<div dir="ltr"><div class="gmail_quote"><div dir="ltr"><pre style="white-space:pre-wrap"><i style="color:rgb(0,0,0)">Dear all,
</i><i style="color:rgb(0,0,0)">
</i><i style="color:rgb(0,0,0)">I am trying to perform source localization in the frequency domain </i></pre><pre style="white-space:pre-wrap"><i style="color:rgb(0,0,0)">from EEG data using 'DICS' . As I have no mri data of the participants, </i></pre><pre style="white-space:pre-wrap"><i style="color:rgb(0,0,0)">I am using </i><font color="#000000"><i>'Subject01.mri' to read the anatomical data with ft_read_mri. </i></font></pre><pre style="white-space:pre-wrap"><font color="#000000"><i>The </i></font><i>head model created with 'bemcp'.</i></pre><pre style="white-space:pre-wrap"><i style="color:rgb(0,0,0)">Code:</i></pre><pre style="white-space:pre-wrap"><font face="arial, helvetica, sans-serif"><i style="color:rgb(0,0,0)">%% </i><font color="#000000"><i>Read the anatomical data</i></font></font></pre><pre style="white-space:pre-wrap"><i style="font-family:arial,sans-serif"><font color="#000000"><font face="arial, helvetica, sans-serif">mri = ft_read_mri('Subject01.mri');</font></font></i></pre><pre style="white-space:pre-wrap"><font face="arial, helvetica, sans-serif"><i style="color:rgb(0,0,0)">%% </i></font><font color="#000000" face="arial, helvetica, sans-serif"><i>Segment the anatomical information & triangulate the surfaces</i></font></pre><div style="font-size:12.8px"><i><font color="#000000">load segmentedmri % load from </font></i><a href="ftp://ftp.fieldtriptoolbox.org/pub/fieldtrip/tutorial/headmodel_eeg/segmentedmri.mat" class="m_-8657161844681314279gmail-m_8088325427694831497gmail-urlextern" title="ftp://ftp.fieldtriptoolbox.org/pub/fieldtrip/tutorial/headmodel_eeg/segmentedmri.mat" rel="nofollow" style="color:rgb(51,153,243);box-sizing:border-box;background-color:transparent;outline:0px;background-repeat:no-repeat;background-position:0px 50%;padding:0px 0px 0px 18px;background-image:url("");font-family:"Open Sans","Helvetica Neue",Helvetica,Arial,sans-serif;font-size:14px;text-align:justify" target="_blank">ftp server</a><span style="color:rgb(102,102,102);font-family:"Open Sans","Helvetica Neue",Helvetica,Arial,sans-serif;font-size:14px;text-align:justify;background-color:rgb(255,255,204)"> (segmentedmri.mat).</span><i><br></i></div><div style="font-size:12.8px"><i><font color="#000000">load bnd</font></i></div><div style="font-size:12.8px"><i><font color="#000000"><br></font></i></div><div style="font-size:12.8px"><i><font color="#000000">%% </font></i><font color="#000000"><i>Create the headmodel</i></font></div><div style="font-size:12.8px"><i><font color="#000000"><div>cfg = [];</div><div>cfg.method = 'bemcp'; </div><div>vol = ft_prepare_headmodel(cfg, bnd);</div><div><br></div><div>%% Position of the electrodes<br></div><div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><div style="display:inline">load('Face_sub.mat'); % data of participants' electrode positions</div> </div></font></i><br></div><div>electrodes = Face_sub.elec;</div></div><div><br></div><div>%% Interactive alignment<br></div><div><div>cfg = [];</div><div>cfg.method = 'interactive';</div><div>cfg.elec = electrodes;</div><div>cfg.headshape = vol.bnd(3); % scalp</div><div>elec_aligned = ft_electroderealign(cfg);</div><div><br></div><div>%% Compute leadfield:<br></div><div><div>cfg = [];</div><div>cfg.elec = elec_aligned;</div><div>cfg.vol = vol;</div><div>cfg.channel = {'EEG'};</div><div>[grid] = ft_prepare_leadfield(cfg);</div></div></div><div><br></div><div><div>%% Source Analysis</div><div>cfg = []; </div><div>cfg.method = 'dics';</div><div>cfg.frequency = 10; </div><div>cfg.grid = grid;</div><div>cfg.vol = vol;</div><div>cfg.dics.projectnoise = 'yes';</div><div>cfg.dics.lambda = 0;</div><div>sourceFace = ft_sourceanalysis(cfg, face_data); % face_data is obtained