The Nineteenth Byte

12:09 AM

@trichoplax I've awarded it to NinjaBearMonkey's Black Knight. Though the controller will remain up and functional, so please do submit yours when finished :)

trichoplax

@Calvin'sHobbies That's well deserved - I've been struggling to beat Black Knight for 3 weeks :)

Calvin's Hobbies

Now to write a challenge about ninjas, bears, and monkeys...

BrainSteel

All things considered, that's not a bad name to write a challenge about :)

Geobits

A ninja, a bear, and a monkey walk into a bar...

Calvin's Hobbies

@Geobits jokes.cc.com/funny-partying---bad-behavior/m255kl/…

The monkey one I found wasn't really chat appropriate

Geobits

12:22 AM

Was it about cue balls and cherries?

Calvin's Hobbies

Yes

Geobits

I'd heard that one before :) I've heard some sort of big pause joke with the bear, but it was a bit different.

I don't know any ninja/bar jokes. I'd assume because nobody notices when the ninja enters.

8

trichoplax

@Calvin'sHobbies Just out of interest, do you still have the output from the 30 rounds?

BrainSteel

"Chat appropriate" Wait, what is that?

Calvin's Hobbies

@trichoplax Yes. The first link in this comment: codegolf.stackexchange.com/questions/50690/…

(i.stack.imgur.com/a3zgK.png)

trichoplax

12:25 AM

Ah - I was looking in the chat... And I'd read that comment and not noticed the link...

Your Baseline beat Black Knight in 2 games...

trichoplax

12:53 AM

@Calvin'sHobbies I love the fact that you needed to use a link shortener in order to fit in the link from the question to the comment announcing the BBBF winner.

Mitch Schwartz

1:16 AM

@Lembik changed calculation of central binomial coefficients so it's a little faster now. also added list of optimisations

Mitch Schwartz

2:33 AM

@feersum nice work on j=2 !

New Main Posts

2:51 AM

0

Q: Shifting/Manipulating a byte array as efficiently as possible for LCD Display

Using C# I am trying to create some text visualizations for an LCD character display using the net micro framework..so efficiency is key.. The desired output is to create a "slide-in" text from either left to right or right to left. The final resting place of the string should be the center, but...

feersum

Thanks

Nathan Merrill

anybody have the template response for questions that don't belong on code golf?

trichoplax

@NathanMerrill Looks like Doorknob beat us to it...

(if you mean the question above)

Doorknob

stackapps.com/q/6167/17430 </plug type='shameless'>

3

trichoplax

Welcome to Programming Puzzles & Code Golf Stack Exchange! This site is for programming contests / challenges, not general programming questions. For those, try Stack Overflow, but be sure you read their help center first to make sure your question is of high quality and on-topic. Thanks! — Doorknob ♦ 2 mins ago

BrainSteel

3:12 AM

The mod hammer has been swung!

Mitch Schwartz

3:38 AM

@Lembik for the N = 1228 entry, could you change the wording from "using an exact formula" to "using another exact formula" to clarify that there are two different formulas? SE won't let me suggest the edit as it is not 6 characters

Lembik

5:25 AM

@MitchSchwartz done

@feersum I just really enjoy probabilistic combinatorics type questions

and once I find a problem I can't solve, I do obsess over it slightly :)

@MitchSchwartz have you seen codegolf.stackexchange.com/questions/37270/… ?

Mitch Schwartz

@Lembik i hadn't seen that before

Lembik

@MitchSchwartz turns out some of my questions are even useful :)

pypy Mitch-j1-faster.py |tail gets to 3250 on my machine

@MitchSchwartz Now I get to spend the day trying to work out what feersum has done :)

@MitchSchwartz do you have any idea?

Mitch Schwartz

5:47 AM

@Lembik no, but it looks nice :)

Lembik

@MitchSchwartz that is my current view too :)

New Meta Posts

6:04 AM

0

Q: Should I delete my comment after OP fixes/golfs OP's code?

