The Nineteenth Byte

himarm jr

18:00

Random website of the day: wikipeetia.org

2

> Iin probalibity thoery, one sasy taht en evennt hapens allmost surelly (somtimes abbrieviated as a.s.) if it hapens wiht probalibity one. Teh consept is analagous to teh consept of "allmost everiwhere" iin measuer thoery.

Sherlock9

Well, John Bytheway (a preacher, apparently) was tired of jokes about his name, but he did have a favorite. A woman who met him in an airport asked if he was going to name his son Owen.

Martin Büttner

@TimmyD did you see Sp's Labyrinth answer to Stretch the word?

TimmyD

I've not yet. goes to look

zyabin101

> Q.E.D. is en enitialism of teh Laten phrase , whcih trenslates as "whcih wass to be demonstrated" or "as wass to be ekspected".

lol

aditsu

@Sherlock9 reminds me of this interview

El'endia Starman

18:06

@Doorknob Eh, I found myself agreeing more with the counter arguments in the answers. What are the reading levels of other top posts on our Meta?

Stefnotch

(Might not be on topic here, should I rather ask it on blender.stackexchange? And wait until I get a response...)

Does anybody know Blender's shrink/fatten? "translates selected vertices/edges/faces along their own normal"

How does it keep the points in the correct position? If I had a sphere, shouldn't it end up with a bunch of vertices that have a space between them?

El'endia Starman

@Stefnotch I know Blender. What kind of object do you have?

New Main Posts

3

Q: Palindromizing the strings

Introduction For the ones who don't know, a palindrome is when a string is equal to the string backwards (with exception to interpunction, spaces, etc.). An example of a palindrome is: abcdcba If you reverse this, you will end up with: abcdcba Which is the same. Therefore, we call this a p...

zyabin101

@NewMainPosts A sphere.

Stefnotch

I am asking, because I want to implement it myself (and reinvent the wheel. :P )

(And, yep, a sphere)

El'endia Starman

18:17

....ah, okay. Hmmm.

zyabin101

8 / 3 = 2.67

El'endia Starman

There is definitely a tool for doing that to faces, and if you don't care about vertices being split, that's what happens. If you do, that's the same thing as normal scaling.

Lembik

@Geobits I just read your very sad statement... :(

hi @El'endiaStarman

Geobits

@Lembik I've made a few of those. Which one?

Lembik

@Geobits The one about my challenge being designed to put you off

Geobits

18:19

Oh, ha. No offense. I'm sure it's fine for more mathy types ;)

Lembik

I wonder if I should add a terrible answer to encourage people :)

@Geobits no offence taken! :)

Stefnotch

@El'endiaStarman Well, how does Blender manage to not split the faces? (Does it take the average of the normals around the vertex?)

Lembik

anyone interested in my mathy challenge? codegolf.stackexchange.com/questions/77051/…

El'endia Starman

@Stefnotch Not sure what you mean. (In any case, you can extrude individual faces by going to edit mode, changing selection mode to faces, and clicking "Extrude Individual" in the Mesh Tools sidebar.)

Lembik

actually at this point a very naive algorithm would do well

with no math knowledge whatsoever

Sherlock9

18:22

@aditsu That was fun :D

Lembik

hi @quartata

@quartata That's a great statement for PPCG!

Downgoat

Does anyone know why this code causes an infinite loop? I removed all the left-recursion :/

ven

aw no, tryapl is down :(

Lembik

hi @MitchSchwartz

Stefnotch

@El'endiaStarman Well, I am trying to recreate it in JS. So, I got a model with a bunch of vertices and face normals. If I move the vertices along the face normals, they get split. How do I prevent that? (Is that clearer? )

Downgoat

18:26

@Stefnotch +1 for JS

Grace Note

@Sherlock9 Nothing brings me by at this time in particular. Had to reboot so rejoining all rooms looked like entry.

El'endia Starman

@Stefnotch If you don't want to split the vertices, then there is no difference between what you're describing and normal scaling of the whole object.

himarm jr

@ven isup.me/tryapl.com

ven

@himarmjr it's down.

TimmyD

> A nearly massless cat

Don't starve kitties.

