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Hello,</div>
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Just to update, I have checked more subjects and I found that the sign flip is in a lot of subjects ( but my labels were only affected in 3 subjects). </div>
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Wouldnt this make results unreliable? as reproducibility of results is affected.</div>
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Kind regards</div>
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Bushra Riaz</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> fieldtrip <fieldtrip-bounces@science.ru.nl> on behalf of Bushra Riaz Syeda via fieldtrip <fieldtrip@science.ru.nl><br>
<b>Sent:</b> 01 September 2021 13:25<br>
<b>To:</b> FieldTrip discussion list <fieldtrip@science.ru.nl><br>
<b>Cc:</b> Bushra Riaz Syeda <bushra.riaz@gu.se><br>
<b>Subject:</b> [FieldTrip] Sign flip in lcmv spatial filter with different versions of MATLAB</font>
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<span lang="EN-US" style="">Hello, </span></p>
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<span lang="EN-US" style=""> </span></p>
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<span lang="EN-US" style="">I am having a strange error. I calculated lcmv beamformer for my
<span style=""> </span>Neuromag dataset couple of years ago. I ran some beamformer based analysis and now I thought I will redo some part of the analysis. </span></p>
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<span lang="EN-US" style="">I noticed during the rerun of my scripts that the spatial filter calculated for 3 subjects ( out of 20) has a sign flip for 3-5 % of the vertices. After investigating for a week, I found that I get sign flip for these vertices when
I run the same script with MATLAB 2013b and MATLAB 2017a ( fieldtrip version was same for both runs). </span></p>
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<span lang="EN-US" style=""> </span></p>
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<span lang="EN-US" style="">I have attached the figure for one of the vertex of spatial filter with both MATLAB versions. </span></p>
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<span lang="EN-US" style=""> </span></p>
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<span lang="EN-US" style="">Now my question is, as this sign flip is affecting my further analysis, I would like to know , how to figure out which one is correct and if anyone has any idea where the error could be coming from. </span></p>
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<span lang="EN-US" style="">Thank you </span></p>
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<span lang="EN-US" style="">Any help would be highly appreciated. </span></p>
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<span lang="EN-US" style=""> </span></p>
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<span lang="EN-US" style="">Kind regards </span></p>
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<span lang="EN-US" style="">Bushra Riaz </span></p>
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