megrealign, head models

[Robert Oostenveld]

On 12 May 2005, at 15:58, Montez, T. wrote:

> 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.

No, please read my original mail below. Log in as anonymous and put the
stuff in /pub/incoming. You should not use the eegmeg2005 account, that
is only for the write protected course pfd material.

> ??? Index exceeds matrix dimensions.
>
> Error in ==> timelockgrandaverage at 85
>   varargin{i}.avg = varargin{i}.avg(chansel,:);
>
> (It works for a reduced number of subjects.)

Do some subjects have fewer channels than other subjects? If so, please
download the latest fieldtrip release from teh ftp server.

> 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?

In timelockanalysis you should do keeptrials=no prior to
timelockgrandaverage.

best,
Robert


> -----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
>
>
----------------------------------------------------------------------
Robert Oostenveld, PhD
F.C. Donders Centre for Cognitive Neuroimaging
Radboud University Nijmegen
phone: +31-24-3619695
http://www.ru.nl/fcdonders/
----------------------------------------------------------------------
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