Stefnotch

18:29

(Wow, Downgoat gave out a +1)

What's a normal scaling?

himarm jr

@GraceNote You are automatically in every room at once? O_O

@TimmyD AMEN!!!

ven

It still is down.

himarm jr

um

ven

yes?

Downgoat

@ven check your DNS / firewall it should be up

himarm jr

18:30

^

ven

it's down. the website is up, but you can't type anything in, because it errors

himarm jr

I had the same problem with imgur a while ago.

ven

therefore; another time: it's down.

himarm jr

Give me some apl code pls.

It works for me?

ven

might be back up now

Downgoat

18:31

^^

ven

update or whateverelse

Downgoat

if it isn't run traceroute on whatever the AJAX is

Sherlock9

@GraceNote Fair enough :D

CoolestVeto

Holy damn.

19676

A: Why is processing a sorted array faster than an unsorted array?

You are a victim of branch prediction fail. What is Branch Prediction? Consider a railroad junction: Image by Mecanismo, via Wikimedia Commons. Used under the CC-By-SA 3.0 license. Now for the sake of argument, suppose this is back in the 1800s - before long distance or radio communication...

ven

@Downgoat ...

@CoolestVeto That's mysticial for you

himarm jr

18:32

holy crap that is a lot of votes

ven

Mysticial doesn't click rep:

himarm jr

wtf

ven

:D

CoolestVeto

Dddddamn son.

New Main Posts

0

Q: Where will the cat go?

A nearly massless cat is dropped in space at the point (x, y, z) with velocity (vx, vy, vz). There is an infinitely dense planet (with volume of 0) at the point (0, 0, 0) and it attracts objects at distance r with acceleration 1/r^2. According to Newtonian gravity, where does the object go after ...

code-golf math

Downgoat

18:34

Jon Skeet eats that much rep for breakfast

himarm jr

^

ven

year-long breakfasts, then :P

Downgoat

> Instead we went for a "small and fast" computation of only 12.1 trillion digits

._.

himarm jr

^

ven

that guy's insane, yes

Mitch Schwartz

18:36

@Lembik Ƿes hāl

Downgoat

12 mins ago, by Downgoat

Does anyone know why this code causes an infinite loop? I removed all the left-recursion :/

pls halp

himarm jr

working on it

What does exec do?

Maltysen

@himarmjr idk what lang this is, but it probably executes a string as code

Downgoat

that just runs the provided grammar

E -> O E α
     ( E ) α
     P α
     L α
α -> O E α
     O α
     ε

does that grammar look fine?

Maltysen

omg what happened to ur name?

himarm jr

18:39

himarm

im himarm jr now

Downgoat

3 hours ago, by Downgoat

@himarmjr what did you do to your username

himarm jr

go ping @Randal'Thor and @himarm about it here.

Downgoat

done

TimmyD

@Downgoat You're defining E = CheddarExpressionToken inside class CheddarExpressionToken ... that seems bad?

himarm jr

@Downgoat as the not so prod owner of speleing prpoblms, YOU ARE HIMARM JR JR JR

Downgoat

18:42

@TimmyD it's just recursion, it shouldn't cause a problem (because there's no left-recursion)

himarm jr

Found the problem.

Downgoat

pls tell

himarm jr

Infinite recursion?

El'endia Starman

Oh my gosh. I hope today's xkcd isn't another long-time one...

himarm jr

somehow it isn't blowing the call stack tho.

Downgoat

18:43

well yeah, but why's that there is no left-recursion

himarm jr

@El'endiaStarman Is like hoverboard.

El'endia Starman

@himarmjr It's not like Hoverboard at all.

himarm jr

bai for now

El'endia Starman

More like Time.

himarm jr

@El'endiaStarman I mean the interactiveness.

El'endia Starman

18:44

I think.

himarm jr

@El'endiaStarman Click and drag?

Yeah, more like that one.

El'endia Starman

...[resigns myself to waiting]...

TimmyD

How does E -> O E α not have left-recursion?

himarm jr

^

El'endia Starman

On a side note, I do like how Randall is pushing the boundaries of "web comic".

Downgoat

18:45

@TimmyD Because there is a O?

that way it won't be starting from the same position

El'endia Starman

! An octopus grew!

