The Nineteenth Byte

Geobits

5:00 PM

How "tailored"? What features are you looking for?

cjfaure

@githubphagocyte there aren't, but you just jynxed it.

githubphagocyte

jynxed? You mean now there will never be? Or now there are bound to be?

cjfaure

@githubphagocyte I'm already making it.

githubphagocyte

@cjfaure yay! Which languages...? ;)

Geobits

Make sure you golf the source to the IDE also. Preferably in a dedicated golfing language.

TheDoctor

5:01 PM

/me hits @Rainbolt with a diamond shovel

cjfaure

@githubphagocyte i was joking; but i might xD Python probably.

githubphagocyte

@Geobits golf the source?!? Is to ensure it can never have an update...? :)

cjfaure

@Geobits The sacrifice between features and code length...

Rainbolt

@TheDoctor /me Jumps inside of TheDoctor's backback. I suppose it's better than being picked up by an Enderman.

cjfaure

I've been Minecraft-sober for 3 months now.

Geobits

5:03 PM

@githubphagocyte How else to prove you know how to golf? Why should I trust golf-related source that isn't even golfed? :P

cjfaure

@Geobits Technically, a blank program is a golfing IDE. You open it in your code editor.

i am the king

Geobits

I'd call that a golfing template instead.

It starts with the minimum boilerplate needed.

cjfaure

@Geobits "ide" is shorter than "template".

TheDoctor

/me places @Rainbolt around a beacon to protect it

cjfaure

now i wanna play mc with you guys xD

FireFly

5:25 PM

Speaking of golfing tools, I think something that folds constant expressions would be useful

Should be easy to do, too

. o O ( Perhaps easy enough that it could be a suitable golfing task itself )

Martin Büttner

Peter Taylor

@FireFly Fold in the sense of code hiding?

@MartinBüttner, you do realise it's not a popcon? ;)

githubphagocyte

I assumed @FireFly meant combining expressions involving several constants into one literal

FireFly

@PeterTaylor as in evaluating expressions consisting only of constants

Peter Taylor

I think that's already been asked for integers.

Martin Büttner

5:32 PM

@PeterTaylor yeeaaaah, I do... that's why this gif is all the way at the bottom of the pos... but the specified version of the problem was just a bit too boring :D

Eric Tressler

That seems to be a blueprint for a Trigonometer

They're used to measure trigons

Martin Büttner

6:07 PM

@VisualMelon it looks like the new version of your solver is throwing an index out of bounds exception

did you test it after golfing it down to fit in the character limit?

on another note, depicting Yggdrasil as a Christmas tree is making me incredibly sad :(

Eric Tressler

Where

Martin Büttner

there's an yggdrasil related kolmogorov challenge today

have a look at the front page

VisualMelon

@MartinBüttner I didn't golf it, I just only used one space for indents... I'll investigate - do you have a line number for the exception?

Martin Büttner

no but I've got

Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at dominoPrinter.Program.<>c__DisplayClass5.<printDominoes>b__4(Int32 x, Int32 y, String str)
   at dominoPrinter.Program.printDominoes(TextReader reader, TextWriter writer, Boolean moreverbosemaybe)
   at dominoPrinter.Program.Main(String[] args)

you've got an avatar!

VisualMelon

yes, what's the verdict? :P

Eric Tressler

6:21 PM

Too low-contrast

githubphagocyte

it looks like lemony infinity

Eric Tressler

Should be on another color background

Martin Büttner

I can't reconcile your avatar with your name

it's like using an off-centre turtle, my head just doesn't wanna process it

githubphagocyte

@MartinBüttner is it better since I got rid of the off centre dancing turtles and replaced them with just one reasonably central one?

Martin Büttner

much better! ;)

githubphagocyte

6:23 PM

@MartinBüttner you realise you are off centre in your avatar?

Eric Tressler

Maybe his head's just off-center from the rest of him, and you're being rude

Martin Büttner

lol I knew this was coming

githubphagocyte

sorry @MartinBüttner I didn't mean to draw undue attention to your off centre head

2

Martin Büttner

which made me think why photographs should never be centred on what their showing, while we really like symmetry in all sorts of abstract graphics

Eric Tressler

the rule of thirds is pretty accurate for a lot of things

VisualMelon

6:26 PM

OH DEAR

I didn't do that, really...

no apparently I did

Martin Büttner

you're really fun to "watch" debugging

VisualMelon

@MartinBüttner it seems I replaced " "*4 with " " instead of tab, so a certain set of important strings containing spaces MAY have broken

Martin Büttner

(about as much as Rainbolt is fun to watch codereviewing)

@VisualMelon oh

githubphagocyte

debugging is always more fun when you're not involved in it

Martin Büttner

@VisualMelon you did keep around the previous version though, didn't you?

because you never sent me the fixed but indented version, so that I'd have it in the git already

VisualMelon

6:28 PM

@MartinBüttner aye, just submitted

I'm so used to indenting stuff last just before posting that I assumed it wouldn't be an issue (because replacing tabs won't be an issue)

but because it was an afterthought after replacing tabs, clearly it went wrong

Martin Büttner

well you can still have a look at the version in the git to fix it

github.com/mbuettner/ppcg-domino-circuits/blob/master/…

VisualMelon

I've uploaded a "fixed" copy

TheDoctor

@PhiNotPi are you sure you don't program Propeller chips?

