The Nineteenth Byte

12:02 AM

@Quill If I were to extend the script to other sites as well, do you think it'd be worth it to include all of the A51 statistics?

user2284570

@trichoplax : edited.

Quill

@AlexA. Yeah, definitely

trichoplax

@user2284570 I'm not sure what this means: "insert the ascii nul character at the end of the 1ˢᵗ half of it’s name"

VoteToClose

@AlexA. waddat

trichoplax

@user2284570 "(replace\0with the nul byte)" sounds like a task, even though I can see from the context that you mean "\0 represents the null byte". It's only a minor potential source of confusion, but removing as much confusion as possible will help.

user2284570

12:08 AM

@trichoplax : if you have a filename consisting of an odd number of characters, then put the null byte in the first part.

trichoplax

@user2284570 Perhaps a few example inputs and outputs would help clarify this? Oh I see you added some already :)

Alex A.

30 mins ago, by Alex A.

On an entirely unrelated note: Get PPCG graduation stats whenever you want

trichoplax

@user2284570 Your first example seems to be missing a space in the output

user2284570

@trichoplax : thank you, edited.

trichoplax

@user2284570 With an even number of characters, should that space be before the \0?

user2284570

12:13 AM

@trichoplax : facepalm.

edited again.

trichoplax

:)

@user2284570 It might help to have at least one example with a file extension to make clear how that affects things

Alex A.

It looks like Area 51 doesn't use the answer ratio from the past two weeks. By my calculations, we've had a ratio of 7 over the past two weeks, but A51 lists 9.9. (cc @Doorknob @Quill)

trichoplax

@AlexA. Best file a bug report quick before we accidentally graduate early!

Alex A.

XD

I don't know whether it's a bug

I'm not really clear on how A51 gets a lot of its numbers

user2284570

@trichoplax : done.

Geobits

12:18 AM

@AlexA. I'm not saying it's aliens, but...

DJ McGoathem

Hey @AlexA. Will you add me to the steam group?

steamcommunity.com/id/drop-drop-drop-the-bass

quartata

@Geobits it's aliens

Alex A.

@DJMcGoathem Sure! Give me just a sec.

DJ McGoathem

Awesome!

trichoplax

@AlexA. Can I ask your opinion on the challenge I'm giving feedback on? We're getting it more clear but it occurs to me that testing solutions could be difficult. Do you think that would be an obstacle to reopening?

Alex A.

12:19 AM

@DJMcGoathem Surely I couldn't deny someone as goaty as yourself.

trichoplax

codegolf.stackexchange.com/questions/72030/…

Alex A.

@DJMcGoathem Alright, invitation sent.

@trichoplax Let me take a look...

DJ McGoathem

@AlexA. Alright, Invitation accepted.

Thanks!

trichoplax

@user2284570 We like to keep challenges as open as possible so as many people as possible can compete. Is there a reason for excluding non-Intel computers and dos based operating systems that can't be dealt with by making a different restriction? Perhaps excluding just the problem aspect rather than the whole computer/operating system?

Doorknob

I can't wrap text in an SVG? -_-

user2284570

12:26 AM

@trichoplax : The purpose was mainly that I stay able to test answers. For example, I already know an Atari 512 st *(motorola based)*wouldn’t have this problem by design of it’s os. But this would require real hardware.

Liam

Anyone used golf-cpu before that could maybe answer a couple questions for me?

New Main Posts

0

Q: How drunk am I and when can I drive again?

It's weekend and what are the cool guys doing on weekends? Drinking of course! But you know what's not so cool? Drinking and driving. So you decide to write a program that tells you how loaded you are and when you are gonna be able to drive again without getting pulled over by the cops and loosin...

trichoplax

@user2284570 Ah I see. Often code-golf challenges are tested by others as there may be more languages in use than the challenge author has experience with, so I wouldn't worry about testing them all yourself. Perhaps you could restrict to systems where this is non-trivial?

Quill

@Doorknob Wat?

