Equivalent Angle-Axis of Rotation

等效旋转轴

\[R = \left [ \begin{array}{} n_x & o_x & a_x & p_x \\ n_y & o_y & a_y & p_y \\ n_z & o_z & a_z & p_z \\ 0 & 0 & 0 & 1 \\ \end{array} \right ]\]