[FieldTrip] ft_headmodelplot coordinate system origin problem

[Ion Lavado]

Thank you for your help Jan. I tried all you told but i continue with my
problem. The coordinates for the head (volume) and mri are the same, with
the function ft_determine_coordsys i see this.
I think that the problem is about the sensor (helmet) origin of
coordinates. Please see the images i adjunt here,* the sensors origin is
very low*(nearly out of the helmet) and when ploting everything i suppose
that every origin align to each other, so that the brain comes a little bit
low.

Best whishes,

Ion

2012/1/2 jan-mathijs schoffelen <jan.schoffelen at donders.ru.nl>

> Dear Ion,
>
> Are you sure that the sensor positions are defined in the same coordinate
> system as are the volume conductor model and the source positions? If not,
> then this is the likely cause of the shift. You can have a look here for
> more information about the different coordinate systems:
> http://fieldtrip.fcdonders.nl/faq/how_are_the_different_head_and_mri_coordinate_systems_defined
>
> In order to coregister the anatomical mri to the sensor array, you can use
> ft_volumerealign.
>
> Best wishes,
>
> Jan-Mathijs
>
>
> On Jan 2, 2012, at 5:11 PM, Ion Lavado wrote:
>
> Hello, i'm working with MEG data from Elekta Neuromag. My problem comes
> when i try to plot the headmodel with the function ft_headmodelplot(cfg).
> This should plot the head model(volume) + brain grid + sensors. As you can
> see in the adjunted image, my head volume and grid is not centered and part
> of the head could not be read by the sensors. Is it possible to modify this
> so i can center the head in the sensors(helmet)?
> Thank you very much.
>
> Ion Lavado
> <headmodelplot.jpg>_______________________________________________
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>
>
> Jan-Mathijs Schoffelen, MD PhD
>
> Donders Institute for Brain, Cognition and Behaviour,
> Centre for Cognitive Neuroimaging,
> Radboud University Nijmegen, The Netherlands
>
> Max Planck Institute for Psycholinguistics,
> Nijmegen, The Netherlands
>
> J.Schoffelen at donders.ru.nl
> Telephone: +31-24-3614793
>
>
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