FFT Lib?

[Fawzi Mohamed]

On 30-lug-10, at 16:14, dsimcha wrote:

> [...]
> Part of the preprocessor abuse is necessary for supporting
> fixed point FFTs.  Does anyone care about these (I sure don't), or  
> can I just get
> rid of them?

I don't care about them

> I'm hoping I can refactor this code into a nice D interface, but it  
> may end up
> being that I have to basically start from scratch.  One thing I will  
> absolutely
> not do is contribute code without a proper D-style (i.e. templated,  
> works with
> std.complex, etc.) interface.  If I can't understand kissfft well  
> enough to do
> this refactoring, then maybe I'll just start from scratch using the  
> Wikipedia FFT
> article and a textbook.

The main thing that you should probably do (apart documenting the  
factors and order that you assume/generate)
is splitting fft in initialization of a given size (creating a struct/ 
class environment) and executing an fft of that size (which might be a  
method of the environment (probably better) or a free function taking  
the env as parameter).
Both fftpack (http://www.netlib.org/fftpack/doc) and fftw (http://fftw.org/doc/ 
) have that structure.
This because you can prepare/precompute things to then do the actual  
fft in the optimal way.
Then you can still provide easy to use wrappers that call the two  
things in sequence.

ciao
Fawzi