Primes and Squares

PhiNotPi

01:49

Twisty Tree

►

has science gone too far?

El'endia Starman

02:02

Top comment: "You went too far Oskar". :P

orlp

02:44

So I wanted a beta key for the next version of a game I play, but didn't want to spend $ to get it, so I wrote a script that checks the subreddit every 5 seconds, and if it finds the word key or something that looks like a key it notifies me on discord.

I now have beta access :P

El'endia Starman

Well, you wanted it, and you got it. Nice job. :P

PhiNotPi

02:55

I guess that works.

El'endia Starman

I thought this was an interesting read about flow: blog.bulletproof.com/wp-content/uploads/2014/04/… .

Nathan Merrill

05:49

so, if I drop a 3D object onto a floor, the floor is basically an infinite 2D plane.

...but what do I drop a 4D object onto?

an infinitely big 3D cube?

flawr

09:15

@NathanMerrill also known as hyper plane=)

In an n-dimensional space, an (n-1)-dimensional subspace is called hyperplane and a 2-dimensional subspace is usually called plane

a finite 3d cube would correspond to a square in the 3D case

if it was only a 2d plane (in the 4d case) you'd have to "balance" it like you would have to balance a 3d object on a piece of string

Nathan Merrill

12:18

@flawr that seems crazy to me

like logically, I can see how that works, but 4D is so hard to visualize

flawr

just a thought: let's use time as a foruth dimension. consider a table top as 2d surface. if it is persistent through time it is actually a 3d hyperplane in 4d spacetime.

if it only exists at a certain point of time, e.g. t = 0, then it is actually only a 2d surface

so to balance a 3d cube on that, it might fall e.g. off in t direction, so you have to move it back and forth in time in order for it to stay balanced :)

oh and are you aware of miegakure?

Nathan Merrill

@flawr lol

flawr

miegakure.com

(a 4d video game still ind evelopment)

you have to watch those videos though

Nathan Merrill

I think I've seen some videos of it

you simply try to walk to the exit, right?

flawr

ah I don't actually know the objective ^^

(I mean, I do not pretend to be able to actually imagine 4d, but still it is nice challenge to try to think of how certain things would behave:)

feersum

12:29

Is there any 4-dimensional chess or game with similarly geometric movements?

I think that would be fun to try.

flawr

A 4d rubiks cube I think

superliminal.com/cube/cube.htm

Martin Ender

Rubik's Cube even exists in 5D: gravitation3d.com/magiccube5d

Nathan Merrill

I seriously doubt anybody has actually solved that

assuming you don't count computers as people

Martin Ender

I find that offensive.

Nathan Merrill

:P

Martin Ender

12:44

some discussion on 4D go: lifein19x19.com/forum/viewtopic.php?f=18&t=3521 (because searching for 4D chess just brings up trump...)

flawr

@MartinEnder from the perspective of a computer of from the perspecitve of a human?

trichoplax

For 5D would a 2x2x2x2x2 instead of the 3x3x3x3x3 they have there make it approachable by humans?

feersum

Unfortunately I cannot understand even 2d go (the scoring is confusing).

Martin Ender

@feersum play.chessvariants.com/joe-joyce-hyperchess

@feersum what's confusing about the scoring? just add up your area and prisoners. (I admit there are some weird edge cases but they're so rare that you don't really need to worry about them as a beginner)

feersum

I couldn't understand the algorithm for determining who owns an area.

Martin Ender

12:47

I played very actively for 2.5 years and attended about 30 tournaments or so and I think I played a single game where the outcome depended on such an edge case that makes the outcome depend on the specific rule set. in terms of the basic rules, I think it's one of the simplest games.

Nathan Merrill

it's not intuitive to me either. It takes me a couple of games to remember how area works

feersum

Or rather couldn't find it.

Martin Ender

oh I think I know what you mean

I was just gonna say "everything that is enclosed by your stones" but it can happen that there are enemy stones inside your territory

trichoplax

It looks like in the 4D case area doesn't count for anything, so you don't need to keep track of it. So you only have to keep track of hypervolumes...

Nathan Merrill

and you don't actually have to enclose it, right? Like if I have a wall that goes to the edge, but not completely, it still counts as my area?

