Time frequency Analysis!

[Muthuraman Muthuraman]

Hello ,

Thankyou for correcting some of the errors in the parameters

Do you get a warning when executing the
singleplotTFR-function?
I do get any warning while executing the singleplotTFR function

If there are only nans in your TFRmult, then I don't get it, because your
configuration looks OK to me?
I use now Fieldtrip 20070109 version



i have changed the code as you have suggested

hdr     = read_fcdc_header('pd_mof_tr0_c_0306.cnt');
emgindx = strmatch('M', hdr.label);
rstindx = setdiff(1:length(hdr.label),emgindx);

trl = [];
trl(:,1) = [21:1000:74520-1000]';
trl(:,2) = [1020:1000:74520]';
trl(:,3) = 0;


cfg.dataset = 'pd_mof_tr0_c_0306.cnt';
cfg.trl     = trl;
cfg.channel = hdr.label(rstindx);
cfg.blc     = 'yes';
data        = preprocessing(cfg);

cfg.channel  = hdr.label(emgindx);
cfg.hpfilter = 'yes';
cfg.hpfreq   = 10;
cfg.rectify  = 'yes';
emg          = preprocessing(cfg);

for j = 1:length(emg.trial)
  emg.trial{j} = blc(emg.trial{j});
end
data         = appenddata([],data,emg);

%---freqanalysis-mtmconvol
cfg=[];
cfg.ouput='powandcsd';
cfg.method='mtmconvol';
cfg.channel    = channelselection({'all' 'M1'}, data.label);
cfg.foi=2:2:30;
numfoi=length(cfg.foi);
cfg.t_ftimwin=zeros(1,numfoi);
cfg.t_ftimwin(:)=0.5;
cfg.toi=-1.0:0.05:1.0;
cfg.taper='hanning';
cfg.pad=2;
cfg.keeptrials='no';
TFRmult=freqanalysis(cfg,data);


cfg=[];
cfg.baselinetype=[0.1 1.0];
cfg.zlim=[-2e-27 2e-27];
cfg.showlabels='yes';
cfg.channel='FC3';
singleplotTFR(cfg,TFRmult);
I get only one warning that is the analysis uses one taper

But now after changing the code i get some values and all other values to be
Nan's in the 'mtmconvol' function
I have attached the Figure with this mail which i get from the analysis
I will send the cnt file through yousentit.com
Please let me know what could be the problems still in the code

Thanking you

with regards
M.Muthuraman.



>From: Jan Mathijs Schoffelen <Jan.Schoffelen at FCDONDERS.RU.NL>
>Reply-To: FieldTrip discussion list <FIELDTRIP at NIC.SURFNET.NL>
>To: FIELDTRIP at NIC.SURFNET.NL
>Subject: Re: [FIELDTRIP] Time frequency Analysis!
>Date: Tue, 30 Jan 2007 17:34:44 +0100
>
>Dear Muthuraman,
>
>It pleases us that we finally got you to try multi-tapers for your spectral
>analysis! Sometimes it's hard convincing people, but in the end...
>
>First of all there's a typo in your configuration for the frequency
>analysis; this does not explain your results, but as an extra service to
>you
>I'd like to point it out. You specify cfg.ouput, where I guess you mean
>cfg.output. Moreover, since you have an EMG-channel in your data, you might
>be interested in computing the coherence, but therefore you have to specify
>cfg.output = 'powandcsd'.
>
>Regarding your nans: did you check whether there are any numbers in
>TFRmult.powspctrm. If this is the case, your problem most likely arises in
>the plotting. You specify cfg.baselinetype = 'relative', but you do not
>specify the baseline-interval. Do you get a warning when executing the
>singleplotTFR-function?
>If there are only nans in your TFRmult, then I don't get it, because your
>configuration looks OK to me?
>
>By the way, which version of fieldtrip are you using? If you are using an
>old one, it might be worthwile to download the latest version (there's a
>daily update on the FTP-server, you can get there through the
>fieldtrip-website), and try the script again (with the small changes
>suggested).
>
>Yours,
>
>Jan-Mathijs
>
>
>-----Original Message-----
>From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
>Of Muthuraman Muthuraman
>Sent: Tuesday, January 30, 2007 3:40 PM
>To: FIELDTRIP at NIC.SURFNET.NL
>Subject: [FIELDTRIP] Time frequency Analysis!
>
>Hello Fieldtrippers,
>
>I have question regarding the Time-Frequency analysis using tapers,
>'mtmconvol' or time frequency analysis using wavelets 'wltconvol'
>these are the parameters i use, i get all the values to be Nan's
>Is there something wrong which i need to change in the parameters for the
>timefrequency analysis
>
>hdr     = read_fcdc_header('pd_mof_tr0_c_0306.cnt');
>emgindx = strmatch('M', hdr.label);
>rstindx = setdiff(1:length(hdr.label),emgindx);
>
>trl = [];
>trl(:,1) = [21:1000:74520-1000]';
>trl(:,2) = [1020:1000:74520]';
>trl(:,3) = 0;
>
>
>cfg.dataset = 'pd_mof_tr0_c_0306.cnt';
>cfg.trl     = trl;
>cfg.channel = hdr.label(rstindx);
>cfg.blc     = 'yes';
>data        = preprocessing(cfg);
>
>cfg.channel  = hdr.label(emgindx);
>cfg.hpfilter = 'yes';
>cfg.hpfreq   = 10;
>cfg.rectify  = 'yes';
>emg          = preprocessing(cfg);
>
>for j = 1:length(emg.trial)
>   emg.trial{j} = blc(emg.trial{j});
>end
>data         = appenddata([],data,emg);
>
>%---freqanalysis-mtmconvol
>cfg=[];
>cfg.ouput='pow';
>cfg.sgn='data';
>cfg.method='mtmconvol';
>cfg.channel    = channelselection({'all' 'M1'}, data.label);
>cfg.foi=2:2:30;
>numfoi=length(cfg.foi);
>cfg.t_ftimwin=zeros(1,numfoi);
>cfg.t_ftimwin(:)=0.5;
>cfg.tapsmofrq=zeros(1,numfoi);
>cfg.tapsmofrq(:)=10;
>cfg.toi=-0.5:0.05:1.0;
>cfg.taper='dpss';
>cfg.pad=2;
>cfg.keeptrials='no';
>TFRmult=freqanalysis(cfg,data);
>
>%---Plotting
>cfg=[];
>cfg.baselinetype='relative';
>cfg.zlim=[-2e-27 2e-27];
>cfg.showlabels='yes';
>cfg.channel='C3';
>singleplotTFR(cfg,TFRmult);
>
>
>Thanking you
>
>With regards
>M.Muthuraman.
>
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