@flawr: Posted on Math.SE.

@El'endiaStarman closes as duplicate of CMC

@El'endiaStarman upvoted

@BetaDecay ಠ_ಠ

@El'endiaStarman I think I have a solution if the number of heptagon is allowed to be fractional

@flawr .......interesting. Do tell.

@zyabin101 05AB1E 17 bytes

This means you have 4/23 vertices

(at least that would provide a planar solution)

@Sparr It is only day two of the notion - advertising and awareness increasing must increase before you start counting attendees.

Ooh, I'm in a RtD challenge mood.

Another CMC: Roll the Dice: 10d10c10 (c10 means count 10s in roll).

@zyabin101 smq9OTT

Rofl, I just got another interview request sent to my minxomat email address. But this time it's from the publication I actually work for as a guest author under my real name.

Let's see how they react if I answer from my author email.

@flawr: I just realized that you can represent the problem as how to pair up a list of coordinates. For instance, let A1, A2, ..., A7 be the edges of the first heptagon, B1, B2, ..., B7 be the edges of the second heptagon, and so forth. Pair these edges up such that no edge appears in more than one pairing. With that, there's an easy "solution" with four heptagons, but I don't know if it fulfills the "at least three heptagons around each vertex" rule.

The possible "solution" is A1-B1, C1-D1, A2-D2, B2-C2, A3-B3, C3-D3, A4-D4, B4-C4, A5-B5, C5-D5, A6-D6, B6-C6, A7-B7, C7-D7.

Oh, I (not very consciously) restricted myself to having only one common edge per heptagon

That would certainly be preferable, but I'm just trying to find any solution at the moment since I think we can tweak it later.

@flawr You mean every pair of heptagons has at most one shared edge?

yes at most

8 heptagons would suffice for that, wouldn't it?

I don't think so

I'm trying it out in MS Paint, incidentally.

hm that seems to work,

@El'endiaStarman But that looks like a very strange shape

my eyes hurt

Hehe. Anyway, I think I'm running into consistency issues, but I'm not totally sure if that's just because I'm making poor choices.

Gonna try doing it with pairs of coordinates.

You could try it with 8 different coloured string/rubber loops

Sure, I could... after I determine whether it's plausible. :P

@quartata In retrospect, that feels sort of unfair, and I should’ve done these two things the other way around, oops

> alias vi="wine wordpad.exe"; alias vim="wine winword.exe"

@TùxCräftîñg RulePlot's a thing? Was it added in 11?

School is starting, i can't risk my pc crashing

> removes Arch installs Debian

@El'endiaStarman Some background noise for better thinking:

@ΛεγίωνΜάμμαλϠΟΗʹ idk, it's visibly the thing used in ANKS to visualise rules so i think it's pretty old

@flawr Year of No Light are pretty good but I think I preferred Ausserwelt

Quite a bold suggestion though, unless El'endia has indicated at some point that he likes black metal? :D

It is not too metallic.

Quite drone-y though.

So this is what you talk about at this time of day.

Music!

@MartinEnder Well now he has to like it.

There is no way back.

:D

day is a pretty unclear notion here :P

I'm currently doing Music homework actually. Which reminds me, I should be doing it and not chatting here. :-/

@MartinEnder Do you listen a lot to similar stuff like this?

Hm not a lot of black metal actually. A lot of instrumental rock (and some metal) though.

@MartinEnder Can you name some examples?

> The server is experiencing unexpected issues and could not process your request. Please try again in a few minutes.

(ノಠ益ಠ)ノ彡┻━┻

@MartinEnder Yeah, I agree.

@MartinEnder Perhaps you might like Inter Arma too.

@flawr: I think there are actually three distinct ways to stitch together 8 heptagons.

@flawr Haven't heard of them, but I'll check them out tomorrow.

@flawr Mono, This Will Destroy You, If These Trees Could Talk, 65daysofstatic, We Lost the Sea, And So I Watch From Afar, Ef, yndi halda, ... ... ...

@MartinEnder Great, thank you!

You start with stitching A to every other heptagon like so: A1-B1, A2-C1, A3-D1, A4-E1, A5-F1, A6-G1, A7-H1. This forces B2-H7, C2-B7, D2-C7, E2-D7, F2-E7, G2-F7, H2-G7. At that point, B and C, for example, are already connected to A, B, C, H and A, B, C, D, respectively. There is a heptagon that connects to both B and C, and it must be E, F, or G. Each of these three choices, I think, results in a consistent layout.

