title: Reading channel locations in MNE Python
body: <p>I am new to MNE Python and I am working with .set files from EEGlab(Matlab) for source estimation analysis. The data were recorded from 66 channels (64 EEG and 2 EOG) from EasyCaps, with 10-20 IS. In Matlab, the EEG.chanlocs correctly shows the coordinates of each electrode (labels, type, theta, radius, X, Y, Z, sph_theta, sph_phi, sph_radius, urchin, ref). But it seems that I cannot read these locations in MNE Python.</p>
  
  <pre><code>import mne
  
  #The .set files are imported ok
  data_path = r"D:\EEGdata";
  fname = data_path + '\ppt10.set'
  mydata = mne.io.read_epochs_eeglab(fname)
  
  #The data look ok, and channel labels are correctly displayed
  mydata
  mydata.plot()
  mydata.ch_names
  
  #But the channel locations are not found
  mydata.plot_sensors()     #RuntimeError: No valid channel positions found
  </code></pre>
  
  <p>Any suggestion on how to read the channel locations from the .set files? Or alternatively, how to manually create the locations based on the coordinates from EEG.chanlocs?</p>
  
  <p>I have also tried to use the default montage 10-20, selecting only the channels I used, but I cannot make it work.</p>
  
  <pre><code>#Create a montage based on the standard 1020, which includes 94 electrode labels in upper case
  montage = mne.channels.make_standard_montage('standard_1020')
  [ch_name.upper() for ch_name in mydata.ch_names] #it correctly convert the channel labels into upper case
  mydata.ch_names = [ch_name.upper() for ch_name in mydata.ch_names] #doesn't work
  #File "&lt;ipython-input-62-69a7053dc310&gt;", line 1, in &lt;module&gt;
  #mydata.ch_names=[ch_name.upper() for ch_name in mydata.ch_names]
  #AttributeError: can't set attribute
  
  montage = mne.channels.make_standard_montage('standard_1020',mydata.ch_names]
  </code></pre>
  
  <p>I also thought I could use a conversion tool to convert the .set files into .fif files. I have checked the online documentation, but I cannot find such tool. Any idea?</p>