The Nineteenth Byte

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:04 PM

What is it an image of? (domain blocked at school)

El'endia Starman

A non-duck bird sitting in the water.

Optimizer

pegion -pigeon

El'endia Starman

Did you mean: pigeon?

I thought about bolding that like Google, but figured that'd be a little obnoxious. :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Did you mean: penguin?

Optimizer

stupid google.. keeps giving me wrong results

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:06 PM

#obnoxious

flawr

@El'endiaStarman I think he's not gonna be around any time soon.

El'endia Starman

Yeah, the signal-to-noise ratio dropped too low for his liking. :/

flawr

5

A: The state of chat

As the person whose comment triggered Nathan's question, I think I should answer. Yes, there's far too much off-topic chatter The FAQ for chat says: This site is an extension of The Stack Exchange Network, so discussion should more or less revolve around the same topics you'd find at The St...

Cᴏɴᴏʀ O'Bʀɪᴇɴ

if you had to make a name for a shell, what would you call it? (think bash, batch, cmd, etc.)

El'endia Starman

shell is presumably already taken... :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:14 PM

yeah >_>

flawr

sudo

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Presumably untaken.

El'endia Starman

That would shadow the actual sudo. :P

flawr

sudont

3

Morgan Thrapp

turtle?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:15 PM

idk what sudo is :P

@MorganThrapp not a bad idea

flawr

Really?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Really.

I use windows.

flawr

Well it is a command for unix systems.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Like Linux?

flawr

superuser do

El'endia Starman

6:16 PM

@CᴏɴᴏʀO'Bʀɪᴇɴ .....even as a Windows user, this is unacceptable.

flawr

Basically for executing commands that require super user access.

El'endia Starman

Basically, it's Window's "Run as Administrator".

Cᴏɴᴏʀ O'Bʀɪᴇɴ

"Super user"? Like superman?

oh

@El'endiaStarman Thanks, that's more useful than the jargon :D

flawr

If any command mycommand does not work, the first thing you do is type sudo mycommand.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Ah. That explains a lot of xkcd and foxtrot :P

flawr

6:18 PM

So that might give some people the impression that sudo is your house slave.

FryAmTheEggman

@flawr That's actually often a bad idea, you should only do that if you know the reason it didn't work was that you didn't use sudo and you know that you should :P

Dennis

58

Q: The versatile integer printer

Write a piece of code that is executable in at least three different languages. The code must output the integer 1 in language number one, 2 in language number two, 3 in language number three etc. Rules: The output must be only the integer, but trailing newlines are OK. The code can't take in...

Just call me Recently Featured Questions.

flawr

@FryAmTheEggman @FryAmTheEggman Yes I know, this was somewhat exaggerated=)

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Trying to make a stupid CMD joke, I learned there's a way to print a file with CMD

FryAmTheEggman

Exaggerating when people don't know what's going on can lead to bad things, I figured you knew, but didn't want to give Conor the wrong idea :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:20 PM

thanks :)

El'endia Starman

@FryAmTheEggman I think I remember reading an article about how Linux is actually pretty insecure, and that this was one of the reasons. :P

FryAmTheEggman

Linux is very secure, not all the people who use it are, though ;)

Cᴏɴᴏʀ O'Bʀɪᴇɴ

ECHO @ECHO Execution successful.>sudo.bat - sudo polyfill in BATCH files

El'endia Starman

@FryAmTheEggman I don't remember what else was said about Linux, but I do remember that for Macs, it is or used to be the case that all you needed to bypass the login screen or override the password was the installation CD.

flawr

@QPaysTaxes Sure!

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:23 PM

@QPaysTaxes Somewhere not in the chat right now

flawr

@El'endiaStarman Use any live cd.

El'endia Starman

@QPaysTaxes Most questions you Google on Python will have the official documentation as one of the top results. :P

@QPaysTaxes Arrays are not a specific type in Python, that might be why.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@_@

El'endia Starman

@QPaysTaxes Yep, lists. I'll go get the doc link.

docs.python.org/3.1/tutorial/datastructures.html

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Hi!

Xanderhall

6:24 PM

Gaaaaah

Finally get to sit down

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Xanderhall Welcome! Let us waste your time.

El'endia Starman

@QPaysTaxes Yes, that should work.

Well, probably more like {key: val for key, val in list}.

Xanderhall

@CᴏɴᴏʀO'Bʀɪᴇɴ I've already wasted plenty here :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Xanderhall Let us waste more of your time! :D

El'endia Starman

@QPaysTaxes Yep. a, b = [1, 2] => a == 1, b == 2

No problem. :)

FryAmTheEggman

6:30 PM

Fun stuff: first, *rest = [1, 2, 3, 4, 5] => first == 1, rest = [2, 3, 4, 5]

Cᴏɴᴏʀ O'Bʀɪᴇɴ

-1 you didn't use assert

@FryAmTheEggman whoa. what if you do first, *middle, last = [1, 2, 3, 4, 5]?

