Error in mne.viz.plot_topomap()?

💬 Support & Discussions
1

The plot_topomap() function is not working for me in that the head/ear/nose contour is not showing up… or perhaps it is but it is really small in the very middle of the image (black dot)?

image

raw = mne.io.read_raw_eeglab('185_channel_data.set')

mne.viz.plot_topomap(np.array(range(185)), 
                     pos=raw.info, 
                     )

print(raw.info['chs'])

One output from raw.info.chs:

{‘loc’: array([ 6.2257 , 5.96982, -1.0809 , 0. , 0. , 0. ,
nan, nan, nan, nan, nan, nan]), ‘unit_mul’: 0 (FIFF_UNITM_NONE), ‘range’: 1.0, ‘cal’: 1e-06, ‘kind’: 2 (FIFFV_EEG_CH), ‘coil_type’: 1 (FIFFV_COIL_EEG), ‘unit’: 107 (FIFF_UNIT_V), ‘coord_frame’: 4 (FIFFV_COORD_HEAD), ‘ch_name’: ‘1’, ‘scanno’: 1, ‘logno’: 1}

  • MNE-Python version: 0.23.0
  • operating system: NAME=“Ubuntu”/VERSION=“20.04.2 LTS (Focal Fossa)”
2

6.2257 , 5.96982, -1.0809

is interpreted in meters so it’s too big for a head

Alex

3

OK, thanks @agramfort

4

I have the same issue. How exactly did you solve it?

5

You need to set a DigMontage with DigPoint in the correct unit/scale.
Have a look through the documentation and through this tutorial: Working with sensor locations — MNE 1.5.0 documentation

Mathieu

1 Like