Please add information if you're using EGI data and want to share info with other FieldTrip users.

Net Station can export data to several data formats that FieldTrip can read in.

• *.egis, *.ave, *.gave, *.ses, *.sbin can be read in by FieldTrip (I have no details on how well they work, and what the known issues are).
• Simple binary (.raw), only the channels from the hdEEG net are exported, the PIB channels, for instance, are not. Channel labels are not present in this format, and are thus made on the fly by FieldTrip. Events are present and read in correctly. Data sets containing multiple epochs are exported by NetStation as separate .raw files. The events are, however, exported as one file, which make it tricky (read impossible) to align data and events properly when having multiple discontinuous epochs.
• EDF+ (.edf) All channels, including PIB channels, are read in correctly, including channel labels. However, the events, which are stored on the annotation channel, are written in a way by Net Station that is not compatible with the edf+ reading implementation in FieldTrip. So, events do not come out properly. Also discontinuous epochs are “glued” together as one “continuous” data stream.

The beta version of NetStation 4.5 (and up) writes data in mff, which is now (April 21, 2011) fully supported by FieldTrip. FieldTrip reads in the data of all signals (hdEEG-net, PIB, etc). Data sets containing multiple epochs are supported, FieldTrip keeps track of the offset to the start of the recording for all epochs. Also events are read in, and also with discontinuous epochs aligning of events to data works. Implementation is not rigorously tested yet, if you work with mff data, and have questions or issues please contact Ingrid Nieuwenhuis: inieuwenhuis - at - berkeley.edu.

In short, the code in ft_read_header and ft_read_data does

case {'egi_mff_v1' 'egi_mff'}
 % do the old stuff
case {'egi_mff_v2'}
 % do the new stuff

The V1 implementation is the first implementation by Ingrid, which works for quite a few datasets but also has a number of known limitations (a.o. no support for multiple signal files, slow reading of events). The V2 implementation is provided by the EGI company and is based on their general-purpose Java library and should support all data format features. As soon as the V2 code works at least as good as the old V1 implementation, the 'egi_mff' case will move from the v1 to the v2 implementation, causing the default behaviour to switch.

At this moment the default is to use the egi_mff_v1 implementation. This can be overruled by specifying

cfg.dataformat = 'egi_mff_v2'
cfg.headerformat = 'egi_mff_v2'

to ft_preprocessing and all other high-level FT functions that read data. Furthermore, by specifying

ft_read_header(...., 'headerformat', 'egi_mff_v2')
ft_read_data(...., 'headerformat', 'egi_mff_v2', 'dataformat', 'egi_mff_v2')

also the low-level fileio functions will use the v2 reading functions.

The egi_mff_v2 implementation in MATLAB depends on a generic Java implementation of the reading functions. To install the .jar file, you have to add a path to the MFF-1.0.jar (java) file by typing “edit classpath.txt” on your matlab prompt add the path to the .jar file, which will look like:

/fieldtrip/external/egi_mff/java/MFF-1.0.jar

You will have to quit and restart MATLAB after doing that.