Re: [Haskell-cafe] Projects using Shake
hi frerich, On May 31, 2013, at 2:17 AM, Frerich Raabe wrote: Is anybody aware of open source projects which I could look at, or is there maybe a conventional file extension for… what do you call them, Shakefiles? other than .hs which I could google for? we are using a shake-based build system for our mobile sound engine [1]; see the shakefile here [2] and associated modules [3]. the focus is on cross-compilation of static/shared libraries for mobile platforms (currently ios, android in the works) so it might not be what you're looking for. however, most of it is quite generic (if you're working with c, c++, objc, asm) and we're going to release it as a library as soon the features and the API have settled a bit. cheers, sk [1] http://methc.la [2] https://github.com/samplecount/methcla/blob/develop/engine/shakefile.hs [3] https://github.com/samplecount/methcla/tree/develop/engine/Shakefile ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell] [ANN] hsndfile 0.7
I am happy to announce version 0.7 of hsndfile [1], a set of Haskell bindings to the venerable libsndfile library. This release is a bugfix and maintenance release, thanks to Roman Cheplyaka for his contributions! Changes since 0.6 [3]: * Read and write signed instead of unsigned integer samples and rename `sf_readf_wordXX` and `sf_writef_wordXX` to `sf_readf_intXX` and `sf_writef_intXX`, respectively * Add new supported header and sample formats Have fun, sk [1] http://hackage.haskell.org/package/hsndfile [2] http://www.mega-nerd.com/libsndfile/ [3] https://github.com/kaoskorobase/hsndfile/blob/master/ChangeLog.md ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell-cafe] Mobile app development?
On Jan 19, 2013, at 10:29 PM, Nathan Hüsken wrote: Recently I managed to get ghc to target android working (this still needs some work): [4]. this is great news, thanks! Of couse, ffi bindings for all these platforms would be needed to get serious. i think that you can get quite serious already if the main model is implemented in haskell and you only need bindings for communicating with a native user interface. sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: any successfull ghc registerised builds on arm?
hi nathan, On Jan 14, 2013, at 6:15 PM, Nathan Hüsken nathan.hues...@posteo.de wrote: Did anyone succesfully build ghc on an arm system which produces non crashing executables? I am asking, because I build a arm-linux-androideabi cross compiler, but the executables crash. Only in an unregisterised build, they work. So I wonder if it is a general arm problem or has to do with android. stephen blackheath's ghc port to iOS cross compiles to armv7 [1] (using llvm, registerised, i assume?). see [2] for a list of libraries i've built and run on iOS. here [3] is some info on cross compiling for blackberry arm (QNX). maybe it would be worthwhile asking on the iphone mailing list [4], too? sk [1] https://github.com/ghc-ios/ghc/wiki [2] https://github.com/kaoskorobase/ghc-ios-cabal-scripts [3] http://www.haskell.org/pipermail/iphone/2012-November/000142.html [4] http://www.haskell.org/mailman/listinfo/iphone ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
[Haskell] ANN: hsc3-process-0.8 and hsc3-server 0.5
I am happy to announce the release of version 0.8 of hsc3-process [1] and version 0.5 of hsc3-server [2], both providing additional features and abstractions for the excellent hsc3 interface [3] to the SuperCollider synthesis server [4]. hsc3-process allows to start external scsynth processes and run actions that communicate through the associated OpenSoundControl transport. hsc3-server builds on hsc3 and hsc3-process and adds the following features: * A `Server' monad for accessing synthesis server state from concurrent threads, * Resource ID allocators for nodes, buffers and buses, * A composable `Request' abstraction that allows to assemble synchronous and asynchronous server commands into OpenSoundControl bundles for efficient scheduling, * A type-safe interface to the SuperCollider synthesis server command set. hsc3-server has been in use internally for some time but this is the first release that is ready for consumption by the general public. Have a look at some examples here [5]. Any feedback welcome! Happy synthesis! [1] http://hackage.haskell.org/package/hsc3-process [2] http://hackage.haskell.org/package/hsc3-server [3] http://hackage.haskell.org/package/hsc3 [4] http://supercollider.sourceforge.net/ [5] https://github.com/kaoskorobase/hsc3-server/tree/master/examples ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell-cafe] Profiling with QtHaskell
On 20.04.12 10:07, Øystein Kolsrud wrote: Hi! Does anyone know if it is possible to use QtHaskell with profiling turned on? afair i've used it when profiling an application (not qtHaskell itself). what's the problem you're running into? you need to compile the library with profiling support enabled, i have library-profiling: True in ~/.cabal/config sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Open-source projects for beginning Haskell students?