Doorknob

I'm trying to have wrapped text in an SVG but apparently that's not possible

Quill

12:34 AM

@AlexA. maybe they're also using deleted answers?

trichoplax

@Quill What's that? We can graduate by posting lots of spam?

Quill

@trichoplax That's answers, not questions

Which is not the metric that need[s|ed] work

@Doorknob developer.mozilla.org/en-US/docs/Web/SVG/Element/text

trichoplax

@Quill I see my mistake now - the 9.9 made me think of questions - I should have read what was actually written...

Doorknob

@Quill this does not help

user2284570

@trichoplax This is what I did with Dos : the fat filesystem was designed for dos (not to mention you have full access to hardware). So it’s obvious the task would be easy.

Alex A.

12:36 AM

lel

rekt

Quill

SVG's positioning system is similar to HTML, you might be able to make styling classes in the SVG document to apply to them

Alex A.

@trichoplax I'm a little out of my element because I don't understand file systems that well (especially the abomination that is FAT), but I think I understand what the challenge is now. However, it seems like it would be near impossible for folks not on Windows to test their answers.

And if that's not the case, then I'm back to not understanding the challenge

trichoplax

@AlexA. I can assure you I'm further out of my depth than you - all I've been doing is pointing out what isn't clear... With dos (and presumably Windows) excluded, so that all solutions are untestable, does that also make it off topic?

Quill

For testing : on an unix system, it would be impossible to see the full path. On a Windows® system the nul byte don’t appear at all. — user2284570 17 mins ago

Sounds like a literal impossible challenge

Alex A.

Possible on Windows I guess

Quill

12:41 AM

it could be rewritten to be a string operation, but then it would be a simple find and insert operation

trichoplax

@Quill Does that mean that everything up to the null byte would be visible? That might be enough for testing the first half, if that's considered sufficient

Quill

@trichoplax I think he's saying the null byte wouldn't be visible at all

Alex A.

I think if you try to insert a null byte on Unix at all, it'll cause an error

user2284570

@trichoplax : yes the first half would be visible on Posix.

trichoplax

@Quill I was imagining on a unix system that the path might just be truncated, but I have no unix experience

Alex A.

12:43 AM

@user2284570 What is Pousx?

user2284570

@trichoplax : yes it would be truncated.

Alex A.

I'm not familiar with that

user2284570

@AlexA. : corrected.

somebody

@AlexA. why one page at a time for the stats script?

Alex A.

@somebody If you're referring to the Python thing on my GitHub, that's how the SE API handles requests with a large set of results.

At least based on my understanding

somebody

12:45 AM

oh

user2284570

@Quill : Microsoft Windows® would strip the 0 byte so it would appear as if nothing exists.

Quill

3 mins ago, by Quill

@trichoplax I think he's saying the null byte wouldn't be visible at all

yep

Alex A.

@somebody For contrast, the YouTube API has a maxResults parameter, but if the size of the result exceeds that, you still have to perform pagination.

AFAIK there's no such parameter for SE

user2284570

@Quill : but only on Windows.

Geobits

Marky died :/

Alex A.

12:47 AM

D:

ETHproductions

:(

Alex A.

RIP

ETHproductions

Now ETHbot has no-one to chat with

somebody

@AlexA. so SE's pagesize is a diferent thing?

Quill

It's called max, but I can't seem to work it

trichoplax

12:48 AM

@user2284570 I can't help with testability - I'm confused already. The only other thing I'd change apart from that is the exclusion based on the availability of pre-compiled binaries. If you're happy for other people to test the solutions then this doesn't seem as important.

somebody

@Quil what's called max? SE's max is max votes

Quill

3 mins ago, by Alex A.

AFAIK there's no such parameter for SE

trichoplax

@Geobits What was his perplexity in the end?

Quill

@somebody oh, okay

I thought there was one for max page size though...

somebody

yeah, pagesize

Geobits

12:50 AM

@trichoplax Dunno. Not at home. I'm guessing his learning process is still running. The chatbot part isn't responding, but they're separate.

trichoplax

@Geobits Oh, so it's more like he's lost his voice? His mind might still be intact?

