[SciPy-dev] Cleaning and fixing fft in scipy ?

[Travis Oliphant]

David Cournapeau wrote:
> Hi,
>
>     When fixing the fft problem with prime number in numpy, I came again 
> across the fft implementation in scipy, and related problems (suboptimal 
> solution for fftw, see eg scipy ticket #1). I would like to improve the 
> situation:
>     - First, I think the module needs serious cleaning, as for now, it 
> is a bunch of C files with many #define all accross the code, making it 
> difficult to track things. 

Could you be more clear about where the problem in your eyes lies?   
There are multiple sources for the fft (original fftpack files + 
interface files to other fft libraries if the user has those installed). 

The ifdefs that I could find are just in the interface files to the 
"other" fft libraries that a user might have installed.  I don't care if 
that is redone so that the setup.py file just uses different sources as 
opposed to defining pre-processor variables, but you might check with 
Pearu since he is the author of those interfaces.

But, I also don't really see the problem with the way it is done, now.

> I propose to split the sources by 
> implementation (fft_fftw3.c, fft_fft2, fft_mkl, etc...); this can be 
> done without any consequence on the implementation.
>     - Then, improving fft where it is needed.
>   

Please indicate what improvements you will be making.    The fft's are 
performed by external libraries, I'm hesitant to start altering what 
those libraries are doing without clear justification.   If you want to 
improve the interface to the optional fftw and mkl libraries that is one 
thing, but just saying you are going to "fix the fft implementation"  is 
not re-assuring.

-Travis