Martin Ender

12:49

if you have some experience you'll see which stones are "dead" and can be taken off the board for counting. if you don't see that, you can just keep playing until all areas are adjacent only to one colour. the score won't change after the "normal" end of the game

@NathanMerrill no you have to enclose your area completely, but you don't have to explicitly capture the dead enemy groups inside

feersum

I also don't understand in what cases can the edge of the board count as part of your boundary.

PhiNotPi

@trichoplax if it's 2x2x2x2x2 then isn't everything an edge and it's impossible to enclose anything?

Martin Ender

@feersum always

@PhiNotPi I think trichoplax was talking about rubik's cube

feersum

@MartinEnder If I make a circle, surely it does not enclose both the inside and outside though?

err not a circle

Martin Ender

presumably your opponent has some stones on one side of the circle. otherwise it would indeed enclose both

feersum

12:53

But a path from one part of the edge to another.

trichoplax

@PhiNotPi Yes I was referring to the Rubik's cube - sorry the topic changed while I was typing and I forgot to link back

Martin Ender

it would enclose both if the opponent has no living groups on either side

which is unlikely...

feersum

Does "living" have a simple definiton?

Martin Ender

well "can't be captured". you can always play out the game to determine it. the rule of thumb is "has two eyes" (i.e. two disjoint enclosed regions), but there are exceptions. with a bit of experience it becomes very obvious which groups are alive and which aren't.

#####
#.#.#
#####

^ this the prototype of a living group, because it has two eyes

the opponent can't place a stone in either eye because it would be suicide, but both eyes would need to be filled in order to capture the group.

(there are smaller examples, especially on the boundary, but this is the simplest example I guess)

trichoplax

Are the diagonals required?

Martin Ender

12:57

some of them

there are so-called "false eyes"

.####
#.#.#
.####

trichoplax

Because the leftmost stone is vulnerable?

Martin Ender

if the opponent has those two . on the left and otherwise also encircles the single # on the left, then they can set a stone into the left eye, capturing the left-most stone

trichoplax

I think I get it now

Martin Ender

it's also worth noting that this is no longer a single group (because only orthogonal adjacency is counted as a group) but it's possible to form two eyes with two groups as well

###.
#.#.
.#.#
.###

this is made up of two groups but the structure has two (safe) eyes

feersum

So captures by the player who just moved resolve befoer captures by the other player?

Martin Ender

12:59

because both groups are adjacent to both eyes

yes

flawr

13:12

does anyone have a good solution for spellchecking latex documents on windows?

(or online?)

trichoplax

Would copying and pasting into a text file give you the raw text without any of the formatting text?

flawr

from the .tex file?

or from the .pdf file?

trichoplax

I mean from the output (so the pdf in your case)

flawr

ah no, I've tried that and get too many strange symbols

trichoplax

Ah OK

flawr

13:19

e.g. all the 'fi' are recognized as one character

(and tons of other things seem to go wrong aswell)

Martin Ender

@flawr All I usually do is hit F6 in Sublime and scroll through the tex files. Not very robust I guess.

flawr

is sublime worth buying?

Martin Ender

I'd say so (I did buy it and I'm very happy with it). But I'd personally say it's also very usable if you don't buy it. It nags you occasionally when saving a file but it didn't seem to unreasonably often (although I've heard people disagree with that).

flawr

ah so you could use the free version indefinitely?

Martin Ender

yes

El'endia Starman

13:33

Yep. I used it (Sublime) without buying it for a couple weeks and then decided that it was worth the cost to buy a personal license.

flawr

Looks like a great software so far.

Wha do you use it for?

El'endia Starman

I use it primarily for work, but that's mostly because I've been doing an order of magnitude more coding at work than at home.

flawr

would be awesome if they'd opensoruce it one day

trichoplax

Just had a look at the Sublime website and noticed it has a map of the document down the right hand side that is more zoomed in (less zoomed out?) than in gedit, which I'm currently using. I'm tempted just for that...