On 25.03.12 09:38, Heinrich Apfelmus wrote: John Lato wrote: From: Heinrich Apfelmus Also, as far as I am aware, you can't do low-level audio programming in SuperCollider, i.e. play a list of samples that you've calculated yourself. That's cool if you're only interested in sound design, but bad for learning how audio programming works. I think this charge is a bit unfair. If you really want to do low-level stuff, it's possible within SC. You just have to work in SuperCollider, not Haskell (AFAIK). Ah, right, I meant from within Haskell, i.e. by communicating with the SC3 server component. Even in SC you have to write unit generators in C, I think, but I may well be mistaken. there's a more functional option, too: faust [1] ;) sk [1] http://faust.grame.fr/index.php/documentation/what-faust ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] matrix manipulations and calculations
On 9/9/11 1:44 PM, Aleksey Khudyakov wrote: If you install hmatrix with -fVector key it will use storable vectors from vector package. that flag defaults to True, so the representations are actually the same by default: http://hackage.haskell.org/packages/archive/hmatrix/0.12.0.0/hmatrix.cabal sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] how to generate source code from TH Exp?
hi, i was wondering if it's possible to directly generate Haskell source code from a Template Haskell `Q Exp', i.e. use TH as a kind of preprocessor? i am asking because currently the iOS port of ghc doesn't support TH and i need to generate some instances for the persistent package [1,2]. i've been toying with fmap ppr . runQ $ q but the result needs to be edited by hand quite a bit. any ideas where to start? thanks, sk [1] http://hackage.haskell.org/package/persistent [2] http://hackage.haskell.org/package/persistent-template ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] how to generate source code from TH Exp?
On 5/12/11 4:03 PM, Serguey Zefirov wrote:
Just pretty-print a Exp.
It seems that show $ ppr exp will produce exactly what you need.
The same goes for Dec (declarations), etc.
ah ok, thanks!
fwiw, here's a way to extract a list of module names that need to be
imported, adapted from an example by Neil Mitchell using generics:
extractModules :: Data a = a - [String]
extractModules = sort . nub . everything (++) ([] `mkQ` f)
where f (NameQ x) = [modString x]
f (NameG _ _ x) = [modString x]
f _ = []
which can be used to output a source code module:
mkModule :: (Data a, Ppr a) = [String] - String - a - String
mkModule exts name e =
unlines ([ {-# LANGUAGE ++ intercalate , exts ++ #-}
, module ++ name ++ where ]
++ map (import qualified ++) (extractModules e))
++ show (ppr e)
good enough for now ;)
sk
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Re: [Haskell-cafe] [Cabal-devel] Cabal license combinations
On 10.02.11 12:12, Duncan Coutts wrote:
We are already working on a feature that will show the full set of
licenses that the end user must comply with (a patch has been submitted
and it's been through one round of review so far). In your example that
would mean you expect the set to be {BSD} but the tool will show you
that it is in fact {BSD, GPL}. You can then use that as your warning
that the set of licenses is not what you expected.
that would be quite useful for those who want to distribute executables!
may i also suggest the following feature: collect all the copyright notices and
license files from each dependency (many licenses require those to be displayed
and distributed along with the executable) and optionally bundle them with the
applicaton's data-files? i briefly looked into this, but couldn't find a way to
retrieve the installed License-File from ~/.cabal using Cabal. doing this by
hand turns out to be quite tedious when there are many dependencies ...