Quill

anyone for a cat burrito?

Geobits

Oh, yea, he's not permadead. He just needs to go back to his last save point.

ETHproductions

@CᴏɴᴏʀO'Bʀɪᴇɴ I got it working! :D jsfiddle.net/99k66kqm

Alex A.

The maximum pagesize is 100. I wonder what the default is.

30

user2284570

12:52 AM

In the meantime, I already said you’re free for the ᴏꜱ. It would even be ok to use something you created yourself.

@trichoplax : edited.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@ETHproductions whoa

I am impressed holy cow!

ETHproductions

:D

Cᴏɴᴏʀ O'Bʀɪᴇɴ

This is like the first javascript function I couldn't understand on the first three reads in a while o_O

ETHproductions

Maybe I shouldn't have golfed it so much, but I built it golfed from the ground up

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Wow. What does loop do?

ETHproductions

1:02 AM

Makes sure it doesn't go into an infinite loop for some reason. I added it for testing, but it can (maybe) be removed.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Ah, that's a nice touch.

Alex A.

@somebody I set the page size to max. Nice idea, thanks!

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

1-up your average quine code-golf quine A 1-up quine is a program which is very similar to a quine. The one major difference is that instead of printing itself once, when n copies of the code are concatenated, the result prints the code n+1 times. Example If your code is 1+"q_"o: 1+"q_"o ->...

quartata

@Quill mm

Alex A.

@quartata Are you saying you like to eat cat meat burritos four meals a day?

quartata

1:12 AM

five but yes

Alex A.

Oh, okay. That's good because I was just about to say that you aren't getting your daily recommended amount of cat meat.

trichoplax

@user2284570 That seems pretty clear now. Whether it is reopened will now depend on whether it is on topic, with the testability concerns. I can't help with that. Hopefully someone in here can help, or otherwise it might need to be discussed on our Meta site first.

quartata

@AlexA. I'm very careful about my diet.

Alex A.

@trichoplax I've been thinking about the testability stuff and I'm afraid I haven't come up with a good answer. The level to which this is OS-dependent exceeds that of most of the other challenges I've seen.

@quartata That's good, I don't want you getting hypokittyism.

user2284570

@AlexA. maybe editing /dev/sda directly (it can also be done on windows) ?

trichoplax

1:18 AM

@AlexA. I feel like it might need a meta discussion, but I'm not sure I even know what to ask apart from "This question, is it on topic?"

Alex A.

@user2284570 What's the Windows equivalent of /dev/sda?

@trichoplax Yes, agreed to everything you just said.

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

The guidelines for a community advertisement are: The image that you create must be 300 x 250 pixels, or double that if retina. Must be hosted through our standard image uploader (imgur) Must be GIF or PNG No animated GIFs Absolute limit on file size of 150 KB If the background of the image is ...

Alex A.

@Doorknob, @Dennis :: Are you two around?

trichoplax

Is it just the sandbox that has no rep requirement now, or all of meta?

user2284570

@AlexA. : Something like \\device\HardDisk0\Partition1

Dennis

1:20 AM

@AlexA. Yes.

user2284570

I’ don’t exactly remember.

Dennis

@trichoplax All of meta.

@Dennis Thanks.

@Dennis Halp

With what?

1:21 AM

user2284570's challenge. Is it on topic?

user2284570

@AlexA. : in the meantime, cygwin and the official Microsoft interix can provide a transparent layer for getting the same path and device names.

Quill

It's exceptionally localised, would only do with a few languages

Alex A.

Not necessarily; I think a lot of (at least mainstream) languages can access/modify the file system.

user2284570

@Quill : I thought there were questions asking a codegolf to be implemented in a particular language.

Alex A.

No, that's generally discouraged here.

user2284570

1:25 AM

There are also several userland libraries for bitwise handling fat filesystems (dosfstools).

@AlexA. : Sure, a lot of languages allow direct hard/flash drive access (even python).

