A Wednesday 01 April 2009, Greg Novak escrigué:
> Hello,
> I'd like to do an FFT of a moderately large 3D cube, 1024^3. Looking
> at the run-time of smaller arrays, this is not a problem in terms of
> compute time, but the array doesn't fit in memory. So, several
> questions:
>
> 1) Numerical Rec
Greg Novak wrote:
> This last issue leads to another series of things that puzzle me. I
> have an iMac running OS X 10.5 with an Intel Core 2 duo processor and
> 4 GB of memory. As far as I've learned, the processor is 64 bit, the
> operating system is 64 bit, so I should be able to happily memor
Hi,
In any case, the OS will have to swap a lot of your data :
- if you use floats (32bits), you use 4GB for your input array
- this does not fit inside your memory
- it even fit less if you count on the fact that FFT needs a least one
array as large, so at least 8 GB.
So you should, in every cas
On Wed, Apr 1, 2009 at 9:26 AM, David Cournapeau <
da...@ar.media.kyoto-u.ac.jp> wrote:
> Greg Novak wrote:
> > 1) Numerical Recipes has an out-of-memory FFT algorithm, but looking
> > through the numpy and scipy docs and modules, I didn't find a function
> > that does the same thing. Did I miss
Hi,
> 1) Numerical Recipes has an out-of-memory FFT algorithm, but looking
> through the numpy and scipy docs and modules, I didn't find a function
> that does the same thing. Did I miss it? Should I get to work typing
> it in?
No please don't do that; I'm afraid the Numerical Recipes book has
Greg Novak wrote:
> 1) Numerical Recipes has an out-of-memory FFT algorithm, but looking
> through the numpy and scipy docs and modules, I didn't find a function
> that does the same thing. Did I miss it?
I don't think so.
> Should I get to work typing
> it in?
>
Maybe :)
> 2) I had high
Hello,
I'd like to do an FFT of a moderately large 3D cube, 1024^3. Looking
at the run-time of smaller arrays, this is not a problem in terms of
compute time, but the array doesn't fit in memory. So, several
questions:
1) Numerical Recipes has an out-of-memory FFT algorithm, but looking
through