sk
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Re: [Haskell-cafe] Haskell for Gingerbread
On 28.12.10 21:25, John Meacham wrote: jhc generated C works on the android/ARM just fine. Android specific libraries arn't available, so you would have to bind to what you want with the FFI. is there a recommended procedure for porting code from GHC to JHC? i'd like to port an application of mine to ios/android, but my naive approach of specifying the jhc compiler in ~/.cabal/config fails with the first dependency (binary), because the base library does not have the required version. any hints? thanks, sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC Out of memory
On 23.11.10 09:36, Christopher Done wrote: What version of GHC/qtHaskell? i've also noticed this on linux and osx with ghc 6.12.1/6.12.3 and qtHaskell 1.1.3.5/1.1.4. possibly a memory leak in ghc --make? sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GUI Designer
On 18.11.10 21:28, c8h10n4o2 wrote: There's a tutorial on how to use qtDesigner with qtHaskell ? sorry, i don't know of any tutorial, but there are some examples in the `examples' directory of the source distribution (e.g. tetrix.hs). basically you load the ui file, retrieve named widgets and attach signal handlers in haskell. signals and slots of compatible types can also be connected directly in Designer. sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] deploying applications that use plugins
hi all, i am working on an application that evaluates haskell code entered by the user using the plugins package [1]; now i want to deploy the application as a self-contained .app bundle on OSX, i.e. the end user should not have to install anything in addition. what do i need to bundle in order for plugins to work on a vanilla machine? i suppose i need ghc in PATH and have to ship modified versions of the package.conf files that point to the corresponding libraries within the application bundle? is there a parser for package.conf files? any pointers would be greatly appreciated! thanks, sk [1] http://hackage.haskell.org/package/plugins ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell] analogous functions in Sound.File.Sndfile
following up on haskell-cafe ... On 07.07.10 04:07, Maria Gabriela Valdes wrote: Does anybody know what are the analogous functions and data types in the haskell library Sound.File.Sndfile of the libsndfile library in C ? the decision may be debatable, but where it seemed appropriate the C identifiers map to identifiers commonly used in haskell. data type : SNDFILE Sound.File.Sndfile.Handle function: sf_open Sound.File.Sndfile.openFile function : sf_read_short the most lowlevel interface is the hGetBuf method of Sample; you have to allocate buffer memory yourself. hGetBuffer returns a newly allocated instance of Buffer; see the packages hsndfile-vector [1] and hsndfile-storablevector [2] for instances and examples [3]. hGetContents returns the contents of the whole file at once while hGetContentChunks returns a lazy list of buffers. readFile and readFileChunks are just wrappers around openFile and hGetContents. i just noticed though that the lazy versions don't work correctly because they don't take closing the file handle into account properly. i think they should be removed from the API, for incremental processing an iteratee interface would probably be more appropriate. sk [1] http://hackage.haskell.org/package/hsndfile-vector [2] http://hackage.haskell.org/package/hsndfile-storablevector [3] http://hackage.haskell.org/packages/archive/hsndfile-vector/0.4.0/doc/html/src/Sound-File-Sndfile-Buffer-Vector-Examples.html#normalizeSoundFile ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Can't install Criterion package on ghc ..
On 13.04.10 14:46, Mozhgan kabiri wrote:
I am trying to install Criterion package, but I keep getting an error
and I can't figure it out why it is like this !!
[...]
[8 of 9] Compiling Data.Vector.Algorithms.Intro (
Data/Vector/Algorithms/Intro.hs, dist/build/Data/Vector/Algorithms/Intro.o )
ghc: panic! (the 'impossible' happened)
(GHC version 6.10.4 for i386-unknown-linux):
idInfo co{v a9WB} [tv]
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
fwiw, the latest version of vector-algorithms (0.3.1) seems to build with ghc
6.10.4.
sk
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[Haskell] ANN: hsndfile 0.4
i'm pleased to announce version 0.4 of hsndfile [1], a haskell interface to libsndfile [2]. in version 0.4 the buffer i/o interface has been simplified and instances for i/o based on the vector package [3] is provided by hsndfile-vector [4]. enjoy! sk [1] http://haskell.org/haskellwiki/Hsndfile [2] http://www.mega-nerd.com/libsndfile/ [3] http://hackage.haskell.org/package/vector [4] http://hackage.haskell.org/package/hsndfile-vector ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell-cafe] vector stream fusion, inlining and compilation time
This is a general problem when working with RULES-based
optimisations. Here is an example of what happens: suppose we have
foo :: Vector Int - Vector Int
foo xs = map (+1) xs
Now, GHC will generate a nice tight loop for this but if in a
different module, we have something like this:
bar xs = foo (foo xs)
then this won't fuse because (a) foo won't be inlined and (b) even if
GHC did inline here, it would inline the nice tight loop which can't
possibly fuse instead of the original map which can. By slapping an
INLINE pragma on foo, you're telling GHC to (almost) always inline the
function and to use the original definition for inlining, thus giving
it a chance to fuse.
thanks for the insight, roman!
the downside after adding the INLINE pragmas is that now some of my modules
take
_really_ long to compile (up to a couple of minutes); any ideas where i can
start looking to bring the compilation times down again?
