[FieldTrip] volume conduction model missing .mat

[Akiko Ikkai]

Hi,

I'm trying to create a volume conduction model for my EEG study based on
anatomical MRI, and having trouble with ft_prepare_bemmodel

when I run
cfg                = [];
cfg.tissue         = [7 4 1]; % value for brain, skull, and scalp
cfg.conductivity   = [1 1/80 1]*.33; % after standard_BEM.zip data
cfg.isolatedsource = true;
cfg.method         = 'dipoli';
cfg.sourceunits = 'mm';
cfg.mriunits = 'mm';
vol = ft_prepare_bemmodel(cfg, seg4bem);

I get the following error message while ft_prepare_bemmodel is running:

Fatal error in dipoli:  interface
/private/tmp/tpd8a04422_e19e_4978_9b9b_56d1f2696492.tri and
/private/tmp/tp313c9a32_1991_4df6_a404_8efc41b6302e.tri intersect
 at vertex 1402 of /private/tmp/tpd8a04422_e19e_4978_9b9b_56d1f2696492.tri

Warning: an error ocurred while running dipoli
> In dipoli at 94
  In ft_prepare_bemmodel at 112
Error using ==> fread
Invalid file identifier.  Use fopen to generate a valid file identifier.
Warning: File '/private/tmp/tp0c0779e3_a657_4ca5_b9e1_845f41e9574a.ama' not
found.
> In dipoli at 102
  In ft_prepare_bemmodel at 112


and the output vol is missing .mat, which causes an error
during ft_sourceanalysis.
>> vol
vol =
            cond: [0.3300 0.0041 0.3300]
             bnd: [1x3 struct]
          source: 3
    skin_surface: 3
            skin: 1
            type: 'dipoli'

Does anyone know how to correct for "fatal error" so
that ft_prepare_bemmodel creates the correct volume conduction model? I
opened .tri file and removed line 1402, but got the same results.

Thanks in advance! Akiko

-- 
Akiko Ikkai, Ph.D.
Postdoctoral Fellow
Department of Psychological and Brain Sciences
Johns Hopkins University
Ames Hall, 3400 N. Charles St.
Baltimore, MD 21218
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