Differences in channel numbers and MEG Interpolate

[Robert Oostenveld]

Hi Durk,

No, that is not possible. Megrepair will only interpolate an existing
channel (using nearest neighbours). What you can do is to manually
add the channel to your preprocessed dataset. E.g.

cfg = ...
raw = preprocessing(cfg);
raw.label{end+1} = 'MLO21';
for i=1:length(data.trial)
   data.trial{i}(end+1,:) = 0;
end

Btw. I suggest to call MERREPAIR, MEGREALIGN and MEGPLANAR seperately
and not use the MEGINTERPOLATE (in the old days, there was this one
function, but that was split up into its logical components).

best,
Robert


On 15-aug-2005, at 13:34, Talsma D wrote:

> Hi Fieldtrippers,
>
> I have the following question regarding meginterpolate: Is it possible
> to use MEG interpolate to add a channel to the dataset that was never
> recorded in the first place? I have data from a limited number of
> subjects that is recorded with one channel (MLO21) less (149 channels)
> than the data from the other subjects (150 MEG channels). From what I
> can tell, this is not a channel that is just marked as 'Bad', but one
> that was never recorded in the first place. I tried interpolating this
> channel using meginterpolate, but after this procedure, I still have a
> dataset with 149 channels. Below are the settings I used. Needless to
> say, I tried various variations, but none appeared to work.
>
> For now, I'm going to try and remove the offending channel from the
> remaining subjects that were recorded with 150 channels.
>
> Thanks in advance,
> Durk
>
>
> templatefile    =   {   'pp01/corr-resp.ds',
>                         'pp01/incor-resp.ds',
>                         'pp02/corr-resp.ds',
>                         'pp02/incor-resp.ds',
>                         'pp03/corr-resp.ds',
>                         'pp03/incor-resp.ds',
>                         'pp04/corr-resp.ds',
>                         'pp04/incor-resp.ds',
>                 'pp06/corr-resp.ds',
>                         'pp06/incor-resp.ds',
>                 'pp09/corr-resp.ds',
>                         'pp09/incor-resp.ds',
>                 'pp10/corr-resp.ds',
>                 'pp10/incor-resp.ds',
>                         'pp11/corr-resp.ds',
>                         'pp11/incor-resp.ds',
>                         'pp12/corr-resp.ds',
>                         'pp12/incor-resp.ds',
>                         'pp13/corr-resp.ds',
>                         'pp13/incor-resp.ds',
>                         'pp14/corr-resp.ds',
>                         'pp14/incor-resp.ds',
>                         'pp15/corr-resp.ds',
>                         'pp15/incor-resp.ds'
>                         };
>
> cfgrepair = [];
> cfgrepair.repair         = 'yes';
> cfgrepair.realign        = 'no';
> cfgrepair.planar         = 'no';
> cfgrepair.template    =templatefile;
> cfgrepair.hdmfile     ='standard.hdm';
> cfgrepair.badchannel  = {'MLO21'};
>
> dataCor_corrected   = meginterpolate(cfgrepair, dataCor);
> dataInc_corrected   = meginterpolate(cfgrepair, dataInc);
>
>

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