Alas, stream fusion (and fusion in general, I guess) requires what I
would call whole loop compilation - you need to inline everything into
loops. That tends to be slow. I don't know what your code looks like
but you could try to control inlining a bit more. For instance, if you
have something like this:
foo ... = ... map f xs ...
where
f x = ...
you could tell GHC not to inline f until fairly late in the game by adding
{-# INLINE [0] f #-}
to the where clause. This helps sometimes.
thanks, i'll check it out.
I'm surprised -Odph doesn't produce faster code than -O2. In any
case, you could try turning these flags on individually (esp.
-fno-method-sharing and the spec-constr flags) to see how they affect
performance and compilation times.
in the end it turned out that i had forgotten another INLINE pragma and in my
crude benchmarks -O2 and -Odph give basically the same results, -O2 being a
little faster. i hope i'll have time next week to do proper benchmarks, and i
also want to try ghc HEAD with the llvm patches.
conv_1 conv_2 conv_3
-Odph 1.004 2.715 1.096
-O2 1.000 2.710 1.097
i'm still curious, though, why my three versions of direct convolution perform
so differently (see attached file). in particular, i somehow expected conv_3 to
be the slowest and conv_2 to perform similar to conv_1. any ideas? i haven't had
a look at the core yet, mainly because i'm lacking the expertise ...
sk
import Data.Vector.Generic (Vector, (!))
import qualified Data.Vector.Generic as V
conv_1, conv_2, conv_3 :: (Num a, Vector v a) = v a - v a - v a
{-# INLINE conv_1 #-}
conv_1 h x = V.generate (l+m) f
where
m = V.length h - 1
l = V.length x
{-# INLINE f #-}
f n = g 0 n (max 0 (n-l+1)) (min n m)
g y n m k = if m = k
then let y' = y + (h ! m) * (x ! (n-m))
in y' `seq` g y' n (m+1) k
else y
{-# INLINE conv_2 #-}
conv_2 h x = V.generate (l+m) f
where
l = V.length x
m = V.length h - 1
{-# INLINE f #-}
f n = let j = max 0 (n-l+1)
k = (min n m) - j + 1
in V.sum (V.zipWith (*) (V.slice j k h) (V.reverse (V.slice (n -
j - k + 1) k x)))
{-# INLINE conv_3 #-}
conv_3 h x = V.generate (l+m-1) f
where
m = V.length h
l = V.length x
p = V.replicate (m-1) 0
x' = p ++ x ++ p
{-# INLINE f #-}
f i = V.sum (V.zipWith (*) (V.reverse h) (V.slice i m x'))
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Re: [Haskell-cafe] Re: How many Haskell Engineer I/II/IIIs are there?
On 12.02.10 16:29, Simon Marlow wrote: I'm aware that some people need a GC with shorter pause times. We'll probably put that on the roadmap at some point. for some applications (like realtime audio processing) it would be interesting to even have short pause times with a guaranteed upper bound, but i realize this is a very specialized need that could be better served by making the GC implementation swappable (which otoh doesn't seem to be trivial). sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] vector to uvector and back again
On 10.02.10 19:03, Bryan O'Sullivan wrote: I'm thinking of switching the statistics library over to using vector. that would be even better of course! an O(0) solution, at least for me ;) let me know if i can be of any help (e.g. in testing). i suppose uvector-algorithms would also need to be ported to vector, then. uvector is pretty bit-rotted in comparison to vector at this point, and it's really seeing no development, while vector is The Shiny Future. Roman, would you call the vector library good enough to use in production at the moment? i've been using the library for wavelet transforms, matching pursuits and the like, and while my implementations are not heavily optimized, they perform reasonably well (no benchmarking done yet, though). the key arguments for using vector instead of uvector were the cleaner interface and Data.Vector.Storable for interfacing with foreign libraries (such as fftw, through the fft package). sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] vector to uvector and back again
On 11.02.10 18:55, Henning Thielemann wrote: i've been using the library for wavelet transforms, matching pursuits and the like, Nice I have also worked on this topics, even with Haskell. However, at that time I used plain lists. interesting! was performance acceptable for practical work? at the moment i'm not too concerned about performance -- the base line maybe could be to be competitive with matlab. in the long run i hope i'll be able to scale my stuff to larger amounts of data, however ... and while my implementations are not heavily optimized, they perform reasonably well (no benchmarking done yet, though). the key arguments for using vector instead of uvector were the cleaner interface and Data.Vector.Storable for interfacing with foreign libraries (such as fftw, through the fft package). Btw. Data.StorableVector can also be used for this interfacing, and I would be very interested in an interface to FFTW. Actually, I have already used FFTW on StorableVector i'm simply using the fft package and adapted some of it's internals to work on Data.Vector.Storable; nothing fancy though, and only for RC and CR transforms. let me know if you're interested in the code ... There is also Data.StorableVector.Lazy which is nice for processing stream data. yes, i know about storablevector, but i already had some code using uvector, so in the end vector was the easier upgrade. to me the relative merits of storablevector vs. vector are still unclear; the lazy interface could be implemented on top of vector as well, i suppose? sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] vector to uvector and back again
