Iāve observed a strange behaviour (not sure if a bug) when saving Raw files, and a split is required. This only happens with the BIDS split naming version and if the BIDS naming convention is not followed, so thatās why it may be the expected behaviour.
Is this the expected behaviour or is it a bug?
The easier workaround is to use the neuromag naming convention but the BIDS one fits better some additional funtions that I have developed
The file name doesnāt conform to BIDS. By the spec, the last bit represents the modality; thatās why the split modality goes before that.
I have to say Iām not sure why MNE supports something called āBIDS split namingā if it doesnāt check whether the filename is even BIDS-compatible in the first place ā¦ this probably should not be part of the public API at all.
I think we added the BIDS split naming back then to make something possible in mne-bids. I donāt remember why we made it part of the public API, instead of another route.
Now that itās in the public API itās probably worth keeping there. Especially since people could potentially have legitimate use cases where they want to write their own BIDS-filename-formatted data, or even donāt care about the BIDS-ness but prefer how the BIDS option operates. To me we should just update the docs to say what the option will actually do, and note that itās there primarily for compat with MNE-BIDS. I donāt think we should check BIDS path validity in MNE-Python.