Hi all,
I am trying to get the channel locations right in the EEGLAB by manually entering the values I got from the Biosemi website. We have a 64-channel set-up. Now, the Biosemi file lists θ (Inclination), φ (Azimuth), X/Y/Z in the Cartesian coordinates, and sph_theta and sph_phi in the geographic coordinates. The EEGLAB also requires polar radius and spherical radius. We did not record the circumference of the head of each subject (we used it for choosing the appropriate cap, but we didn't know we were supposed to write it down and keep for the analysis). Is there anything we can do at this point or are we absolutely required to know each subject's head radius? I feel very dumb.