hi, i've been using the vector [1] library for implementing some signal processing algorithms, but now i'd like to use the statistics [2] package on my data, which is based on the uvector [3] library. is there a (straightforward) way of converting between vectors and uvectors, preferrably O(1)? thanks, sk [1] http://hackage.haskell.org/package/vector [2] http://hackage.haskell.org/package/statistics [3] http://hackage.haskell.org/package/uvector ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] OpenAL and Hsndfile
hi matthew, On 09.12.09 14:37, Matthew wrote: Yesterday, I set out to accomplish the challenge of loading and playing a sound from a file. So far, my attempts have resulted only in silence... rather disheartening after all the effort it took to get everything to build and run cleanly. I currently take the following steps: - Load samples from file into an IOCArray using hsndfile - Create an OpenAL buffer which points to the IOCArray - Play sound using OpenAL code is at: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=13836 could you isolate the problem by checking if the array returned by hsndfile actually contains non-zero sample frames? e.g. by computing the maximum amplitude: (Data.List.foldl' (max) 0 . fmap abs) `fmap` Data.Array.MArray.getElems buffer you could also try to test OpenAL with a synthesized sound, e.g. sin(2*pi*f/fs*k); i'm not familiar with OpenAL, though. sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: usb-0.3
On 09.12.09 14:35, Bas van Dijk wrote: I made a new release of my usb library for high-level communication with usb devices from Haskell. looks great, thanks! do you happen to have some example code for working with HID devices (mice, keyboards, etc.)? sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: usb-0.3
hi roel, On 09.12.09 16:50, Roel van Dijk wrote: On Wed, Dec 9, 2009 at 4:20 PM, stefan kersten s...@k-hornz.de wrote: looks great, thanks! do you happen to have some example code for working with HID devices (mice, keyboards, etc.)? The usb package does not support the various device classes directly. You won't find a function like isKeyPressed ∷ Device → KeyCode → IO Bool. But you could write it based solely on functions from the usb package. Enumerate the devices connected to your system, find your HID device, open a handle (or enter a safe region), choose an interface and an alternative and finally send some sort of control request encoded in a ByteString. The actual bytes you need to send in order to discover if some key on your USB keyboard is pressed is defined somewhere in the USB HID device class specification. ok, thanks. i just thought you might have something ready to use ;) If you really need that kind of functionality then you could create a package usb-hid that offers an abstraction over the HID device class. But if you just want to know if some key is pressed then a much simpler solution would be to use a library like SDL or GLUT. i'm interested in headless appliances, where no window system is actually running. on linux i could use the input device layer, but it would be nice to have something more portable ... sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: Yi 0.4.1
On Sun, Jul 27, 2008 at 03:08:04PM +, Jean-Philippe Bernardy wrote: I'm very pleased to announce the 0.4.1 release of the Yi editor. great, i can't wait to check it out ... i get the following error when installing via hackage/cabal (ghc 6.8.1, cabal 1.4.0.1): Yi/Buffer.hs:253:0: No instance for (Typeable4 RWS) arising from the 'deriving' clause of a data type declaration at Yi/Buffer.hs:(253,0)-(254,101) Possible fix: add an instance declaration for (Typeable4 RWS) When deriving the instance for (Typeable1 BufferM) Yi/Buffer.hs:256:0: Can't make a derived instance of `Typeable4 RWS' (even with cunning newtype deriving: the representation type has wrong kind) In the stand-alone deriving instance for `Typeable4 RWS' any ideas what's going wrong? is it finally time to upgrade my ghc installation? sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Complex.magnitude slow?
On 17.07.2008, at 21:46, Lennart Augustsson wrote: If scaleFloat and exponent are implemented with bit twiddling they can be quite fast. is there a way in ghc to 'cast' between float/int32 and double/int64 (without going through memory)? sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Complex.magnitude slow?
