@brief Set the AMotor axes.
@param anum selects the axis to change (0,1 or 2).
@param rel Each axis can have one of three `relative orientation'' modes
\li 0: The axis is anchored to the global frame.
\li 1: The axis is anchored to the first body.
\li 2: The axis is anchored to the second body.
@remarks The axis vector is always specified in global coordinates
regardless of the setting of rel.
@ingroup joints
@brief Set the AMotor axes. @param anum selects the axis to change (0,1 or 2). @param rel Each axis can have one of three `relative orientation'' modes \li 0: The axis is anchored to the global frame. \li 1: The axis is anchored to the first body. \li 2: The axis is anchored to the second body. @remarks The axis vector is always specified in global coordinates regardless of the setting of rel. @ingroup joints