The APL Orchard

      n←?⍨100000
      cmpx '{m←⌈/l←1+⌊10⍟1⌈⍵⋄(10⊥⊖(m⍴10)⊤⍵)÷10*m-l}n' '{10⊥⌽10⊥⍣¯1⊢⍵}¨n' '{⌽⍎⌽⍕⍵}n'
  {m←⌈/l←1+⌊10⍟1⌈⍵⋄(10⊥⊖(m⍴10)⊤⍵)÷10*m-l}n → 5.4E¯3 |     0% ⎕
  {10⊥⌽10⊥⍣¯1⊢⍵}¨n                         → 1.9E¯1 | +3414% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  {⌽⍎⌽⍕⍵}n                                 → 3.0E¯2 |  +450% ⎕⎕⎕⎕⎕⎕

rak1507

      a←?⍨100000
      ]runtime -c '{⌽⍎⌽⍕⍵}a' '{m←⌈/l←1+⌊10⍟1⌈⍵⋄(10⊥⊖(m⍴10)⊤⍵)÷10*m-l}a'

  {⌽⍎⌽⍕⍵}a                                 → 1.0E¯1 |     0% ⎕
  {m←⌈/l←1+⌊10⍟1⌈⍵⋄(10⊥⊖(m⍴10)⊤⍵)÷10*m-l}a → 3.0E0  | +2869% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕

how strange

ngn

  {m←⌈/l←1+⌊10⍟1⌈⍵⋄(10⊥⊖(m⍴10)⊤⍵)÷10*m-l}n → 7.4E¯2 |      0%
  {10⊥⌽10⊥⍣¯1⊢⍵}¨n                         → 1.5E1  | +20141% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  {⌽⍎⌽⍕⍵}n                                 → 2.4E¯1 |   +224% ⎕

rak1507

?!?!?!

do you think it could be windows vs linux?

how does {(10⊥⊖(m⍴10)⊤⍵)÷10*m-⍵⍸⍨0,10*⍳m←1+⌊10⍟⌈/1⌈⍵} compare, it's a lot faster for me

Marshall

It's 30% faster.

rak1507

it's 99% faster for me

this is very strange

do you have any idea why there'd be such a big difference between performance on my pc and yours?

Marshall

1:34 AM

I think Dyalog uses libc for logarithms, but something is going very wrong if the Windows version is like a thousand times slower.

Dyalog APL

<moon-child> j uses sleef

ngn

who uses windows for serious performance anyway

Dyalog APL

<moon-child> it's cool: vectorized impls of math functions

Marshall

moon-child: That's based on my recommendation.

What does cmpx '0.1*n' '10⍟n' give you? The logarithm is 86% faster for me.

rak1507

was just about to ask if you had any test ideas

what's n here?

Marshall

1:36 AM

Oh, you called it a.

rak1507

oh are you ⎕IO←1?

Marshall

Yes, but I tested both ways.

rak1507

ok

      cmpx '0.1*b' '10⍟b'
  0.1*b → 1.8E¯1 |     0% ⎕⎕⎕
* 10⍟b  → 2.3E0  | +1151% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕

yikes!

ngn

* <- means results differ

rak1507

that's what marshall had

yes, but they do here

Marshall

1:37 AM

Is that also true for bases other than 10? log10 is used for base 10 specifically.

rak1507

      cmpx '0.1*b' '5⍟b' '10⍟b' '17⍟b'
  0.1*b → 1.9E¯1 |     0% ⎕⎕⎕
* 5⍟b   → 2.2E0  | +1106% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
* 10⍟b  → 2.2E0  | +1056% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
* 17⍟b  → 2.1E0  | +1032% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕

yep

Marshall

Time for a support email to Dyalog probably. I don't know whether libc is linked statically or dynamically; maybe it's dynamic and there's a problem with your setup. PQAs are normally done on Windows so it would be hard for logarithm to be this slow without anyone noticing.

rak1507

I've noticed log being very slow before, but didn't think much of it

I should probably update to the latest version first before emailing just in case

Marshall

Power looks kind of slow too: mine finishes in 1.0E¯2 seconds.

rak1507

your pc is probably a lot better than my laptop

Marshall

1:48 AM

It's an i5 from 2017 so maybe not.

