ffrprep.preproc.make_difference_evokeds

ffrprep.preproc.make_difference_evokeds(evoked_dict, pairs=None)[source]

Compute A - B Evokeds for one or more trial-type pairs.

Parameters:

  • evoked_dict (dict[str, mne.Evoked]) – Per-trial-type Evoked outputs, typically the dict returned by make_evoked(epochs, by_event_type=True).

  • pairs (list[tuple[str, str]] | None) – Pairs to subtract. When None, the single (A, B) pair is auto-built from insertion order if and only if the dict has exactly two entries; otherwise an empty dict is returned and the caller is expected to opt in explicitly via pairs.

Returns:

diffs – Tuple-keyed dict. Each Evoked has .comment = "diff_{A}Vs{B}" so reports can label by pair.

Return type:

dict[tuple[str, str], mne.Evoked]

Raises:

KeyError – If any requested pair references a trial type missing from evoked_dict.