[FieldTrip] problems with channel layout autoscaling by ft_prepare_layout

[Rodolphe Nenert]

David,

i had the same issue with my own layout. The position of my electrodes was
not fitting the head, even if the proportion were right, like in your first
image.
I solved this problem by multiplying the position with different numbers
until i found the perfect one.

This is the part of code that does this:

lay = ft_prepare_layout(cfg);
lay.pos(:,1) = 1.5*lay.pos(:,1);

Replace 1.5 by something that works for you.

Hope this helps,

Rodolphe.

On Fri, Jan 14, 2011 at 3:36 PM, David Groppe <dgroppe at cogsci.ucsd.edu>wrote:

> Hi Fieldtripians,
>   I'm trying to export some EEGLAB data to Fieldtrip and am having
> trouble plotting the data topographically. I constructed a layout file
> for my 31 electrodes (see attached) and tried to plot the topography
> of my data using ft_topoplotER.m.  This produced the attached figures
> all_chans.jpg and just_scalp_chans.jpg.  The topography should look
> like that in the attached image, eeglab_topo.jpg.  As you can see, the
> electrodes are shrunk too far into the head and can be off center.
> Trying to change the channel layout file to fix this has little effect
> because ft_prepare_layout.m automatically normalizes the electrode
> coordinates to fill a unit circle.  Given the topoplots in the
> fieldtrip tutorial, there's obviously a way around this problem but
> save for editing the ft_prepare_layout.m, I don't know what to do.
>     thanks in advance for your help,
>            -David
>
> --
> David Groppe, Ph.D.
> dgroppe at cogsci.ucsd.edu
> http://www.cogsci.ucsd.edu/~dgroppe/
>
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