The Nineteenth Byte

Pavel

12:21 AM

Is there a way to comment on a GitHub repo without leaving an issue?

Like, if I wanted to tell a language author that their work has an online interpreter at TIO now.

Adám

@Pavel You could make that an issue/PR against the readme.

Zacharý

1:41 AM

@Pavel, just comment on one of the commits, I've had entire conversations that way

Pavel

@Zacharý Good thought. I'll do that.

Zacharý

Don't let it get out of hand, as I've said: I've had entire conversations over Github comments. Don't go down that route

Pavel

1:58 AM

@Zacharý Well, some things take converstaions to get resolved. GitHub has an unfortunate lack of a this conversation has been moved to chat button like SE does.

user202729

@WheatWizard @Mr.Xcoder How is that similar? I don't understand...?

Zacharý

ATaco's progress on getting a taco?

user202729

2:25 AM

Question: When should I delete vote a post?

orlp

2:53 AM

@LeakyNun TIL of the rational root theorem

very interesting

Leaky Nun

@orlp nice

Pavel

@orlp Fuck the rational root theorem. --Every Algebra II student ever

Leaky Nun

3:13 AM

1

A: Really Basic Question on Square Roots

Ordering axioms: $O1$ (reflexivity): $x \le x$ $O2$ (anti-symmetry): $x \le y$ and $y \le x$ imply $x = y$ $O3$ (transitivity): $x \le y$ and $y \le z$ imply $x \le z$ $O4$ (totality): $x \le y$ or $y \le x$ $O5$ (additive compatibility): $a \le b$ implies $a+c \le b+c$ $O6$ (multiplicative com...

axiomatic approach, next level

And here I though my answer was overkill! (+1) — Xander Henderson 3 mins ago

@orlp

orlp

haha

Doorknob

@user202729 gonna go out on a limb here and say when you think the post should be deleted

ATaco

3:47 AM

@EsolangingFruit Oh, that's because I forgot to define the encoding for the page... I'll fix that right now...

Pavel

Huh, PowerShell is changing the name of the windows binary from PowerShell.exe to pwsh.exe. The Linux package has provided it as /bin/pwsh for a while now.

ATaco

@EsolangingFruit Patched.

New Main Posts

5:05 AM

0

Q: Can't figure out the datatype to use for this object

For a practice problem, I have to create an object called Window which have to hold the following operations: 1) Create a window 2) Bring a window to the top 3) Put a window to the bottom 4) Destroy a window 5) Output what percentage of a window is visible (i.e., isn't covered by windows abo...

algorithm

Doorknob

6:17 AM

.#%d
@:#\!^m*^m&^9*mD*,c'!'!,iiioor&D*is*D!i&+&&*p*E!i&w&E*o

working on a new esolang, here's a program that outputs its input plus 1

Pavel

y tho

You can't leave that here without an explanation

Doorknob

sure I can

but if you insist

ATaco

6:40 AM

"Documentation"

Pavel

@ATaco The face docs are more complete than for most esolangs

ATaco

Yeah, I did find it.

DJMcMayhem

7:18 AM

@Doorknob That's beautiful

Pavel

@Doorknob If argc is 1, Face should assume that the infile is stdin, rather than failing, imo.

Adám

@Doorknob Wow, that almost motivates me to learn it, as my first low level language.

Pavel

7:33 AM

^. Honestly, the concept behind Face is brilliant and I'm amazed I've never seent it before.

Adám

Is there any reason not to use Face for real-world applications?

New Sandboxed Posts

7:48 AM

0

A: Sandbox for Proposed Challenges

Shift a word down in the alphabet Given an input of alphabetic characters, output the characters one letter down in the alphabet, feeding back around if necessary. Rules: Input will only be alphabetic characters (A-Z & a-z). Leave spaces as is. Examples: ABCD -> BCDE ABCD ABCD -> BCDE BCDE ...

New Meta Posts

8:01 AM

0

Q: What should count as a compression algorithm?

