AW: [FIELDTRIP] complex wavelet output

Hanneke Van Dijk Hanneke.vanDijk at MED.UNI-DUESSELDORF.DE
Wed Oct 7 11:24:36 CEST 2009


Dear Juergen,

As far as I can see, you can specify cfg.output = 'fourier' for the cfg.method = 'mtmconvol' when you want to have a time axis as well (it's also possible for 'mtmfft'). It will give you the fourierspectrum. You can set the parameters of mtmconvol such that it operates simmilar to a wavelet transform as you can see on this website:

http://fieldtrip.fcdonders.nl/tutorial/timefrequencyanalysis

An example of the parameters could be:

cfg = [];
cfg.output     = 'fourier';
cfg.channel    = 'MEG';
cfg.method     = 'mtmconvol';
cfg.taper      = 'dpss';        % sleppian taper but you can use different tapers/windows here.
cfg.foi        = 1:2:30;        % frequencies of interest.
cfg.t_ftimwin  = 5./cfg.foi;    % the window length is 5 cycles of the specified frequency long.
cfg.tapsmofrq  = 0.4 *cfg.foi;  % frequency smoothing of +/- 0.4*the specified frequency.
cfg.toi        = -0.5:0.05:1.5; % time of interest.
cfg.pad        = 'maxperlen';  
TFRmult = freqanalysis(cfg, dataFIC);

Hope it helps!

Yours,

Hanneke


-----Ursprüngliche Nachricht-----
Von: FieldTrip discussion list im Auftrag von Juergen Fell
Gesendet: Mi 07.10.2009 10:14
An: FIELDTRIP at NIC.SURFNET.NL
Betreff: [FIELDTRIP] complex wavelet output
 


Dear fieldtrip users:

I've just started digging into fieldtrip and came across the following
question: is it possible to obtain the complex output of the continuous
wavelet transform, i.e. the original wavelet-transformed complex signal
(instead of power and/or cross-spectral density)?

Any help would be greatly appreciated.

Juergen.

----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/neuroimaging/fieldtrip.


----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/neuroimaging/fieldtrip.



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