cfg.output = trial, cov cfg.keeptrials = yes, no

timelock.avgtrial = Nchan X Ntime timelock.avgcov = Nchan X Nchan timelock.trial = Nrpt X Nchan X Ntime timelock.cov = Nrpt X Nchan X Nchan

compute average over the single-trial covariance compute the covariance of the average