Unable to import neuromag raw file (.fif)

Francois · May 28, 2020, 3:41pm

Hi Ling,

First make sure you don't have anything saved in your Matlab path that does not belong to the Matlab installation itself. Having other toolboxes that shadow some basic Matlab functions is a common source of problems.

BST> Error: Could not find measurement data:
Unrecognized function or variable 'desc'.

This error is generated here:

github.com

brainstorm-tools/brainstorm3/blob/master/toolbox/io/in_fopen_fif.m#L62


      
              end
          end
          
          %% ===== OPEN FIF FILE =====
          % Open file
          [ fid, tree ] = fiff_open(DataFile);
          if (fid < 0)
              error(['Cannot open FIFF file : "' DataFile '"']);
          end
          % Read info structure
          try
              [ info, meas ] = fiff_read_meas_info(fid, tree);
          catch
              err = lasterror;
              disp([10 'BST> Error: Could not find measurement data: ' 10 err.message 10]);
              info.chs = [];
              info.dig = fif_read_headpoints(fid, tree);
              meas = [];
          end
          
          % Check if file was opened successfully

This is related with an error generated in function brainstorm3/external/mne/matlab/fiff_read_meas_info.m, which is part of the external MNE-matlab library, which is maintained by a different group of developers.

There is most likely some error or unexpected data in you .fif file.
If you want help with this issue, please:

create a new issue on the mne-matlab github repository:
Issues · mne-tools/mne-matlab · GitHub
in this new issue, include a link to download you faulty .fif file
post here the link to the github issue, so that we can follow the updates

** Error: Line 131: Reference to non-existent field 'meas_date'.
**
** Call stack:
** >in_fopen_fif.m at 131
** >in_fopen.m at 68
** >import_raw.m at 126
** >bst_call.m at 28
** >tree_callbacks.m>@(h,ev)bst_call(@import_raw,,,iSubject) at 636

I posted a fix for this issue:

Update Brainstorm and try again. It will not make your data readable, but will crash in a different, hopefully slightly more elegant, way.