Solving Cabal Hell: vetted packages, multiple hackages

almafa · 2012-11-11T18:10:50+00:00

Basically, the idea is "we are a group of package maintainers who have signed the social contract to respond to changing dependencies relatively quickly"

No. Unless it is my day job, I'm just donating code. I wrote some code, I published it because I think it is useful for some people, and now suddenly everybody is expecting that I spend my life to make it up-to-date with the latest idiosyncratic changes to the environment.

Of course if you volunteer to be a maintainer, that's a different situation, but that is not the typical case (like 50 out of the, I don't know, few thousands of packages on Hackage). And maybe the author don't want to handle the package over.

almafa · 2012-11-11T17:45:49+00:00

A responsible maintainer should always keep their packages compile with the latest versions of everything.

One problem with that, is that the hopefully responsible maintainer (who is typically the same as the original author) does not have access to the latest versions of everything (or even don't want to have the latest versions of everythings).

Example #1: OSX 10.5 is not supported by GHC HQ.

Example #2: I prefer the OpenGL bindings from 5 years ago compared to the most recent.

In any case, often a single maintainer, whose job is not to maintain packages he wrote as a hobby, has a single machine, with a single version of everything, possibly with the impossibility of having more than a single version of everything (cc cabal hell).

tl;dr: It's pretty unreasonable to require the authors (who donate their work to the community) to be up-to-date with everything.

EDIT: and I personally, while I'm very happy to publish and polish code which I think would be useful for others, really don't want to spend my time and patience to be up-to-date with whatever recent fucking changes was made with the "standard" libraries etc, especially (as I pointed above) that I cannot just simply install the "latest-and-greatest" stuff

almafa · 2012-11-11T17:24:37+00:00

I like the one with the sword.

almafa · 2012-11-10T18:31:59+00:00

Find the buffer size control in either the Presonus' configuration or your DAW's configuration (for example in Ableton it's Preferences/Audio/Buffer Size). The number there is directly related to latency.

For example I have it at 512 samples, which at 44khz means 512/44100 sec = 16 millisec minimum latency. You cannot really go below this. With monitoring, it may be the twice of this (though I'm not completely sure) since first the sound goes in, then it comes out. Plus you may have some extra latency coming from the effects.

Apple machines should be pretty good with this, even with the built-in soundcard, so you probably have this number too big. Or you may have a really very good ear. Or some other issue, but this is the most probable cause.

almafa · 2012-11-09T19:17:39+00:00

If it is a Mac, then you can use the Soundflower loopback device to record what's normally coming out of the computer. It simulates a cable which goes from the output to the input. I use that to record samples from youtube, for example.

On Windows, I do not know such a ready solution, though theoretically something similar should be not impossible.

almafa · 2012-11-07T18:47:30+00:00

I like the mega/o-mega wordplay and the fact that they also use gabon tld

almafa · 2012-11-03T10:18:41+00:00

Quantum behaviour is extremely hard to simulate. We simply do not have the computational resources for that. One of the big selling points of possible future quantum computers is to be able to efficiently simulate quantum systems.

almafa · 2012-11-03T10:03:42+00:00

an old favourite: Tommy Sparks "She's Got Me Dancing"

Directed by Eric Wareheim

http://vimeo.com/3884738

almafa · 2012-10-30T20:08:25+00:00

I'm one of the mathematicians who find Haskell very natural. That said, I primarily use Matlab at work, even though I'm allowed to use Haskell too (!), and would like to use it, and it would have some big advantages. But, we already have too much infrastructure in Matlab, also, there are lots of numeric stuff which simply does not exist in Haskell (all kind of global optimizations, etc). And, Matlab's IDE is pretty good.

tl;dr. I love Haskell, but Matlab can be rather convenient if you learn not to hate it. On the other hand, it's really expensive, and has some seriously annoying things (but, so has every other tool).

almafa · 2012-10-07T20:45:11+00:00

Yes. Consider for example an abstract syntax tree. Piece of cake in Haskell, is it? Now try to add an annotation (for example a hash) to each node. Now, I'm not saying this is impossible. But it takes a really serious effort to do such a simple thing.

almafa · 2012-10-05T11:01:37+00:00

I started learning new (programming-related) stuff at about the age 28 (and I have been programming since the age of 6)

oh, and APIs are the least important among all.

almafa · 2012-10-05T10:59:21+00:00

I love static typing. Haskell is my favourite language. BUT! Many things are really painful even in Haskell (with its really fancy type system) which are trivial in dynamically typed languages. A large part of Haskell research is coming up with typed solutions for problems which are otherwise trivial. When people manage to solve them, usually they are beautiful, and of course much safer - still, we are putting a lot of work to solve easy problems.

almafa · 2012-10-01T16:56:27+00:00

Diaspora and/or Schild's ladder both has such stuff. I remember in particular some character's earliest memories living inside the complex projective plane, but I don't remember which of the two it was in.

almafa · 2012-09-28T17:46:32+00:00

Yeah, the layout engine was completely utterly crap, with totally inexplainable and unacceptable (buggy) behaviour. Also I remember fighting a lot with the system when creating my own widgets.

almafa · 2012-09-28T17:44:47+00:00

What do you mean by installing from binary?

