quaternion.py 文件源码

def _get_angle_axis(self):
        lim = 1e-12
        norm = np.linalg.norm(self.q)
        if norm < lim:
            angle = 0
            axis = [0, 0, 0]
        else:
            rnorm = 1.0 / norm
            angle = acos(max(-1, min(1, rnorm * self.q[3])));
            sangle = sin(angle)
            if sangle < lim:
                axis = [0, 0, 0]
            else:
                axis = (rnorm / sangle) * np.array(self.q[0:3])

            angle *= 2

        return (angle, axis)