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<div class="moz-cite-prefix">Hey Nenad,<br>
<br>
the problem is simply that in the beginning of your TFR there are
nans and you are using that part as a baseline.<br>
You cannot have a 0.5s timewindow at t=-0.5s up until t=0s when
your preprocessed data starts at t=-0.5s, you would need
preprocessed starting at -1s. When plotting, you chose to use a
baseline which starts within the nan area, so all your data will
be substracted with nans resulting in nans itself.<br>
<br>
Three solution possible: <br>
1) Use a baseline outside the nan area (for you t>=0)<br>
2) Re-do your processing starting at t=-1s or <br>
3) Use shorter time windows for your freq analysis of only 300ms
(because then your baseline starting at 200ms would work, since
500-300 = 200)<br>
<br>
I'd recommend the second one - always use data padding when doing
analysis.<br>
<br>
Best regards,<br>
Jörn<br>
<br>
On 10/19/2012 11:46 AM, Nenad Polomac wrote:<br>
</div>
<blockquote
cite="mid:CAEk4EpEEN-K0cWOQztYKpLvuDN-cMJNStccyYs2-Z5ns80qQvw@mail.gmail.com"
type="cite">
<div> </div>
<div>
<div>Dear all,</div>
<br>
I have one problem with the ft_freqanalysis. When I calculate
time-frequency analysis with the Hanning taper everything works
ok, but when I try to plot data with ft_multiplotTFR
or ft_topoplotTFR I get empty plots. You can check that in
the attached image. However, when I calculate time-frequency
with the multitapers plot looks fine. Here is my problematic
code:
<div>
<br>
</div>
<div><br>
</div>
<div>%Hanning taper</div>
<div>cfg = [];</div>
<div>cfg.output = 'pow';</div>
<div>cfg.channel = 'MEG';</div>
<div>cfg.method = 'mtmconvol';</div>
<div>cfg.taper = 'hanning';</div>
<div>cfg.foi = 2:2:30;</div>
<div>cfg.t_ftimwin = ones(length(cfg.foi),1).*0.5; % length
of time window = 0.5 sec</div>
<div>cfg.toi = -0.5:0.05:1.5; % time
window "slides" from -0.5 to 1.5 sec in steps of 0.05 sec</div>
<div>cfg.polyremoval = -1;</div>
<div>wr11_freq = ft_freqanalysis(cfg, data_clean);</div>
<div><br>
</div>
<div><br>
</div>
<div>cfg = [];</div>
<div>cfg.baseline = [-0.2 -0.1];</div>
<div>cfg.baselinetype = 'absolute';</div>
<div>cfg.zlim = [-4e-29 1e-28];</div>
<div>cfg.showlabels = 'yes';</div>
<div>cfg.layout = 'CTF275.lay';</div>
<div>cfg.colorbar= 'yes';</div>
<div>cfg.interactive= 'yes';</div>
<div>cfg.hotkeys = 'yes';</div>
<div>figure</div>
<div>ft_multiplotTFR(cfg, wr11_freq);</div>
</div>
<div><br>
</div>
<div>Please help!</div>
<div>Thank you in advance!</div>
<div><br>
</div>
<div>Nenad</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
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</div>
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<pre wrap="">_______________________________________________
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</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>
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