I am working on a new challenge (sandbox link) that has something in common with my old challenge Paint Starry Night. In these challenges the goal is essentially to design a compression algorithm tailored to a particular input. (For the new challenge the input is text rather than an image.) In P...

discussion

Erik the Outgolfer

10:18 AM

@ConorO'Brien well, I didn't VTC as off-topic yet, although I think the two parts are completely separate 1) convert from roman to arabic 2) execute arithmetic operations on a stack

betseg

11:07 AM

@Doorknob you should make a bootstrap interpreter

dzaima

1:13 PM

\o/ my ascii-art language is producing ascii-art-ish results :D

Doorknob

@Pavel You can pass an argument of - to read from stdin. The issue with having it do that by default is that it closes stdin, making it pretty much impossible for the program to take input.

@dzaima Nice!

Leaky Nun

1:30 PM

CMC: every permutation can be written in cycle notation. e.g. {12345->54321} can be written as (15)(24) because 1 and 5 are swapped and 2 and 4 are swapped. e.g. {12345->23145} is (123). Then, each permutation is associated with a cycle type, (15)(24) is 2+2 and (123) is 3. Now, permutations with the same cycle type are groupped together and form a conjugacy class. The set of permutations of n letters has n! elements and are grouped by conjugacy class:

for n=3, the conjugacy classes are {{id},{(12),(23),(13)},{(123),(132)}}. Each class has 1,3,2 members respectively, and the class equation is 1+2+3=6. Now, given n, return the class equation of the permutations of n letters.

(you may return a list e.g. [1,2,3]. order doesn't matter.)

Cows quack

just to be clear, when given 3 as input, the associated output is [1,3,2]?

Leaky Nun

yes

Mr. Xcoder

sighs tfw you're creating a minimalistic esolang and ... and ... you realise you forgot to add loops

3

Ian Gödel

Hey folks! I was wondering what is / are the the best language(s) designed by the users of this site for string usage / ascii art?

user202729

ASCII art... probably Charcoal. [I don't know it]

Cows quack

1:40 PM

what do you mean by string usage? From what I understand, I think you might want Charcoal github.com/somebody1234/Charcoal

Mr. Xcoder

@IanGödel Charcoal, SOGL

You can search them though Github

Cows quack

V also excels at string challenges

Ian Gödel

Ah yes Charcoal. I think I saw it before, but couldn't remember it

thanks

@cowsquack Ok, good to know about V too. I'll consider learning one of them

betseg

anyone in 2018 yet? what is it like?

Mr. Xcoder

Probably a new-year's usual feel :P

dzaima

1:47 PM

@Mr.Xcoder I had that happen while making SOGL. Forgetting to add loops from the start (and implementing them horribly afterwards) is one of the main reasons why I dislike SOGL so much :p

Mr. Xcoder

At least I am not too far into it. It's going to be a minimalistic ascii-only language, with some basic functions, some stack manipulation functions and a few useful-for-golfing built-ins.

Leaky Nun

no love for my cmc?

Mr. Xcoder

Still reading. :P

Hey I got a hat

user202729

@LeakyNun That's what happen when it's too hard.

But let's see...

dzaima

@Mr.Xcoder ..again you have a leading \x08 to your message

user202729

1:57 PM

I switch to Linux so I don't see it now...

Mr. Xcoder

@dzaima Uhm, strange

Yay I got an unknown secret hat :)

user202729

@Mr.Xcoder "unknown" -> So it's known.

(I guess)

Mr. Xcoder

@user202729 Not there yet.

Apparently it's for getting stars in chat in 2018 anywhere in the world :)

user202729

Hm..... I don't think I can get star.

@LeakyNun Probably something like [integer partition] [factorial] [inverse] [tally] [something]...

Let's see... consider a set {a_1, a_2, ..., a_k} of cycle length, where `a_1 + a_2 + .. + a_k = n.

The number of cycles satisfy ^ is n! / Product(a_i !) / Product(Tally values !)

Tally values in Jelly

Leaky Nun

@user202729 I'm quite skeptical

user202729

2:06 PM

Is the formula correct?

Leaky Nun

@user202729 skeptical

Mr. Xcoder

VTC without reading much, shall we?

