The idea of J with APL (or APL-like) characters is a perennial topic.
Many of us (myself included) feel that there is a beauty in those symbols.
But I don't think the Jsoftware group should devote *any* time to such
a project. (And I don't think there is any danger of that.)
There are other extensions of J that I would love to see. I recall that
the reason I switched from APL to J (*long* ago) was that I was doing some
calculations that used complex numbers. At that time J had them but APL
(al least any APL available to me) did not. Since then J has added other
data types (rationals, extended precision, etc).
I would like to see an extension into the realm of what is called
"geometric algebra" or the related Grassmann algebra. At some point
this is going to become a standard tool in the physical sciences.
(E.g., "Linear and Geometric Algebra" by Alan Macdonald).
Patrick
On Fri, 28 Feb 2014, Devon McCormick wrote:
Also, you're sacrificing some of the nice relations between some of the J
symbols and making it less well-integrated if you throw in random APL
characters. In the above cases, I'm thinking of the relationships between
the variants of "power":
^ exponentiation, ^. log, ^: power conjunction.
Working on extending J's capabilities in other areas makes much more sense
than sprinkling APL characters into the language. Better integration of
multi-processing, compilation of a subset of the language, better
integration on the browser, more rosetta equivalences for different
languages - all of these deserve more work.
We need to make J more mainstream, not weirder.
At the APL Moot two years ago, I pointed out that I could cut-and-paste
Chinese characters into my emacs session from the web more successfully
than I could do this with APL - some of the special APL characters show up
as blobs.
On Fri, Feb 28, 2014 at 1:10 AM, Roger Hui <[email protected]>wrote:
You may think you are close to a solution but there are serious problems.
e.g.
- does * denote times or exponentiation (is * the APL * or the ASCII *)?
- you can enter i. as ⍳ but for i: you must enter i:
- |. is not ⌽ but ⊖, depending on which APL you are talking about
- / is not / but ⌿, depending on which APL you are talking about
- etc.
I will say no more, except to repeat: don't go there.
On Thu, Feb 27, 2014 at 9:39 PM, bill lam <[email protected]> wrote:
> With some modicitions, J can accpet both ascii and about
> 30 APL symbols as primitive,
>
> ⌈ >. Ceiling
> ⌊ <. Floor
> ⍴ $ Shape
> ∼ -. Not
> ∣ | Absolute value
> ⍳ i. Index generator
> ⋆ ^ Exponential
> − - Negation
> ⌹ %. Matrix inverse
> ○ o. Pi times
> ⍟ ^. Logarithm
> ⌽ |. Reversal
> ⍋ /: Grade up
> ⍒ \: Grade down
> ⍎ ". Execute
> ⍕ ": Monadic format
> ⍉ |: Monadic transpose
> ∈ e. Membership
> ↑ {. Take
> ↓ }. Drop
> ⊥ #: Decode
> ⊤ #. Encode
> ≤ <: Less than or equal
> ≥ >: Greater than or equal
> ≠ ~: Not equal
> ∨ +. Or
> ∧ *. And
> ⍱ +: Nor
> ⍲ *: Nand
> ← =. Is
>
> × * Signum
> ÷ % Reciprocal
>
>
> [A←4 3⍴⍳12
> 0 1 2
> 3 4 5
> 6 7 8
> 9 10 11
> ⌽
> |.
> ⌽A
> 9 10 11
> 6 7 8
> 3 4 5
> 0 1 2
> |.⌽|.A
> 9 10 11
> 6 7 8
> 3 4 5
> 0 1 2
> f=: '⍳'&⍳
> 5!:5 <'f'
> (226 141 179{a.)&i.
>
> Furthermore, I guess a new global parameter 9!:50/51 could
> be used to control 5!:x to print ascii or APL symbol
>
> Other APL symbols are rejected becuase J uses different concepts.
> Rotation (first axis) ⊖
> Reduce (first axis) ⌿
> Scan (first axis) ⍀
> Outer product ∘.
>
> --
> regards,
> ====================================================
> GPG key 1024D/4434BAB3 2008-08-24
> gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
> gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
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For information about J forums see http://www.jsoftware.com/forums.htm
--
Devon McCormick, CFA
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For information about J forums see http://www.jsoftware.com/forums.htm
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For information about J forums see http://www.jsoftware.com/forums.htm
