denoise_synthetic

[Ingrid Nieuwenhuis]

Dear Michael

I think you can also read in ctf data that are saved in 3rd gradient mode
without any problems. If you look in data.grad.balance.current it should
then be G3BR after preprocessing. When we were testing, one of the things we
did was compare 3rd order data made by DataEditor with 3rd order data made
by FieldTrip. That looked fine. But again, it's not tested thoroughly yet.

Hope this helps,
Ingrid

-----Original Message-----
From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On Behalf
Of Michael Wibral
Sent: Thursday, July 17, 2008 5:16 PM
To: FIELDTRIP at NIC.SURFNET.NL
Subject: Re: [FIELDTRIP] denoise_synthetic

Dear Robert,

I have a question regarding the use of the new preprocessing function and
denoise synthetic:
If the ctf data are saved in 3rd gradient mode - will preprocessing and
denoise_synthetic treat this correctly? I.e. will these functions not
perform any (unnecessary/wrong) computation and simply update the relevant
information fields in the data structure? Or do I have to save the ctf data
in raw format and then let fieldtrip do the rest?
Sorry if this question is somehow redundant. Just wanted to be sure.

Many thanks,
Michael

> -----Ursprüngliche Nachricht-----
> Von: "Robert Oostenveld" <r.oostenveld at FCDONDERS.RU.NL>
> Gesendet: 17.07.08 17:07:06
> An: FIELDTRIP at NIC.SURFNET.NL
> Betreff: [FIELDTRIP] denoise_synthetic


> Dear all,
> 
> I just noticed that it was possible to do denoise_synthetic (i.e.  
> apply 3rd order gradients to CTF data) without all required channels  
> being present in the data. It requires the MEG channels and the  
> reference channels to be both present in the preprocessed data.
> 
> If you have beein doing cfg.channel=MEG in preprocessing and then  
> denoise_synthetic, then the data will not be correct 3rd order  
> gradients. If you have been doing cfg.channel=all, then  
> denoise_synthetic will have done its job correct (I hope). I have now  
> added an explicit check on the presence of the required channels, so  
> now it will give an error if the reference channels are missing.
> 
> best regards,
> Robert
> 
> PS the update will be available this evening on the ftp
> 
>   
> 
> ----------------------------------
> The aim of this list is to facilitate the discussion between users of the
FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG
and EEG analysis. See also
http://listserv.surfnet.nl/archives/fieldtrip.html and
http://www.ru.nl/fcdonders/fieldtrip.
> 



----------------------------------
The aim of this list is to facilitate the discussion between users of the
FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG
and EEG analysis. See also
http://listserv.surfnet.nl/archives/fieldtrip.html and
http://www.ru.nl/fcdonders/fieldtrip.

----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/fcdonders/fieldtrip.