Wheat Wizard

0

Q: Prefixless Palindromes

Write a program or function that takes N, and S and outputs the number of palindromes of length S you can build using an alphabet of size N such that any prefix of size between 2 and S-1 is not a palindrome. For example if N were 2 and S were 5 The valid palindromes would be 01110 10001 And ...

code-golf string combinatorics

I just editted this question to make it more on topic. Any thoughts?

user202729

Another case where other user edit it to make on topic. The OP get rep without doing anything.

Anyway this OP is unregistered, and rep is not really important.

Mr. Xcoder

^^

@WheatWizard Why don't you post an improved version yourself?

user202729

2:08 PM

Should you post a separate question?

Wheat Wizard

Nah, I don't need the rep.

It's not a very interesting question anyway

Here's why

Mr. Xcoder

I thought you found it interesting since you have put quite a lot of effort into it

Wheat Wizard

I didn't put that much effort into it

user202729

I'm new to Haskell, what does $ do in print$?

And I suppose the code define a infix function?

Wheat Wizard

$ is the applies operator it applies print to whatevers to the right. It's meant to lower the precendence of print

Erik the Outgolfer

2:11 PM

@WheatWizard well, I don't think you can add tags like that? did OP agree it should be code-golf? usually that's the case, but OP might not want code-golf

New Main Posts

-2

Q: Convert .csv data frame into time series in R for further use

i have a .csv data frame including 3 columms (date, value, value). I'm trying to build up an ARIMA time series analysis and therefore i need the data from the .csv in a TS instead of an data.frame class in R. Hope someone can help? Cheers, Kai

data-structures r

Wheat Wizard

Yes, infix functions are generally cheaper

Leaky Nun

so print $ a b c instead of print (a b c)?

user202729

So it's equivalent to (print (...))?

Wheat Wizard

Basically, there are a few caveats $ has really low precendence so It can make a difference in more complex statements

Leaky Nun

2:11 PM

ninja'd :P

Wheat Wizard

@EriktheOutgolfer Huh?

OP is unregistered and hasn't visited in 3 days. I figured they've abandoned the question at this point.

Mr. Xcoder

@LeakyNun What does {id} mean? The set formed by the element itself?

Leaky Nun

the id is the identity permutation

it is {123->123}

Mr. Xcoder

Yeah... That's what I meant

Wheat Wizard

@user202729 Welcome to Haskell! It's a lot of fun for golf.

Leaky Nun

2:13 PM

@WheatWizard a lot of fun also not for golf

haskell is essentially lambda calculus

one can learn much from it i presume

Mr. Xcoder

Its types are very strong too

Wheat Wizard

it is a lot of fun. I wouldn't call it essentially lambda calculus though.

user202729

Sorry, they're same (conjugacy class)

Mr. Xcoder

Is it just Husk, or Haskell lists are also homogeneous? Can Haskell lists contain elements of different types?

Erik the Outgolfer

@WheatWizard hm, tbf that would fit better as code golf

Leaky Nun

2:15 PM

(123) = {123->231}
(132) = {123->312}

user202729

IIRC only same types.

But tuples can contains multiple types.

Wheat Wizard

@Mr.Xcoder Haskell lists must be homogeneous.

Mr. Xcoder

Ok thanks. I couldn't recall clearly

@LeakyNun The class equation is basically the summation of the lengths of each of the conjugacy classes?

user202729

Ok... I got the formulas screwed up.

Leaky Nun

@Mr.Xcoder yes

it's literally an equation

1+2+3=6 is the class equation

Mr. Xcoder

2:18 PM

Ok then, shouldn't it be 1+3+2=6 or they should be sorted?

Leaky Nun

doesn't matter

addition is commutative

Mr. Xcoder

I know, just asking to be sure

Leaky Nun

btw "conjugacy class" is a concept from group theory if anyone is interested

@Mr.Xcoder are you?

Mr. Xcoder

@LeakyNun test case for 5 please?

@LeakyNun What?

Leaky Nun

are you interested in the group theoretic definition?

