Errors with Neuromag 306 raw data

[Jon Houck]

Hello,

I encountered a few problems in preprocessing using the latest fieldtrip
version (fieldtrip-20060131) with raw Neuromag 306 channel data.
Following are the error messages and the changes that seemed to clear them
up.

The first error was: ??? Undefined function or variable 'iscontinuous'.

Error in ==> fieldtrip-20060131\private\trialfun_neuromag at 13
trigger = read_fcdc_data(cfg.datafile, hdr, 1, nsamples, chanindx,
iscontinuous);

Error in ==> definetrial at 151
     trl   = feval(cfg.trialfun, cfg);

Error in ==> preprocessing at 270
[cfg] = definetrial(cfg);

To work around this, I edited
fieldtrip-20060131/private/trialfun_neuromag.m to replace iscontinuous on
line 13 with 1.  The edited line reads  "trigger =
read_fcdc_data(cfg.datafile, hdr, 1, nsamples, chanindx, 1);"

And the second was: ??? Subscripted assignment dimension mismatch.

Error in ==> read_fcdc_data at 392
       dat(:,((i-begepoch)*hdr.nSamples+1):((i-begepoch+1)*hdr.nSamples)) =
buf(:,chanindx)';

Error in ==> fieldtrip-20060131\private\trialfun_neuromag at 13
trigger = read_fcdc_data(cfg.datafile, hdr, 1, nsamples, chanindx, 1);

Error in ==> definetrial at 151
     trl   = feval(cfg.trialfun, cfg);

Error in ==> preprocessing at 270
[cfg] = definetrial(cfg);

To fix this one, I edited fieldtrip-20060131/read_fcdc_data.m to replace
buf(:,chanindx)' on line 392 with buf(chandindx,:).  The edited line reads
"dat(:,((i-begepoch)*hdr.nSamples+1):((i-begepoch+1)*hdr.nSamples)) =
buf(chanindx,:);"

These changes seem to work well on Matlab 7.1(R14) service pack 3 on
Windows XP and Matlab 6.5 (R13) on HP-UX 10.20.  If there are better
workarounds or (equally likely) if I've irreparably broken something,
please let me know.

Regards,

Jon Houck













--------------------------------------------------
Jon Houck, M.A.
Department of Psychology
MSC03 2220
University of New Mexico
Albuquerque, NM 87131
Office: (505) 277-0607  Lab: (505) 277-4725
Fax: (505) 277-1394  CASAA: (505) 925-2381