BUG: incorrect freq bandwidth in FilterEstimator

@trachelr I’m not entirely sure but I think there is a problem with the transition bandwidths in your FilterEstimator.

Can you confirm or infirm that the low and high bandwidth are adequate? https://github.com/mne-tools/mne-python/blob/master/mne/decoding/transformer.py#L484

If not, I’ll mark the issue as a bug, but don’t worry about submitting a PR soon (although you may), we’re about to refactor all decoding transformers and estimators.

If it’s working as intended, well, my bad…

[jasmainak]

@kingjr maybe this could be combined with #3395 and fixed in a single PR

[kingjr]

@jasmainak We’ll do our best 😉 I think one possible solution would be to recognize the input type (epochs, 2D array, 3D array).

@Eric89GXL Ok, I’ll open an issue, but I have too many PRs to finish first.

Regarding the present issue, do you agree that the following lines seem weird:

if self.l_freq is None and self.h_freq is not None:
    epochs_data = \
        low_pass_filter(epochs_data, self.info['sfreq'], self.h_freq,
                        filter_length=self.filter_length,
                        trans_bandwidth=self.l_trans_bandwidth,  # XXX <=====
                        method=self.method, iir_params=self.iir_params,
                        picks=self.picks, n_jobs=self.n_jobs,
                        copy=False, verbose=False)

if self.l_freq is not None and self.h_freq is None:
    epochs_data = \
        high_pass_filter(epochs_data, self.info['sfreq'], self.l_freq,
                         filter_length=self.filter_length,
                         trans_bandwidth=self.h_trans_bandwidth, # XXX <=====
                         method=self.method,
                         iir_params=self.iir_params,
                         picks=self.picks, n_jobs=self.n_jobs,
                         copy=False, verbose=False)

if self.l_freq is not None and self.h_freq is not None:
    if self.l_freq < self.h_freq:
        epochs_data = \
            band_pass_filter(epochs_data, self.info['sfreq'],
                             self.l_freq, self.h_freq,
                             filter_length=self.filter_length,
                             l_trans_bandwidth=self.l_trans_bandwidth,  # XXX <=====
                             h_trans_bandwidth=self.h_trans_bandwidth,  # XXX <=====
                             method=self.method,
                             iir_params=self.iir_params,
                             picks=self.picks, n_jobs=self.n_jobs,
                             copy=False, verbose=False)