Mr. Xcoder

2:21 PM

I am not sure I'd understand all of it, but sure

Wheat Wizard

Oh what are we talking about? I heard group theory

Mr. Xcoder

@WheatWizard conjugacy classes

Leaky Nun

51 mins ago, by Leaky Nun

CMC: every permutation can be written in cycle notation. e.g. {12345->54321} can be written as (15)(24) because 1 and 5 are swapped and 2 and 4 are swapped. e.g. {12345->23145} is (123). Then, each permutation is associated with a cycle type, (15)(24) is 2+2 and (123) is 3. Now, permutations with the same cycle type are groupped together and form a conjugacy class. The set of permutations of n letters has n! elements and are grouped by conjugacy class:

51 mins ago, by Leaky Nun

for n=3, the conjugacy classes are {{id},{(12),(23),(13)},{(123),(132)}}. Each class has 1,3,2 members respectively, and the class equation is 1+2+3=6. Now, given n, return the class equation of the permutations of n letters.

50 mins ago, by Leaky Nun

(you may return a list e.g. [1,2,3]. order doesn't matter.)

@WheatWizard here

@Mr.Xcoder 1+10+20+15+30+20+24=120 (credits groupprops)

brb

user202729

@NewSandboxedPosts The oneboxes are huge! (I intentionally ... (see rev history)

Leaky Nun

@user202729 sorry for that

New Sandboxed Posts

2:23 PM

0

A: Sandbox for Proposed Challenges

Generate a heap of boxes (The text asks how many boxes are in the picture) Now you are required to generate such a problem and its answer. Input an integer n Output can be a 3D array A[n][n][n], where A[i][j][k] => (i==0 || A[i-1][j][k]) && (j==0 || A[i][j-1][k]) && (k==0 || A[i][j][k-...

Mr. Xcoder

@LeakyNun (No rush, when you're back): Out of curiosity, what did you study so far in College?

user202729

Seems that I got it right...

@WheatWizard BTW.. what does your program do? The 2-1 looks weird... unless the div has more priority. (still not very familiar with Haskell)

Wheat Wizard

Functions have the highest priority so div happens first

user202729

@LeakyNun Jelly, 18 bytes (warning: Don't see that, contains mathematical formula, potential spoiler) TIO

17 bytes also work thanks to Dennis implementing some atom satisfy some properties.

16 bytes

Wheat Wizard

@user202729 Does that clear up how my program works? It is a pretty simple formula but it might be pretty hard if you're not familiar with haskell

user202729

2:33 PM

Better 16 bytes

@WheatWizard Yes. Because it has simple formula, it's not really good as a challenge (better a puzzle)

Wheat Wizard

Yeah I'd have to agree, It was a little fun finding the solution, but once you know it it's kind of over.

If Dennis could beat 21 bytes of Haskell I'd be pretty damn impressed.

That's not what I mean by beat ...

Mr. Xcoder

nvm

Leaky Nun

@Mr.Xcoder the official syllabus is foundation, calculus, linear algebra, and statistics

@user202729 nice

Mr. Xcoder

Uhm. Out of those listed above, I think I only like calculus

Cows quack

@LeakyNun J, 35 bytes [:+/@(="0 1~.)+/"1@(i.="1 i.@!A.i.)

Wheat Wizard

2:39 PM

@LeakyNun What is foundation? We have a course called foundations, but it's probably different.

Leaky Nun

@Mr.Xcoder I see

@WheatWizard the fundamentals of maths :P

Wheat Wizard

Ah our foundations is a "how to prove stuff course"

Leaky Nun

ya, it includes that

Wheat Wizard

You do that before calculus? We take calculus with all the engineers so things end up very far from rigourous

Leaky Nun

we do all the four courses together

we did

each course is maths only

Wheat Wizard

2:46 PM

Oh wow, that must be something. Next semester will be my first semester taking 4 math courses

Mr. Xcoder

That's why it's called "College for Pure Mathematics"

user202729

CMC: Given a set of integers, find the smallest m such that the hash function x => x % m is injective for that set of integer.

(is that a duplicate?)