VisualMelon

(to the question)

Martin Büttner

ah okay

githubphagocyte

6:30 PM

@VisualMelon if you start with the unbroken version, can you replace "\n " rather than " "?

Martin Büttner

did you click "submit" yet? :D

@githubphagocyte or just "^ "

editors are usually in multiline mode

VisualMelon

@MartinBüttner I did, but I didn't notice this message "Body is limited to 30000 characters; you entered 30028."

give me a minute

Martin Büttner

:D

Eric Tressler

3

I fixed it

Martin Büttner

what?

PhiNotPi

6:31 PM

I'm reasonably sure.

TheDoctor

@PhiNotPi i thought you were forums.parallax.com/member.php/45432-Phil-Pilgrim-(PhiPi)

PhiNotPi

Well, I'm not.

TheDoctor

oh

well back to code

VisualMelon

AH, I reimplemented strness, I'll have to remove a comment

@MartinBüttner reposted

Martin Büttner

k

thx

Eric Tressler

6:33 PM

@MartinBüttner I fixed @VisualMelon's avatar

Martin Büttner

oh lol

I didn't even notice that those eyes were lemons

wait

lemon <-> melon O.O

mind blown

FireFly

It's an anagram!

Eric Tressler

I know, I'm working on putting googly eyes on a watermelon for him

githubphagocyte

@MartinBüttner you missed @VisualMelon's explanation earlier...

Martin Büttner

oh

link anyone? :)

FireFly

6:35 PM

Speaking of avatars and anagrams and things, how obvious is it that my avatar is an ambigram?

Martin Büttner

@FireFly very

VisualMelon

so, you guys reckon the contrast is too low?

Martin Büttner

(in your profile, not the scaled down version in here)

FireFly

Hehe

githubphagocyte

@MartinBüttner I found it but I don't know how to link to a specific chat post

Martin Büttner

6:37 PM

found it myself, don't worry

Eric Tressler

@VisualMelon I think I'm the only one who complained

githubphagocyte

@EricTressler not everyone can have such a high contrast avatar as you... :)

Martin Büttner

but if you hover over it, there's a link button on the left (if you're in the frozen transcript) or just the usual menu on the left, where there's a permalink option

githubphagocyte

@MartinBüttner yes, that's exactly where I hovered and still managed to miss the permalink option...

VisualMelon

addressing everyone other Eric whom has already expressed his a sour opinion - how can I improve my rather yellow/green profile picture?

githubphagocyte

6:40 PM

@VisualMelon how about purple and orange stripes in the background?

cjfaure

@VisualMelon cell closeup! yeeaaah

githubphagocyte

For the sake of the tiny avatar in chat, you could zoom in slightly so the lemons touch the edges of the box

VisualMelon

@githubphagocyte well, that sounds like a very good suggestion, but I've managed to not save the iteration where I cut the cut lemon out, so it would require alot of effort

githubphagocyte

ah ok

Martin Büttner

@VisualMelon okay, I'm quickly testing an improvement of the controller, and then I'll get you some results for your solver

VisualMelon

6:42 PM

@MartinBüttner roger

githubphagocyte

for what it's worth, I like it as it is. Won't be mistaken for anyone else.

FireFly

I think it's fine as is, @VisualMelon

cjfaure

lol, my avatar comes from the same place as @EricTressler's

VisualMelon

ok, if I'm not feeling lazy some time I made add a mad purple background, but if it's not too objectionable as it is I'll defer that thusly

Eric Tressler

VisualMelon

6:44 PM

now Eric is it look easy!

/me samples the purple

cjfaure

where's full res? I wanna try ;D

VisualMelon

my apologies to anyone who doesn't want the chat filled with pictures of ~~melons~~ lemons

Martin Büttner

3 hyphens

cjfaure

three dashes :P

~~yay~~

FireFly

Huh, I thought ~~foo~~ was the semi-standard markdown extension

Eric Tressler

6:49 PM

okay, I'm done.

cjfaure

Yay. :P

FireFly

Hm

cjfaure

i could do better, lol

VisualMelon

I like the background though

githubphagocyte

Hmmm.. in-chat popularity contest... :)

FireFly

6:52 PM

I wonder how I managed to get transparency working in my avatar.. I uploaded a new one now and it didn't like the transparency anymore

perhaps it doesn't like semitransparent pixels

cjfaure

I think transparency works via .gif and only .gif :P

:(

Single frame gif?

