Hi Mike,
I see. What is important for GNU APL is compatibility with IBM
APL2,
whatever the reason might have been.
I could also imagine that enclosing a simple scalar would give a
nested simple scalar,
that would also satisfy the conditi
Hi Jürgen,
When James A. Brown wrote APL2, he based his arrays on Trenchard
More's "Array Theory", an attempt to give nested rectangular arrays an
axiomatic foundation equivalent to that of set theory. The major
implementation of this idea is in the language NIAL, of which Q'NIAL
is a popular inc
Hi Elias,
yes, thanks. SVN 700.
/// Jürgen
On 03/03/2016 02:41 PM, Elias Mårtenson
wrote:
The original question is as of yet unresolved
though. Wouldn't it make sense to extend GNU APL's iota function
Hi Mike,
I probably did not get it back in September. To me it is not
quite obvious why enclosing a nested scalar is different from
enclosing a simple scalar. But since ISO and APL2 agree in
this regard, I should follow suit.
/// Jürgen
Hi Jürgen,
I commented on this enclose issue back on the 14th of September. I
actually liked the way GNU APL did it.
https://lists.gnu.org/archive/html/bug-apl/2015-09/msg00061.html
Regards,
Mike
Hi,
I'm playing with this definition and noticed that if the argument was
scalar (if the term is correct) and more than 2 then it returns
strange result
i 1
┌─┐
│1│
└─┘
i 2
┌2──┐
│1 2│
└───┘
i 3
┌2──┐
│┌2──┐ ┌2──┐│
││1 2│ │1 3││
│└───┘ └───┘│
└∊──┘
i 4
┌2──
Hi,
I have changed GNU APL so that B ≡ ⊂B if and only if B is a simple
scalar.
Before the change B ≡ ⊂B
also for non-simple scalar B.
Unfortunately Elias' correct observation that (⊂⊂B) ≡ ⊂B in GNU APL was
almost
an axiom in GNU APL
The original question is as of yet unresolved though. Wouldn't it make
sense to extend GNU APL's iota function to do the same as Dyalog? It
wouldn't cause any compatibility issues since it raises an error right now.
Regards,
Elias
On 3 March 2016 at 20:26, Juergen Sauermann
wrote:
> Hi,
>
> I s
Hi,
I see. I guess I overlooked the 'simple' attribute in both
definitions.
I will fix this in GNU APL.
/// Jürgen
On 03/03/2016 12:53 PM, Kacper Gutowski
wrote:
On Thu, Mar 3, 2016 at 12:40
On Thu, Mar 3, 2016 at 12:40 PM, Juergen Sauermann
wrote:
> the IBM APL2 language reference says (page 111):
>
> If R is a simple scalar, ⊂ R is R. If R is not a simple scalar, the depth of
> R is 1+ ≡R.
>
> And the ISO standard says the same (page 169):
>
> Z ← ⊂B
> Note: If B is a simple-scalar
On 3 March 2016 at 11:40, Juergen Sauermann
wrote:
> Therefore I believe Elias' statement
>
> My understanding was that (⊂⊂x)≡⊂x for all x?
>
> is correct as far as ISO, IBM APL2, and GNU APL are concerned.
It is clearly not true in APL2!
x←1 2 3
(⊂⊂x)≡⊂x
0
(Same result in NARS2000
Hi,
the IBM APL2 language reference says (page 111):
If R is a simple scalar, ⊂R is R. If R is not a simple scalar,
the depth of R is 1+ ≡R.
And the ISO standard says the same (page 169):
Z ← ⊂B
Note: If B is a simple-s
On 3 March 2016 at 08:12, Elias Mårtenson wrote:
> What is the purpose of the double-enclose ⊂⊂⍬ ?
>
> My understanding was that (⊂⊂x)≡⊂x for all x?
No! ⊂ is a no-op on simple scalars like 42, but not on enclosures like
⊂⍬. You can enclose most arrays (i.e. anything except simple scalars)
as many
What is the purpose of the double-enclose ⊂⊂⍬ ?
My understanding was that (⊂⊂x)≡⊂x for all x?
Regards,
Elias
On 3 March 2016 at 16:05, Jay Foad wrote:
> Right. Here's a variation on Elias's solution that gets IOTA ⍬ right,
> but doesn't handle the singleton cases correctly!
