The Nineteenth Byte - 2015-08-31 (page 2 of 3)

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12:00 PM

v. interesting!

can I add these to the question?

the n/2 aspect is surprising!

in fact very surprising indeed

looking at your code they are optimal, right?

yeah i checked all possibilities, without loss of generality (we can fix the first element as 1, and the second element as 1 as well)

why can you fix the first two?

negating the matrix doesn't change the dot products

I can see why you can fix the first one

but really the first two?

and there must be two of the same element adjacent in the first row, so you can always rotate to get them at the beginning

12:04 PM

I would need to implement a completely brute force solution to check :)

but I trust you

if you alternate 1, -1, 1, -1, 1, -1 you can't get above m=1

oh I see what you mean!

I feel you have understand this problem very well!

so could the answer just be n/2?

seems odd this isn't mentioned in the literature if so :)

oh.. 14?

what do you get for n = 14?

or n = 10?

so consider a1, a2, ..., an

sec

i'm just trying to see a simple way to explain the parity argument

for (a1,a2), (a2,a3), ... (a{n-1},an), (an,a1)

in order for m >= 2 we need exactly half of them to be same sign

but (an,a1) is determined by the ones before it

so for (a1,a2), ..., (a{n-1},an), you'll have (same sign, different sign) = (n/2, n/2-1) or (n/2-1, n/2)

@BetaDecay What's this about? (Probably me using a conversational tone)

essentially, for n = 4k, (an,a1) will be the right value, and for n = 4k + 2 it won't be

12:17 PM

@MitchSchwartz do you mean m>=n/2 ?

@Lembik no

@MitchSchwartz there can't be a simple argument as this has been an open problem for years

oh ok.. sorry

I am wondering why you get m = n/2 so much

what do you get for n = 6?

oh ok, simple explanation: for n = 4k + 2, you would need an odd number of the pairs in { (a1,a2), (a2,a3), ... (a{n-1},an), (an,a1) } to have elements with different sign, but that's impossible because it would imply that a1 = -a1

@Lembik those are all m=1, that's what i've been saying multiple times

12:35 PM

there aren't too many matrices that reach the record for each of these small n; i'll print them all out and look for a pattern

@MitchSchwartz oh yes you did.. sorry I was distracted

it would definitely be amazing if the answer is either 1 or n/2 !

well i'm not seeing a nice pattern that would allow you to construct a matrix with m = n/2 for arbitrary n = 4k, it would be cool if someone found one

or not necessarily a pattern, any way to generate them ofc

that is not too slow

1 hour later…

1:50 PM

@Lembik I'm a bit confused by orthogonality

could you help me?

why are the vectors [-1, -1] and [1, 1] orthogonal?

their dot product is not 0, so supposedly they are

but they lie on one line, no?

@orlp they need to be at right angles

but they point in the same direction

oh wait I'm stupid

if the dot product is 0 they're orthogonal

[-1,1] and [1,1] are at right angles

not nonzero

yes :)

I had another version of the problem to minimize the maximum dot product between rows :)

maybe next time

1:56 PM

This looks like fun :)

i'm finding that the second half is often the negation of the first half except for a single reversal, in rows that reach max

or, a single non-reversal, if that's clearer

so for example with n = 24, the first one found was 110000001011001111010100, and the second half of that is almost the bitwise not of the first in this representation

@Shebang what does?

Your question!

@Shebang great! :)

If I get enough time today I will try it out, but I'm getting ready to move tomorrow :P

2:08 PM

good luck!

Tomorrow gets moved every day. What's so special about this time?

i'll try a heuristic and see how it goes

@MitchSchwartz good plan!

is it correct that there is no partial circulant matrix for N=6 that even has two rows?

yeah, i wrote about that above

2:13 PM

oh

ok

is this true in general for 4k+2?

yup

how to sort questions by specific things?

so shouldn't the question be edited then?

like number of answers.

from 'all even N' to 'all N=4k'

2:18 PM

@orlp well... it could be edited or an answer or comment could give the answers for all the other cases :)

well the odd N case is trivial and the N = 4k + 2 case takes a little thought to prove, but yeah that's an option

is there an easy way to construct orthogonal vectors to a set of bases?