El'endia Starman

@CᴏɴᴏʀO'Bʀɪᴇɴ Syntax error (IIRC). :(

Cᴏɴᴏʀ O'Bʀɪᴇɴ

:(

FryAmTheEggman

@CᴏɴᴏʀO'Bʀɪᴇɴ It works fine for me

Cᴏɴᴏʀ O'Bʀɪᴇɴ

:D

El'endia Starman

6:31 PM

No wait, it works fine in 3.5.

FryAmTheEggman

In 3.5 anyway

ah there's the rub :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

What about a, *b, c = [1,2]?

FryAmTheEggman

b is empty

works fine

Cᴏɴᴏʀ O'Bʀɪᴇɴ

So, b == []?

Agawa001

@El'endiaStarman the unique role of mass is generating a gravity, and i dont see planetes falling downhill to the sun when crazily augmenting their mass !

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:32 PM

Well, I guess Python got it right then.

El'endia Starman

Huh, the *middle thing works in 3.3 as well.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@QPaysTaxes Just because you don't like the paradigm doesn't mean it's wrong.

El'endia Starman

I don't have 3.0, 3.1, or 3.2 on my computer, so I can't keep testing.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@QPaysTaxes Pray.

El'endia Starman

Try python3.5.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:33 PM

@QPaysTaxes Beg the computer.

Morgan Thrapp

You can do that syntax for any number of items in Python.

a,*b,c,d = [1,2,3,4,5].

FryAmTheEggman

3.4 is the last stable one, that's probably why it says that

Morgan Thrapp

Nah, 3.5 is stable.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@QPaysTaxes ):< is a devil with a mustache

Morgan Thrapp

@QPaysTaxes That I'm not sure about.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:34 PM

@QPaysTaxes wait what does that do?

El'endia Starman

>>> first, *second, *third, last = [1, 2, 3, 4, 5]
SyntaxError: two starred expressions in assignment

FryAmTheEggman

Weird, maybe they didn't update the package thing yet? Idk :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@El'endiaStarman Good. phews

I could see *first, center, *end = [1,2,3,4,5] making sense, but it's far too subjective

I said I could see It making sense, not that it did.

Morgan Thrapp

What about *first, center, *end = [1,2,3,4,5,6]?

Yeah, thankfully the Python interpreter is sane.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@MorganThrapp If I had to define behavior, I'd have first == [1,2,3], center == None, and end == [4,5,6].

Morgan Thrapp

6:36 PM

@QPaysTaxes I meant that as a counter example to Conor saying multiple starred assignment could make sense.

@CᴏɴᴏʀO'Bʀɪᴇɴ Except thats counter to the normal behavior.

El'endia Starman

Ah-ha, you can't do a, *b, c in a function definition.

>>> def foo(a, *b, c):
	print("a",a)
	print("b",b)
	print("c",c)

>>> foo([1,2,3,4,5])
Traceback (most recent call last):
  File "<pyshell#22>", line 1, in <module>
    foo([1,2,3,4,5])
TypeError: foo() missing 1 required keyword-only argument: 'c'

Morgan Thrapp

The non-stared item always gets a value.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@MorganThrapp There is no normal behaviour >_>

Oh, that type of behaviour.

Morgan Thrapp

@QPaysTaxes You can't have positional arguments after a catchall, only keyword args.

FryAmTheEggman

@QPaysTaxes It would mess up the grouping of arguments. f(a,*b,c) would make it impossible to specify c when calling f.

Morgan Thrapp

6:38 PM

def foo(a, *b, key=None):
    return True

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@FryAmTheEggman Or just make c the last argument.

Morgan Thrapp

Works fine.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

^

Though I've never seen it work like that.

FryAmTheEggman

Sorry, by "impossible" I meant the interpreter couldn't handle it :P

Morgan Thrapp

The whole point though is that whatever argument is the catchall should be able to have 0 items.

El'endia Starman

6:39 PM

Python is, sadly, not perfect.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@Downgoat make splats be centered in cheddar!

El'endia Starman

Pytek will be, though!

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@El'endiaStarman s/Python/literally all languages except for Pytek/

Is this Ruby?

I'll have to take a look at it.

Module.

(IIRC)

FryAmTheEggman

import sys; sys.argv IIRC

Cᴏɴᴏʀ O'Bʀɪᴇɴ

^ IIRC

El'endia Starman

6:43 PM

argparse is a standard library module for that stuff.

FryAmTheEggman

Oh, you mean one that parses that?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

^^

Morgan Thrapp

Yeah, argparse or click if you wanna get super fancy.

