You have done all the right checks I would do given such an error and
it seems the problem is quite low-level and would require the
attention of the person who wrote the low-level converter, Joe Dien.
As he seems to be out of e-mail contact at the moment, I'll recycle
something from our earlier e-mail exchange that might be helpful:
Begin forwarded message from Joe Dien to Vladimir on Sep 12, 2008:
EGI has three formats that they support. The primary one, the
NetStation format, is proprietary. The simple binary format and the
older EGIS format are the two publicly available formats. I've
contributed code to FieldTrip to support both formats. A qualifier on
that statement is that there are two versions of the simple binary
format, one for segmented (epoched) data and one for continuous data.
I've only provided support for segmented data. It would be pretty
simple to support continuous data too but I haven't seen the need to
do so. The data format codes are:
'egi_sbin' segmented simple binary format (code named eGLY)
'egi_egis' EGIS session format
'egi_egia' EGIS average format
One other issue is that although the EGIS format has a byte order
field, I've had to make the assumption in the Field Trip code that
files are big-endian (that is, the PowerPC endian rather than the
Intel endian). NetStation makes the same assumption.
So one problem might be that your file is continuous rather than
segmented and this is not supported by Joe's reader. What I'd suggest
is that you try to export your data into EGIS file. That format should
be better supported and it's preferable according to Joe because there
is some additional problem with the simple binary that has to do with
representation of stimulus triggers.
I hope this helps at this stage and I'll wait with you for Joe to give
us a more comprehensive answer.
On Mon, Oct 13, 2008 at 8:12 PM, Kate Fissell <[log in to unmask]> wrote:
> Can anyone tell me how to read EEG data from EGI into SPM8b ?
> I have installed SPM8b with the spm8b_updates_r2333 patches.
> I have the biosig toolbox installed.
> When I try to read in an EGI "simple binary" file using the
> SPM8b GUI m/eeg Convert button it seems that because of the
> .raw filename extension, the file is taken to be a yokogawa MEG file.
> If I try calling
> h = fileio_read_header('seg1/NP146_AX002.raw', 'headerformat', 'egi_sbin');
> to specify the format explicitly, I get the error
> ERROR: This is not a simple binary file. Note that NetStation does
> not successfully directly convert EGIS files to simple binary format.
> I think I might be getting this error because I am running on a little-endian
> platform and the EGI file is big-endian, but the fopen() call in
> read_sbin_header.m does not specify machine format.
> From the comments at the top of external/fileio/private/read_header.m
> it sounds like a number of EGI formats are supported, in addition to
> simple binary. But when I try to convert an EGI session file I get
> a number of errors/warnings including:
> Warning: could not determine filetype
> Are EGI native files as well as export files supported ?
> thank you,