Doorknob

@AlexA. yes

user2284570

Hey, I think I may have found the solution : Java ME. (2 nul byte for termination). It might be as simple as creating a file.

Doorknob

10.4 questions per day, by the way

2

Alex A.

@Doorknob Halp

Doorknob

halp how

Alex A.

1:31 AM

user2284570's challenge. Is it on topic?

Doorknob

can haz link plz

Alex A.

1

Q: Insert the ascii nul character in the middle of filename on a fat volume

The purpose Unlike many filesystems, the use of the nul byte on fat volumes is legal in filenames when it's not the first character of the name. So the purpose is to test implementations of the fat filesystem in terms of security. Rules The code needs to be as short as possible. You're free t...

code-golf file-system

Dennis

@AlexA. I guess it's on topic. But:

I'm not sure what at the 1st half of its name means, and at least one of the example file names is invalid except for maybe 8-bit FAT (which I know next to nothing about). It might be a little broad though. All solutions I can think of would require implementing at least a subset of FAT. Also, no part of the challenge specifies which FAT is should be.

Alex A.

@user2284570 ^

Cᴏɴᴏʀ O'Bʀɪᴇɴ

heyyy @ETHproductions how would I undo the process?

user2284570

1:33 AM

@Dennis ok for 8 bit fat.

Alex A.

@Doorknob Did you use my super cool Python script or did you check Area 51?

Doorknob

I checked Area 51

Alex A.

ಠ_ಠ

Dennis

@user2284570 I don't think so. Some stuff has 10 characters. 8-bit FAT had a 9 character limit.

user2284570

@Dennis corrected.

somebody

1:35 AM

@AlexA. i think it would be better if the script is hosted in the cloud and checks only once per day or something

Alex A.

@somebody When what's the point of using it over Area 51? :P

Not that there's really one to begin with...

Doorknob

llama@llama:~$ curl area51.stackexchange.com/proposals/4570 2>/dev/null|grep h-v|head -n1|awk -F'[<>]' '{print $3}'
10.4

you should use my super cool bash script :P

quartata

!!

ӍѲꝆΛҐӍΛПҒЦꝆ

Anyone know how to transpose input in Retina?

Like:
abcd
abcd

to

aa
bb
cc
dd

user2284570

@Dennis : as I said : chat.stackexchange.com/transcript/message/27563600#27563600

Alex A.

1:38 AM

@Doorknob ... :(

user2284570

In the meantime, internal fat structures is definitely common knowledge for those who work in robotics (implementing a fat driver is a repetitive task).

somebody

@AlexA. 1. It can provide different stats/easier to read format? 2. That way it saves API calls if you're connected to the internet. If you want, you could also implement an API for the website, and someone could make a desktop client or something.

Dennis

@user2284570 file or directory on a fat‑formatted filesystem I don't think 8-bit FAT had directories.

user2284570

@Dennis : I remembered about directories on the microship infrared remote controls I worked.

don’t remember if it was Fat 12.

Alex A.

@somebody That's far beyond the scope of what I had hoped to accomplish with my little script. The fact that someone starred the repo is even more than I expected. :P

Doorknob

1:44 AM

eh:s`M.wk"http://area51.stackexchange.com/proposals/4570""h-v\D*([^<]*)"4

@AlexA. Pyth script to get q/day

Alex A.

ಠ_ಠ

Doorknob

llama@llama:~$ pyth -c 'eh:s`M.wk"http://area51.stackexchange.com/proposals/4570""h-v\D*([^<]*)"4'
10.4

Geobits

Clearly you have a bug. 10.4 is way too much for PPCG ;)

Doorknob

haha

llama@llama:~$ alias qpd='pyth -c '\''eh:s`M.wk"http://area51.stackexchange.com/proposals/4570""h-v\D*([^<]*)"4'\'
llama@llama:~$ qpd
10.4

this is going in my zshrc :P

Dennis

@user2284570 FAT 12 is an entirely different beast. Directories aside, I'm still concerned about the broadness. The method you mention would still require finding than operating system that supports 8-bit FAT and doesn't run in real mode. I'm not suret that such a thing doesn't exist, but I somehow doubt it.