FryAmTheEggman

Oops, ninja'd :P

El'endia Starman

Be warned: the examples aren't really thorough enough.

PhiNotPi

6:45 PM

@El'endiaStarman Have you ever heard of tropical geometry?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

GG

El'endia Starman

@PhiNotPi I saw you mention that yesterday(?), but otherwise, nope.

PhiNotPi

I figured you might be interested in obscure/abstract math stuff.

@QPaysTaxes tropical

El'endia Starman

@QPaysTaxes No, it really is "tropical". :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Sounds fun. I could use a vacation :P

El'endia Starman

6:47 PM

yesterday, by quartata

Tropical geometry

Tropical geometry is a relatively new area in mathematics, which might loosely be described as a piece-wise linear or skeletonized version of algebraic geometry. Its leading ideas had appeared in different forms in the earlier works of George M. Bergman and of Robert Bieri and John Groves, but only since the late 1990s has an effort been made to consolidate the basic definitions of the theory. This has been motivated by the applications to enumerative algebraic geometry found by Grigory Mikhalkin. == Basic definitions == We will use the min convention, that tropical addition is classical minimum...

PhiNotPi

My main motivation of messing around with it is that, by simply touching it, I'm putting myself at the forefront of mathematics research.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

True

PhiNotPi

I've been trying (to no avail) to add "imaginary numbers" to the tropical semiring... meaning, numbers X and Y such that X+Y=3 and min(X,Y)=2.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@QPaysTaxes I'd only parse the first, it's the most expected behaviour

IMO

Get some other's opinions first tho :P

El'endia Starman

@PhiNotPi Hmm, wait, if we're only interested in real values for X and Y, then there would no pairs that satisfy these criteria, right? If the sum is 3 and the minimum is 2, then the other must be 1, which is the true minimum, therefore contradiction.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

6:54 PM

okai

El'endia Starman

I agree with parsing in sequence.

PhiNotPi

@El'endiaStarman Hence the fact that I need to invent new numbers.

El'endia Starman

@QPaysTaxes yeah

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@PhiNotPi You could invent a number phinpi

El'endia Starman

@PhiNotPi Oh, so if it were instead X + Y = 5, then there would be two pairs, (2,3), (3,2)?

FryAmTheEggman

6:56 PM

@CᴏɴᴏʀO'Bʀɪᴇɴ The point is you have to define rules for the new invented numbers so that they work :P

El'endia Starman

^

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@FryAmTheEggman Yeah. That is a rule.

;P

El'endia Starman

Oh, I've been looking at the definition of tropical geometry wrong. I get it now.

(x plus y) plus (x plus z) would be min(x,y,z).

PhiNotPi

yes

Cᴏɴᴏʀ O'Bʀɪᴇɴ

o-o

El'endia Starman

7:04 PM

And this doesn't work with complex numbers because there is no minimum?

PhiNotPi

@El'endiaStarman Hence the fact that I need to invent new numbers.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Can't you define min(a+bi,x+yi) to be the one with minimal distance from 0?

El'endia Starman

Right. What if you used the minimum of the magnitudes?

Which is what Conor just suggested.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

That's what it's called.

I forgot the term.

PhiNotPi

That doesn't solve the X+Y=3, min(X,Y)=2 issue.

El'endia Starman

7:06 PM

You could've also called it the absolute value and been technically right but not really. :P

FryAmTheEggman

You need it to meet a bunch of criteria for it still to be a simiring, I'm not super good at this, but I don't think that will work because that addition doesn't give complex numbers ever.

El'endia Starman

There are actually very few criteria for a semiring.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

2i+5i yields an imaginary...

FryAmTheEggman

Actually I'm wrong hang on >_<

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Oh, I forgot we're in topical geometry >_<

I was just defining min for complex numbers.

El'endia Starman

7:08 PM

@PhiNotPi And you could get that, when? Hmm, if X = 2 + i and Y = 1 - i, then min(|X|,|Y|) would give you sqrt(5). Yeah, that would be an issue.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@FryAmTheEggman no, aren't you right?

El'endia Starman

What about doing what Conor actually suggested, which is that you're not taking the minimum of the magnitudes, but whichever one has the minimum magnitude?

FryAmTheEggman

No the min would return 2i... I think the problem is the distributive property?

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@El'endiaStarman They aren't the same things?

FryAmTheEggman

Yeah I got Elendia's mixed up with yours :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

7:10 PM

Oh nevermind

I get the difference

FryAmTheEggman

No you said return the number with smallest magnitude, Elendia said to return the smallest magnitude

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Subtle difference I didn't pick up on :'D

FryAmTheEggman

Me either :P

El'endia Starman

The confusion is my fault since I said they were the same. :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Blame the star man.

