def torque(pos, torque, ax=0):
    """creates plot from torque vs position"""
    k = 20
    alpha = np.linspace(pos[0], pos[-1],
                        k*len(torque))
    f = ip.interp1d(pos, torque, kind='quadratic')
    unit = 'Nm'
    scale = 1
    if np.min(torque) < -9.9e3 or np.max(torque) > 9.9e3:
        scale = 1e-3
        unit = 'kNm'
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Torque / {}'.format(unit))
    ax.grid(True)
    ax.plot(pos, [scale*t for t in torque], 'go')
    ax.plot(alpha, scale*f(alpha))
    if np.min(torque) > 0 and np.max(torque) > 0:
        ax.set_ylim(bottom=0)
    elif np.min(torque) < 0 and np.max(torque) < 0:
        ax.set_ylim(top=0)