>
> IOTA ← {⊃∘.,/(⍳
Right. Here's a variation on Elias's solution that gets IOTA ⍬ right,
but doesn't handle the singleton cases correctly!
IOTA ← {⊃∘.,/(⍳¨⍵),⊂⊂⍬}
On 3 March 2016 at 01:08, Nick Lobachevsky wrote:
> There is at least one other degenerate case, namely the "legacy"
> singleton, or one element vector.
There is at least one other degenerate case, namely the "legacy"
singleton, or one element vector. With a scalar argument, monadic
iota returns a result depth one. With a vector argument, iota returns
a result depth two. Except when there is only one element.
≡⍳⍳0 ⍝ can't find zilde
2
Not easily. That said, I'm not sure I agree that the should give a DOMAIN
ERROR:
* ∘.+/ ⍬*
DOMAIN ERROR
∘.+/⍬
^ ^
Regards,
Elias
On 2 March 2016 at 17:38, Jay Foad wrote:
> Cool! For bonus marks can you make it work in the degenerate case:
>
> ⍳⍬ ←→ ⊂⍬
>
> ?
>
> Jay.
>
> O
Cool! For bonus marks can you make it work in the degenerate case:
⍳⍬ ←→ ⊂⍬
?
Jay.
On 2 March 2016 at 02:23, Elias Mårtenson wrote:
> Looking at it further, I realise you need do disclose the result in order to
> make them equivalent:
>
> IOTA ← {⊃∘.,/⍳¨⍵}
>
> Regards,
> Elias
>
> On 2
thank you very much, I now understand how it work !
looks so easy for you ;-) and so hard for me :-(
Xtian.
On 2016-03-01 21:43, Elias Mårtenson wrote:
On 2 March 2016 at 10:28, Christian Robert mailto:christian.rob...@polymtl.ca>> wrote:
IOTA ← {∘.,/⍳¨⍵}
yes, it does the trick (you
On 2 March 2016 at 10:28, Christian Robert
wrote:
> IOTA ← {∘.,/⍳¨⍵}
>
> yes, it does the trick (you are really good btw)
>
I don't consider myself good. :-)
Anyway, it's quite simple. Let me break it down:
First of all, ¨⍳⍵ will simply create the individual iotas:
* ⍳¨2 3 4*
┌→
I see, but what is the "/" doing ?
Xtian
{⍳¨⍵} 1
┌───┐
│┌→┐│
││1││
│└─┘│
└∊──┘
{⍳¨⍵} 1 2
┌2┐
│┌→┐ ┌2──┐│
││1│ │1 2││
│└─┘ └───┘│
└∊┘
{⍳¨⍵} 1 2 3
┌3┐
│┌→┐ ┌2──┐ ┌3┐│
││1│ │1 2│ │1 2 3││
│└─┘ └───┘ └─┘│
└∊┘
{∘.,/⍳¨⍵} 1
IOTA ← {∘.,/⍳¨⍵}
yes, it does the trick (you are really good btw)
but I had to disclose the result
IOTA 2 3 5
┌─┐
│┌5──┐│
│2┌3┐ ┌3┐ ┌3┐ ┌3┐ ┌3┐││
│││1 1 1│ │1 1 2│ │1 1 3│ │1 1 4│ │1 1 5│││
│3└
Looking at it further, I realise you need do disclose the result in order
to make them equivalent:
* IOTA ← {⊃∘.,/⍳¨⍵}*
Regards,
Elias
On 2 March 2016 at 10:19, Elias Mårtenson wrote:
> I don't know about a loop, but wouldn't this do the same thing?
>
> *IOTA ← {∘.,/⍳¨⍵}*
>
> Regards,
I don't know about a loop, but wouldn't this do the same thing?
*IOTA ← {∘.,/⍳¨⍵}*
Regards,
Elias
On 2 March 2016 at 09:57, Christian Robert
wrote:
> I have this function,
>
> ∇IOTA[⎕]∇
> ∇
> [0] z←IOTA v
> [1] z←⍳↑v
> [2] v←1↓,v
> [3] Loop: →(0=⍴v)/0
> [4] z←z∘.,⍳↑v
> [
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