:P

El'endia Starman

7:11 PM

So, then, the example I gave above would return 1 - i. I guess the real problem is when you have min(1 + i, 1 - i).

Cᴏɴᴏʀ O'Bʀɪᴇɴ

mmmm.

maybe 1 - i, because the iPart is negative? :P

El'endia Starman

Get that Apple scum out of here! :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

XD

Blame TI-BASIC

Who in here knows there Erdo''s number?

El'endia Starman

Mine is infinity.

Cᴏɴᴏʀ O'Bʀɪᴇɴ

Is that what the default is? :P

El'endia Starman

7:14 PM

@CᴏɴᴏʀO'Bʀɪᴇɴ Good try, but what about (-1 - i) and (1 - i)?

@CᴏɴᴏʀO'Bʀɪᴇɴ Yep. :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@El'endiaStarman -1 - i because it's the most negative?

Well, I gotta go.

BAi

FryAmTheEggman

Just to make sure I'm not crazy, the additive identity in tropical topology is -infinity and the multiplicitave identity is +infinity?

El'endia Starman

That seems right.

PhiNotPi

multiplicative identity is 0

FryAmTheEggman

But that doesn't destroy the value? I'm confused :P

poi830

7:18 PM

what about (3+4i) and (5)

El'endia Starman

x mul y = x + y, so x mul 0 = x.

FryAmTheEggman

Oh, whoops I didn't mean identity, my bad, I meant the "zero".

El'endia Starman

I wonder what that is called.

"In the reals, 0 is the multiplicative destroyer."

FryAmTheEggman

I propose: "Annihilating Identity"

El'endia Starman

Destroyer is more pithy. :P

"Destructive identity" could work too.

FryAmTheEggman

7:21 PM

IMO the more things sound like a saturday morning cartoon the better :P

El'endia Starman

So, additive destroyer is -infinity and multiplicative destroyer is +infinity; additive identity is +infinity and multiplicative identity is 0.

Doorknob

p   b        ɪ̈   ʊ̈
ɸ   β        ɐ   ɞ̞
pɸ  bβ       ɪ̈ʊ̈  ɐɞ̞
pʼ  ɓ        ʊ̈ɪ̈  ɞ̞ɐ
ʙ   ʙ̥
ʔ   h
12 consonants × 8 vowels = 96 possible syllables

Finished a draft of the phonetic inventory for my conlang idea \o/

El'endia Starman

This Video Has Consumed 20601.7 Grams of Chocolate!

►

The title changes!

When I clicked on it, it said 20275.9 grams of chocolate.

FryAmTheEggman

They set up a bot to scrape view count? lol...

El'endia Starman

@AlexA., this reminded me of you. :P

PhiNotPi

7:35 PM

@El'endiaStarman Most relevant: en.wikipedia.org/wiki/Ideal_(ring_theory)

flawr

@El'endiaStarman I don't get it=)

El'endia Starman

@PhiNotPi Oh yeah, absorption property.

@flawr Alex says some form of "420 blaze it" all the time despite not being a marijuana user himself. :P

poi830

@Doorknob so it's consonant vowel like japanese?

Optimizer

what is at 4/20?

flawr

@El'endiaStarman Still have no clue^^

El'endia Starman

7:50 PM

@flawr 4/20 is popular within the marijuana community for some reason, and the comic is basically that someone is getting excited about 4/20, but they don't use weed themselves, so they have no reason to do so.

420 (cannabis culture)

420, 4:20, or 4/20 (pronounced four-twenty) is a code-term that refers to the annual consumption of cannabis and by extension, as a way to identify oneself with cannabis culture. Observances based on the number 420 include smoking cannabis around the time 4:20 p.m., as well as smoking and celebrating cannabis on the date April 20 (4/20 in U.S. form). == Origins == A group of people in San Rafael, California, calling themselves the Waldos because "their chosen hang-out spot was a wall outside the school", used the term in connection with a fall 1971 plan to search for an abandoned cannabis crop...

flawr

@El'endiaStarman 5/7

cat

2 hours ago, by cat

1 hour ago, by cat

Could someone tell me; was my edit here comprehensive enough for this to be reopened? (also, please let me know of any loopholes or things I forgot!) http://codegolf.stackexchange.com/questions/22/the-luhn-algorithm-for-verifying-‌credit-card-numbers-etc

flawr

@El'endiaStarman TIL =)

cat

24

Q: The Luhn algorithm for verifying credit card numbers, etc

Write the shortest program or function to calculate the Luhn Algorithm for verifying (credit card) numbers. From RosettaCode, this algorithm for the purposes of this challenge is specified as such, with the example input of 49927398716: Reverse the digits: 61789372994 Sum the odd digits: ...