Downgoat

wat.

TimmyD

Oh, wait, I get ya now.

Hmm.

himarm jr

@El'endiaStarman screenshot pls

Dennis

Screenshots? Permalink!

himarm jr

18:48

^

El'endia Starman

permalink

There are also two trees now!

And some grass, I think.

himarm jr

Mine has done nothing........

El'endia Starman

> Relax.

zyabin101

@El'endiaStarman wai not live ;_;

himarm jr

fine

El'endia Starman

18:50

@zyabin101 Huh? It's read-only for you, but I think it should update automatically.

Dennis

@El'endiaStarman How long did it take for that stuff to appear?

El'endia Starman

Cactus!

@Dennis A few minutes.

It's been about 8 or 9 minutes now.

And another tree!

And the trees sway in the wind!

Downgoat

oh, in my xkcd garden a pot grew, if that is good

zyabin101

@Downgoat You can copy the URL to share your garden. From other browsers, it will be view-only.

Downgoat

xkcd.com/#8a22a194-fa95-11e5-8005-42010a8e0003

Dennis

18:56

My ~~garden~~ collection of rocks.

Downgoat

@Dennis beautiful

Dennis

Nothing is happening... ._.

Downgoat

mine grew the tree in like a minute :/

Lembik

@MitchSchwartz I am impressed by your old English!

El'endia Starman

> Relax.

Dennis

18:58

(╯°□°）╯︵ ƃuᴉxɐlǝɹ

zyabin101

xkcd.com/#2b998a2e-fa96-11e5-8012-42010a8e0006

Mitch Schwartz

@Lembik your postmodern English isn't half bad either

Downgoat

@Dennis relaxing ノ( º _ ºノ)

Lembik

@MitchSchwartz very kind! How are things?

muddyfish

I've got rocks too. I'm no good at gardening

I cant even get plants to gow

Mitch Schwartz

19:00

i'm actually on the way out the door to the airport, so i won't be able to talk until later

Lembik

no problem.. have a good trip

Dennis

i have try for thirtee minut and no gardn

Downgoat

how juic xkcd

Morgan 'Venti' Thrappuccino

bug-report No avocad.

Lembik

hi @Dennis

Dennis

19:02

Hello!

zyabin101

@Downgoat us the buttons at th top. or did u men Gardn?

Downgoat

xkcd.com/1663/#99676484-fa48-11e5-8001-42010a8e0008

El'endia Starman

@NewMainPosts Wow, +0/-18. .... [makes it +0/-19 just for kicks] :P

trichoplax

I'm finding areas with just red light get lots of cacti

Nathan Merrill

woah:

xkcd.com/1663/#0fdfc5d8-fa68-11e5-8001-42010a8e0009

zyabin101

19:05

@Downgoat It's wonderful.

El'endia Starman

Makes sense - it's like a desert. Blue light produces octopi, at least.

Nathan Merrill

there's a birdbath in the tree

Downgoat

@NathanMerrill @trichoplax is that you on top of the cactus? :P

quartata

This new xkcd is confusing

where are the carnivorous plants

0/10

Dennis

-1/10 I only have rocks

Downgoat

19:07

you have a stick

Dennis

Something grew!

No clue wtf it is, but something grew!

Downgoat

\o/

wait wat.

muddyfish

I got part of stonehenge!

xkcd.com/#151b2b8a-fa97-11e5-8001-42010a8e0015

Downgoat

you got pi

muddyfish

@Dennis there's a tree in that garden!

Optimizer

19:10

how long do i have to wait to see anything happening?

Dennis

@muddyfish And some extraterrestrial pi platform. \o/

muddyfish

I found a turtle in mine!

OMG

himarm jr

what?

Downgoat

@muddyfish s/a turtle/trichoplax/

himarm jr

Turtle?

Downgoat

19:11

@Optimizer thirtee minut

muddyfish

@Dennis now you've got a place to work at!

Dennis

A desk and a chair... Back to golfing.

trichoplax

@Downgoat Lol no I think that's a land-dwelling cousin (but I can't be sure...)

Optimizer

@Downgoat this is not .... an April's fool, right?