I usually comment under an answer if I've found a mistake in the answerer's code. I also do it when the code can be golfed more. After the answerer fixes/golfs his/her code, should I delete my comment? Also, if the answerer has comment something like Thanks! replied to my comment, should I flag...

discussion comments

Mitch Schwartz

7:03 AM

@Lembik for the 3250 did you use the updated code?

just asking because you wrote "using the same implementation"

Martin Büttner

7:52 AM

@Dennis on Refined Partitions, I think CJam can do 13 bytes if you borrow the input format from another answer

Lembik

8:08 AM

@MitchSchwartz you are right to pick up on this.. your speed up didn't speed up the cpython version

@MitchSchwartz well only a tiny amount so I was a little lazy and didn't make an extra entry for it. I hope that is OK

@Min_25 In case you didn't see... feersum has added an implementation of a "closed-form" solution for j = 2 it seems.

not that I understand it yet :)

Martin Büttner

9:27 AM

@Dennis meh, my idea didn't work for empty partitions, but it's possible in 16

Optimizer

11:04 AM

@MartinBüttner what is it ?

Katenkyo

Hi everyone

New Sandboxed Posts

11:57 AM

0

A: Sandbox for Proposed Challenges

Solve the nonogram code-golfgame Nonograms, also known as Hankie or Picross, are fascinating. They are really simple is essence, but to solve the most complexe one, some tricks as to be learned. Basics Nonograms are usually presented this way : 1 2 1 2 3 2 1 2 3 ...

Mitch Schwartz

12:12 PM

@Lembik sure, that's no problem

Lembik

1:11 PM

@MitchSchwartz hi

hi @feersum

Mitch Schwartz

ello ello

Lembik

1:53 PM

how things?

Mitch Schwartz

things are going swimmingly

Katenkyo

It's pretty calm down there today

Dennis

2:13 PM

Nevermind. Should have until I'm fully awake...

Optimizer

waited*

Dennis

That.

Katenkyo

Haha, so everybody's sleeping?

Optimizer

I am pretty sure at no point in time does everybody sleeps at the same time

trichoplax

I'm awake just typing in the sandbox

Katenkyo

2:20 PM

I am sure, at one point in history, it happened !

Optimizer

@Katenkyo at/before big bang - maybe.

Dennis

Argh, stupid empty lists...

Katenkyo

@Optimizer If there's no one, can we say that everyone is sleeping?

Optimizer

sure, who will care ? :P

Martin Büttner

@Dennis I did mean that

Katenkyo

2:35 PM

so nobody==everybody, kind of paradoxal :)

Martin Büttner

(with that exact form I think it's 15 actually)

@Dennis yeah those...

Dennis

@MartinBüttner If I read the input as "1,0,9 1,3,8"\n"1 0,9 1,3 8", I can get down to 13 bytes, I think.

That's with actual quotes in the input.

Optimizer

too much

Martin Büttner

@Dennis not bad, I had 16 with that format, but without ""

but yeah, "" would make it 13, because then you don't need to handle empty lists separately

Dennis

@MartinBüttner Without the quote, I can get down to 14 if I use ea.

Precisely.

Martin Büttner

2:39 PM

I found a really nice way to handle the empty cases though: _1>-!

actually, no that doesn't work

Katenkyo

@MartinBüttner From heaven to despair :)

Dennis

@MartinBüttner So the million dollar question, is "1,0,9 1,3,8"\n"1 0,9 1,3 8" (quotes and all) an acceptable input format? And how badly would I be ripping off edc65 if I post this?

Martin Büttner

@Dennis yes, I'd accept that input format. you should credit edc, but it's not like you hadn't beaten him anyway

would still be good to have a meta post about taking multiple parameters as an array

Dennis

@MartinBüttner: Didn't have the time yesterday. Since command-line arguments essentially form an array, I don't think reading them as an array from STDIN would be that odd.

Martin Büttner

2:57 PM

yeah that's a good point actually

that makes it 12 then?

oh, nevermind

Dennis

Not sure. I think it wouldn't help since evaluating the input would remove the quotes.

For the record, with ea I had QQeaz", "a-z~=.

The dot not being part of the code.

Katenkyo

I'm leaving for now, could you please guys tell me if there's some big thing to change to my nonogram solving challenge ? :)

Lembik

3:15 PM

@MitchSchwartz Great! :)

and very impressive your ranking was 5 for Euler!

