Re: [eigen] FFT for Eigen

[Benoit Jacob <jacob.benoit.1@xxxxxxxxx>]

Many people who need a linear algebra library, also need a FFT
library. In that case, if both libraries use the same data types
(read: if they both talk in terms of Eigen:: objects like vectors)
then it's extra convenient. They can also share infrastructure for
handling various numeric types, for handling fixed-size/dynamic-size
with a consistent API... Eigen has all that and so it makes sense to
add a small FFT module that integrates well with that. Then, I think
that Mark was very clear that FFTW is "much faster", and that's why I
think we all agree that a must-have feature is that such optimized
libraries may be used as optional backends. The idea is to enjoy their
performance while using a uniform Eigen API. Also Mark notes that
kissFFT provides more flexibility wrt custom datatypes (like
fixed-point).

Cheers,
Benoit

2009/5/18 Robert Lupton the Good <rhl@xxxxxxxxxxxxxxxxxxx>:
> I'm not quite sure why eigen needs an FFT library,
> especially when there's a standard (C) library
> that everyone uses, FFTW?
>
> Now, I can see the advantages of a pure-template
> C++ library if it's competitive computationally,
> so the question that I'd ask is, how do the
> kissfft benchmarks look relative to FFTW?
>
>
>                                R
>
>
>
>
>