Downgoat

it is, but stuff does grow

Lembik

19:12

@Dennis do you think I should add a really naive solution to codegolf.stackexchange.com/questions/77051/… ? I am a little worried people might not get it

Dennis

Eventually.

Optimizer

then how is it?

quartata

Nothing has grown in my garden yet.

xkcd.com/#266799e4-fa99-11e5-8001-42010a8e0011

himarm jr

I has dude.

quartata

I even have the optimal light setup

himarm jr

19:13

\o/

CUEBALL COME TO ME

Downgoat

@quartata add 1 more lite

himarm jr

BUNNY

Lembik

sorry to ask you directly.. does anyone have a view on this?

himarm jr

AND CUEBALL

@Lembik what?

Downgoat

@himarmjr what

Lembik

19:14

@himarmjr ?

himarm jr

> sorry to ask you directly.. does anyone have a view on this?

quartata

@Downgoat still nothing

Lembik

I asked Dennis a question but I think I should have just asked generally

Optimizer

you guys are all lying

Lembik

for my challenge codegolf.stackexchange.com/questions/77051/…

quartata

19:15

@Optimizer Nah, things do grow.

Downgoat

@Optimizer do you think I would lie to you? :(

Dennis

@Lembik A reference implementation? Sure, those are always a good idea. (If it's not competitive, it belongs in the question.)

Optimizer

@Downgoat even without a sweat!

trichoplax

@Optimizer It's really real. Honestly. Mine has lots, including a plant pot in a tree

Lembik

@Dennis thanks

Downgoat

19:16

@trichoplax brb copying your lites'

Lembik

@Dennis in general, do you think the challenge is too hard?

Martin Büttner

@Lembik if it's nowhere near competitive, don't make it answer though

trichoplax

@Downgoat Lol I can't guarantee it was the lights that lead to such growth - it's been sitting in its own window in the background for many hours...

Dennis

@Lembik No clue without trying. I have terrible intuition when it comes to fast code.

Lembik

@MartinBüttner thanks.... I am hoping someone will post an answer at some point :)

quartata

19:18

Still nothing, maybe watched gardens never grow

At least my lights are very aesthetically pleasing

trichoplax

Writing fast code is a slow process

Lembik

@trichoplax that is true

El'endia Starman

@quartata I'm actually wondering if watched gardens do grow in this case.

Downgoat

fastest-fast-code-golfer-in-the-west

trichoplax

@quartata I've seen one bush appear while I was looking at the screen, but everything else was introduced in my absence

El'endia Starman

19:19

Oh, just saw a counter-example happen. :P

Downgoat

@El'endiaStarman they do

quartata

wtf my lights just disappeared

I must have accidentally pruned my garden

Lembik

@Dennis I don't think I can guess that easily too. I don't know a very clever way to attack the problem

quartata

and of course a table grew

trichoplax

@quartata I had mine reset every so often when it was open in a Firefox tab. Since giving it its own Firefox window it hasn't reset again

FliiFe

19:20

Can someone explain me why my garden grew a balloon and a rock ?

xkcd.com/#9cf2e02e-fa98-11e5-800c-42010a8e0007

Lembik

@MartinBüttner there is actually a mathematica function for my challenge although it might not be obvious

Downgoat

while (true) if (Math.random() * 10000 < 2) growSomething()

trichoplax

@FliiFe They are both in the intersection of the blue and yellow light...

Downgoat

I am very sure that's how it grows something

El'endia Starman

@FliiFe That's an obelisk. Anyway, all kinds of things grow. I have an octopus in mine.

FliiFe

19:21

Still wondering why I'm staring at this garden...

Lembik

@MartinBüttner I would love to know how fast it is

as I don't have a copy of mathematica myself

CoolestVeto

So, question for you SQL peoples.

Downgoat

@CoolestVeto what is it?

mınxomaτ

3

That's pretty neat.

CoolestVeto

How would I go about randomly selecting a set number of questions (20000) from all possible questions?

Downgoat

19:24

\o/ a strand of grass grew

@CoolestVeto you want to get 20000 random questions?

trichoplax

@CoolestVeto All questions on the site or all possible strings?

