗━┛ ┗━┛ ┗━┛ ┗━┛ ┃
┗∊━━━━━━━━━━━━━━━━━━━━━━┛

Regards,

Elias