(not in the rotating part, but the part below it)

0

Q: Back to the future: Post-quantum cryptography

If you know your programming history, you may know that one of the earliest code golf challenges was to implement RSA encryption. Now, I'm challenging you to code golf an encryption system that is post-quantum. The Task Choose a secure post-quantum asymmetric encryption system and a secure pos...

code-golf cryptography

2:36 PM

I just read an interesting article about election fraud, and how they used statistics to detect it in the Iowa caucus.

Link?

There's actually two related articles: here and here

The basic idea is that, when looking at the precinct level, there should be no relationship between the size of the precinct and the percentages of voters who vote for each candidate.

oof, the heuristic failed for n = 32

this is what an election should look like:

user image

@Lembik ideone.com/U1VqrC

2:42 PM

Interesting. I was going to make an argument regarding rural vs urban, but it looks like they've already accounted for that.

the x-axis is cumulative vote count, ordered from small to large precincts

This is the result from the 2012 republican Iowa caucus

user image

Notice how one candidate slopes upwards while all others slope downwards

The logic is that someone looking to change the results of an election focuses on rigging the larger precincts and doesn't attempt to rig the smaller precincts.

Hmm. Couldn't you also say that someone looking to win would focus campaigning in the larger precincts?

Each precinct is very small, in the above chart, the average precinct only had 67 votes.

Oh wow. Iowa isn't Florida, I guess.

That would require an extremely detailed campaign strategy.

2:49 PM

There were more than 67 people in line at any given precinct all day here.

(well, maybe not all precincts, but many)

Oh wait, this is caucus, not general election. Ok, I can see many fewer votes for that.

An important point is to look at the distribution of votes in counties with and without a "central tabulator" machine.

(like on page 5 of my second link) they point out that all counties without a central tabulator machine had flat lines.

Yea, just now looking at that.

Sadly, I don't think there's anything to be done without (non-statistical) proof. It's been three years since these papers were published, yet no real action has been taken. I can only assume that the DoJ would be pursuing this if "concrete" evidence was there, considering they're headed by a Democrat and they've been on the losing side of the alleged fraud.

3:07 PM

Somebody is currently suing the state of Kansas to obtain the original voting records, since the state has blocked her previous request.

only news article I could find: kshb.com/news/state/kansas/…

I hope something interesting comes out of this.

We'll see, but I'm not holding my breath. OpEd from Kansas SecState lays out the state's case in brief.

I have a feeling it'll just be thrown out (unless significant outside pressure is applied).

Martin Büttner

3:30 PM

We've got a little surprise on meta for you...

2

For me?

Martin Büttner

plural you

Oh look, Alex didn't have to murder Dennis after all :D

I'm starting to worry that our ecosystem is getting unbalanced. We need more trolls, flamers, and spambots or else our mods might starve!

A heartfelt welcome to our new moderator...s!

19

3:37 PM

Looks like we need more pizza.

5

So we can call you Diamond Dennis now, right?

Martin Büttner

2 days ago, by Martin Büttner

@Calvin'sHobbies I'm not saying why, but you may have posted that a bit too early.

Woah, bombshell

Well done @AlexA. :D

@NewMetaPosts I'm going to go ahead and pin that

@Geobits Dennis Diamond, please.

3:51 PM

This is a party... We need cake :D

Blue Dennis

Wow, not just Dennis!

Achievement get! Diamonds for you

So, 40% of the candidates became mods?

In the end, there can be only, um, two.

And all mods were nominated by Alex.

4:01 PM

This is not at all a scalable model!

4:21 PM

What's Hitler doing in this chat room? :|

Chris Jester-Young

@BetaDecay I hereby invoke Godwin's Law. :-P

Also, Big Brother is watching us.

picture falls off the wall

Congratulations @AlexA.

@trichoplax Thank you so much! :D

@Dennis Really?

4:36 PM

@AlexA. No :)

Yup, two for two.

(You should know.)

Oh - all mods, not all nominations - ignore me...

