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Essie Rivers

1:25 AM

Can anyone think of a reason why APL\360 gives a rank error for ⍳3 3 when it could return a result with shape 3 3 2

5 hours later…

LdBeth

6:15 AM

@EssieRivers I don't think APL\360 has nested array

And ⍳x should have shape of x

I wonder what v∘.,v←⍳3 would give for that

The problem for iota is it was not defined for any argument other than an integer for that time.

Adám

@LdBeth "operators" (they were not really identified as such, initially) were only defined for dyadic primitive scalars functions.

@EssieRivers It could have, but wasn't defined like that. And if it had been, then we couldn't have had today's definition. And even so, it is pretty easy to get that result: ⍉y⊤y⍴⍳×/y←3 3

@Richard No. "Judging" is entirely automated, and only permissible solutions are accepted.

@RubenVerg I didn't remember that (paywall and all that…)

@RubenVerg A couple of new whats?

RubenVerg

6:56 AM

@Adám entries with a ??? description

Adám

Oh.

@RubenVerg ⌹[X] is "QR Factorization", A∘B is "Matrix product" (a subset of +.× for performance reasons — I know, very silly; why didn't they just optimise +.×‽)

Adám

7:16 AM

@RubenVerg Missing GNU from "

@RubenVerg It might be interesting to have the two standards appears as "dialects", so one can e.g. explore how a given dialect differs from the standard, or what was actually added from the old standard to the new.

2 hours later…

Adám

8:58 AM

@RubenVerg Since there needs to be enough horizontal space for even the most well-supported meanings, maybe better (=narrower) to simply have a narrow column per dialect?

RubenVerg

9:08 AM

@Adám I still haven't found a free source for the first standard

@Adám wdym?

Adám

@RubenVerg I think I can look up any questions, or have a colleague do so. I'll look into that.

@RubenVerg You currently have a "Meaning dialects" column. Replace that with one column per dialect, each one only wide enough to have a • or ✔ or similar.

RubenVerg

@Adám yeah about QR factorization, I a) have no idea what it is or how to summarize it and b) don't know if it should be in the Domino entry or in a separate one

Adám

Nothing to summarise, that's what it's called, just like addition is called addition:

QR decomposition

In linear algebra, a QR decomposition, also known as a QR factorization or QU factorization, is a decomposition of a matrix A into a product A = QR of an orthonormal matrix Q and an upper triangular matrix R. QR decomposition is often used to solve the linear least squares (LLS) problem and is the basis for a particular eigenvalue algorithm, the QR algorithm. == Cases and definitions == === Square matrix === Any real square matrix A may be decomposed as A = Q R , {\displaystyle A=QR,} where Q is an orthogonal matr...

RubenVerg

@Adám the benefit of the current system is that it can split on multiple lines on small screens

Adám

That's true.

RubenVerg

9:17 AM

@Adám thanks. on which dialect is it based on? and of course my first question is "what are the differences"?

Adám

APL.SV

RubenVerg

also, suggestions on names that separate iota-one-number, iota-nested and iota-ravel?

Adám

Btw, typo "Indices with shaoe"

@RubenVerg Maybe Range, Indices, Enumerate, but "Index Generator" with a paren saying Range/Indices/Enumeration might be clearer.

1 hour later…

Adám

10:40 AM

@RubenVerg You don't actually need the whole standard, only the ToC.

RubenVerg

11:17 AM

@Adám thanks, this might be enough! I'll come back with any questions

though today I don't have much time to work on it

RubenVerg

11:32 AM

@Adám is it complex? it lists + as "Conjugate" but as it's based on SV which is real so idk

Adám

@RubenVerg I've quite sure it isn't, but I'll enquire.

RubenVerg

oh also how do you input functions? the usual Del?

Adám

Yes.

4 hours later…

Adám

3:19 PM

@Marshall So, I went to add A+, but it already says "Dialects with this feature include Dyalog APL, NARS2000, A+" — was there something else you had in mind to add?