def test_view_setattr_machinery(attr, subset_func, subset_func2):
    # Tests that setting attributes on a view doesn't mess anything up too bad
    adata = gen_adata((10, 10))
    view = adata[subset_func(adata.obs_names), subset_func2(adata.var_names)]

    actual = view.copy()
    setattr(view, attr, getattr(actual, attr))
    assert_equal(actual, view, exact=True)
def voltage_fft(title, order, voltage, ax=0):
    """plot FFT harmonics of voltage"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('{} / V'.format(title))
    ax.grid(True)
    if max(order) < 5:
        order += [5]
        voltage += [0]
    try:
        bw = 2.5E-2*max(order)
        ax.bar(order, voltage, width=bw, align='center')
    except ValueError:  # empty sequence
        pass