must be a 2x2 symmetric matrix. outlet 0: angle (only makes sense with a 2x2 matrix) as int outlet 1: radiuses (from biggest to smallest) as float grid inlet 0: variance matrix (aka covariance matrix), from [#moment 2] or compatible. needs OpenCV finds the angle and radiuses associated with a variance matrix (aka covariance matrix). those matrices are output by [#moment 2] and by [#labelling 0].