def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def i1beta_torque(i1, beta, torque, title='', ax=0):
    """creates a surface plot of torque vs i1, beta"""
    if ax == 0:
        _create_3d_axis()
        ax = plt.gca()
    azim = 210
    if 0 < np.mean(beta) or -90 > np.mean(beta):
        azim = -60
    unit = 'Nm'
    scale = 1
    if np.min(torque) < -9.9e3 or np.max(torque) > 9.9e3:
        scale = 1e-3
        unit = 'kNm'
    if title:
        _plot_surface(ax, i1, beta, scale*np.asarray(torque),
                      (u'I1/A', u'Beta/°', title),
                      azim=azim)
    else:
        _plot_surface(ax, i1, beta, scale*np.asarray(torque),
                      (u'I1/A', u'Beta/°', u'Torque/{}'.format(unit)),
                      azim=azim)