Optimizer

@Dennis you still have quotes in your link

Dennis

@Optimizer In the input? That's intentional. It won't work properly without the quotes.

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Ant Queen of the Hill Contest king-of-the-hill javascript grid game To be clear up front: I have other KotH ideas for which I'd like to use other languages or be language agnostic, but for this one, I'm very attached to the idea of it being a Stack Snippet question (or at the very least a jsf...

Optimizer

@Dennis why ?

Martin Büttner

because empty strings

Dennis

3:21 PM

@Optimizer Because z ignores empty arrays. ["" "abc"]zz pushes ["abc"].

Optimizer

I see.

trichoplax

@Geobits I've sandboxed that vaporware I mentioned.

BrainSteel

3:49 PM

@trichoplax This challenge idea is so cool. I am excited for a controller!

trichoplax

@BrainSteel Thank you! I think I have the specification more or less complete, but writing the controller may take a while since I'm still fairly new to JavaScript. I'll be posting a new sandbox question when I have the controller ready to test, and then working on it until it isn't broken...

BrainSteel

4:07 PM

Have you considered letting the queen have access to a very limited set of memory? I'm curious why you haven't allowed it.

Geobits

@trichoplax Nice :)

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Tupper's Self-Referential Formula (copied from Wikipedia) Tupper's self-referential formula is a formula defined by Jeff Tupper that, when graphed in two dimensions at a very specific location in the plane, can be "programmed" to visually reproduce the formula itself. It is used in various math ...

Geobits

First sandbox question (too many or few colors): When I first started reading, I was thinking this was true color (for some reason, dunno), so I was thinking of using it as pheremone counters. Like... choose a nice color for my team, and increment it each time I step there. So you could follow the 'strongest path' like ants do. Not sure how to do that with 16 colors, though.

New Meta Posts

0

Q: Defaults for reading several pieces of input

When reading several pieces of input as command-line arguments, it is common practice to read each piece as a different argument. The command-line arguments now provide an array of the input pieces. Should submissions that use different input formats also be allowed to read an array of input pie...

discussion policy code-golf answers defaults

trichoplax

@Geobits I did think about making colours fade over time to allow shortest path finding, which would have required a larger number of colours, but I settled on fixed colours (only changing when changed by an ant) so I mentally ruled that out. However, I do like the idea of the ants themselves gradually incrementing/decrementing different aspects of the colour so I'll need to have another think...

(sorry @BrainSteel I pinged you by mistake)

Geobits

4:18 PM

Hmm, well that was just my first thought on it. I can't say I've given the 16-color version a long think about how to use it well, so there might be something nice there, too.

trichoplax

I'm settled on the ants (even the queen) having no memory. I'll try and explain my thinking:
Biologically, I'm fascinated by the fact that ants coordinate tasks that they don't have the brains for, simply by leaving pheremone trails on their environment. I want to see what these ants can achieve using only colours to guide them.
Computationally, I like the idea of all the competing ants having to share one memory (the arena cells). By denying them any other memory but the shared one it means that they will have to work with the fact that their memory may have been changed by an enemy, and t…

@BrainSteel no idea if the immediately previous message pinged you

On my screen it is showing as :22216734 rather than an @

ProgramFOX

@trichoplax It did ping him... but it seems like the :digits show up when you click "see full text" on the message.

BrainSteel

@trichoplax I agree that it is an incredibly interesting mechanic to have to rely on the arena cells as memory, and this is in part what draws me to the challenge (it also vaguely reminds me of the Lab Rat Race which can't be a bad thing). I think, however, that not letting the queen have any memory means that efficient answers have to implement ridiculous workarounds in some cases. I think even just giving the queen # of workers is sufficient.

And yeah, I was pinged :)

trichoplax

@Geobits I've thought about strategies using only 2 colours (marked or unmarked) and it's still possibly to create paths that can be followed since the field of view is 3x3. 3 colours allows a path with a direction (abcabcabc) to allow quickly getting back to the queen when food is found. So I'm confident that there will be a wide variety of strategies available with 16 colours, but I still want to consider what might be possible with 256 colours or true colour. I'm intrigued...

