<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">Dear Xiao,<br>
<br>
the DICS algorithm computes power of a certain frequency band of <b>one
</b>time window (it works in the frequency domain with the
cross-spectral density matrix, i.e. no time axis anymore). The
source.avg.pow field contains thus the power value of this one
time-frequency bin. I assume you want to get time-spectral
evolution information? In that case it might be best to use the
LCMV beamformer in the time-domain, extract the spatial location
(voxel) of interest and apply the whatever-Fourier transform
(short time, wavelet, welch, taper) on that. Please have a look at
our various tutorials, for example:<br>
<br>
<a class="moz-txt-link-freetext" href="http://fieldtrip.fcdonders.nl/tutorial/beamformer">http://fieldtrip.fcdonders.nl/tutorial/beamformer</a> (on DICS)<br>
<a class="moz-txt-link-freetext" href="http://fieldtrip.fcdonders.nl/tutorial/beamformingextended">http://fieldtrip.fcdonders.nl/tutorial/beamformingextended</a>
(appendix for LCMV)<br>
<a class="moz-txt-link-freetext" href="http://fieldtrip.fcdonders.nl/tutorial/connectivity">http://fieldtrip.fcdonders.nl/tutorial/connectivity</a> (also includes
LCMV)<br>
<br>
And here for the DICS paper:<br>
<a class="moz-txt-link-freetext" href="http://www.ncbi.nlm.nih.gov/pubmed/11209067">http://www.ncbi.nlm.nih.gov/pubmed/11209067</a><br>
<br>
Best regards,<br>
Jörn<br>
<br>
<br>
On 4/1/2013 4:05 PM, 陈雪 wrote:<br>
</div>
<blockquote
cite="mid:CADiddyVjq6iZpuP+nm9E+ztNFXUeVF=e9r6xm16Jq=_HqAgnFw@mail.gmail.com"
type="cite">
<div>Dear all,</div>
<div> I use DICS-beamformer to get the source,as follow:</div>
<div>cfg = [];<br>
cfg.frequency = freqP.freq;<br>
cfg.elec = grid.cfg.elec;</div>
<div>cfg.method = 'dics';<br>
cfg.keeptrials = 'yes';<br>
cfg.grid = grid;<br>
cfg.vol = vol;<br>
cfg.dics.lambda = '5%';;<br>
cfg.dics.realfilter = 'yes';<br>
source = ft_sourceanalysis(cfg, freqP);</div>
<div> </div>
<div>source = </div>
<p> dim: [19 25 19]<br>
freq: 17.9481<br>
cumtapcnt: 3<br>
pos: [9025x3 double]<br>
inside: [1x4686 double]<br>
outside: [1x4339 double]<br>
method: 'average'<br>
avg: [1x1 struct]<br>
cfg: [1x1 struct]</p>
<p>source.avg</p>
<div> pow: [1x9025 double]</div>
<div>is it right? if I want to get the waveforms in order to do
the correlation,how can I do ? </div>
<div> </div>
<div>thanks,</div>
<div>best</div>
<div>xiao</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
fieldtrip mailing list
<a class="moz-txt-link-abbreviated" href="mailto:fieldtrip@donders.ru.nl">fieldtrip@donders.ru.nl</a>
<a class="moz-txt-link-freetext" href="http://mailman.science.ru.nl/mailman/listinfo/fieldtrip">http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a></pre>
</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
Jörn M. Horschig
PhD Student
Donders Institute for Brain, Cognition and Behaviour
Centre for Cognitive Neuroimaging
Radboud University Nijmegen
Neuronal Oscillations Group
FieldTrip Development Team
P.O. Box 9101
NL-6500 HB Nijmegen
The Netherlands
Contact:
E-Mail: <a class="moz-txt-link-abbreviated" href="mailto:jm.horschig@donders.ru.nl">jm.horschig@donders.ru.nl</a>
Tel: +31-(0)24-36-68493
Web: <a class="moz-txt-link-freetext" href="http://www.ru.nl/donders">http://www.ru.nl/donders</a>
Visiting address:
Trigon, room 2.30
Kapittelweg 29
NL-6525 EN Nijmegen
The Netherlands</pre>
</body>
</html>