Leaky Nun

testcase?

user202729

[1,2,3,4,5] -> 5 (trivial test case)

Leaky Nun

@user202729 Jelly, 10 bytes: 0µ³%Q⁼$µ1#

user202729

3:00 PM

Yes, I was trying something with 1#... I didn't think about Q⁼, though.

wizzwizz4

Any PHP gurus here?

I'm stuck with a situation involving eval and variables.

Cows quack

@LeakyNun if you let the J train I gave to your cmc be assigned to the variable Q, you get an interesting pattern dividing Q"0 >:i.10 by a matrix formed by combinations |:(1+i.10)!/1+i.10

Leaky Nun

@Cowsquack I see

Anonymous

@wizzwizz4 Have you tried not using PHP? :P

Cows quack

but I can't yet find a clear pattern in 1 2 9 44 265 1854 14833 133496

wizzwizz4

3:08 PM

@Mego I can't avoid it.

I'm trying to patch a wiki.

Anonymous

Then may the great goat in the sky have mercy on your soul

7

wizzwizz4

Basically, I need to associate constant names (coming straight from an authentication system) with changeable usernames in PmWiki.

I've got almost everything working, except ?action=diff.

I'll skip a few steps.

Basically, a string is eval'd to produce a value that's then substituted into a proprietary format string.

I need to get a variable into it, but I can't reference it.

if ($action == "diff") {
	$FmtPV['$DiffAuthorName'] = 'PageVar(ResolvePageName(\'Profiles.\' . $GLOBALS[\'FmtV\'][\'$DiffAuthor\']), \'$Title\') ?: \'$DiffAuthor\'';
	SDV($DiffStartFmt,"
      <div class='diffbox'><div class='difftime'><a name='diff\$DiffGMT' href='#diff\$DiffGMT'>\$DiffTime</a>
        \$[by] <span class='diffauthor' title='\$DiffHost'>\$DiffAuthorName</span> - \$DiffChangeSum</div>");
}

I need to replace Profiles with the contents of the variable $AuthorGroup.

At runtime, not define-time, since it isn't defined up until then.

Anonymous

Well, I am definitely not a PHP guru, so my only advice is "good luck" and "don't drink yourself into an early grave"

wizzwizz4

@Mego Oh, I'm not touching alcohol within a month of touching PHP, just in case it drives me to AA meetings.

2

Anonymous

I'm fairly certain alcohol won't drive you anywhere. In fact. the opposite is the usual advice.

wizzwizz4

3:14 PM

@Mego I meant PHP.

(PHP -> drinking)+ -> drinking -> addiction -> AA meetings.

Anonymous

In order for PHP to drive you anywhere, you'd have to write 13 Wordpress modules for integration with your car, and then patch the PHP source so that activate_brakes isn't a stub

2

wizzwizz4

@Mego In order for PHP to drive you anywhere, you'd have to be completely mad.

Cows quack

you're already mad if you use php

Zacharý

^

betseg

no its actually real_acivate_brakes, activate_brakes doesnt work

2

Zacharý

3:17 PM

HAPPY STAR YEAR

Anonymous

Oh no

Zacharý

I'm saying that because there are three starred messages, I won't spam them.

wizzwizz4

@Zacharý Good.

Anonymous

To reiterate: abusing SE systems to get hats is not okay. If you post starbait/nonsense to try to get a hat, you will be kicked.

7

wizzwizz4

@Mego Pin plz.

betseg

3:19 PM

@Mego there is a hat for starred messages?

Zacharý

I love how the things that get the most stars are always meta

3

Anonymous

@betseg Apparently

wizzwizz4

@betseg Every year.

It's a tradition to create a room for people to star-spam.

I participated last year, but I don't think I will this year.

Anonymous

Just use the Sandbox chat room if you want to get stars

Cows quack

I am not participating this year as well, WB is too distracting

Zacharý

3:21 PM

J'ai deux étoiles! (I have two stars, and need to practice my French)

Anonymous

Last year, I tried to get all of the hats. This year, I just put on the first hat I got, and since then haven't really gone out of my way to get more.

