[Haskell-cafe] Benchmark of DFT libraries in Haskell

[Ertugrul Söylemez]

Takayuki Muranushi <muranushi at gmail.com> wrote:

> * vector-fftw with wisdom was more than 1/2 times faster than fftw in
> C with wisdom (and with communication overhead.)
> * vector-fftw without wisdom was significantly _faster_ than fftw in C
> without wisdom. I wonder why.
> * vector-fftw over vector was faster than fft over CArray.
> * any library that doesn't use fftw is much slower than those that
> does.

I have no experience with FFTW, but in general a result like this often
means that you may not have actually calculated the values themselves.
One easy way to ensure this is to print out the whole result.  If you
feel like printing takes too much CPU time for comparison, you need to
force deeply like with deepseq.

Notably Data.Vector is a lazy data structure.  If you force the vector
itself, you are not forcing the individual values.  For FFT I would
assume that the length of the resulting vector does not depend on any
values.


Greets,
Ertugrul

-- 
Not to be or to be and (not to be or to be and (not to be or to be and
(not to be or to be and ... that is the list monad.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: not available
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20120806/f2ab9e40/attachment.pgp>