Export to EDF using pyEDFLib

[skjerns]

Problem
Right now it is only possible to export data using FIF, which is not a very useful and widely used file format. I do remember seing an issue about integration of some EDF library, but at this point I can't find it again.

Suggestion
I'd like to make a first, basic addition to integrate pyEDFlib for writing EDF+ files to disk. I'm using this library since some time and have good experience with it.

However I have a few questions regarding the approach:

• Would it be okay to use an external library for saving EDF instead of re-inventing the wheel?
• Where should I insert the code? I thought to extend BaseRaw with a function save_edf(), however it would also be possible to alter .save() to accept different file types
• in the basic version, this would save channels (and annotations?) only as raw as they are. I have no experience with all the Evoked, Epoched, etc. and if we could save them appropriately via EDF.

Alternatives
Write a native EDF-writer, which at this point I do not have the time for.

edit:
I've created a gist as requested here: https://gist.github.com/skjerns/bc660ef59dca0dbd53f00ed38c42f6be

[agramfort]

2 reactions: - @holgern @robertoostenveld (author of pyedf) and anyone interested in this should team up so there is one reference implementation of EDF files in Python - pyEDFlib has a dependency on cython so it's not an option to use this in mne. Packaging compiled code is too much work. I would support adding an entry in the MNE doc to document how to write edf+ files with mne. You could put a link to a gist you use.

[massich]

The entire EDF business needs some care. (see #5741)

[skjerns]

@agramfort I've created a gist, however, I doubt where exactly I should place it.. As an example? inside the IO docs? Inside an existing doc?

[agramfort]

yes I would add a link to the gist at the end of the edf section here https://github.com/mne-tools/mne-python/blob/master/doc/manual/io.rst#european-data-format-edf

[cbrnr]

Closing since this was fixed in #5777, but if a pure-Python solution emerges in the future, feel free to open a new issue.