I'm not saying the challenge shouldn't be reopened, but I don't know enough about the topic to reopen it myself.

Alex A.

1:51 AM

@Doorknob Okay, I get it, my script is unnecessary. ._.

Doorknob

haha, it's just the relentless desire of the programmer to optimize :P

If I had a Raspberry Pi as a closet server, I could make it automagically post in chat whenever q/day increased...

somebody

@Doorknob *code golfer

trichoplax

@Doorknob Or whenever we hit a new all time best :)

Doorknob

Yeah, that's what I meant

trichoplax

That would be great. Is there a way to do it without the Raspberry Pi?

If not, the Pi Zero is only $5...

Doorknob

1:55 AM

I could use AWS, but I think they charge bills after a year

Or find some other cloud service

Or just find someone who perpetually keeps a computer on and ask them to run this script please :P

trichoplax

Lots of people keep their mobile phone perpetually on...

Doorknob

(I would be giving login details to them unencrypted, though)

@trichoplax That would probably be an annoying battery drain though

Dennis

@trichoplax You can turn them off?

trichoplax

@Doorknob Oh yeah...

@Dennis :P

Doorknob

I've been wanting to experiment with the Raspberry Pi for a very long time now anyway. Maybe this can be my excuse. :P

Alex A.

1:59 AM

I want to build a supercomputing cluster out of Raspberry Pis.

Doorknob

I saw a guy at CodeDay who did just that!

Dennis

Is there anything you can actually do with these things?

Doorknob

He did a demo with three RaspPis that cracked an MD5 surprisingly quickly.

Alex A.

How fast would the same algorithm have been in serial?

/the same/an equivalent/

somebody

Raspberry Pi + Lego = Supercomputer

►

ӍѲꝆΛҐӍΛПҒЦꝆ

2:00 AM

@ӍѲꝆΛҐӍΛПҒЦꝆ anyone?

Doorknob

@AlexA. I dunno; there are probably laptops with more processing power than three Pis, but it's still an interesting experiment (especially considering it worked)

Dennis

mmmh three pies

Alex A.

El'endia Starman

@quartata: good idea on doing a video stress test. I downloaded and ran FurMark, and my computer crashed within a minute. Several seconds after reaching and maintaining a peak temperature of 90 C.

Or was it F? Either way, hot.

Alex A.

UM WHAT

user2284570

2:03 AM

@Dennis : that new question worth an another question on electronics.se (what is allowed on fat).

Dennis

90 F would barely be warm.

El'endia Starman

True. So C.

Alex A.

90 C would be danger

Dennis

That depends. 90 °C is perfectly acceptable for some CPUs.

user2284570

@Dennis : Yeah en.wikipedia.org/wiki/Philae_(spacecraft)

El'endia Starman

2:05 AM

Indeed. After all, there's no water in the CPU/GPU. :P

Alex A.

._.

That just seems so hot to me

El'endia Starman

Pretty non-intuitive, yeah. :P

PhiNotPi

@El'endiaStarman The vote-happy culture of PPCG also gets a lot of messages on the starboard.

El'endia Starman

Of course. :P

Alex A.

El'endia Starboard

Doorknob

2:08 AM

Molstarmanful

user2284570

@Dennis : I still think the record is below -150℃ en.wikipedia.org/wiki/Voyager_1 (they shutted down heaters to save energy)

Dennis

@AlexA. My CPU has a max. temperature of 105 °C at the die.

El'endia Starman

@AlexA. Just opened up CPUID HWMonitor and it says that my CPU is currently at 105 C.

Alex A.

@Doorknob "Molstar" sounds... bad.

Calvin's Hobbies

@AlexA. Saw this out of context and got confused...

quartata

2:09 AM

@El'endiaStarmanI actually meant the in game stress test

Alex A.

@Calvin'sHobbies ( ͡° ͜ʖ ͡°)

PhiNotPi

I asked this earlier, but do we have independent confirmation that n=36 gives that really weird big number?

quartata

It's on the main menu.