And So I Watch You From Afar ♥

:)

codegolf.stackexchange.com/a/93595/53745

ಠ_ಠ

@Lynn Hewwo~<3

walks into room, mind explodes, falls down

and then eyes fall out

Ambulance is an amazing song

@Lynn My absolute favourite is Homes - Samara to Belfast... unfortunately they've never played that one live T_T (except for the one time where they played all of Gangs from front to back)

@El'endiaStarman I think there could still be more possibilities.

@flawr Perhaps. I think the first round of stitching (A to every other heptagon) is w.l.o.g. though.

Basically you can connect BC to lets say E in two ways, namely sucht that all three have the "front" facing in the sime direction, or that the face of E points in the "back" direction of the other both.

@El'endiaStarman Yes, that is what I arrived at independently

But I have the feeling that none of those are going to be torroidal.

I have a math question: when people talk about Gaussian curvature and stuff they talk about curvature having a sign, but in vector calc I learned that curvature is always positive cuz its |dT/ds|. what am i missing?

@Maltysen Negative curvature looks like a horse saddle.

@El'endiaStarman that's for gaussian curvature

@Maltysen You probably heard of the curvature of a line

@flawr yeah, but gaussian curvatire is product of curvature of curvature of perpendicular curves

@Maltysen you can define a signed curvature for lines in a 2d plane

now you can consider a differentiable surface locally as a 2d plane

@flawr how does the fit in with |dT/ds|?

@Maltysen You just need to define an orentation (basically a continuous normal vector field) on the curve

Or imagine some potato as a surface.

@flawr: Looking more closely at the pairing diagram I've got right now, I spotted an edge that's used by two triplets of heptagons (A-B-H and A-C-B). Bah.

now pick a point at which you want to compute the gaussian curvature.

draw two though that point which are perpendicular in that poitn

I wonder if this problem is solvable by picking one of the other two choices out of the three I listed earlier...

now you need to have an orientation of the surface

> One of the problems with poetry, the reason most of us read it less often than prose, is that it requires so much attention. Reading a novel is like completing a marathon, but that doesn’t mean that reading a poem is like doing the 100 metres. Rather, it’s another experience entirely, more akin, say, to solving a crossword puzzle with a slight headache while smoking opium.

Consider one of those lines: If it curves upward, in the direction of the orientation, you assign it a positive sign, and vice versa.

@flawr that's where you say which way the normal vector is right?

Shoot....it looks like this contradiction is forced by the very first choice I made. That doesn't make sense.

@Maltysen exactly

Oh, the pairing diagram doesn't include orientation, that's why.

@flawr oh i see, signed curvature for plane curves doesn't need to be defined, because it only matters if they are different or the same

@Maltysen exactly!

thanks

@Maltysen so now you easily see why a hyperbolic paraboloid has negative curvature:

Another thing you can easily see: If a surface is isometric to the plane, it has curvature 0

This means you can (locally) bend a sheet of paper into that shape

and it also means that you can always find a straight line

@flawr cuz one of the curves is a line

@Maltysen yay!

@flawr isn't this called being developed or something?

Does anyone know of an IRC service/config that allows only a certain amount of people to have voice in a channl at a time?

I could make it myself but was wondering

@Maltysen No idea, I had my last dg class in german.

@Maltysen yes, seems to be correct: en.wikipedia.org/wiki/Development_(differential_geometry)

And it is also useful for eating pizza.

@flawr nother question, for the isometric to plane thing, e.g. a cone, one of the curves is 0 if you take the isoparametric curves, but what happens if I randomly pick some other perpendicular curves (if it thinking about it correctly, which im probably not, wont both have positive curvature?)

(With pineapple of course.)

@flawr haha cool

PSA - chrome ppl also know that Chrome's usage of high memory causes other apps running on the system to slow down. [1]

@Maltysen Well you actually cannot pick any curves, you have to pick curves in the principal curvature direction (loosely translated, lets see if there is something like that in english)

in other words, it does not free up memory when others need

@flawr oh ok

i guess that works out to be the isoparametric curves

@Maltysen ah here: en.wikipedia.org/wiki/Principal_curvature

oh max and min values

@Maltysen Yes you could say that

@flawr well, i don't understand a single word of the definition at the top about the "eigenvalues of the shape operator" :P

@Maltysen If you're interested, I recommend the DG book by do carmo

it is really accessible (well as accessible as it gets) and it has pictures!

cool thanks

:D

And it is quite cheap

so that is three things you do not find very often in a math book^^

"course in linear algebra" :/ guess i should bite the bullet and actually learn some

Linear algebra is cool!

