plot_show_read_apply_custom_montage.py

# Authors: Denis Engemann <denis.engemann@gmail.com>
#          Lakshmi Krishnan <lakshmik@umd.edu>
# License: BSD (3-clause)

import mne
import numpy as np
from scipy import io

# x,y convention is inverted in Mat file
mat = io.loadmat('electrode_loc/chanlocs.mat',chars_as_strings=1)
ch_info = mat['chanlocs']

# stupid type problem on reading mat file + reorder dims
pos = np.array([np.array([float(f) for f in ch_info[k][0]]) for k in
               ('Y', 'X', 'Z')]).T
pos[:, 0] *= -1  # flip

# assemble info
ch_names = ch_info['labels'][0]
ch_names = [str(x[0][:]) for x in ch_names]
ch_types = ['eeg'] * len(ch_names)
info = mne.create_info(ch_names=ch_names, ch_types=ch_types, sfreq=1000)

# ceate random data and put in Evoked
rng = np.random.RandomState(seed=42)
data = rng.randn(64)[:, None]
evoked = mne.EvokedArray(data=data, info=info, tmin=0)   

# create custom montage
from mne.montages.montage import Montage
montage = Montage(pos=pos, ch_names=ch_names, kind='custom-montage',
                  selection=np.arange(64))

# apply to evked
mne.montages.apply_montage(evoked.info, montage)

# plot
evoked.plot_topomap(ch_type='eeg', times=[0], size=5, show_names=True, scale=1,
                    unit='Arb.Un.', contours=0)