I never ignore you. <3

:)

@Dennis @AlexA. the blue looks good

:D

4:39 PM

Have you tried out your new powers yet?

javascript:$(".username").addClass("moderator")

^ Everyone gets to be a mod!

Well, I looked at them.

I'm still figuring things out

slow...

4:54 PM

So if there's no real question in a question, we should close as "unclear what you're asking", right? :P

wields close hammer

If we start doing that, main will be empty though. :P

Nah, just rephrase them all as "What is the shortest blah blah blah?"

oh, closing that was just a joke?

retracts close vote

5:19 PM

@Optimizer If you run that does it actually work?

u can run it, u no

i on fone

yolo

2

It strikes again :D

I see.

5:24 PM

I sincerely hope we don't start posting links back and forth whenever a meme rears its head. The stars will never stop.

I am gonna add this to my about section:

> Originator of 2 PPCG Memes

I'm sure there are more.

Martin Büttner

@Optimizer put it on your CV

@MartinBüttner I don't want to make the "percentage of actually useful content in my CV" less than 1%

If it's already low enough that that would push it under 1%, you might as well go all out.

5:34 PM

@Geobits just that line won't, but knowing me, I won't stop there, once started

You say that as if it's a bad thing.

Its a bad thing for health.

no job -> no money -> no food

Martin Büttner

@Geobits it might be empty so far

so the current percentage might just be undefined

given that I am working, it can't be empty

"Working" doesn't necessarily imply that you're doing something which increases the percent of useful content on your CV.

5:36 PM

but it still can't be empty

After all, you are in here, where all work is abandoned.

also, even when I am not here, I am still here

There are valid reasons to omit certain jobs from your CV. So it doesn't have to have something in it if you're working.

@Optimizer That sounds really deep.

there are other mandatory sections apart from "job experience" too

for ex., Name

5:37 PM

Sure, but if you haven't written it yet, it's empty.

Name: Optimizer. Occupation: Llama. Achievements: 2+ PPCG memes.

Pl0x to hire 4 teh jobz

@Geobits since I have a job, I had to have a cv to show to the interviewers.

I've gotten at least two jobs without one.

I dunno how it works there, though.

"coz java"

Neither were java jobs :D

5:39 PM

@Geobits I've gotten two or three without a CV but I was in my teens. If you managed to do it older then I salute you.

@Geobits that was for me

@AlexA. Yea, I meant in my teens. Apparently at a certain age people expect you to "grow up" and "be prepared for an interview" or some such.

So your CV just said "coz java" and you got the job? Nice work.

@Geobits It's BS. All interviews should be conducted by surprise, where the interviewers crawl into your bedroom window and wake you up in the middle of the night.

I'd still be awake in the middle of the night

Do you work a night shift?

5:43 PM

@AlexA. Kudos to them for bringing a decent ladder. I'd be impressed enough to hear their pitch.

I laughed at your deleted comment. I saw it before it was deleted.

:23786545 Correct. Cackles maniacally

Yes

(removed)

Chris Jester-Young

something something Streisand effect something

As in Barbra?

Chris Jester-Young

@AlexA. Barbra.

Streisand effect

The Streisand effect is the phenomenon whereby an attempt to hide, remove, or censor a piece of information has the unintended consequence of publicizing the information more widely, usually facilitated by the Internet. It is named after American entertainer Barbra Streisand, whose 2003 attempt to suppress photographs of her residence in Malibu, California, inadvertently drew further public attention to it. Similar attempts have been made, for example, in cease-and-desist letters to suppress numbers, files, and websites. Instead of being suppressed, the information receives extensive publicity...

5:48 PM

@ChrisJester-Young That's what I said. :P

Chris Jester-Young

@AlexA. :tuibillboard:

Uh, what?

Chris Jester-Young

Tui is a New Zealand brewery that's famous for its Yeah Right ads. Here's some examples: tui.co.nz/competitions-and-events/yeah-right-gallery

@AlexA. So when people say "Tui billboard" in New Zealand, they're saying "yeah right". :-)

A famous New Zealand brewery. Yeah right. :P

Chris Jester-Young

The winners of that contest ("I just bought my first home in Auckland! Yeah right." and "I'm saving for a house in Auckland. Yeah right.") are hilarious. If you're a New Zealander, you'll instantly get it. :-)

@Geobits Touché.

