[Eeglablist] pop_spectopo jagged spectrum

[Makoto Miyakoshi]

Dear Maximilien,

I completely agree with Andreas. Your data must have a signal with very
high amplitude. Use 'trimOutlier' plugin to find where it happens in your
data (in both time domain and channels)
http://sccn.ucsd.edu/wiki/Plugin_list_process

'File' -> 'Manage EEGLAB extensions' and find trimOutlier.

Makoto



On Fri, Aug 28, 2015 at 12:28 AM, Andreas Widmann <widmann at uni-leipzig.de>
wrote:

> Hi Max,
>
> pwelch is quite sensitive to stronger DC offsets. I have seen similar
> patterns before. Do you possibly analyze raw Biosemi data? Could you please
> try to highpass filter the data?
>
> Best,
> Andreas
>
> > Am 27.08.2015 um 12:22 schrieb Maximilien Chaumon <
> maximilien.chaumon at gmail.com>:
> >
> > Hi,
> >
> > Running a spectopo command on a continuous dataset as follows:
> > spec = pop_spectopo(EEG,1,[],'EEG','noplot','on','percent',5);
> > I get a terrible jagged spectrum, really ugly like a saw.
> > I tried to get to the bottom of the problem and ended up looking at the
> point where this pwelch function from signal toolbox is called. The
> spectrum that comes out of it is messed up (similar to above).
> > So I made sure this pwelch function isn't used and it shows a much nicer
> (normal) power spectrum.
> >
> > Anyone had this issue already? How did you solve it?
> >
> > I filed a bug: Bug 1791
> >
> >
> > Max
> > _______________________________________________
> > Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> > To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> > For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>



-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20150902/a9f5d90e/attachment.html>