query on coherence source analysis

[Muthuraman Muthuraman]

Hello

Thanks for the suggestions

i have been trying to use the freqanalysis_mtmwelch which you have send to
me in the previous mail
i get a error when using this program
i have attached all the statements in this mail
please go through and tell me is there a problem in the specifications



cfg=[];
cfg.output='powandcsd';
cfg.method='mtmwelch';
cfg.foi=1:2:30;
numfoi = length(cfg.foi);
cfg.taper='hanning';
cfg.t_ftimwin=zeros(1,numfoi);
cfg.t_ftimwin(:)=0.5;
cfg.channel=channelselection({'EEG' 'EMG2'},data.label);
cfg.channelcmb={'EEG' 'EMG2'};
freq=freqanalysis(cfg,data);

??? Error using ==> freqanalysis_mtmwelch
unexpected dimord

Error in ==> freqanalysis at 187
[freq] = feval(sprintf('freqanalysis_%s',lower(cfg.method)), cfg, data);





>From: Robert Oostenveld <r.oostenveld at FCDONDERS.RU.NL>
>Reply-To: FieldTrip discussion list <FIELDTRIP at NIC.SURFNET.NL>
>To: FIELDTRIP at NIC.SURFNET.NL
>Subject: Re: [FIELDTRIP] query on coherence source analysis
>Date: Tue, 23 May 2006 12:33:24 +0200
>
>Dear Muthuraman
>
>At the Donders we usually use the multitaper method for computing the
>cross spectral density, in freqanalysis that is cfg.method='mtmfft'  or
>'mtmconvol'. If you would use the mtmconvol method, you will get a
>frequency decomposition for multiple sliding time windows (that can  be
>overlapping or not). If you then would average these frequency
>decompositions over time, you have performed Welch's method. We  already
>implemented that in a function, see attached  freqanalysis_mtmwelch (i.e.
>it even allows you to combine  multitapering and Welch). Add it to your
>fieldtrip directory and  specify cfg.method='mtmwelch' for freqanalysis.
>
>This new function is still rather poorly documented, and it does not  have
>default settings for most of the cfg options. Probably you will  want
>cfg.taper=hanning (i.e. no multitapering), in which case you do  not have
>to specify cfg.tapsmofrq. The function will use maximally  overlapping
>windows for Welch method (which takes a lot of memory).  You should specify
>the frequencies of interest (cfg.foi) and window  length per frequency
>(cfg.t_ftimwin).
>
>best
>Robert
>


><< freqanalysis_mtmwelch.m >>


>
>
>On 22 May 2006, at 14:15, Muthuraman Muthuraman wrote:
>>hello
>>
>>Thankyou for the previous suggestion
>>
>>I have gone through the article, in which for the 'DICS' algorthim  it is
>>mentioned that they use welch method to calculate the cross  spectral
>>density, for the freqanalysis program is there a  cfg.method with welch to
>>use it for the 'DICS'.
>>
>>I do not find the freqanalysis_mtmwelch
>>I have the 20060131 version of fieltrip is it updated in the latest
>>versions
>>
>>with regards
>>muthu
>>
>>
>>>From: Robert Oostenveld <r.oostenveld at FCDONDERS.RU.NL>
>>>Reply-To: FieldTrip discussion list <FIELDTRIP at NIC.SURFNET.NL>
>>>To: FIELDTRIP at NIC.SURFNET.NL
>>>Subject: Re: [FIELDTRIP] query on coherence source analysis
>>>Date: Tue, 2 May 2006 14:57:56 +0200
>>>
>>>Dear Muthuraman
>>>
>>>Fieldtrip implements DICS in the SOURCEANALYSIS function. You can   find
>>>the literature reference to the DICS algorith on the page  http://
>>>www2.ru.nl/fcdonders/fieldtrip/doku.php?
>>>id=fieldtrip:documentation:references_to_implemented_methods
>>>
>>>best regards,
>>>Robert
>>>
>>>On 2 May 2006, at 11:02, Muthuraman Muthuraman wrote:
>>>
>>>>Hello
>>>>
>>>>Thanks for the Previous suggestions
>>>>
>>>>i would like to know whether there is prescribed algorithm in
>>>>Fieldtrip
>>>>to calculate the coherent source analysis  between the EEG and  EMG
>>>>data
>>>>
>>>>with regards
>>>>muthuraman
>>>>
>>
>