Internal function to get some demo EEG electrode coordinates. Will be removed from public API. Do not use this.
eeg_coords(label_subset = NULL)
data.frame with one row per electrode, and the following 3 columns: 'label': the electrode name, 'theta': the azimuth in degrees, 'phi': the latitude in degrees.
vector of character strings, electrode names like 'Nz' or 'RPA'. ÖLeave at the default value `NULL` to get all available ones.
See http://wiki.besa.de/index.php?title=Electrodes_and_Surface_Locations