(But that didn't go well when I tried it on dzaima.)

ngn

which reminds me, i need to buy a new laptop. any recommendations?

rak1507

there must be something weird going on then with maths on the windows version or on my installation

does anyone else here use windows....?

crap! I restarted dyalog to see if that would change anything but lost my 'good' solution

I think it was this {10⊥(-+⌿∧⍀0=d)⊖⊖d←10⊥⍣¯1⊢⍵}

Marshall

Slightly slower than mine, but the hybrid {(10*+⌿∧⍀0=d)÷⍨10⊥⊖d←10⊥⍣¯1⊢⍵} is faster. Fastest is still your interval index version.

ngn

@rak1507 and that, children, is what files are for. rak had a function. rak restarted the interpreter. rak doesn't have a function anymore. don't be like rak.

rak1507

lmao

actually, I was wrong, I had a copy in one of the 5 notepad windows I had open

ngn

2:00 AM

@rak1507 shh!

:D

rak1507

still a bit of a pain, the point still stands

@Marshall interesting

     ]runtime -c '{10⊥(-+⌿∧⍀0=d)⊖⊖d←10⊥⍣¯1⊢⍵}b' '{(10⊥⊖(m⍴10)⊤⍵)÷10*m-⍵⍸⍨0,10*⍳m←1+⌊10⍟⌈/1⌈⍵}b'

  {10⊥(-+⌿∧⍀0=d)⊖⊖d←10⊥⍣¯1⊢⍵}b                  → 1.1E¯3 |    0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  {(10⊥⊖(m⍴10)⊤⍵)÷10*m-⍵⍸⍨0,10*⍳m←1+⌊10⍟⌈/1⌈⍵}b → 3.0E¯3 | +170% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕

interval index is slower for me

@Razetime you use a mac right? can you try cmpx '0.1*b' '5⍟b' '10⍟b' '17⍟b' out of interest? (b←?⍨100000)

Razetime

ok

rak1507

for some reason on my pc it seems to be much much slower than for marshall and ngn, wonder how mac compares

Razetime

      cmpx '0.1*b' '5⍟b' '10⍟b' '17⍟b'
  0.1*b → 9.0E¯3 |   0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
* 5⍟b   → 1.4E¯3 | -84% ⎕⎕⎕⎕⎕⎕
* 10⍟b  → 1.2E¯3 | -87% ⎕⎕⎕⎕⎕
* 17⍟b  → 1.4E¯3 | -84% ⎕⎕⎕⎕⎕⎕

rak1507

something is seriously up with my installation

Marshall

2:05 AM

@rak1507 How does the hybrid perform? And b is still ?⍨100000, right?

rak1507

yep

I'll try the hybrid rn

Marshall

Wouldn't be super surprising for that dyadic ⊖ to work very differently across CPUs. It's probably doing a transpose then rotating rows then rotating back.

rak1507

      ]runtime -c 'mine b' 'ii b' 'hybrid b'

  mine b   → 1.7E¯3 |   0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  ii b     → 2.3E¯3 | +35% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  hybrid b → 2.8E¯3 | +64% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕

annoying how inconsistent timing can be

confusing stuff

Marshall

Ah, I guess the * and ÷ are also too slow.

rak1507

really odd

can't think of any reason why basic arithmetic operations would be far slower on windows

Marshall

2:10 AM

But your solution takes 7.3E¯3 seconds for me so at least the non-math stuff is running well.

ngn

it would be interesting to compare against j, it's good at maths ops

rak1507

maybe instead of + from now on I should use ≢,⍥(⍴∘1)

and ≢∘,1⍴⍨, instead of ×

Marshall

Along those lines, what about {(×⌿10*∧⍀0=d)÷⍨10⊥⊖d←10⊥⍣¯1⊢⍵}?

ngn

@rak1507 maybe in a universe made only of natural numbers

rak1507

who needs negative numbers anyway

do they really exist? I thought not

don't even mention complex numbers!