CoolestVeto

@Downgoat I want to get the up vote count of 20000 random questions from SO and from Arqade.

Downgoat

185

Q: Select n random rows from SQL Server table

I've got a SQL Server table with about 50,000 rows in it. I want to select about 5,000 of those rows at random. I've thought of a complicated way, creating a temp table with a "random number" column, copying my table into that, looping through the temp table and updating each row with RAND(), and...

sql sql-server random

CoolestVeto

\o/ Thanks

Downgoat

select top 10 percent * from [yourtable] order by RAND()

that could also work

trichoplax

19:26

Weird. Deleting items from my garden also removes them from other tabs and windows showing the same address. So the content isn't encoded in the address...

Martin Büttner

@Lembik if you have code, I can test it :P

mbomb007

@MartinBüttner Can you please un-delete my post for me? I fixed it but a mod deleted so I can't.

Martin Büttner

sure, but how about this: retina.tryitonline.net/#code=T14kc2AuCg&input=YWJjZGVm

works with any characters whatsoever

Downgoat

@MartinBüttner O_o how does that work?

mbomb007

@MartinBüttner I'm just going to use what I have since that wasn't available at my original time of posting.

Martin Büttner

19:31

@Downgoat match a character then "reverse sort by" the substitution (which is empty, so all characters are identical, and the sorting itself becomes a no-op, but the reversing reverses all the characters))

Lembik

@MartinBüttner thaniks!

@MartinBüttner do you run it on a raspberry pi?

Martin Büttner

no

Lembik

even better !

muddyfish

xkcd.com/1663/#99676484-fa48-11e5-8001-42010a8e0008

El'endia Starman

....oh wait, is it possible that xkcd knows when I'm being active in any window?

muddyfish

19:33

This person's got a deer with a tortoise sniffing it

Maltysen

roflmao

Lembik

@MartinBüttner I believe it is SiegelTheta in Mathematica

@MartinBüttner SiegelTheta[Ω,s] In my case s = 0 and Ω = iP/pi

Optimizer

oh

3 grass grew

trichoplax

Welcome to the club!

isaacg

This answer is weird:

quartata

19:35

Hey look I got a deer

isaacg

0

A: Palindromizing the strings

Pyth, 11 bytes .VkI_IJ+zbB Test suite This code exploits a bug in the current version of Pyth, commit b93a874. The bug is that _IJ+zb is parsed as if it was q_J+zbJ+zb, which is equivalent to _I+zb+zb, when it should (by the design intention of Pyth) be parsed as q_J+zbJ, which is equivalent ...

quartata

xkcd.com/#5fb550b8-fa9b-11e5-800d-42010a8e0007

@isaacg haha nice

isaacg

It only works because of a bug that I didn't know about until I used it in the code

Martin Büttner

@Lembik iP?

Lembik

@MartinBüttner I have hardly ever actually used Mathematica. I just saw using the online docs that it had such a function

@MartinBüttner sqrt(-1) times the matrix P in my problem

Maltysen

19:36

@isaacg lel

isaacg

I'l update it in an hour or two.

zyabin101

@Dennis do the same in a hour or two. /sarc

isaacg

?

Martin Büttner

@Lembik looks like s is supposed to be a vector. do you mean the zero-vector of the same dimension as P?

Lembik

@MartinBüttner yes exactly

Martin Büttner

19:39

do you know a neat way to generate a random positive definitive matrix?

Lembik

@MartinBüttner yes... here is what I do. Generate a random m by n matrix M with elements from -1,1 with m < = n. Now let P = I_n + M^T M

where I_n is the n by n identity matrix

I could even provide python code but I don't suppose it would help :)

Nathan Merrill

hmmm...since we define a language by its interpreter, shouldn't we have some sort of requirements on what an "interpreter" is

Martin Büttner

@Lembik seems to work :)

Lembik

@MartinBüttner good :)

Nathan Merrill

I mean, if I have an interpreter only only my machine, is it valid?

Geobits

19:42

@NathanMerrill You can define the interpreter by its language :P

Martin Büttner

(Mathematica does have PositiveDefiniteMatrixQ)

Lembik

@MartinBüttner what does it do?

tests if a matrix is positive definite?

