Re2: [FIELDTRIP] freqanalysis_wltconvol variance

[Amr Ayoub]

Dear Ingrid,

The analysis is painfully slow; it would need weeks to finish. Is there a MEX implementation of the time freq. analysis? Which is faster wltconvol or mtmconvol?
Below is the configuration of the time freq. analysis.

    cfg.sgn          = 'MEG';
    cfg.method       = 'mtmconvol';   
    cfg.output        = 'pow';
    cfg.foi          = 40:2:100 ;
    cfg.toi          = -1.4:0.01:1.4;
    cfg.keeptrials='yes';
    cfg.t_ftimwin    = ones(length(cfg.foi),1).*0.5;   % length of time window = 0.5 sec
    cfg.taper        = 'hanning';  
    TFR = freqanalysis(cfg, TFA_slo_fz); 

vs

    cfg.sgn          = 'MEG';
    cfg.method       = 'wltconvol ';
    cfg.width        = 7;
    cfg.output        = 'pow';
    cfg.foi          = 40:2:100 ;
    cfg.toi          = -1.4:0.01:1.4;
    cfg.keeptrials='yes';
    TFR = freqanalysis(cfg, TFA_slo_fz); 

Data configuration:
Number of channels:151
Sampling rate:250
Number of trials:391

PC configuration: Windows Vista Business SP1 64 bit - Intel Core 2 CPU 6320 @ 1.86Ghz  1.86Ghz - RAM 4GB 


Best regards,
Amr




________________________________
From: Ingrid Nieuwenhuis <ingrid.nieuwenhuis at DONDERS.RU.NL>
To: FIELDTRIP at NIC.SURFNET.NL
Sent: Thursday, August 6, 2009 2:26:28 PM
Subject: Re: [FIELDTRIP] freqanalysis_wltconvol variance

 
Dear Amr,
 
If you do freqanalysis with cfg.keeptrials
= ‘yes’, you get the power per trial. If you subsequently use
freqdescriptives (see help for detailed options) you can compute the variance
over trials.
 
Best Ingrid
 

________________________________
 
From:FieldTrip discussion list 
[mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Amr Ayoub
Sent: Thursday, August 06, 2009
1:56 PM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: [FIELDTRIP]
freqanalysis_wltconvol variance
 
Hello,

I am expecting that you are averaging the power spectrum across the trials in
freqanalysis_wltconvol. Is there a way to compute the variance across the
number of trials?

Thanks in advance
Amr Ayoub
 
----------------------------------
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.
http://listserv.surfnet.nl/archives/fieldtrip.html
http://www.ru.nl/fcdonders/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.
http://listserv.surfnet.nl/archives/fieldtrip.html
http://www.ru.nl/fcdonders/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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