On 18.07.2008, at 13:05, Henning Thielemann wrote: On Fri, 18 Jul 2008, stefan kersten wrote: On 17.07.2008, at 21:46, Lennart Augustsson wrote: If scaleFloat and exponent are implemented with bit twiddling they can be quite fast. is there a way in ghc to 'cast' between float/int32 and double/ int64 (without going through memory)? What speaks against going through memory? If you want to write a large chunk of Doubles to disk, you may write it to a StorableVector and write that to disk. However shipping internal bit patterns to disk may violate portability, because on different machines there can be different floating point formats. What other situations might be there, where you want to cast Float to Int32 and so on? for implementing scaleFloat and exponent on the bitlevel as lennart suggested, it would be preferable if the cast would be compiled to a register move/reinterpretation, rather than a store/load through several layers of abstraction (such as Data.Binary). i'm just curious ;) sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Complex.magnitude slow?
On 18.07.2008, at 19:47, Don Stewart wrote: sk: On 17.07.2008, at 21:46, Lennart Augustsson wrote: If scaleFloat and exponent are implemented with bit twiddling they can be quite fast. is there a way in ghc to 'cast' between float/int32 and double/int64 (without going through memory)? Yeah, fromIntegral/Int-Float fromIntegral = int2Float truncate/Float-Int truncate = float2Int truncate/Double-Int truncate = double2Int with appropriate no-op fromIntegrals for the 32 and 64 variants. i actually meant something like *(uint32_t*)fptr, but thanks anyway ;) sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Data.Complex.magnitude slow?
hi, i've attached an example program which seems to indicate that the magnitude function from Data.Complex is very slow compared to a more naive implementation (for Complex Float). on my machine (intel core2 duo, osx 10.4) the CPU time using the library function is about 6-7 times as much as when using the other function. any ideas what might be going on? any flaws in my measurement code? thanks, sk magnitude.hs Description: Binary data ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Complex.magnitude slow?
On 17.07.2008, at 17:42, Ian Lynagh wrote:
On Thu, Jul 17, 2008 at 05:18:01PM +0200, Henning Thielemann wrote:
Complex.magnitude must prevent overflows, that is, if you just square
1e200::Double you get an overflow, although the end result may be
also
around 1e200. I guess, that to this end Complex.magnitude will
separate
mantissa and exponent, but this is done via Integers, I'm afraid.
Here's the code:
{-# SPECIALISE magnitude :: Complex Double - Double #-}
magnitude :: (RealFloat a) = Complex a - a
magnitude (x:+y) = scaleFloat k
(sqrt ((scaleFloat mk x)^(2::Int) +
(scaleFloat mk y)^(2::Int)))
where k = max (exponent x) (exponent y)
mk = - k
So the slowdown may be due to the scaling, presumably to prevent
overflow as you say. However, the e^(2 :: Int) may also be causing a
slowdown, as (^) is lazy in its first argument; I'm not sure if
there is
a rule that will rewrite that to e*e. Stefan, perhaps you can try
timing
with the above code, and also with:
{-# SPECIALISE magnitude :: Complex Double - Double #-}
magnitude :: (RealFloat a) = Complex a - a
magnitude (x:+y) = scaleFloat k
(sqrt (sqr (scaleFloat mk x) + sqr (scaleFloat
mk y)))
where k = max (exponent x) (exponent y)
mk = - k
sqr x = x * x
and let us know what the results are?
thanks ian, here are the absolute runtimes (non-instrumented code)
and the corresponding entries in the profile:
c_magnitude0 (Complex.Data.magnitude) 0m7.249s
c_magnitude1 (non-scaling version) 0m1.176s
c_magnitude2 (scaling version, strict square) 0m3.278s
%time %alloc
(inherited)
c_magnitude0 91.6 90.2
c_magnitude1 41.7 49.6
c_magnitude2 81.5 71.1
interestingly, just pasting the original ghc library implementation
seems to
slow things down considerably (0m12.264s) when compiling with
-O2
-funbox-strict-fields
-fvia-C
-optc-O2
-fdicts-cheap
-fno-method-sharing
-fglasgow-exts
when leaving away -fdicts-cheap and -fno-method-sharing the execution
time for
the pasted library code reduces to 0m6.873s. seems like some options
that are
useful (or even necessary?) for stream fusion rule reduction, may
produce
non-optimal code in other cases?
sk
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Re: [Haskell-cafe] Data.Complex.magnitude slow?