Martin Büttner

checks positive definiteness

Lembik

ok

Martin Büttner

all ...Q functions are predicates

Lembik

19:43

ye of little faith :)

Nathan Merrill

@Geobits I disagree. interpreters have bugs, and is actually the definition of the language. Similar to how a class is the implementation of a interface

Lembik

@MartinBüttner Thanks.. now I know 1 thing about mathematica

Martin Büttner

;)

Geobits

@NathanMerrill I tried really hard to make that an obvious joke. I'll work harder next time.

Nathan Merrill

oh, sorry :)

its a monday

trichoplax

19:44

The :P gave it away for me...

Martin Büttner

@Lembik hm, weirdly, SiegelTheta throws some internal errors but does produce a result

Lembik

can you test it with any of the matrices in my question?

Nathan Merrill

regardless, intuitively, an interpreter that only exists on my machine seems invalid, but an interpreter that isn't free should be valid

CoolestVeto

Okay, yes, I'm terrible at this (never used SQL before and I'm stumbling through it, I'm sorry). How would I sum up the up votes and down votes given a list of questions?

Nathan Merrill

that said, if the only valid interpreter was university specific, and not allowed outside of the university, is it valid?

or maybe a language designed for a company

isaacg

19:47

@NathanMerrill Well, we allow paid-only langauges, and we allow languages that only work on very specific machines, so one that only works on your machine would probably be technically legal, but very unpopular/standard loophole

Geobits

I'm not a fan of that, tbh. You run into the same problem as some of our TI-BASIC answers used to have; they don't work at all, but keep getting voted up because nobody says otherwise.

Martin Büttner

@Lembik yeah, still throws that error

Lembik

hmm.. do the examples at reference.wolfram.com/language/ref/SiegelTheta.html also throw an error?

Nathan Merrill

well, if it only exists on my language, how do I prove its existence?

for all you guys know, I've got an interpreter to English

isaacg

Publish a VM snapshot of your machine?

Geobits

19:49

"This interpreter is on my machine only and I will not share" should just be straight-up disallowed.

himarm jr

@NathanMerrill just post the source code.

Geobits

Otherwise, I'm going to start answering with zero-byte answers for everything. I've got a ton of interpreters laying around, ya know.

himarm jr

rofl

Nathan Merrill

but say I had a company/university specific language (A DSL), that I wasn't allowed to share

isaacg

@himarmjr The point is that the source code won't work on anyone else's machine

quartata

19:50

The interpreter already has to be publicly available in some manner

Nathan Merrill

is that invalid as well?

himarm jr

@Geobits Then you hit the "newer than the challenge" limit.

quartata

Now you could offer to charge $999,999,999.999 for an English interpreter and I suppose that would be valid...

Geobits

@EasterlyIrk No, I have them all laying around now. I'm letting you know this now, so I'll be answering new challenges with them.

Nathan Merrill

@quartata that seems underpriced

Easterly Irk

19:50

@Downgoat name changed back

Lembik

@MartinBüttner is the result that is outputted correct at least?

quartata

@NathanMerrill Good point; oracles are priceless or at the very least a couple more 0s than that

Martin Büttner

yes

took 60 seconds for the last example though

isaacg

I think either freely available or owned by a reasonable number of other people is reasonable. That being said I'd rather not make a rule until it comes up.

Lembik

interesting.that's slow!

Downgoat

19:51

@EasterlyIrk \o/

Lembik

mathematica.stackexchange.com/a/109993/6316 is an awesome answer by the way

@MartinBüttner my suspicion is that mathematica is doing something much too complicated for this case where s = 0

Martin Büttner

possibly

@Lembik thank you :)

Lembik

if you literally just try all vectors x with x_i in {-1,0,1} you don't do too badly

Geobits

@quartata I'm not greedy, so I'll just settle for the billion dollars.

Though I think "English interpreter" would turn into "evil AI bent on destruction" soon enough that the price wouldn't matter.

quartata

@Geobits small loan of a million dollars

Lembik

19:56

@MartinBüttner there are 3^n of those which is doable for small n if not great

Solver

Nice answer @MartinBüttner

Easterly Irk

^

Epic answer.

Martin Büttner

thanks :)

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