@Marshall way faster!

hang on let me do a proper timing

      ]runtime -c -repeat=5s 'mine b' 'ii b' 'hybrid b' 'another b'

  mine b    → 3.9E¯3 |   0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  ii b      → 3.9E¯3 |  -1% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  hybrid b  → 3.0E¯3 | -23% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
  another b → 9.2E¯4 | -77% ⎕⎕⎕⎕⎕⎕⎕⎕⎕

no idea why now ii and hybrid are faster

¯\_(⍨)_/¯

Marshall

2:17 AM

Yeah, so it was just 10*int being slow, and 10*bool just uses a lookup instead of calling libc.

rak1507

the performance seems very variable anyway

If I run it tomorrow, it'll probably be totally different

ngn

2:54 AM

@KamilaSzewczyk {i[⊃⍵;2⊃⍵]} -> {⍵⌷i} -> ⌷∘i

(⊃,/) -> ∊ (under some assumptions)

(⊂(!⍵-1)⍴⍵-1),⍨∇⍵-1 -> (∇,∘⊂!⍴⊢)⍵-1

ngn

3:17 AM

{⍺⍺/⍵⍵/¨⌷∘⍵¨¨(⊂⍳n),¨¨↓⍉↑1+{1=⍵:,⊂,0⋄∊¨(⍳⍵)⌽¨⊂(∇,∘⊂!⍴⊢)⍵-1}n←⊃⍴⍵}

Morten Kromberg

6:59 AM

@Marshall @rak1507 Interesting performance data on * and ⍟. cpmx reports the logs as about 10x faster on both my Windows and Mac machines. I will investigate.

Morten Kromberg

7:16 AM

@olabaz If you have an example of a small but real problem (with "real" data) that you are currently solving in Julia and would like to compare to an potential APL solution, please get in touch. I think we'd be happy to set some time aside to take a look at it.

Kamila Szewczyk

9:38 AM

      {(1 2 3 +⍥⍦ 2 4 5).f 3}dx⍬
53
      ⍝ f(x) = x^2 + 2x + 3, g(x) = 2x^2 + 3x + 4
      ⍝ h(x) = f(x) + g(x), h(3) = 53

I added polynomials

ngn

@KamilaSzewczyk what is ⍦?

Kamila Szewczyk

it builds a polynomial

it's a fancy version of {+/⍺⍺×⌽1,×\⍵⍴⍨1-⍨≢⍺⍺}

ngn

@KamilaSzewczyk looks like ⊥⍨ (at least for scalar ⍵)

Kamila Szewczyk

hmm

if i was to allow 1 2 3 + 2 3, what should it yield

Dyalog APL

<moon-child> I don't think it should be allowed, but most sensible thing would be the same as 1 2 + 2 3 (i.e. truncate at the lowest of the shapes)

Kamila Szewczyk

9:54 AM

i thought about padding the shorter vector

but i'm not sure if i should pad front or pad back

ngn

@KamilaSzewczyk inspired by dyalog's tradfns: the shorter array should be padded with some data from the caller's argument(s) :)

Kamila Szewczyk

hahaha

ngn

@KamilaSzewczyk why not make it a choice? ⎕pad :)

Kamila Szewczyk

i wonder how hard would it be to intercept system functions inside my thingy

      60⌶'⎕a'
┌──┐
│⎕A│
└──┘

seems like they're interpreted as a single token, so it should be fairly easy :)

@ngn what do you think about rational index origin and index granularity

ngn

@KamilaSzewczyk this is a joke, right?

not the same as rational indices but maybe worth mentioning: k9 has "step functions" - they are specified at certain values of the argument, and if you try to index them (i.e. call them) between those values, they default to the smaller one

rak1507

11:43 AM

@MortenKromberg Sorry, are you saying you have the same issue as me (slow logs) or it's fine for you?

dzaima

@rak1507 I too see 10⍟b being faster than 0.1*b (though only by 2-6x, not 10x)

rak1507

Hmmm

RGS

12:08 PM

Is it possible to print in a line, and then reprint on the same line?

rak1507

doubt it, you could try ansi escape characters

RGS

I am not sure how that works, but I think it's the carriage return char (ASCII 13 right?) that would allow me to rewrite the same line..?

