code: def _matrix3_to_dcm_array(self, m):
          
          assert(isinstance(m, Matrix3))
          return np.array([[m.a.x, m.a.y, m.a.z],
                           [m.b.x, m.b.y, m.b.z],
                           [m.c.x, m.c.y, m.c.z]])
docs: Converts Matrix3 in an array
          :param m: Matrix3
          :returns: 3x3 array