megrealign, head models

[Montez, T.]

Dear Robert,

I can not access the ftp://ftp.fcdonders.nl.
I can access ftp://eegmeg2005@m50-336.azn.nl/ but I do not have permission
to copy things there.

Can you please tell me another place to put the files?
(The average file is just around 6 MB.)

I also tried to define the head model manually by:

cfg.vol.r = 7.5
cfg.vol.o = [0, 0, 5]

and it still does not work, so it seems to not be related to the headmodel
file.


Meanwhile I got errors with the grandaverages functions (applied to the non
aligned files):

??? Index exceeds matrix dimensions.

Error in ==> timelockgrandaverage at 85
  varargin{i}.avg = varargin{i}.avg(chansel,:);

(It works for a reduced number of subjects.)

And I run out of memory when I have to load 18 subject, so maybe I have to
do the grand average in steps for a higher number of subjects?

Thanks for your help,
Teresa





-----Original Message-----
From: Robert Oostenveld [mailto:r.oostenveld at FCDONDERS.RU.NL]
Sent: Monday, May 09, 2005 9:10 AM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: Re: [FIELDTRIP] megrealign, head models


On 9 May 2005, at 0:17, Teresa Montez wrote:

> I get the error message:
>
>  ??? Error using ==> svd
> NaN or Inf prevents convergence.

There seems to be a problem with your head model, the forward model has
a nan or an inf.

> - Should I use a local spheres head model?

In general you should not use a local spheres model for realignment.

I have no idea what is causing the problem. Could you send me a matlab
file with an averaged ERF that you want to align and the headmodel
file? Please
use ftp://ftp.fcdonders.nl and put the files in the directory
/pub/inccoming (the directory is one-way-traffic: you cannot see them
there after copying, but I can pich them up from there).

Robert