@rak1507 What would that/those be?

dzaima

@RGS Not in the REPL/IDE at least, I'd say

RGS

Yeah :/

rak1507

ascii-table.com/ansi-escape-sequences-vt-100.php

RGS

12:11 PM

@rak1507 ⍨ do you have any idea how to work with those?

rak1507

in a terminal, you output them and they do stuff

dzaima

@RGS you just (⎕ucs 27),'[whatever'

RGS

Yeah well it works in a regular terminal

Not inside the IDE, like you expected.

rak1507

@RGS do you use windows?

rak1507

12:29 PM

CMC: find the index of the first duplicate item in a vector

(oh, there's an easier solution to the one I had, oops)

Kamila Szewczyk

@rak1507 {⊃⍸~≠⍵}

rak1507

yep

Morten Kromberg

@rak1507 ⍟ is 10x faster than * on my Windows laptop AND my MacBook Air

rak1507

really weird

going to update and see if it stays the same

Morten Kromberg

I will update and check my Linux machine later today...

rak1507

12:42 PM

must be something strange with my pc or my installation

RGS

@rak1507 Yes, why?

rak1507

can you run b←1⌈?⍨100000 and ]runtime -c '0.1*b' '5⍟b' '10⍟b' '17⍟b'

huh, updating fixed it!

      ]runtime -c '0.1*b' '5⍟b' '10⍟b' '17⍟b'

  0.1*b → 7.9E¯3 |   0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
* 5⍟b   → 8.5E¯4 | -90% ⎕⎕⎕⎕
* 10⍟b  → 7.2E¯4 | -91% ⎕⎕⎕⎕
* 17⍟b  → 8.6E¯4 | -90% ⎕⎕⎕⎕

¯\_(⍨)_/¯

so weird lol oh well at least it's fixed now and I can finally use logs

RGS

      ]runtime -c '0.1*b' '5⍟b' '10⍟b' '17⍟b'

  0.1*b → 1.1E¯2 |   0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
* 5⍟b   → 1.8E¯3 | -83% ⎕⎕⎕⎕⎕⎕⎕
* 10⍟b  → 1.5E¯3 | -86% ⎕⎕⎕⎕⎕⎕
* 17⍟b  → 1.8E¯3 | -84% ⎕⎕⎕⎕⎕⎕⎕

rak1507

yeah

I wonder what was causing it to be so slow for me before

RGS

Wait, on my machine everything is 10 times slower

Morten Kromberg

12:51 PM

@rak1507 It appears that there is significant room for improvement of both * and ⍟, which we will be investigating. My first guess would be that vector instructions are being used for some cases and not others.

rak1507

@RGS 10 times slower than what?

@MortenKromberg well it seems fine now... maybe it was just an issue with that particular version or something I did to the installation

RGS

Ok not 10 times slower, but my timings are consistently slower than yours.

rak1507

what's your cpu?

Morten Kromberg

In more and amore cases, Dyalog APL selects different algorithms depending on whether different types of vector instructions are available on the machine. We've had cases where clients complained and we found out that although the chip had AVX, the VM was configured to pretend that it wasn't.

RGS

This? Processor Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz, 2592 Mhz, 6 Core(s), 12 Logical Processor(s)

rak1507

12:53 PM

that's a lot better than mine

should be faster... who knows

Morten Kromberg

Me: Core i7-6820HQ @ 2.7GHz

RGS

      ]runtime -c '0.1*b' '5⍟b' '10⍟b' '17⍟b'

  0.1*b → 5.8E¯3 |   0% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕
* 5⍟b   → 6.0E¯4 | -90% ⎕⎕⎕⎕
* 10⍟b  → 5.3E¯4 | -91% ⎕⎕⎕⎕
* 17⍟b  → 6.0E¯4 | -90% ⎕⎕⎕⎕

plugged it in, now it goes faster.

rak1507

Ah

Makes sense

RGS

vrum vrum 🚗

rak1507

Now I have a new installation... how do I set default ⎕IO again?

RGS

12:55 PM

you set it to whatever you want

rak1507

Ah, options -> configure

RGS

then close the interpreter and ask it to save the config

or that

rak1507

OH! It was ⎕FR!

