def METHOD_NAME(q1, q2):
    r"""Compute the rotation in angle-axis format that rotates q2 into q1.
    .. math::
        \omega = 2 \log (q_1 * \overline{q_2})
    Parameters
    ----------
    q1 : array-like, shape (4,)
        First quaternion
    q2 : array-line, shape (4,)
        Second quaternion
    Returns
    -------
    a : array-like, shape (4,)
        The rotation in angle-axis format that rotates q2 into q1
    """
    q1 = check_quaternion(q1)
    q2 = check_quaternion(q2)
    q1q2c = concatenate_quaternions(q1, q_conj(q2))
    return axis_angle_from_quaternion(q1q2c)