Re: [eigen] A complex FFT for Eigen |

[ Thread Index |
Date Index
| More lists.tuxfamily.org/eigen Archives
]

Matthias Pospiech wrote:

Tim Molteno schrieb:

Hi,
Eigen is great. Thanks to everyone who has done so much work on it.

`I've written a complex fft algorithm for eigen. It uses template
``metaprogramming, and is fairly snappy.
`

`Are you sure that it matches in performance with the FFTW Libary? I
``just say that because I personally would use eigen for matrixes and
``FFTW for FFT.
``But maybe you can convince of the improvements of you solution
``compared to mine. The first that would come to my mind is, that FFTW
``requires a plain 1D C-Array for a Matrix (of 2 or 3 dimensions).
`

`Thanks for the comment. It will not be as fast as fftw, but might get
``close.
`
But it has other advantages
1) It is templated (fftw does not play nicely with fixed point for example)
2) It is very simple to use

`3) If you're only doing one fft, it might even be faster than fftw since
``fftw requires a two-pass approach
`4) It is GPL 3.
5) It is only a few lines of code (130)
Other Disadvantages
1) Requires a power of 2 length

`2) Only one dimension at the moment. I'll get 2D transforms incorporated
``into Eigen when I next require them.
`
Cheers
Tim
---