El'endia Starman

@quartata Oh well I got what I needed. :P

ӍѲꝆΛҐӍΛПҒЦꝆ

@Doorknob Umwat

quartata

2:09 AM

yea

somebody

@PhiNotPi yes, orlp ran it multiple times

i did too

ӍѲꝆΛҐӍΛПҒЦꝆ

@ӍѲꝆΛҐӍΛПҒЦꝆ no one?

PhiNotPi

Independent meaning more than one program gives that result?

quartata

I'm actually seriously considering posting my Perl problem on SO. Is that sort of debugging still on topic there?

El'endia Starman

@ӍѲꝆΛҐӍΛПҒЦꝆ I don't know Retina.

somebody

2:10 AM

idk, haven't checked yet

Doorknob

@quartata SO is basically if (rand() < 0.5) closeQuestion();

2

El'endia Starman

@quartata When I answered Python questions for a week, basically every question was a debugging question.

quartata

@Doorknob haha

anyways I gotta go

El'endia Starman

@PhiNotPi Gimme a moment to write a program to check.

Doorknob

this is probably a stupid question, but does the Raspberry Pi ship with internet access out of the box? Or do I need a dongle or some thingy to plug it into if I want wifi?

quartata

2:15 AM

It has an Ethernet port.

Calvin's Hobbies

@Doorknob The rpi2 has an Ethernet port that you can use to attach it to a router, but there is no built in wifi, you need to buy a dongle (some canakits come with a wifi dongle)

quartata

at least model B does

Alex A.

@Doorknob ( ͡° ͜ʖ ͡°)

( ͜ಠ ͡ʖ ͜ಠ)

Doorknob

Do any of the other models have Ethernet ports?

user2284570

@Dennis : Ok, I made a radical change to the post. But It still allows the same the same objective.

Calvin's Hobbies

2:18 AM

@Doorknob I don't think so

@Doorknob Though they all have some form of usb port so you can get wifi with a usb dongle

Doorknob

Okay, thanks

PhiNotPi

@El'endiaStarman IDK if anyone has already pointed this out, but 174762 in binary is 101010101010101010

Doorknob

yesterday, by Doorknob

101010101010101010

PhiNotPi

k

Doorknob

Hmm. If I'm okay with accessing my Raspberry Pi solely via SSH (which I am), then all I need is a Pi Zero and a wifi dongle.

El'endia Starman

2:30 AM

Yep, I get 174762 as well, and I wrote my code from scratch.

Doorknob

Every place I can find says the Pi Zero is sold out though ;(

PhiNotPi

@El'endiaStarman well then

somebody

@PhiNotPi same as the JS code

El'endia Starman

It honestly amuses me a bit how strong our instinct/desire to cram n=36 into a pattern is. :P

PhiNotPi

Are there any other values that break the 2^a-2 pattern?

somebody

2:34 AM

n=36 has a pattern - it's 524286/3

@PhiNotPi idk

also, it's not 2^a-2 - it's (2^a-1)*2^b

someone check with these

1 1
2 2
3 1
4 6
5 4
6 14
7 1
8 14
9 12
10 62
11 8
12 126
13 28
14 30
15 1
16 30
17 28
18 1022
19 24
20 126
21 124
22 4094
23 16
24 2046
25 252
26 1022
27 56
28 32766
29 60
30 62
31 1
32 62
33 60
34 8190
35 56
36 174762
37 2044
38 8190
39 48
40 2046
41 252
42 254
43 248
44 8190
45 8188
46 16777214
47 32
48 4194302
49 4092
50 510
51 504
52 134217726
53 2044
54 2097150
55 112
56 1022
57 65532
58 1073741822
59 120
60 2147483646
61 124
62 126
63 1
64 126
65 124
67 120
68 8388606

PhiNotPi

@somebody I'm just referring to the even numbered n

El'endia Starman

Wat. The one for 73 is 1010101010101010100.

