problems while calculating leadfield

[Nathan Weisz]

hi,

i have a problem while performing prepare_leadfield.
the data is some old CTF data i collected ~2 years ago. i calculated a
multisphere model in fieldtrip using prepare_localspheres. this step
works (i.e. i get a vol structure that looks ok in my opinion).
however when continuing with prepare_leadfield the the program crashes.

here's the code:
cfg=[];
cfg.grid.xgrid='auto';
cfg.grid.ygrid='auto';
cfg.grid.zgrid='auto';
cfg.vol=vol;
cfg.channel='MEG';
cfg.grad=dataCLeConI.grad;
cfg.inwardshift=0;
cfg.grid.resolution=1;
cfg.reducerank=2;

lf=prepare_leadfield(cfg);

i get this error message:
??? Error using ==> prepare_headmodel at 301
synthetic gradients not supported during volume conductor setup

Error in ==> prepare_leadfield at 223
[vol, sens, cfg] = prepare_headmodel(cfg, data);

Error in ==> newcat_calcgrid at 52
lf=prepare_leadfield(cfg);

i messed around with different headmodels just to see how
prepare_leadfield behaves:
*when the headmodel is a single sphere (cfg.singlesphere='yes')
prepare_leadfield works fine
*when using the nolte headmodel (via prepare_singleshell),
prepare_leadfield does not crash, but the leadfields contain only
NaN ... is that perhaps related to the issue above?

again, any help is greatly appreciated.

best,
nathan






--------------------------------------------
Dr. Nathan Weisz

OBOB-Lab
University of Konstanz
Department of Psychology
P.O. Box D23
78457 Konstanz
Germany

Tel: ++49 - (0)7531 - 88 45 84
Email: nathan.weisz at uni-konstanz.de
Homepage: http://www.uni-konstanz.de/obob

"Nothing shocks me. I'm a scientist." (Indiana Jones)


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