from the FT_FREQANALYSIS % <i><font color="#000000"> <div style="display:inline"><div style="display:inline"> </div></div></font></i></div><div><i><font color="#000000"><div style="display:inline"><div style="display:inline"><br></div></div></font></i></div><div><i><font color="#000000"><div style="display:inline"><div style="display:inline">[%% time frequency analysis </div> </div></font></i><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div>| cfg = []; <i style="color:rgb(34,34,34)"><font color="#000000"> <div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div> </font></i> cfg.channel = 'EEG'; <i style="color:rgb(34,34,34)"><font color="#000000"> <div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div> </font></i><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><div style="display:inline"> cfg.method = 'mtmfft'; </div> </div></font></i><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div> </font></i> cfg.output = 'powandcsd'; <i style="color:rgb(34,34,34)"><font color="#000000"> <div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div> </font></i> cfg.tapsmofrq = 4; <i style="color:rgb(34,34,34)"><font color="#000000"> <div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div> </font></i> cfg.foi = 1:1:40; <i style="color:rgb(34,34,34)"><font color="#000000"> <div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div></font></i></div><div><i style="color:rgb(34,34,34)"><font color="#000000"><div style="display:inline"><i style="color:rgb(34,34,34)"><font color="#000000">|</font></i></div> </font></i> face_data = ft_freqanalysis(cfg, Face_sub); ]</div></div></font></i></div><pre style="white-space:pre-wrap"><i style="color:rgb(0,0,0)">When running DICS with these settings </i><i style="color:rgb(0,0,0)">I am getting the following error message:</i></pre><pre style="white-space:pre-wrap"><i><font color="#000000">Error using svd
Input to SVD must not contain NaN or Inf.
Error in beamformer_dics>pinv (line 650)
[U,S,V] = svd(A,0);
Error in beamformer_dics (line 339)
filt = pinv(lf' * invCf * lf) * lf' * invCf;
% Gross eqn. 3, use PINV/SVD to cover rank
deficient leadfield
Error in ft_sourceanalysis (line 568)
dip(i) = beamformer_dics(grid, sens, vol, [],
squeeze(Cf(i,:,:)), optarg{:});
Error in SourceAnalysis (line 133)
sourceFace = ft_sourceanalysis(cfg, face_data);<br></font></i></pre><div style="font-size:12.8px"><br></div><div style="font-size:12.8px"><pre style="white-space:pre-wrap"><i><font color="#000000"> I am not able to detect, where is the problem. Another issue I have found that 'vol.mat' or 'grid.leadfield' are all NaN value. I cannot understand how to solve it. I would be very thankful if you can help me in this regard. </font></i></pre></div><span class="HOEnZb"><font color="#888888"><br><div><br></div></font></span></div></div><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr">Thanks & Regards<div><br></div><div><font color="#0000ff"><b>Kasturi Barik</b></font><br><div><b><br></b></div><div><span style="color:rgb(102,0,204);font-family:tahoma,sans-serif">MS Research Scholar</span><br style="color:rgb(102,0,204);font-family:tahoma,sans-serif"><span style="color:rgb(102,0,204);font-family:tahoma,sans-serif">Audio and Bio-signal Processing Lab</span><br style="color:rgb(102,0,204);font-family:tahoma,sans-serif"><span style="color:rgb(102,0,204);font-family:tahoma,sans-serif">Department of Electronics and Electrical Engineering</span><br style="color:rgb(102,0,204);font-family:tahoma,sans-serif"><span style="color:rgb(102,0,204);font-family:tahoma,sans-serif">Indian Institute of Technology Kharagpur</span><br style="color:rgb(102,0,204);font-family:tahoma,sans-serif"><span style="color:rgb(102,0,204);font-family:tahoma,sans-serif">Mob: +91-8902400644</span><b><br></b></div></div></div></div></div></div>
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