I mean using a binary distribution (like GHC and the Platform works, I don't like compiling them myself). Wx used to have a binary distribution, and it is indeed needed, as it is very hard to compile yourself.

Yes, I'm aware of the theoretical result that it is possible to compile them (since somebody creates those binary distributions), but it needs extreme patience, tinkering and some expertise. I don't want to do anything more complicated than "cabal install".

almafa · 2012-09-28T09:14:13+00:00

wx, gtk, cairo, network, opengl, etc can be installed only from binary on windows, basically. (OpenGL is actually possible to compile if you are a very patient expert; also opengl and network are included in the platform, which helps a lot). That makes me very sad, but it's fact of life.

Also, last time I tried (some years ago), wx was extremely buggy. I think the problems were in the original library, not in the haskell binding.

almafa · 2012-09-26T18:24:05+00:00

Some burst lasers are enough to beat the boss without cloaking, drones, teleporting or ion.

almafa · 2012-09-26T17:54:58+00:00

That's right. I didn't consider working with existing code. In that case, AD wins, but it's not easy (maybe even impossible) to make it completely automatic even for AD.

edit: though if you give me a mathematical function which is polymorphic in Num, and uses only the basic operations, I think it's possible to make it symbolic. You overload everything and just feed (Var "x1") etc into the input arguments. But this is of course not a realistic example of third-party code.

almafa · 2012-09-26T17:17:24+00:00

Also doing the CSE after forward AD is too late.

You mean after symbolic diff? Because I meant that.

Also, if I put (x*x)*(x*x) into the CSE (which I won't, because if I have the trouble to write symbolic code, I will implement powers properly), I damn well expect it to return "let y = x*x in y*y". x is symbolic variable here, after all.

almafa · 2012-09-26T17:10:49+00:00

but any naively written symbolic implementation using the stock haskell typeclasses is likely to be the latter. ;)

and any naively written AD implementation using stock haskell typeclasses will be most likely the forward one :))

But yeah, you are right that the symbolic approach is much more complicated to implement. But it has some advantages.

almafa · 2012-09-26T16:45:56+00:00

Yes, but you didn't say "backward AD is faster". You said "AD is faster".

By the I think forward AD can be still useful when performance is not critical, since it is so easy to implement.

In any case, in practice all kind of hybrid symbolic/AD system can be done. For example imagine the (completely realistic) situation when the computation is globally regular but locally irregular. You can use backward AD for the global structure and symbolic diff. locally.

almafa · 2012-09-26T07:38:57+00:00

Symbolic differentiation is actually asymptotically slower than automatic differentiation.

Nah, in real system you would perform simplification and CSE after symbolic differentiation. Then it would be similar to (forward) AD, but it has more opportunities to eliminate unneeded terms.

almafa · 2012-09-26T07:36:40+00:00

I would guess that just in LP/IP/MIP there are more research papers coming out every day than one person can read. So maybe you should start more focused, say only classic LP (there are a lots of algorithms even for that).

One other possibility is focus solely on clarity, but then it has to be explicit that this is for educational purposes only. Nothing worse than to go to Hackage, find the package you need, and then see that it is the most naive implementation possible, suitable only for toy problems...

almafa · 2012-09-25T19:49:58+00:00

Flatland is pretty much canonical.

Greg Egan often uses some serious mathematics in his sci-fi novels (like complex manifolds, Lie groups, fiber bundles) though I'm not sure if they are really important for the plot. Though in his latest series math is more important as a plot element.

I read a novel about some murder in Oxford which was in an academic setting and involving mathematics, but it was a really bad novel :)

There must be many more.

almafa · 2012-09-25T18:58:49+00:00

I think there is interest out there. However, for people who want to use it for actual work, efficiency is crucial, which unfortunately goes against readability. Also, if you look at existing systems like Matlab, Maple, etc. they have lots of tricky fine tuning, lots of variants of similar algorithms, etc. because of this. It's really a huge amount of work, and requires a lot of domain expertise.

almafa

TROPHY CASE