rotated_oripref_stats
ROTATED_ORIPREF_STATS - compute mean and dispersion of a set of orientation angle preferences with respect to a reference angle
[MEANANGLE,DISPERSION] = ROTATED_ORIPREF_STATS(ORI_PREF, REFERENCE_ANGLE)
Given a vector of ORI_PREF values (can be in 0..360 but will be converted to 0..180 with MOD)
and a REFERENCE_ANGLE that defines '0' (can be in 0..360 but will be converted to 0..180 with MOD)
returns the mean angle MEANANGLE and the DISPERSION, calculated as the circular variance (CIRC_VAR).