I have ⎕FR←1287 by default

RGS

Mine's at 645

rak1507

Yeah

When I switch to 1287, I get the slow logs, but on 645 it's fine

dzaima

12:58 PM

@rak1507 global variables at it again

rak1507

Yeah, I can't believe I didn't think of FR

Still... logs shouldn't be over 1000 times slower with a higher precision right? idk

not ideal

RGS

@rak1507 changing ⎕FR←1287 and timing again gives those increases for me as well

rak1507

yeah, that'll be it

updated my version for nothing! lol

Morten Kromberg

Decimal floating-point can be expected to be ~50x slower

... but we have been able to speed some things up, so YMMV

dzaima

@rak1507 well, it is native hardware support vs a custom (and inefficient as it's base 10!) number format and presumably custom impls for all operations

rak1507

1:00 PM

@dzaima ah, didn't know it was a custom format for ⎕FR←1287, that explains it

I'll stick with 645

dzaima

@rak1507 yeah, only powerpc or whatever has native support for 128-bit decimal floats

rak1507

@dzaima Ah interesting I didn't know that, I barely know anything about low level stuff so I didn't even consider that it could be ⎕FR making it slow, facepalm

Morten Kromberg

The DECF format is for people who need to do accurate currency conversions on the Norwegian Oil Fund or the US National Debt, DOUBLE won't do any more :)

rak1507

financial calculations using floating point, I think I'm going to be sick

Morten Kromberg

It is a tricky business

dzaima

1:03 PM

@rak1507 well, it's decimal floats, which is somewhat better (unless you're dividing by 3 or something weird for some reason)

rak1507

Ah right yeah fair enough

Morten Kromberg

I think applications that really need it will use DECF for accounting, but might well slip back into DOUBLE to do things like compute an internal rate of return, where you really don't need 30+ digits of precision.

(hence the switch, few people want to use DECF for everything)

To anyone thinking of implementing a new array language, I recommend variable-precision floats and (not or) "rats". We expect to go there eventually.

rak1507

what about high precision ints?

dzaima

@MortenKromberg I'd personally disagree with variable-precision floats. Ideal float usage shouldn't be able to ever strictly break on lower precision; if ints and floats aren't in the same tower, imo even f32 would be just fine

Morten Kromberg

1:19 PM

Can you explain what "ideal float usage" is? If the application knows its range and precision requirements, why should it not use a "custom" data type?

dzaima

@MortenKromberg if you indeed know your precision requirements and manage to make sure all your additions and subtractions are done on the same magnitude numbers to have predictable precision loss, i guess it's fine. But doing that is hard

Morten Kromberg

I think that if, like in a multi-currency accounting system, you have specific precision requirements, it is natural to follow such rules for all the arithmetic that is related to your accounting. The rest of your math you would probably do using the normal numeric tower with DOUBLEs.

dzaima

@MortenKromberg I would hope that an accounting system has precision requirements of "100% correct", and an extra 15 digits of precision just delays the time until it's not correct if the operations aren't guaranteed to be safe

Morten Kromberg

100% correct, rounded off to specified numbers of digits at various points in legally mandated computations.

dzaima

@MortenKromberg if you have mandated rounding, why not just use fixed-point integers?

Morten Kromberg

1:30 PM

If you do a currency conversion, or you own 1/3 of something, you will need to round things off.

Marshall

@dzaima As Morten says, precision requirements are a matter of law, and being more precise would also not be allowed. Fairly sure this subfield of finance is the only kind of programming with a requirement like this, so I think it's very strange to consider when making a general-purpose language.

Morten Kromberg

Fixed point integers are nasty because you're not expressing math naturally.

@Marshall Indeed, these things are all perfectly horrible when making a general-purpose language.

dzaima

@MortenKromberg I mean more as a language type. Use as regular floats, but they're actually precise, sane values

Morten Kromberg

@dzaima Yeah, I realised that a second after making my comment, sorry. I guess you could use them but then you would need to be a bit more careful than if you have floats with known precision.

dzaima

@MortenKromberg I'd say you'd be able to be less careful. For one, magnitude is no longer intermingled with decimal precision

Morten Kromberg

1:35 PM

@Marshall Rational numbers are a better solution for a general-purpose math-oriented language, I guess(?). The problem is that they have unknown cost, which could get catastrophic if used for financial calculations.

dzaima

@dzaima but if there are things mandating strict behavior, there's really no point in supporting things the rules weren't made for i guess

user41805

anyone know how to make ⎕plot work on gnuapl? gnu.org/software/apl says 'you need some of the special purpose system functions (⎕FFT, ⎕PLOT, ⎕RE, etc) that depend on non-default libraries', and while ./configure has a --with-pcre option for ⎕re, idk how to get ⎕plot working

i found stackoverflow.com/questions/58927866/… , and have gnuplot installed, but still doesn't work

Morten Kromberg

@dzaima You may be right, I have not looked carefully enough at those types yet and our financial clients went for IEEE DECF.

