mark.vogelsberger@email.de wrote:
> Well I tried FFTW with 30.000 datapoints. Works fine.
> But with 60.000 it breaks down.
> 
> I think this has something to do with the int n limitation.

what do you mean by "int n limitation"? It seems that MAXINT on your 
system is 32.767. That corresponds to 16 bits. What platform are you 
using? How is your compiler configured?

Jerry
-- 
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Well I tried FFTW with 30.000 datapoints. Works fine.
But with 60.000 it breaks down.

I think this has something to do with the int n limitation.


On 28 Feb., 14:29, cincy...@gmail.com wrote:
> On Feb 28, 6:21 am, mark.vogelsber...@email.de wrote:
>
> > Hello,
>
> > simple question:
> > I have a time series with lots of entries (more than int). How can I
> > use FFTW to do a FFT? The problem is, that
> > FFTW can only handle up to "int n" entries in the datafile...
>
> > Any idea?
>
> > Thanks a lot!
>
> > Mark
>
> What platform are you programming on? Most modern platforms have 32-
> bit ints; you generally only see 16-bit ints on some embedded
> platforms. If push came to shove, it would be possible to edit the
> source code to use longs instead, as those are usually 32 bits
> irrespective of the platform. I'm assuming that you don't really have
> more than 2GSamples of data in your application.
>
> Jason

On Feb 28, 6:21 am, mark.vogelsber...@email.de wrote:
> Hello,
>
> simple question:
> I have a time series with lots of entries (more than int). How can I
> use FFTW to do a FFT? The problem is, that
> FFTW can only handle up to "int n" entries in the datafile...
>
> Any idea?
>
> Thanks a lot!
>
> Mark

What platform are you programming on? Most modern platforms have 32-
bit ints; you generally only see 16-bit ints on some embedded
platforms. If push came to shove, it would be possible to edit the
source code to use longs instead, as those are usually 32 bits
irrespective of the platform. I'm assuming that you don't really have
more than 2GSamples of data in your application.

Jason

mark.vogelsberger@email.de wrote:
> Hello,
> 
> simple question:
> I have a time series with lots of entries (more than int). How can I
> use FFTW to do a FFT? The problem is, that
> FFTW can only handle up to "int n" entries in the datafile...

There is a language problem here, probably with your understanding of 
the (unfortunately English) text you are trying to make sense of.

"Int" is not a number, but a description of a number type: integer.

FFTW can indeed handle "int n" (which means "n, an integer". I believe 
that n may be at least as large as 2^32. The documentation will say.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Hello,

simple question:
I have a time series with lots of entries (more than int). How can I
use FFTW to do a FFT? The problem is, that
FFTW can only handle up to "int n" entries in the datafile...

Any idea?

Thanks a lot!

Mark