6:09 PM

@Geobits I found a java program that is shorter than yours for Hello, World!

I'm trying to run it, but I can't without declaring both the class and constructor public (and fixing what I assume is a mistaken missing ;). How are you getting it to run?

> load: H.class is not public or has no public constructor.
> java.lang.IllegalAccessException: Class sun.applet.AppletPanel can not access a member of class H with modifiers ""

It works if I change it to:

public class H extends java.applet.Applet{public H(){System.out.print("Hello, World!");}}

But then it's not shorter.

@Geobits Looks like it won't work. That's what happens every time I don't test my code.

Well damn. I was hoping to learn a new golfing trick :(

6:36 PM

How to call an Undefined Function?

You don't. It calls you.

No. You can. @UndefinedFunction

6:49 PM

I feel like I have -15 tattooed on my forehead, reading Optimizer's latest edit :D

3

This made me laugh i.imgur.com/SkZTLzH.png

(A lot of stupid stuff makes me laugh though)

Can the author even see his deleted post?

@Lembik That's on my mental list of things to look at at some point.

Martin Büttner

@Rainbolt yes

@PeterTaylor Thanks! I am trying to resist posting a new challenge which is an optimization version of that old one

that is, take n = 40 say and try to find the smallest number of rows that work

it seems there are some nice heuristics which might be helpful for such a search problem

saying as the problem seems to be still wide open

undergroundmonorail

7:05 PM

I wrote pb code that crashed cmd.exe. Huh.

@BetaDecay That seems like the most optimal meme image for -15!

I followed some links starting from HNQ and now my mind is broken

2

such a ho!

@Optimizer Haha I'm happy with it :D

@trichoplax Mathoverflow is the scariest place on SE ;)

@BetaDecay Indeed. I expect to be scared by scary questions, but "what is the volume of a ball" I thought I was safe with...

7:13 PM

Hahaha you know you should have a NSFW warning on that link

NSFL

NSALT

Lost...

NSFNMW

Lost...

undergroundmonorail

7:21 PM

the worst thing about coding in a language you designed is not knowing if your program has a bug or if your language has a bug

or if u urself have a bug

undergroundmonorail

oh dam

@undergroundmonorail At least if you designed both you know who to blame :P

@trichoplax Gödel?

undergroundmonorail

guido van rossem, for the clearly flawed language the interpreter is written in ;)

7:24 PM

@PeterTaylor For the concept of languages having a bug?

I normally blame Heisenberg whenever I'm uncertain of anything.

@trichoplax Something like that.

@Geobits That's unfair. You should blame Gabor.

Wikipedia can't help me with that one - I just get lots of results for shoes

@PeterTaylor I'm not certain I should, so I blame Heisenberg.

I'm going to guess that's a Fourier transform joke, but I'm frequently wrong

7:31 PM

@trichoplax More or less. The Heisenberg inequality (or Heisenberg-Gabor-Weyl inequality) is a particular case of a general Schwartz inequality related to Fourier transforms.

You lost me at Fourier transform ;)

... says the guy who just wrote a language named Fourier.

Technically I did get that from Wikipedia - I was reading up on Fourier transforms last week in an effort to think up questions for the Computer Graphics private beta, so I had a vague recollection that there is an uncertainty principle there

Haha I get the basic concept but I dunno how to apply it

My only real experience with them was doing (shoddy) frequency analysis on audio files to generate on-the-fly guitar hero style tracks (for an android game).

7:34 PM

Haha that sounds pretty awesome :D

And have you finished that game?

Yes and no. It's playable, but... programmer art FTW.

Also, haven't touched it in a few years. Would probably have to update it for newer Androids. I can't imagine the Honeycomb-era code is going to be very smooth now.

I've looked on the Play Store but they don't really work too well

Should I tell you about that typo or wait and then star it??

:)

Mmmm. Homeycomb.

Today is a nice day

7:37 PM

The urge has worn off now

No, that was me

Yes, that was not me.