@ProgramFOX Thanks :)

@BrainSteel yes the challenge of working with no private knowledge is the point. I'm fairly certain I won't let the queen know how many workers she has, but it could have been worse: I toyed with the idea of not letting the queen know how much food she has stored...

BrainSteel

4:34 PM

Haha, fair point. Either way, the challenge is awesome and I won't get hung up on the little things.

trichoplax

At the moment simple strategies are possible such as always produce workers when the food store is higher than 10. Another strategy that sets aside 2 or 3 arena cells to keep a count of workers produced can then have an advantage. So the effort isn't required but it will help...

@BrainSteel Just because I disagree on that point doesn't mean I don't want feedback - thanks for raising things and please mention anything else you think of :)

BrainSteel

It's clear that you've thought this through, and I can't see any obvious flaws or holes in the spec. I'll let you know if I notice something, but you'll likely get a lot more feedback once we have a controller to play with :)

trichoplax

Yes exactly - being able to test out strategies in a controller will be much better than just imagining them in my head. Also being able to see other people's strategies that haven't occured to me. I'd better get writing :)

Nathan Merrill

5:13 PM

if I have the curvature of a warp I want to apply to an image, how would I go about finding anchor points and their offset?

Sparr

5:33 PM

@NathanMerrill need some context. what kind of warp?

Nathan Merrill

say you wrap an image around a cylinder

you want to show what the image looks like on that cylinder

in my case, I'll be wrapping around only a portion of a cylinder (10 degrees of it or so)

Sparr

looks like from what perspective?

and in what projection?

Mitch Schwartz

@Lembik thanks

Nathan Merrill

5:55 PM

@Sparr it looks like I have more researching to do

anyways, I really like it when I see our community on meta

TheNumberOne

6:17 PM

@trichoplax Grumble grumble, I was starting to write up a KOTH challenge identical to that when you posted it.

trichoplax

@TheNumberOne Oh no! Sorry about that... How long have you been working on yours? Can it be made to be different?

TheNumberOne

Half a week. It's okay, keep doing what your doing. I'll be fine :)

trichoplax

I've been mentioning mine in chat since the week before last and working it out on paper for weeks before that, so I don't feel so bad now ;)

@TheNumberOne I'm assuming you mean the ant QotH, not the toroidal bot soccer KotH?

TheNumberOne

Ant, not soccer :)

trichoplax

I was going to suggest you could take over the soccer one if you meant that one, but I'm very protective of my ants... :)

Out of curiosity, how did your ant KotH differ?

TheNumberOne

6:25 PM

Each species of ant could communicate in their own "spectrum" of colors.

And there would be 2^32 different colors.

trichoplax

Does that mean a single cell could hold messages from more than one species, and a given species could not interfere with other species' messages?

TheNumberOne

Yes, but not very good for watching.

trichoplax

I'm still undecided on the number of colours - what Geobits was saying earlier has me wondering about increasing it

If they can't interfere with each other's messages, does that mean the competition is just getting to the food first, or can they attack each other?

TheNumberOne

Attack

trichoplax

Despite the similarity in theme, this actually sounds like it might be different enough to not be a duplicate. Maybe just with a delay before posting

Lembik

6:31 PM

hi @MitchSchwartz

TheNumberOne

@trichoplax Okay, I'll keep that in mind.

When are you planning to post yours?

trichoplax

As soon as I have the controller working

I've put some sandbox questions but apart from that type of fine tuning I think the spec is settled

Was yours going to be a specific language?

TheNumberOne

I haven't planned that yet :)

Lembik

hi @Agawa001

trichoplax

Ah OK.

I'm glad you mentioned yours, and especially the large number of colours. I was leaning towards increasing the number of colours in mine but maybe it would reduce the risk of duplication if I keep the number of colours low?

Also will yours have the same extreme lack of memory, having to determine everything from cell colours?

TheNumberOne

6:38 PM

@trichoplax Not quite as extreme...

More on the order of a 5 character string for memory.

trichoplax

Well that's another difference. If the game is different but it just sounds like a duplicate because of "ant" in the title, maybe you just need a different name (termites or something...)

Will yours have a single piece of code controlling each player's ants, or separate code for each ant?