PhiNotPi

The pattern for odd numbers is pretty simple

for odd n, f(n) = 2*f((n-1)/2) (excluding when n+1 is a power of 2)

trichoplax

I wondered about multiples of 36 but 72 is 1022

El'endia Starman

Yeah, I guessed the next outlier to be 72. Nope, 73.

The mystery deepens...

PhiNotPi

2:38 AM

Not really, the next outlier will be 147, etc.

trichoplax

There are a few larger results before 72 though

58 and 60

El'endia Starman

Outlier in the sense of the pattern in binary.

1 1 1
2 2 10
3 1 1
4 6 110
5 4 100
6 14 1110
7 1 1
8 14 1110
9 12 1100
10 62 111110
11 8 1000
12 126 1111110
13 28 11100
14 30 11110
15 1 1
16 30 11110
17 28 11100
18 1022 1111111110
19 24 11000
20 126 1111110
21 124 1111100
22 4094 111111111110
23 16 10000
24 2046 11111111110
25 252 11111100
26 1022 1111111110
27 56 111000
28 32766 111111111111110
29 60 111100
30 62 111110
31 1 1
32 62 111110
33 60 111100
34 8190 1111111111110
35 56 111000
36 174762 101010101010101010
37 2044 11111111100
38 8190 1111111111110

trichoplax

New sequence: Perform a stable sort on the natural numbers using this result as the key

PhiNotPi

Yeah I think 147 is probably the next outlier

somebody

imgur.com/NC6yTTq <- my craptop is dying

trichoplax

2:42 AM

Oh no my sequence wouldn't work - it would just be all the period 1 ones and never reach anything else :(

Dennis

@user2284570 I know even less about HFS than I do about 8-bit FAT. I don't feel competent to single-handedly decide whether it should get reopened or remain closed.

PhiNotPi

Anybody not understand the f(2a+1) = 2*f(a) rule?

trichoplax

Doesn't work for a=1

PhiNotPi

The sole exceptions are when 2n+1 is a power of 2, in which case it is 1

trichoplax

Ah I see

El'endia Starman

2:46 AM

And the "rule" in this case can't really be considered a rule because of n=36. :P

PhiNotPi

36 doesn't fit the form of 2a+1

trichoplax

Is there an intuitive reason for the formula?

PhiNotPi

yes

I'm trying to format my diagram

El'endia Starman

Oh right, you're only considering odd numbers. Nevermind.

PhiNotPi

> 1 0 0 0 0 0 0 0 0

> 0 1 0 0 0 0 0 0 0

> 1 0 1 0 0 0 0 0 0

> 0 0 0 1 0 0 0 0 0

> 0 0 1 0 1 0 0 0 0

> 0 1 0 0 0 1 0 0 0

> 1 0 1 0 1 0 1 0 0

> 0 0 0 0 0 0 0 1 0

now look at the bolded characters

> 1 0 0 0
> 0 1 0 0
> 1 0 1 0
> 0 0 0 1

It's the same rule, inside of itself.

trichoplax

2:49 AM

Oooh!

El'endia Starman

that's pretty cool

PhiNotPi

It's 2a+1 times as wide and takes twice as long

the exception being when it dies out, because then both the odd and even generations are the same

trichoplax

There's the same pattern in the bottom right too if you ignore the final column

PhiNotPi

That only works because I didn't do any "complicated" steps yet.

trichoplax

So once it reaches the right hand side it will interfere with the neat pattern?

PhiNotPi

2:52 AM

The "neat pattern" being your "same pattern in the bottom right" not my neat pattern.

trichoplax

yes

somebody

@PhiNotPi that means no other weird even numbers yet

PhiNotPi

Since it hasn't bounced off any walls yet, it's just doing the Sierpinski triangle pattern, which is a fractal.

@somebody What means?

somebody

the pattern implies odd number values can be calculated easily, so the only wweird number right now is 36

*are based off even numbers

PhiNotPi

Yes, odd numbers are trivial once we figure out even numbers.

When it comes to the even widths, the trick above doesn't work. You'd end up with something like 1 0 0 0 where one of the bolded letters touches the edge.

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