Using gif worked

what the... the controller just exploded to 5 gig RAM when validating the 3-bit adder

what have I done

githubphagocyte

6:56 PM

@MartinBüttner has it become self aware?

Martin Büttner

ah no, Visual Melon's solution must have been ridiculously large

the solution got ditched before being evaluated, because it had more than 8M cells

(51M in fact)

FireFly

Hm, I guess transparency only works for gravatars for some reason

Martin Büttner

I think I need to improve my controller to do that check first before doing some array-based manipulation on the circuit :D

FireFly

using a gif with transparent pixels caused them to become white when uploading to SE

Martin Büttner

interestingly, the multiplier (which has more outputs) had only 43M cells)

@VisualMelon you might be interested in these numbers ^

VisualMelon

6:59 PM

for >4inputs, the size is proportional to the number of 1s outputable

Martin Büttner

if anyone wants to look at more numbers:

15

Q: Domino Circuits

Scoreboard Here are the raw scores (i.e. domino counts) for VisualMelon's submission. I'll turn these into the normalised scores described below, when more answers come in. The existing solution times out on three circuits and produces too large circuits on 2 others, but solves the rest successf...

VisualMelon

if you read that and thought "I don't want to look at more numbers" consider yourself in the wrong

Martin Büttner

7:14 PM

I wonder how well a brute-force solution would do

I think it might be able to solve the 2-bit circuits optimally

but would obviously fail for the large ones

so it might even be somewhat balanced with your submission

but I wonder how small you can actually get those 2-bit circuits

huh?

VisualMelon

wrong brute force

Martin Büttner

? did you brute force the keyboard?

VisualMelon

I brute the expression tree, then it's all pretty tame after that

Martin Büttner

ah yeah

no I meant brute forcing it cell by cell

VisualMelon

aye, took me a bit of time to work that out

Doorknob

7:34 PM

So apparently Twitter seems to like us, especially the Tweetable Mathematical Art challenge (not surprising). Yay for more users and traffic!

Martin Büttner

Nice :)

FireFly

Nice

Martin Büttner

o.O

two tweets by Jeff Atwood

both for underhanded constests

this is sad

actually no, the first one is a code golf, just the title seemed like it was underhanded

cjfaure

8:00 PM

We should take this and turn it into a challenge to write a program to generate a Golfscript program to generate an input and still be shorter than the input, and then compress the script it outputs to create a text compression format.

Martin Büttner

I had to read that a few times too often to get it

cjfaure

@MartinBüttner lol, wait, let's also make one to compress Golfscript code and then use the best submissions in conjunction

LZMA2 is toast ;D

Eric Tressler

I wonder if GS programs have enough entropy to effectively zip

I guess since they're ascii, yeah

cjfaure

You can compress them further if you know they'll follow specific syntax rules.

the only actual syntax construct in golfscript is a string, right? :P

Martin Büttner

@EricTressler How do you even determine the actual entropy of a program? There's so much information "hidden" in the implicit meaning of the syntax.

Eric Tressler

8:05 PM

This is going to something like TarGolfscript, where the interpreter first unzips the source, then runs a GS interpreter on it

cjfaure

Well

Eric Tressler

@MartinBüttner You can't directly measure entropy (in practical examples), but compression algorithms are a good approximation

cjfaure

entropy is actually really simple to measure if you have a list of every possible thought that could ever exist.

Eric Tressler

Entropy is simple in a mathematical context

But you people, with your "real world", ruin it

3

Peter Taylor

@cjfaure I've seen that either in a question or in the sandbox.

cjfaure

8:08 PM

@PeterTaylor ow.

Peter Taylor

I do actually have a Java program which generates GolfScript programs for pure kolmogorov-complexity questions.

cjfaure

i can haz?

Eric Tressler

I actually had an idea for a code challenge

cjfaure

(i won't use it on questions, I swear! xD)

i wanna make that compression format

Eric Tressler

@PeterTaylor Maybe you know something about this?:

Peter Taylor

8:10 PM

I'll have to see whether it looks presentable enough to make it public.

cjfaure

@PeterTaylor Presentable code is overrated

Eric Tressler

I wanted the challenge to be taking two measures of randomness, and to produce 2 strings, one which scores as high as possible on metric A and low on metric B, and vice versa for the other string

but then I realized that I didn't know any simple metrics for randomness, and the best I could do is rip things out of the Dieharder tests

Since you can't directly measure Kolmogorov complexity

One metric could simply be compressibility under LZMA

do you have any ideas for an easy second choice?

Peter Taylor

An interesting proxy is to lower-bound with two different compression algorithms. It might be quite an interesting challenge to find strings which have very different compressability with LZW and bzip.