TheNumberOne

Single, hence the need for some memory.

trichoplax

It really does sound different then. Unfortunately it will be at the whim of the voters, but if it goes through the sandbox hopefully you will find out anything that needs to change to avoid being a duplicate there

TheNumberOne

Ok, thank you :)

Mitch Schwartz

hi @Lembik

Geobits

6:59 PM

So a termite walks into a bar. He goes up to the guy behind the counter and asks, "Hey, where's the bar tender?"

trichoplax

@Geobits was just about to ping you about the alternative ant Koth...

I see a punchline coming...

Geobits

The punch line is already there ;)

It's not a particularly good one, but...

trichoplax

I was going to say that since TheNumberOne is planning an ant KotH with huge numbers of colours, I'm now more likely to keep mine to small numbers to hopefully allow that one to not be a duplicate

@Geobits I thought that was going to be the set up for something more direct, but subtle is good ;)

Geobits

I see that. I'm interested to see more about his, too. I like swarm mechanics in general, so it sounds funn.

TheNumberOne

@Geobits I still don't see the punchline...

Geobits

7:03 PM

bartender != bar tender

trichoplax

Do you have an idea of how likely it is the community will accept both? I'd really like to see both as I think the approaches could be quite different

Geobits

Can't really say without seeing more of the other.

trichoplax

@Geobits I added some very basic example strategies using very few colours. I might use some of those as a starting point for people to compete against.

Geobits

Ah, the parasitic one is just mean :)

trichoplax

Yeah :)

Geobits

7:09 PM

How does the spiral work? More specifically, how does a worker know whether he's new (and should spiral) or freshly unladen (and should cut across)?

trichoplax

It won't find anyone often but when it does if they aren't prepared for it they're doomed

Vioz-

Hello :)

trichoplax

Hello :)

@Geobits I could probably describe the spiral one more succinctly and avoid that distinction. If a worker sees no spiral, it starts making one. If it sees a spiral, it cuts across to the outside and continues building it.

I'm not sure how the spiral will work with multiple workers though

Geobits

That's kinda what I thought, just wanted to make sure I wasn't missing some mechanic.

Vioz-

Do you guys think you could take a quick look-over of my proposed challenge if you haven't already? meta.codegolf.stackexchange.com/a/5436/38417 :)

trichoplax

7:11 PM

It needs to become several parallel spirals without losing its ability to map back to the queen

@Vioz- I had a look and upvoted earlier - I can't see any obvious ambiguities or anything missing

Vioz-

That's good to know :)

trichoplax

@Vioz- The only thing I'd question is the bonus, but that's just because I lean away from putting bonuses in golf questions.

Plenty of people do put bonuses, I just prefer there to be only one correct way to answer

Since I'm not a golfer, you probably shouldn't take my opinion too seriously... :)

Vioz-

Yeah, I wrote that up just because it was an idea I had, I was sort of iffy on it too

Geobits

I agree about the bonus, especially since it's essentially a whole different task.

trichoplax

I say I'm not a golfer, but the only pure golf question I've answered has only one answer, which means I'm technically winning...

Geobits

7:19 PM

Hmm. I was about to say I'm only a semi-golfer, but apparently that's my top tag :(

trichoplax

Why is that sad...??

Geobits

Because I think of myself as a koth person :P

trichoplax

@Geobits I think of you as a KotH person - I joined up to try and answer Hunger Gaming...

Geobits

Exactly! I can't go around ruining my rep by answering golf questions :D

It's as weird as when CH answers something ;)

trichoplax

That is weird

I still wonder whether we'll see a golf-KotH cross over question

Geobits

7:25 PM

Slightly related, people aren't very amused when you (semi-)golf a KotH entry: codegolf.stackexchange.com/a/45591/14215

Just saw soccer. Sounds ambitious and fun.

trichoplax

lol. If I asked a golf KotH question I'd still want answerers to include ungolfed versions, although an explanation is almost enough

@Geobits Thanks :) I've tried to avoid being ambitious by simplifying like crazy.

@Geobits I must say, I'm both disapproving and amused...

Geobits

lol, I really was mainly trying to conserve scrolling space. I added the explanation to avoid the 'one line of code and that's it' anger from the audience.

trichoplax

It would be great if answers could collapse to a few lines and only expand when clicked on

Geobits

If I obfuscated it, I could understand people being somewhat annoyed. Even though that seems legit by most koth rules.

