choosing time windows in freqanalysis_mtmfft.

Christian Hesse c.hesse at FCDONDERS.RU.NL
Sun Apr 8 10:45:51 CEST 2007


Hi Sameer,

yes, not being able to specify a time window is a "feature" of
FREQANALYSIS_MTMFFT that is somewhat misleading and counter intuitive.

The easy way around it is to use FREQANALYSIS_MTMCONVOL with
appropriate window selection parameters:

cfg.toi = [the centre of the time window you want to analyse];
cfg.foi = [the frequencies of interest];
cfg.t_ftimwin = ones(length(cfg.foi),1).*duration of the window you
want to analyse;

Hope this helps,
Christian



On 2 Apr 2007, at 23:07, Sameer Walawalkar wrote:

> Hello,
>
> I want to be able to see the coherences between different channels
> (using topoplotER). To that end, I know that I must implement
> freqdescriptives after first implementing freqanalysis_mtmfft.
>
> freqanalysis_mtmfft does not seem to allow me to choose the time
> window from which the data can be selected and then analyzed (I
> think so primarily because it does not seem to allow cfg.toilim or
> some such method).
>
> Is there a simple way around it that I am missing, or will I have
> to define new datasets with the data form the time window I want
> each time?
>
> thanks,
> sameer
>

----------------------------------------------------------------------
Christian Hesse, PhD, MIEEE

F.C. Donders Centre for Cognitive Neuroimaging
P.O. Box 9101
NL-6500 HB Nijmegen
The Netherlands

Tel.: +31 (0)24 36 68293
Fax: +31 (0)24 36 10989

Email: c.hesse at fcdonders.ru.nl
Web: www.fcdonders.ru.nl
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