Eric Tressler

I don't know how bzip works; I'll have to read about it

Peter Taylor

But I'm not sure that it would be a very good question for this site.

Eric Tressler

8:13 PM

but yes, that's the general idea. I wanted to choose two things that are trying to measure the same thing, but to thwart them

Peter Taylor

The key element of bzip is the Burrows-Wheeler transform. (Yes, Wheeler is the W of LZW).

Eric Tressler

No? I was thinking of asking people to write their own function to generate the strings from thin air, no using random libraries, and only 32 bits for magic numbers

Peter Taylor

You'd have to find a suitable wording to make the question about code rather than about the strings per se. It's a similar problem to the one with the md5 of ffff...

Eric Tressler

No math constants, etc.

cjfaure

I wrote a compression format once.

I build a sort of matrix around generating a new character mapping to squish the unused bytes out of a string, sometimes going into very many dimensions,

githubphagocyte

8:16 PM

Have you seen the code that compresses any file by 1 byte? (Except an empty file, obviously)

Eric Tressler

@PeterTaylor Do you think, if I could plug all of the obvious holes, that this could work? Or still a bad idea?

cjfaure

and printed the sum of all the values and the product of all the values.

Eric Tressler

@githubphagocyte that's impossible to do losslessly. Is it a joke?

Peter Taylor

Ok, that might work. 32 bits for magic numbers needs a bit of bulletproofing ("But 68 is only 7 bits, even though I'm storing it in a 32-bit type!")

cjfaure

Decoding it, was, of course, O(n log n), but hey

githubphagocyte

8:17 PM

I think it was somewhere between a joke and an educational example. It was lossless.

cjfaure

it worked really well

githubphagocyte

@EricTressler I read the code and found that it worked, and then resented having wasted the time to read and understand it once I got the loophole

Eric Tressler

@PeterTaylor Yeah, but I could just say "you have an array of 32 booleans that you can initialize to whatever you want" or something

@githubphagocyte What's the loophole? Does it delete unimportant file metadata?

githubphagocyte

@EricTressler that wouldn't work iteratively down to zero bytes

@EricTressler hint: doesn't work on Windows

Eric Tressler

Ahhh....... I don't know, does it push it onto dev/random/?

I don't know enough about how linux works. Does it delete the initial '/' from the path?

githubphagocyte

8:20 PM

@EricTressler I'm happy to tell you once you stop guessing - it's really disappointing

Eric Tressler

Ignore that last one, that doesn't work iteratively. Was stupid to say. Okay, tell me

githubphagocyte

@EricTressler it only works because most file systems don't include the size of the filename in the size of the file

Eric Tressler

oh

Peter Taylor

@EricTressler Why would I need 32 booleans? 2 is enough, it's all in the indexes you use to get at them.

githubphagocyte

@EricTressler but that means it won't work on a system that has a cap on filename length

Eric Tressler

8:22 PM

@PeterTaylor I guess I should also include a byte limit on the string generating function

Don't worry, I won't post it unless I can prove to myself that it's not ill-conceived.

githubphagocyte

@EricTressler I knew it was impossible while reading through the code, but I was expecting a more interesting loophole :(

Eric Tressler

Yeah, but really, any OS that allows some more nefarious way to hide bits of files is doing kind of a bad job

githubphagocyte

true

Eric Tressler

Heh. It could corrupt the least significant bits of the loading splash screen, for instance

githubphagocyte

@EricTressler that's a reasonable amount of spare space...

not very portable though

Eric Tressler

8:26 PM

Or I guess even your desktop wallpaper

That would be interesting, to just store all of your passwords in your wallpaper in case you forget

githubphagocyte

@EricTressler not now you've mentioned it publicly ;)

Eric Tressler

I've always been interested in steganography and things like numbers stations. I really wish someone would declassify something that would shed some light on that whole business

It's pure idle curiosity, but I'd really like to know

githubphagocyte

@EricTressler it is indeed fascinating. I don't have much knowledge of it but it's intriguing. I'd be interested to know how much it's in practical use.

Eric Tressler

I don't think there's much to know except that there are radio frequencies that just broadcast sequences of numbers

It could be used to convey any kind of information, or it could be a prank

githubphagocyte

But there's also a whole world of other places to hide information.

Eric Tressler

8:41 PM

Yeah, but coming up with secrets worth that kind of effort is hard

Peter Taylor

@EricTressler Or some half-way house. A way to keep the boss' nephew busy. A service which had cryptographic value back in the 70s but nowadays survives because no-one can work out which office's budget is paying for it.

VisualMelon

not the boss' nephew's son then?

Eric Tressler

@PeterTaylor New conspiracy theory: Imgur is actually run by the CIA to coordinate its spy network

You heard it here first!

VisualMelon

hmm

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