Neuromag data processing

alotof eve alotof_xd at YAHOO.COM
Wed Feb 21 08:09:26 CET 2007


Thank you Christian.
  I can use meg-pd toolbox now. However, it seems all the functions in FieldTrip are for evoked data while my raw data is continuous data.

  I tried your suggestion. read_head works but read_data doesn't work. I don't know this error just due to memory or continuous data format. I remember previous discussion (2-feb-2006) in this emaillist mentioned that read_data couldn't deal with continuous data. The error shows as below:

??? Out of memory. Type HELP MEMORY for your options.
  Error in ==> F:\MATLAB6p5\toolbox\fieldtrip-20070213\private\read_data.m
On line 529  ==>         dat(:,((i-begepoch)*hdr.nSamples+1):((i-begepoch+1)*hdr.nSamples)) = buf(chanindx,:);
  Error in ==> F:\MATLAB6p5\toolbox\fieldtrip-20070213\read_fcdc_data.m
On line 49  ==> [dat] = read_data(varargin{:});

  Even the read_data has been improved as continuous data acceptable, I still wonder the following data processing. Is there tool to convert continuous data to "epoch mode" data?

  Thanks.

  Best,
  Eve

Christian Hesse <c.hesse at FCDONDERS.RU.NL> wrote:
  Hi Eve,

  FieldTrip handles (pretty much) all function calls to the meg-pd toolbox for you (in particular which are the appropriate input arguments to use) so you don't have to deal with these issues yourself.


  See if you can extract the header information and some data from your .fif file using?lt;/DIV>

  filename = "fullpath/name.fif"
  hdr = read_fcdc_header(filename);
  % hdr should be a structure
  dat = read_fcdc_data(filename);
  % dat should be a nchan x nsamp matrix


  see what you get.


  Regards,
  Christian





    On 17 Feb 2007, at 21:03, alotof eve wrote:

    Hi, experts,
  ?lt;/DIV>      Maybe I misunderstood the command. My MEG data is from NeuroMag 306 channels.  Does that mean I should use "Neuromag-306" as argument? Thanks for any suggestion.
  ?lt;/DIV>   Best,
  Eve


alotof eve <alotof_xd at yahoo.com> wrote:
  Hi Christian,

  ?Yes it works. Thank you so much.
  ?But now I met a new problem. I got only a whole .fif data. When I tried the command "MEGMODEL", it said any argument can be left out. However, the error showed up again:
>> MEGMODEL
??? Could not load the coil files

Error in ==> F:\MATLAB6p5\bin\win32\megmodel.dll
  ?
I couldn't find any .fif file like Neuromag-122 or coilfile.fif. How do you settle it?
Thanks.

Best,
Eve

Christian Hesse <c.hesse at FCDONDERS.RU.NL> wrote:   Hi Eve,

  you should be able to use the meg-pd toolbox (also from FieldTrip) in Matlab under Windows. I got the toolbox to work in Matlab7 under WindowsXP as follows:


  ? extract the meg-pd-1.2-10.mswin.zip file to somewhere
  -?then copy (or move) the meg_pd_1.2 directory wherever you want
  -?in the README file in the meg-pd-1.2-10.mswin directory it specifies that you need to copy the DLL file "meg-pd-1.2-10.mswin\lib\i686-pc-cygwin\libmagnet_pd_1.2.dll" into the bin directory of Matlab on your system, in my case this was the directory "MATLAB71\bin\win32"
  -?start up Matlab, add the fieldtrip and meg_pd_1.2 directories to your path and try to read your .fif file


  Let me know if this works on your Windows system


  Regards,
  Christian




      On 15 Feb 2007, at 17:32, alotof eve wrote:

    Hi, experts,
  ?lt;/DIV>        I am a new user of fieldtrip. I try to use meg-pd package to import NeuroMag data but it seems there is something wrong with the environment.
  ?The error?showed as:
      ?Unable to load mex file: F:\MATLAB6p5\toolbox\fieldtrip-20070213\meg_pd_1.2\loadfif.dll.
The specified module could not be found.
      
      ?The true is the .dll is in the same path as .m and the path has been add the Matlab.
      ?I use Latlab 6.5 under WindowXP. I don't know if it affects. I saw the "lib" in the same meg-pd package included a .dll for pc-cygwin. I wonder if I have to use Matlab under Linux/Unix environment. Or if any other limits.
  ?lt;/DIV>        Please help me. Thanks.
  ?lt;/DIV>   Best,
  Eve



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    ----------------------------------------------------------------------
  Christian Hesse, PhD, MIEEE


  F.C. Donders Centre for Cognitive Neuroimaging?lt;/DIV>   P.O. Box 9101?lt;/DIV>   NL-6500 HB Nijmegen?lt;/DIV>   The Netherlands


  Tel.:?31 (0)24 36 68293
  Fax: +31?0)24 36 10989


  Email: c.hesse at fcdonders.ru.nl
  Web: www.fcdonders.ru.nl
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    ----------------------------------------------------------------------
  Christian Hesse, PhD, MIEEE


  F.C. Donders Centre for Cognitive Neuroimaging?lt;/DIV>  P.O. Box 9101?lt;/DIV>  NL-6500 HB Nijmegen?lt;/DIV>  The Netherlands


  Tel.:?31 (0)24 36 68293
  Fax: +31?0)24 36 10989


  Email: c.hesse at fcdonders.ru.nl
  Web: www.fcdonders.ru.nl
  ----------------------------------------------------------------------















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