Error trying filter and plot data using EMG data

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1
  • mne==0.20.8
  • operating system: Linux Mint (using Jupyter notebook)

I need a help about an error just i run epoch.filter(l_freq=20., h_freq=450.)
Error: ValueError: picks (NoneNone, treated as "data_or_ica") yielded no channels, consider passing picks explicitly

That error happen when I use epoch.plot_psd too…
I am working with sEMG data… Anyone known what is it?

A complete error is follow:

obj_filtered = epoch.filter(l_freq=20., h_freq=450.)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-29-b3662d60ef07> in <module>
----> 1 obj_filtered = epoch.filter(l_freq=20., h_freq=450.)

<decorator-gen-111> in filter(self, l_freq, h_freq, picks, filter_length, l_trans_bandwidth, h_trans_bandwidth, n_jobs, method, iir_params, phase, fir_window, fir_design, skip_by_annotation, pad, verbose)

~/repo/lib/python3.8/site-packages/mne/filter.py in filter(self, l_freq, h_freq, picks, filter_length, l_trans_bandwidth, h_trans_bandwidth, n_jobs, method, iir_params, phase, fir_window, fir_design, skip_by_annotation, pad, verbose)
   1923         if pad is None and method != 'iir':
   1924             pad = 'edge'
-> 1925         update_info, picks = _filt_check_picks(self.info, picks,
   1926                                                l_freq, h_freq)
   1927         if isinstance(self, BaseRaw):

~/repo/lib/python3.8/site-packages/mne/filter.py in _filt_check_picks(info, picks, h_freq, l_freq)
   2232     update_info = False
   2233     # This will pick *all* data channels
-> 2234     picks = _picks_to_idx(info, picks, 'data_or_ica', exclude=())
   2235     if h_freq is not None or l_freq is not None:
   2236         data_picks = _picks_to_idx(info, None, 'data_or_ica', exclude=(),

~/repo/lib/python3.8/site-packages/mne/io/pick.py in _picks_to_idx(info, picks, none, exclude, allow_empty, with_ref_meg, return_kind)
    982         raise ValueError('picks must be 1D, got %sD' % (picks.ndim,))
    983     if picks.dtype.char in ('S', 'U'):
--> 984         picks = _picks_str_to_idx(info, picks, exclude, with_ref_meg,
    985                                   return_kind, extra_repr, allow_empty,
    986                                   orig_picks)

~/repo/lib/python3.8/site-packages/mne/io/pick.py in _picks_str_to_idx(info, picks, exclude, with_ref_meg, return_kind, extra_repr, allow_empty, orig_picks)
   1038             if len(picks_generic) == 0 and orig_picks is None and \
   1039                     not allow_empty:
-> 1040                 raise ValueError('picks (%s) yielded no channels, consider '
   1041                                  'passing picks explicitly'
   1042                                  % (repr(orig_picks) + extra_repr,))

ValueError: picks (NoneNone, treated as "data_or_ica") yielded no channels, consider passing picks explicitly
2

Hello, would it be possible for you to update to the latest stable version of MNE and see if the problem still occurs there?

Thanks!

Richard

3

Hello!

I updated to latest version (mne-0.22.1) and the problem continues…
I noticed that set the object info with eeg in ch_types parameter, the problem is solved. But I don’t know if eeg would change something about the signal internally …

it works => info = mne.create_info(ch_names=('1', '2'), sfreq=4000, ch_types='eeg')

1 Like
4

The underlying problem here is that filtering by default only works with “data channels”, i.e. channels that typically contain brain activity. EMG is no data channel.

I think what should work is passing picks='emg' to filter() in order to enforce operation on the emg channel type. Can you give it a shot? :slight_smile:

1 Like
5

Yes, it works now!
In last version, passing the argument picks='emg' showed another error… Something like “data channel not found”.
Thank you!

2 Likes
6

Yep, that’s a bug report I found on GitHub and figured it had been fixed in the meantime. Therefore I was asking you to update MNE :slight_smile: Great to hear it’s working for you now!! Have a good day!

2 Likes
8

yep it worked for me to, thanks