@trichoplax Agreed.

trichoplax

The soccer question was going to be lower priority than the ant QotH anyway, but even more so now that I know TheNumberOne has a related idea - I want to get the ants ready as soon as possible so the other question doesn't have to wait too long for this one to die down

Geobits

7:33 PM

Both sound like fun, but the ants more so. I approve and endorse your decision :P

trichoplax

@Geobits Maybe the single character variable names didn't help ;)

Geobits

Maaaaaybe.....

I'm gonna go smash some stuff in Diablo 3 now, though. Have fun!

trichoplax

@Geobits Excellent. I'm drawing out the layout as we speak

You too!

Vioz-

I'm having trouble thinking of a title for this :P

trichoplax

Something self-referential??

Vioz-

7:47 PM

Hmmm

trichoplax

Formula for a formula?

Formulating a formula?

Formula formula?

The formula formerly known as a formula?

I'll stop now, these are getting formulaic

Vioz-

Haha

trichoplax

:)

Vioz-

Of course when I google "self-referential", a relevant XKCD pops up

What about just "This Is A Self-Referential Problem"?

trichoplax

Wikipedia claims it isn't really even self referential, but don't let that get in the way of a good name...

qwr

8:00 PM

hello

Vioz-

8:14 PM

I noticed something weird: When adding an answer to a question, I can use LaTeX, but the formatting didn't seem to work when I added it to my question. Is there a reason for this?

New Main Posts

1

Q: This Is A Self-Referential Problem

Tupper's Self-Referential Formula (copied from Wikipedia) Tupper's self-referential formula is a formula defined by Jeff Tupper that, when graphed in two dimensions at a very specific location in the plane, can be "programmed" to visually reproduce the formula itself. It is used in various math ...

code-golf image-processing

NinjaBearMonkey

MathJax is only enabled on meta.

Vioz-

Oh, alright

Compass

wait

so that self-referential problem

you can actually find that NINTENDO MUSHROOM IN THERE?

aditsu

@Doorknob no, I don't really use github

@aditsu <-- @Doorknob it was this, but it expired, will repost in a minute

XkcdLang, very slightly improved from last time: dpaste.com/0V43PP3

should last a bit longer :p

feersum

8:43 PM

I don't understand the need for the xkcd-lang. You could use Javascript or PHP and it would be a lot funnier because you could get people to believe they are serious languages.

aditsu

what the heck, it disappeared.. let me try again

XkcdLang, reposted: dpaste.com/153K4B4

@feersum haha, they may not be quite as quirky, but very close :)

Sparr

9:05 PM

@Compass you can find any bitmap of a particular size in that function. That's what it does.

aditsu

9:22 PM

rats, it's gone again.. let me use a different pastebin

or.. blah, I'll just put it on my site

aditsu.net/XkcdLang.java

@Doorknob ^

Vioz-

10:01 PM

@Compass yes, you can find anything, as Sparr said. I like that you appreciate it though, I did that by hand using a color one as reference, took way longer than I'd like to admit :P

PhiNotPi

10:30 PM

Here's a nice screenshot from the PPCG Minecraft server. It's the site logo floating over town.

6

Sparr

I need to try Minecraft again. It's been a long time.

Martin Büttner

@Doorknob you look a bit ill

Doorknob

@aditsu gist.github.com :)

@MartinBüttner I fell in a vat of paint.

in Tavern on the Meta on Meta Stack Exchange Chat, 2 hours ago, by Doorknob

(I'm gonna make up a different story every time someone asks me that :P)

Martin Büttner

@Doorknob that sounds fun :)

Doorknob

@MartinBüttner Yes indeed.

Martin Büttner

10:39 PM

oooo, neat

(I don't currently play any instrument, and my musical education is rather rudimentary, but I love unconventional time signatures)

PhiNotPi

I played a piece once that alternated 7/8 and 11/8 every-other-measure.

Martin Büttner

so essentially 18/8 with an odd beat distribution?

PhiNotPi

Yeah, it's just how the beats were.

