Re: expfit vs harminv - which is faster/smaller ?

[Peter L.]

Another option that might be of interest is the NFFT (non-equispaced
FFT) library from

http://www-user.tu-chemnitz.de/~potts/nfft/

Cheers,

Peter.

tir, 16 12 2008 kl. 06:30 -0800, skrev Sergei Steshenko:
> 
> 
> --- On Tue, 12/16/08, Francesco Potortì <address@hidden> wrote:
> 
> > From: Francesco Potortì <address@hidden>
> > Subject: Re: expfit vs harminv - which is faster/smaller ?
> > To: address@hidden
> > Cc: address@hidden
> > Date: Tuesday, December 16, 2008, 6:18 AM
> > >> By reading the docs, it seems to me that they use
> > different methods,
> > >> are thought for different problems and require
> > different inputs:
> > >> expfit requires you to give it a number of
> > harmonics to find, while
> > >> harminv wants a range where to search for them.
> > >> 
> > >> That said, I should make it clear that I have no
> > experience
> > >> whatsoever with those methods.
> > 
> > >This is what I read in 'man harminv':
> > >   -f nf Specify a lower bound nf on the number of
> > spectral basis
> > >   functions (defaults to 100), setting a lower bound
> > on the number of
> > >   modes to search for.  This option is often a more
> > convenient way to
> > >   specify the number of basis functions than the -d
> > option, above,
> > >   which is why it is the default.
> > 
> > As far as I read, this is a lower bound on the search
> > space.  Expinv, on
> > the other hand, wants you to tell it exactly how many
> > harmonic functions
> > it should find.
> > 
> > -- 
> > Francesco Potortì (ricercatore)        Voice: +39 050 315
> > 3058 (op.2111)
> > ISTI - Area della ricerca CNR          Fax:   +39 050 315
> > 2040
> > via G. Moruzzi 1, I-56124 Pisa         Email:
> > address@hidden
> > (entrance 20, 1st floor, room C71)     Web:  
> > http://fly.isti.cnr.it/
> 
> For me i doesn't matter, i.e. for what I'm doing specifying the minimum
> require number of harmonics is good enough.
> 
> Practically so far it gives exactly this specified number.
> 
> For me the two programs are the same in the sense they both try to
> decompose input into a sum of exponentially modulated sinusoids.
> 
> Thanks,
>   Sergei.
> 
> 
>       
> 
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