Anonymous

@Zacharý English only, please

Zacharý

Edited

wizzwizz4

@Zacharý There's a room for that.

Zacharý

A practically dead room for that

Anonymous

3:23 PM

@Zacharý And why would TNB be more appropriate?

wizzwizz4

@Zacharý Not dead. Just sleeping.

Zacharý

I dunno, probably because I thought of a "Du hast deinen Stern" message from a while back

wizzwizz4

@Zacharý Sorry about that. :-(

betseg

@wizzwizz4 ive been on SE for just over a year

Zacharý

Any body here closing in on 2018 soon?

betseg

3:25 PM

last 5.5 hours

wizzwizz4

@Zacharý Over 6 hours.

Zacharý

13.5 hours >_<

@betseg Has it already been passed for you?

user202729

1.5 hours.

betseg

@Zacharý 2017-31-12T18:27

wizzwizz4

I use UTC as my timezone.

betseg

3:28 PM

> Over 6 hours.

wizzwizz4

Noon is never 12 PM anyway, so it doesn't make much difference.

betseg

yup, correct

dzaima

3:46 PM

CMQ: what should my ascii-art language be called? It's currently basically SOGL but not as annoyingly implemented and actually has built-ins made for ascii-art

Anonymous

@dzaima Canvas

Zacharý

Coal

Mr. Xcoder

@dzaima Drawgolf

Cows quack

is it still made in processing?

dzaima

@Cowsquack nope. It's fully JS

Anonymous

3:47 PM

Definitely Canvas

Mr. Xcoder

Why so definitely?

Anonymous

Made in JS, used for drawing art. Canvas is perfect

Mr. Xcoder

If you say so

dzaima

currently it doesn't have a main canvas (as Charcoal does)

Cows quack

how does the lang work?

dzaima

3:49 PM

@Cowsquack it's a stack-based language like SOGL but has that every ascii character is a part of strings

Anonymous

Besides - esolangs have a long and storied past of name collisions with mainsteam langs/tech

Zacharý

Like what @Mego

Cows quack

"every ascii character is a part of strings" in what sense?

dzaima

@Cowsquack hello＋ is a full program that appends hello to the input. + just adds things horizontally, and no quotes around hello are required

Cows quack

isn't + an ascii character? :P

dzaima

3:52 PM

@Cowsquack that's a full-width character (＋ != +)

Cows quack

ah, like charcoal in that aspect

wizzwizz4

＋+＋+

Anonymous

@Zacharý Alice versus Alice ML, Atom versus Atom, COBOL versus COBOL

user202729

Jelly segfault!

Zacharý

Um ... someone named their esolang COBOL?

Anonymous

3:54 PM

@user202729 Ooh, that's bad

Anonymous

@Zacharý Yes

wizzwizz4

@user202729 Congratulations! :-)

:-(

Anonymous

IIRC it came about as a joke about how bad the original COBOL is

Anonymous

@user202729 I'll give you a cookie if you can segfault Actually

user202729

Yes, I agree about the "congratulation" part.

Cows quack

3:55 PM

@dzaima does it support numbers?

Anonymous

Specifically, if you can produce a segfault on Actually on TIO

dzaima

@Cowsquack mhm, ６８＋ returns 14

user202729

@Mego ... browser cookie?

Mr. Xcoder

@user202729 You can segfault in jelly in 2 bytes

Anonymous

@user202729 Maybe

Zacharý

3:56 PM

@Mr.Xcoder That just keeps calling itself, right>

user202729

@Mr.Xcoder Oh yes....

Mr. Xcoder

Yes

dzaima

eh, I might go for Canvas and just change my Art object to be named Canvas

Cows quack

what sort of special string/ascii-art functions does it have?

user202729

But Python doesn't crash on recursion limit exceeded, so what can go wrong?

Anonymous

3:58 PM

@user202729 You can get a true SO in Actually

dzaima

@Cowsquack palindromization (quad, vertical, horizontal, 0-or-1 overlap, overlap based on remainders), mirroring, reversing, overlapping, repeating in X/Y, X+Y replicate is about how much is implemented

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