Re: FFT Speed
- To: mathgroup at smc.vnet.net
- Subject: [mg121982] Re: FFT Speed
- From: roby <roby.nowak at gmail.com>
- Date: Sat, 8 Oct 2011 05:31:57 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <j6mf50$7hu$1@smc.vnet.net>
On 7 Okt., 11:01, to <todu... at gmail.com> wrote:
> I have a 3D matrix with dimensions {355,647,8}. For each {x,y} I need
> to compute the FFT along the z dimension, i.e. 355*647 FFTs of 8
> elements each. The fastest way I found to do this was
>
> Partition[Map[Fourier[#, FourierParameters -> {1, -1}] &,
> Flatten[data, 1]], dimx];
>
> I was wondering if there are faster ways to do this. The reason I ask
> is because another package for numerical computations can do this a
> lot faster compared to my solution (nearly two orders of magnitude
> faster !)
>
> I tried using ParallelMap but this makes things even slower.
Well,
you may avoid the Flatten:
Map[Fourier[#, FourierParameters -> {1, -1}] &,data,{2}]
no idea what speed gain (if any) this will give.
Regards Robert