Yes, that was you.

It was Geobits, with a pipe wrench, in the Nineteenth Byte.

5

Please no

7:39 PM

No. A one-off occurence is not a meme.

undergroundmonorail

tread carefully. memes being a meme is not a good look

@Geobits You had to say it.

Wait what?

@undergroundmonorail its yingluck

undergroundmonorail

I wasn't here for the dawn of yingluck, but I think "yingluck" would be a dope name for a rapper

7:41 PM

@trichoplax Oh wait, does that encourage people to do it more often so it gains meme status? If so, that was never my intent, and I shall atone in the proper manner if it comes to pass.

it shall never pass

ever

Memes don't pass

So they run the ball?

1, 2, 3 and to the 4
Undergroundmonorail and Yingluck is at the door

user image

Evidence

7:42 PM

@Geobits I'm not sure this is the kind of environment where that can be described as a ball

undergroundmonorail

i wish my murder weapons had branding that slick

I'm being framed! My pipe wrench is not painted; just bare metal.

It was

Until you stoved Dennis' head in for the spot as mod

Now I'm in a ~~dystopian~~ utopian future where everything is branded with Geobits' downvote symbol

@BetaDecay You have me confused with Alex. Just the threat of an... accident... from him was enough for SE to capitulate and give him a diamond :P

7:45 PM

Dennis has too much reputation to be a victim of the downvote pipe wrench

It was Justin! He killed Quincunx and took his account

I remember that name....

Who is Quincunx now?

Justin

^ that guy

O...

I wish ProgrammerDan would come back

7:48 PM

Is ProgrammerDan the same as DanTheMan?

I wish m.buettner would come back

He's right there...

Who?

m

a

7:48 PM

r

t

i

n

b

ü

7:49 PM

t

t

ner

d

ner

butt nerd?

How many times has he heard that in his life I wonder

7:50 PM

Hehe you remember that Geobits?

I remember all.

I grew up being called Rainbow

undergroundmonorail

oh yeah i remember that

I grew up being called Llama!

undergroundmonorail

i remember feeling really creepy about accidentally figuring out your name but now it's in your username so i'm not weird any more

7:52 PM

I grew up being called

@undergroundmonorail Whose name?

Awww, I missed a ping

undergroundmonorail

rainbolt

@Geobits no one used to talk to you at all?

Oh yea. I let my name loose in a Google Docs

7:52 PM

@Optimizer Why would I be called if nobody was talking to me?

@Rainbolt Your name is actually Rainbolt?!

Yes

undergroundmonorail

@Rainbolt ...that wasn't even how i figured it out haha

Sweet

@Geobits you were called <null>

7:53 PM

Still better than being a llama.

@undergroundmonorail How did you find out? My link to my company page? The fact that my profile says I play Magic, along with a tagged picture of me winning a draft?

I found it from your company name and town, which led me to the company page/profile.

undergroundmonorail

it was the link to your company page, but i only narrowed it down because i happened to remember a file in the controller for the wolf KOTH that referenced a windows path that included your username (i.e. first name) and there was only one person with that first name in a dev role

I'm totally not a stalker, by the way.

@Rainbolt Your company page has photos of some of the staff

7:55 PM

@Geobits The correct term's doxxer, right?

It has photos of all of the staff I think

@PeterTaylor That depends. My next comment was going to be to remind him to take out the trash tonight. It's getting full.

I just quickly linked there from your profile - I didn't think to check if the number of employees is the same as the number of photos...

undergroundmonorail

@Rainbolt also i googled your minecraft name because while i was pretty sure it was you, i wasn't 100% certain, and we had already been talking for a couple minutes so i didn't want to be like "by the way who are you". that's the story of how i accidentally found your facebook. sorry

How dare you

7:57 PM

So in short, none of us are stalking you. Everything is perfectly explicable.

Go "not stalk" Martin. He's way cuter without his scarf covering him up.

6

It's a bit long distance for me. Texas isn't close or anything, but...

I play Magic so by default I cannot be worth stalking

@Lembik for n = 32, the optimal is 14

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