On 17.07.2008, at 17:18, Henning Thielemann wrote: i've attached an example program which seems to indicate that the magnitude function from Data.Complex is very slow compared to a more naive implementation (for Complex Float). on my machine (intel core2 duo, osx 10.4) the CPU time using the library function is about 6-7 times as much as when using the other function. any ideas what might be going on? any flaws in my measurement code? Complex.magnitude must prevent overflows, that is, if you just square 1e200::Double you get an overflow, although the end result may be also around 1e200. I guess, that to this end Complex.magnitude will separate mantissa and exponent, but this is done via Integers, I'm afraid. very enlightening, thanks! it might be possible to (almost) get the best of two worlds (ported from dejagnu's libm): c_magnitude4 :: Complex Float - Float c_magnitude4 (x:+y) = if x' y' then mag y' x' else mag x' y' where x' = abs x y' = abs y sqr x = x * x mag a 0 = a mag a b = a * sqrt (1 + sqr (b/a)) is fast and doesn't overflow intermediate results but accuracy isn't so great ... sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] uvector and the stream interface
On 14.07.2008, at 20:48, Don Stewart wrote: Yes, we have long been discussing a generic Stream library to which the various sequence structures can be translated to and from. Already it is useful to say, stream bytestrings into uvectors and out to lists. could the Stream interface be made public in uvector for writing custom adapters? If people are using uvector or stream-fusion (the list version) and are interested in interop please let Roman, Duncan and I know, so we can think more about how best to make it all play together. i'd be interested, just have to gather a little more infrastructure before i start working on real algorithms. sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] vector vs uvector
hi, what's the difference between the vector [1] and uvector [2] packages? should one of those preferred over the other? thanks, sk [1] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/ vector-0.1 [2] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/ uvector-0.1.0.1 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] uvector and the stream interface
currently i'm working on stuff that looks something like this: 1 read soundfile from disk in blocks of N samples (IOCArray, hsndfile package) 2 convert to CArray with unsafeFreeze (simple O(1) cast, carray package) 3 perform FFT (CArray, fftw package) 4 convert to UArr (uvector package) 5 do some stuff with vectors i'd like to minimize copying, and since the FFT returns a new array anyway, the only copying conversion is the one between CArray and UArr in step 4. the approach i've been following is defining a `stream' conversion for CArray, hoping that subsequent carray accesses will be fused with uvector operations without the need for allocating a vector in between. does that make sense? could this be a general strategy for avoiding copying at the boundary between the various array libraries? thanks, sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] uvector and the stream interface
On 14.07.2008, at 18:42, Jules Bean wrote: It would be helpful to see the programs people are writing with uvector, so I can polish up the API some more :) It would also be helpful to have someone explain why we have: Ptr a ByteString IOUArray IOCArray Data.Storable.StorableArray UArr Of course, I know the answers to some of those questions, ByteString is obviously less polymorphic than all the others there, and Ptr a doesn't contain size information. But it seems we have a rapidly bifurcating profusion of 'typed interfaces to chunks of memory' with no obvious consistency to their naming scheme and I think it's starting to get confusing... maybe it would be useful to look at (1) what's expected in terms of the underlying array implementation and (2) in terms of array access. (1) some things that come to mind: * ghc heap or system heap (can the garbage collector move memory during calls to C?) * access to a Ptr for interfacing to external libraries (possible with UArr?) * alignment (most SIMD instruction sets require 16 byte aligned data) * mutability * strict vs (partially) lazy (2) personally i much prefer the list-like interface provided by the stream-fusion powered libraries (ndp, uvector, vector). can't the stream-fusion framework and correspondingly the vector interface be separated from the memory representation, provided a particular concrete representation comes up with a stream/unstream pair? then it would be easy to swap out the underlying representation according to the required characteristics. sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] vector vs uvector
On 14.07.2008, at 18:10, Lyle Kopnicky wrote: You should use the most mature and stable package, which is of course, uvector, being a whole 0.0.0.1 versions past vector. oops, didn't notice the thread announcing vector. i'll stick with uvector then for the time being :) sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] reactive and loop