@flawr but other stuff (like dg) is so much cooler that i never got around to learning it

i learned the very basics, but not past that

@Maltysen yes, but you'll need LA everywhere=)

@Maltysen Have you seen 3Blue1Brown's videos on the subject?

^ I can highly recommend

@El'endiaStarman will check out

^^ Likewise. They are the best introduction to linear algebra I've ever seen. (Granted, I haven't seen that many introductions, but still.)

@Maltysen but true, unfortunately the good stuff always comes late

But enough math for me today, tomorrow my semester starts again, and there is still an exam due =/

Good night everyone.

G'night!

PS: Did you know that the Helicoid is locally isometric to a catenoid?

@flawr Woah, TIL and that's cool.

Hm, hyperpolic paper should be a thing.

When using it for letters you might get problems with the envelope though.

@flawr seems like a good book so far, lots of examples

also, he defined u.v as |u|*|v|*cos which was kinda weird

@betseg How do you pronounce Arda Ünlü?

Haha, I think I know why you're asking. :P

@Geobits @Downgoat @ETHproductions @TùxCräftîñg et al: strawpoll.me/11255023

After investigating a couple these are the three I'm down to.

Gitter and Slack both seem to have relatively robust APIs, and IRC is... IRC

Discord's API looks painful and Miaou doesn't seem to have one aside from using web sockets directly

And even.... well

@quartata does slack have one that isn't web sockets?

Discord's API isn't too bad; there's usually 3 or 4 libraries to interact with the API for each language

Does Slack have REST API?

@EᴀsᴛᴇʀʟʏIʀᴋ slack has integrations

I know gitter does

@Maltysen oic

Well it's websockets but it's relatively simple as far as I can tell

The main reason why it appeals to me is that as far as I can tell I can write services with it

I still prefer IRC though.

slack is money i think?

gitter is mostly free

slack is free?

wow gitter is great

Gitter and Slack both have free plans that are good enough for our purposes

@Downgoat Yeah, Gitter is definitely the easiest of the two.

IRC is easier though

Subtle hint: IRC is the correct choice

then IRC should work

lol

@quartata plus gitter has replies, slack doesn't

It doesn't?

yeah

Huh.

I'm willing to work with Gitter if there's a majority though.

@quartata that was the one thing that stuck out to me

Weird how Google Domains offers legionmammal978.io for $60/yr but also legionmammal978.pw for $9/yr

.io domains are ridiculously expensive

Also, legionmammal978.plumbing is $30/yr

Beautiful

@ΛεγίωνΜάμμαλϠΟΗʹ rofl

Adding that to the gTLD hitlist

CMC: Figure out why .plumbing is even a TLD

@ΛεγίωνΜάμμαλϠΟΗʹ think of all the innuendos for porn sites you could use

@Maltysen please no

Still working on that.

My janitorial powers currently only extend to the lobby.

Hopefully I'll be promoted to legacy systems troll in a few months.

.gopher exists

Actually I like that one

People are going to call me strange for this but I still (very rarely) use Gopher

I hope gopher.it exists.

@El'endiaStarman been squatted

It does, but it redirects to a site that redirects to another site, and there, I just see a blank page.

@El'endiaStarman a few hundred redirects later it took me to a site for me to buy BBQ grilling hoods

sigh What a waste of a wonderfully punny name.

@Maltysen hahahahahahaha

@Maltysen seriously?

It took me to a site to buy Canadian silver bullion coins.

blank page for me

Canadian bullion sounds tasty.... maybe some mayonaise to go with that

on safari it says "your Apple (tm) flash player is out of date" and that's it

and FF gives MacKeeper ad

TOR gives link to purchase said domain

This is like the Umwelt of squatted domains

Can we get someone in England to try it on Chrome?