Nathan Merrill

I liked Sublime as well...but if I remember correctly, my biggest issue was that I couldn't have multiple "unsaved tabs" open

One of the features I really really like is the ability to have lots of tabs open that I haven't explicitly saved anywhere, and for the editor to auto-save them (in a temp folder somewhere)

but so far, the only editor I've found that does that is N++

El'endia Starman

13:44

The three main killer features for me are 1) find/replace across all documents in the project, 2) expand selection (multiple cursors), and 3) hover your mouse over a function to see where it's defined (by that name).

trichoplax

@NathanMerrill I liked that feature of Notepad++ but since leaving Windows I can't use it :(

Nathan Merrill

I know :/

I really tried to get it working with SciTe, but I'm pretty sure I'd have to code my own plugin to get it to work

trichoplax

Even after an update, it would still open up with all my unsaved tabs waiting for me

flawr

@trichoplax what are you using now?

have you considered SciTe?

as far as I know npp is based on the same core as SciTE

trichoplax

gedit at the moment, since it came with Fedora

I like the map down the right hand side, and it does everything I need. Maybe I'd fall in love with extra features if I tried them out though...

Nathan Merrill

13:51

huh...I just checked it with sublime...and it works

I'm not sure why I stopped using sublime. Maybe I'll have to give it another try

El'endia Starman

Maybe they implemented that feature since you used it last?

Nathan Merrill

perhaps?

its not really easily searchable

El'endia Starman

@NathanMerrill How do you mean?

Nathan Merrill

"multiple unsaved tabs sublime" doesn't really return what I'm looking for

the best I've found is this: superuser.com/questions/894021/…

El'endia Starman

Oh, I see.

Nathan Merrill

13:55

which seems to imply that it's been there since 2015

El'endia Starman

Maybe you're older than you feel.

Nathan Merrill

lol, maybe :)

There are a couple of configuration file formats which are "accidentally Turing-complete", most famously sendmail.cf. That would indicate that using an actual scripting language might be beneficial, since that one was actually designed to be Turing-complete. However, Turing-completeness and "Tetris-completeness" are two different things, and while sendmail.cf can compute arbitrary functions, it can not send your /etc/passwd over the net or format your harddisk, which Python or Perl would be able to. — Jörg W Mittag 24 hours ago

I like the term "Tetris-completeness"

El'endia Starman

Me too. I first saw it sometime last year, I think.

Though we may need a better term if/when the Tetris-in-GoL project is completed. :P

PhiNotPi

@El'endiaStarman speaking of which plz unfrizzle room

Nathan Merrill

nah, that just proves that GoL has Tetris-completeness

El'endia Starman

14:03

@NathanMerrill Yeah, but that's only because we built a computer in GoL. What that guy is really talking about is more like the ability to interact with elements outside of the program.

Nathan Merrill

I know :)

you can wipe the hard drive of your virtual computer

maybe set up two virtual computers and network them

(oh that sounds horrific with GoL. Imagine trying to get the waiting right)

El'endia Starman

in The Quest for Tetris, 58 secs ago, by Feeds

El'endia Starman has unfrozen this room.

PhiNotPi

14:27

Thanks

trichoplax

14:37

@flawr That looks very promising. Looks like I'll need to compile it locally for Fedora but I'll have a look

flawr

14:51

@trichoplax I think minxomat knows a lot about SciTE if you need help. As far as I know you can a lot, but you have to do it all in the corresponding config files.

flawr

15:22

language question: If you derive an equation, does that mean you consider the derivative or does it mean you explain how to construct it?

Nathan Merrill

"deriving an equation" means "taking a bunch of data/information and constructing an equation out of it" to me

flawr

and for the other situation you'd use differentiate instead of derive?

Nathan Merrill

I generally "take the derivative"

I don't think I use a single verb for it

flawr

ok

so "derivation" is unambiguously the "working out/constructing" part, and not the "taking the derivative"?

I should have sticked to number theory, where you do not have the problem of derivatives XD

Nathan Merrill

I'm not experienced enough to say "unambiguously"

that's simply how I would use the words

flawr

15:28

ok, thank you!

El'endia Starman

@flawr "differentiate" has an ordinary English meaning too and I would not, at first sight, understand it to mean "take the derivative" (which I would use). I concur with Nathan regarding "derive" and "derivation".

flawr

ah I see, but I mean in the context of an equation

(I have to write something mathy in english)

El'endia Starman

What's the context? (Obviously something to do with derivatives.)

trichoplax

16:10

At school level, I'd expect to see "differentiate" (and "integrate"), and at higher level "take the derivative". I'm not sure quite where the change happens though (even specifically in the UK)

Nathan Merrill

I do use "integrate", funnily enough

though, "take the integral" sounds like something I'd say as well

flawr

17:28

@El'endiaStarman wave equations :)

didn't I post a gif a while ago?=)

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