Elias Mårtenson

2:03 PM

@user41805 You're going to have to provide a bit more details than "it doesn't work"

user41805

right, i get SYNTAX ERROR+ when running ⎕plot ⍳10, for instance

i get the same error when running '2'⎕re'2', which according to doc/apl.html means the cnofigure script doesn't find libpcre. but the doc section for plot doesn't say anything about this

Elias Mårtenson

3:21 PM

@user41805 Are you using the latest version from SVN?

user41805

@EliasMårtenson i downloaded 1.8 from the download page ftp.gnu.org/gnu/apl

why, has there been a fix since 1.8's release?

Elias Mårtenson

@user41805 The versioned releases are very rare, and the author only does them rarely when asked to. Usually it's a couple of years between them.

Always get the latest version from the SVN repository.

user41805

3:38 PM

okay i'll try that

done, and got the same error again

Elias Mårtenson

@user41805 The plot one is strange, since it shouldn't require any compile-time dependencies.

It simply runs the external program. What is the error you're getting?

user41805

4:14 PM

SYNTAX ERROR+
      ⎕PLOT ''
      ^

with ⎕plot ⍳10 there is an addition caret under the iota

rak1507

8:52 PM

CMC: running totals of the counts of each number in a vector, 5 8 2 3 8 3 3 4 5 4 5 5 -> 1 1 1 1 2 2 3 1 2 2 3 4

dzaima

@rak1507 BQN, ⊒

rak1507

Yep, I was playing with BQN and wondered how that could be done in APL succinctly

I have a 7 but I feel like there must be something cleverer

Marshall

@rak1507 The implementation BQN uses is ⊐˜(⊢-⊏)⍋∘⍋. It's the same as the J one in this essay and I think there's one in the FinnAPL idiom library as well.

ngn

9:14 PM

@rak1507 {0 0⍉+\⍵∘.=⍵} and (⌈⌿+\×⊢)∘.=⍨

unftly +\⍤∘.=⍨ is a syn err

k: {|/x*+\'x:x=\:x}

Marshall

+´¨⊢=≠↑↑ in BQN as well.

+´¨⊢=1↓↑ if you want it to include each number in its own count.

ngn

golfing is not fun when done in different languages

Adám

9:31 PM

@dzaima Thanks. Fixed.

rak1507

9:52 PM

@ngn I think I have an 11 in K

ngn

@rak1507 translation of marshall's?

rak1507

No

could easily be the same though

ngn

i'm too hungry to think right now :)

rak1507

yeah it is the same as marshalls {+/'x=,\x}

and my APL one was ⊢+.=¨,\

ngn

10:17 PM

@rak1507 that's 10 - cool!

rak1507

oh oops, I don't know how I miscounted

ngn

that feeling when i'm not even the number two golfer at the language i've so lovingly stolen and reimplemented

rak1507

who are the top K golfers? I've seen a few people on cgcc but I can't remember their names

another cmc: find the maximum number of repeated elements (1 1 1 1 -> 4, 1 2 3 4 -> 1, 1 2 1 1 -> 3) without using ⌈/ or equivalent

dzaima

@rak1507 I have 5

rak1507

ooh

I have 6

got 5

ngn

10:26 PM

@rak1507 @coltim is by far the most prolific. @galen-ivanov has some great shots too. there are people in "the k tree" who are really good at it but don't golf.

rak1507

@dzaima ⎕RL←1⋄2049≡?+/⎕UCS'≢∘⍉⊢⌸'?

oh oops

I meant to put the code in a variable to avoid revealing it

lol

dzaima

@rak1507 yep

ngn

10:43 PM

@ngn i should have mentioned @scrawl and @traws too

ngn

10:59 PM