Interest in filtering for RtEpochs?

[hekolk]

For online experiments, I added causal filtering to RtEpochs (using lfilter in _process_raw_buffer), which circumvents the need for filtering on the segmented data (and needing longer epochs or risking edge artifacts).

Is there interest to include this in MNE? Then I would tidy up the code and create a PR.
Current limitation of my code is that filter delay is not compensated/events are not shifted, so users should use minimal-phase or IIR filters.

[larsoner]

There is already epochs.filter with a phase argument for this

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[agramfort]

sure I think it's a very useful and common feature +1

[jasmainak]

cc @dmalt you might be interested in reviewing the code

[dmalt]

Thanks!