hi, i'm having problems with a very simple example using conal elliott's 'reactive' library: module Main where import Control.Applicative import Control.Concurrent import Control.Monad import Data.Reactive import System.Random main :: IO () main = do (e, snk) - mkEvent forkIO $ forever ((getStdRandom random :: IO Double) = snk threadDelay 1) runE (print `fmap` withPrevE e) return () which starts to output this after a while: reactive_loop.hs: loop this is with ghc 6.8.1 on osx 10.4. any ideas what might be going wrong? many thanks, sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell] ANNOUNCE: hsndfile 0.1.1
Haskell bindings for libsndfile. Libsndfile is a comprehensive C library for reading and writing a large number of soundfile formats: http://www.mega-nerd.com/libsndfile/. Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hsndfile Darcs: http://darcs.k-hornz.de/cgi-bin/darcsweb.cgi?r=hsndfile;a=summary Enjoy! sk ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell] ANNOUNCE: sonic-visualiser 0.1.1
Library for reading and parsing Sonic Visualiser project files. Sonic Visualiser is available at http://sonicvisualiser.org. Hackage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/sonic- visualiser Darcs: http://darcs.k-hornz.de/cgi-bin/darcsweb.cgi?r=sonic- visualiser;a=summary Enjoy! sk ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell-cafe] realtime garbage collector for ghc (was: Why functional programming matters)
On 25.01.2008, at 00:04, Evan Laforge wrote: Well... ghc still has a single-threaded garbage collector, so all the par threads must stop for garbage collection. So scaling to the level of a cluster would be significantly sub-linear. A real time incremental gc would be really cool. Some people claim they exist, but which languages have one? james mccartney's supercollider [1] has a non-copying incremental collector based on [2], though not a parallel one. btw, is an implementation of the incremental collector described in [3] available somewhere? are there any plans to incorporate it into future ghc versions? sk [1] http://supercollider.sourceforge.net [2] P. R. Wilson and M. S. Johnstone. Real-time non-copying garbage collection. In ACM OOPSLA Wsorkshop on Memory Management and Garbage Collection, 1993. [3] A. M. Cheadle, A. J. Field, S. Marlow, S. L. P. Jones, and R. L. While. Exploring the barrier to entry: incremental generational garbage collection for haskell. In ISMM ’04: Proceedings of the 4th international symposium on Memory management, pages 163–174, New York, NY, USA, 2004. ACM. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] library to read/write audio files
hi john, On 11.12.2007, at 18:14, John Lato wrote: I've been working on a library to encode/decode audio files (wave, aiff, etc.) to and from lazy bytestrings, and it's finally in a form where I'm willing to share. It's available at http://mml.music.utexas.edu/jwlato/HSoundFile/, lightly cabalized and haddock-ified. The basic item is a Data.SoundFile datatype and a SndFileCls class. Each file format (wave, etc.) has a datatype with instances of SndFileCls and Data.Binary (thanks to Don S. for suggesting Data.Binary). At least that's the idea, I've only implemented the Wave format so far, but I wanted to make it easy to add new formats. sounds good! I originally intended to use Erik de Castro Lopo's excellent libsndfile (and there are some remnants of that in darcs), but after realizing I wanted a more functional interface I decided to roll my own. It's likely possible to wrap libsndfile in a functional interface, but that is beyond my current abilities. incidentally, i've been working on libsndfile bindings the last few days; here's the darcs repository: http://darcs.k-hornz.de/cgi-bin/darcsweb.cgi?r=hsndfile;a=summary it's not quite finished yet, but if you're interested you could have a look at the interface and make suggestions. maybe both projects could benefit from each other? i personally don't see much advantages in _not_ using libsndfile underneath ... sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] c2hs and cabal
On 02.12.2007, at 22:34, Eric Sessoms wrote: Just add Build-Tools: c2hs And cabal will take it from there. thanks eric, that's really pleasingly simple (it appears that the Build-Tools: line isn't even needed). sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] c2hs and cabal
hi, i'm looking for a way to integrate c2hs (single .chs file) in a cabal build setup; can anybody give me some hints? thanks, sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] The Yampa Arcade: source code available?
On 19.11.2007, at 19:54, Peter Verswyvelen wrote: I can find the paper, but is the source code for that Space Invaders alike game also available somewhere? it's included here: http://haskell.org/yampa/afrp-0.4-src.tgz btw, does anybody know what's the current state of affairs with yampa/ afrp? is the framework still developed further? sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] HTTP actions proxy server
On 16.11.2007, at 13:55, Jim Burton wrote: The docs say Should be of the form http://host:port, host, host:port, or http://host; but none of the variations work. Any ideas where I might find an example of code that does this? this works for me (modulo error handling): simpleHTTP' :: Request - IO (Result Response) simpleHTTP' req = do proxy - catch (getEnv HTTP_PROXY = return . (flip Proxy Nothing)) (\_ - return NoProxy) (_, resp) - browse (setProxy proxy request req) return (Right resp) i.e. run the request in the browser monad. sk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
