Frame ===== A reference frame is a set of three orthonormal basis vectors which are rotated relative to the inertial frame, or some intermediate frame. **Keyword Arguments** :param str ref_point_key: Name of the point where the frame will be centered, for visualization in the diagram. :param str ref_frame_key: Name of the reference frame from which the relative orientation angles are measured. :param str rotation_sequence: Euler angle sequence, for example, 'ZYX' corresponds to a yaw-pitch-roll sequence, where the first_angle is a rotation about the Z-axis of the original reference frame, the second_angle is a rotation about the Y'-axis of an intermediate frame, and the third_angle is a rotation about the X''-axis of a second intermediate frame. :param first_angle: First rotation angle (i.e. yaw rotation in the 'ZYX' example). :type first_angle: str or numeric :param second_angle: Second rotation angle (i.e. pitch rotation in the 'ZYX' example). :type second_angle: str or numeric :param third_angle: Third rotation angle (i.e. roll rotation in the 'ZYX' example. :type third_angle: str or numeric :return str: Message about the created frame Message describing the created frame.