@quartata maybe its just some round robin thing

$ curl gopher.it
<html>
<head><title>403 Forbidden</title></head>
<body bgcolor="white">
<center><h1>403 Forbidden</h1></center>
<hr><center>nginx</center>
</body>
</html>

its sending me to different things now

Hm, I always forget how to change curl's UA

When I set the user agent to Chrome it gives me something

Looks like a blank page with some shady JS

@Maltysen I don't think so.

At minimum it's for sure reacting based on user agent

@quartata IRC (cant vote becuz connection)

'night

@TùxCräftîñg All right

So Gitter and IRC are tied

I think Geobits will vote IRC though

I'm gonna try in Midori browser.

That should probably give the same result as Safari.

Someone needs to try on mobile

This really is a boring Umwelt

what exactly are you expecting out of this

Midori brings me to some site with an invalid cert.

@Quill We have to crack the secret

It beats actually doing work I suppose

After turning https into http, it took me to "phish.opendns.com"

I tried it again from incognito and got redirected to a site that tries to scare you into calling them to avoid corruption of your registry. I'm not 100% sure that it's actually consistent, but I don't want to try again.

That's part of the reason why I'm using curl and reading the HTML instead of actually browsing there :P

@quartata Glavra, of course. :P

@quartata Smart.

@PhiNotPi 10/10

@quartata trying

chrome for android

Just get the UA string and use curl

@Doorknob I mean I would if it was ready

Woah, TF2's had a whole new GUI update

?

No it hasn't?

> win.samsung.todaygifts.net says: Congratulations, you are today's lucky winner!

seems legit

Holy visitors Batman!

This isn't new

Seems new to me

The internet domain namespace is the most wasted of all namespaces. All of the waste of all other namespaces added together cannot compare to the wasteland that is the internet domain namespace.

It's new if you haven't played in 6 months

@ΛεγίωνΜάμμαλϠΟΗʹ It's been around since July

Oh well, I haven't played it in a few months

@Quill @quartata ^

@quartata curl doesn't do js redirects, its giving inaccurate results

@PhiNotPi What about URN namespaces?

Oh true

@mınxomaτ What for?

@ΛεγίωνΜάμμαλϠΟΗʹ A single post on my blog.

how does this look?

Link?

255.wf/2016-09-18-mass-analyzing-a-chunk-of-the-internet

> 255.wf

I didn't know a domain that short was possible

iirc 2 char domains are allowed, but the name has to be 3 chars long

@EᴀsᴛᴇʀʟʏIʀᴋ w.org

@mınxomaτ reminds me of when robert graham tried a similar thing

"I bought a.a, it only costs $10,000,000/s"

@Quill I'm actually discussing that in the HN threads.

@flawr I've added semi-modular indexing for assignment. That means that x = [10 20 30]; x([0 -1] = [40 50] would give (in MATL) [10 50 40]. I call it "semi-modular" because it applies for non-positive values only. Positive values outside the array are interpreted normally for assignments, thus growing the array.

That would have saved one byte in your answer, as you could have used index [1 0] (predefined literal 5L) as synonymous of [1 end]. You can experimentally try it here

(More info on page 21 of the documentation)

@mınxomaτ TIL

this is horrible. I have to do a base conversion worksheet and show work, and the questions are like "what is 110 from binary" and "what is 1 from octal" >_<

@mınxomaτ really interesting, good read :)

I would have put more effort into the post if I knew it was going to explode like this.

@Dennis Please give MATL a pull when you can

I'm starting on a quest to make the most meta language I can. I'm going to write a language in A called B, then write a language called C in B. it's probably easy, but eh

@mınxomaτ alwsl has 476 stars now. Hopefully that'll motivate you to work on it :P

> Agreed. Having an open FTP server with read-only access is no more problematic than having an open HTTP server.

I'm kind of flabbergasted at the power of Hacker News

@quartata Lol, I just wrote an update in my blog about that :D

@quartata This time it was mostly reddit.

Getting some 600 upvotes in the sysadmin r

reddit.com/domain/255.wf

It's also kind of amusing that Perseus was (most likely) infinitely more effort and still sitting at 6 stars

Well, it's written in VB.NET, so I guess that's fair.

And it confuses the hell out of the source code classifier.

Basically found a way to force WSL on Windows 7 through 8.1, too.

Gangnam Style in flipbook form: youtube.com/watch?v=KlwPtIMSWyA

Speaking of which...