def idq_torque(id, iq, torque, ax=0):
    """creates a surface plot of torque vs id, iq"""
    if ax == 0:
        _create_3d_axis()
        ax = plt.gca()
    unit = 'Nm'
    scale = 1
    if np.min(torque) < -9.9e3 or np.max(torque) > 9.9e3:
        scale = 1e-3
        unit = 'kNm'
    _plot_surface(ax, id, iq, scale*np.asarray(torque),
                  (u'Id/A', u'Iq/A', u'Torque/{}'.format(unit)),
                  azim=-60)
    return ax