[Numpy-discussion] Fast sizes for FFT
sturla.molden at gmail.com
Wed Dec 24 08:56:35 EST 2014
On 24/12/14 14:34, Sturla Molden wrote:
> I would rather have SciPy implement this with the overlap-and-add method
> rather than padding the FFT. Overlap-and-add is more memory efficient
> for large n:
(eh, the list should be)
- Overlap-and-add is more memory efficient for large n.
- It scales as O(n) instead of O(n log n).
- For short FIR filters overlap-and-add also allows us to use small
- Small FFT size also means that we can use a small Winograd FFT instead
of Cooley-Tukey FFT, which reduces the number of floating point
- A small look-up table is also preferable as it can be kept in cache.
- Overlap-and-add is also trivial to compute in parallel. This comes at
the expense of using more memory, but it never requires more memory than
just taking a long FFT.
More information about the NumPy-Discussion