I found some random recording of it on YouTube here.

Martin Büttner

I won't have any sound for the next 24 hours but I hope I'll remember to check it out tomorrow night

PhiNotPi

Excuse me, it's actually 11/16 and 7/16

Martin Büttner

10:51 PM

I don't really get the difference between different denominator, other than arbitrary convention

PhiNotPi

The denominator (I think you meant to say denominator) just indicates which type of note represents one beat.

Martin Büttner

I totally said "denominator"

PhiNotPi

Mathematically, it is just an arbitrary conversion.

Martin Büttner

@PhiNotPi well yes... but I mean you could just rewrite everything with the next longer/shorter notes and double/halve the bpm (or whatever you use to denote the speed)

PhiNotPi

For example, two of the most common time signatures are 4/4 (common time) and 2/2 (cut time).

But there is a difference in style.

BrainSteel

10:54 PM

They usually use whatever denominator makes the piece easiest to write/read, and occasionally use a different denominator to denote a different musical style. Cut time is often a march thing, whereas common time is a more general piece.

But no, there's no mathematical difference.

PhiNotPi

Both pieces would have 4 quarter notes in a measure, but a 2/2 piece often moves so fast that you couldn't actually conduct all 4 quarter notes, so you conduct 2 half notes instead.

BrainSteel

^

Martin Büttner

uh, no I'm not talking about the difference between 4/4 and 2/2 (because those would imply different stresses I think). more like the difference between 4/4 and 4/8 (which are not the same mathematically, but to me only the 4 in the numerator tells me anything about how the beats are stressed, whereas the denominator is only meaningful in relation to some form of bpm)

or, since we were talking about unconventional time signatures 5/4 vs 5/8

BrainSteel

As phi pointed out, the biggest difference is generally in the way the music is conducted, not necessarily how it is played.

Or at least, that's what my band teachers usually told me.

PhiNotPi

I think I've found a potential difference.

BrainSteel

11:06 PM

Oooh?

PhiNotPi

Maybe, it's just a stylistic thing. I you consider the "strong" beats in the measure to represent quarter notes, then some weird denominators arise when those strong notes are irregularly spaced.

If this is your strong beat pattern:
|.|.|.|.|.
Then you would do 5/4
But if this were your beat pattern:
|..|.
Then, if those strong beats serve a musically similar purpose to regular quarter notes, then those subdivisions (3 and 2) represent eight notes. Since the "quarter note beats" aren't regular, you have to measure in 8th notes, giving a 5/8 signature.

For example, if a time signature has a _/4 then each of those notes is potentially a strong beat. In 4/4 each note could have stress, in 3/4 each not could have stress. On the other hand _/8 are always grouped. You never have each 8th note get stress, just groups of 8th notes.

Martin Büttner

hm, interesting. that sort of makes sense.

PhiNotPi

In 5/4 you would count {1, 2, 3, 4, 5} while playing the music. In 5/8 you would count {1, 2} or {1, 2, 3} depending on how they were grouped.

BrainSteel

Ah, yes, that's a good reason.

Martin Büttner

completely unrelated: it seems we haven't had a challenge on quad-trees. I wanna write one but there are at least three ways to do it and I can't make up my mind: 1. given a set of coordinates, return an actual tree datastructures containing those points. 2. given a set of coordinates, render the resulting quad-tree. 3. ascii-art of the above, where each cell indicates the depth of the tree there

for the ascii art, if you were given this:

          #
  #            #
    #
        #  #
   #       #

   #

# #
        #
         #
          ##
    #
      #
         #
             #

you'd print this:

2233222222432233
2243222222332234
2222432233332222
2222332243342222
2234111122341111
2233111122331111
2234111122221111
2233111122221111
4343111133221111
3333111143221111
2222111134331111
2222111133441111
1111433322222222
1111334322222222
1111222234223322
1111222233223422

PhiNotPi

11:21 PM

Of course, there's no single reason to justify all time signatures. Take the piece Rhosymedre, which is written in 4/2. My assumption is that the composer wanted 4 beats in a measure but didn't want to write 16th notes because it is supposed to be a slow piece.

From my perspective, that just made it hard for me to read the music and I would have preferred regular 4/4 time.

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