[Eeglablist] Singular matrix error for Laplacian plugin

[Arnaud Delorme]

I agree. This plugin is not stable (you are talking about the plugin 
available on this web page I guess 
http://80.33.136.211/fbos/projects/kolmogorov.html). I tried to use it 
and after intense debugging, I still had some conceptual problem (even 
when I used a high degree of spherical harmonic expansion, I obtained 
topographic plots that did not totally resemble the classical topoplots 
(they had some strong similarities and strong dissimilarities)), so 
there might still be a problem? I can send the edited version of the 
plugin to whoever is interested (I sent it to the author so he could 
update his web site with a functional version but he probably did not 
have time to do it).

Arno

Scott Laurence Fairhall wrote:

>Hi,
>
>when I attempt to use the lap_perrin function contained within the EEGLAB laplacian 
>plugin I receive an error. When matlab attempts to inv(mat) where mat is (i think!) some 
>form of spline I get a message saying my matrix is badly scaled or singular (and 
>therefore has no inverse).
>
>Does anyone have any suggestions about what it is in my electrode coordinates that 
>may cause this to arise?
>
>Regards
>Scott
>
>
>Scott Fairhall
>Research Centre for Cognitive Neuroscience 
>Department of Psychology
>University of Auckland
>Auckland, 92019
>Ph: 649-3737599 ext. 88421
>
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-- 

*Arnaud Delorme, Ph.D.*
Computational Neurobiology Lab, Salk Institute
10010 North Torrey Pines Road
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*Tel* : /(+1)-858-458-1927 ext 15/
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