def test_view_of_view(matrix_type, subset_func, subset_func2):
    adata = gen_adata((30, 15), X_type=matrix_type)
    adata.raw = adata
    if subset_func is single_subset:
        pytest.xfail("Other subset generating functions have trouble with this")
    var_s1 = subset_func(adata.var_names, min_size=4)
    var_view1 = adata[:, var_s1]
    var_s2 = subset_func2(var_view1.var_names)
    var_view2 = var_view1[:, var_s2]
    assert var_view2._adata_ref is adata
    obs_s1 = subset_func(adata.obs_names, min_size=4)
    obs_view1 = adata[obs_s1, :]
    obs_s2 = subset_func2(obs_view1.obs_names)
    assert adata[obs_s1, :][:, var_s1][obs_s2, :]._adata_ref is adata

    view_of_actual_copy = adata[:, var_s1].copy()[obs_s1, :].copy()[:, var_s2].copy()

    view_of_view_copy = adata[:, var_s1][obs_s1, :][:, var_s2].copy()

    assert_equal(view_of_actual_copy, view_of_view_copy, exact=True)
def mcv_hbj(mcv, log=True, ax=0):
    """plot H, B, J of mcv dict"""
    import femagtools.mcv
    MUE0 = 4e-7*np.pi
    ji = []

    csiz = len(mcv['curve'])
    if ax == 0:
        ax = plt.gca()
    ax.set_title(mcv['name'])
    for k, c in enumerate(mcv['curve']):
        bh = [(bi, hi*1e-3)
              for bi, hi in zip(c['bi'],
                                c['hi'])]
        try:
            if csiz == 1 and mcv['ctype'] in (femagtools.mcv.MAGCRV,
                                              femagtools.mcv.ORIENT_CRV):
                ji = [b-MUE0*h*1e3 for b, h in bh]
        except Exception:
            pass
        bi, hi = zip(*bh)

        label = 'Flux Density'
        if csiz > 1:
            label = 'Flux Density ({0}°)'.format(mcv.mc1_angle[k])
        if log:
            ax.semilogx(hi, bi, label=label)
            if ji:
                ax.semilogx(hi, ji, label='Polarisation')
        else:
            ax.plot(hi, bi, label=label)
            if ji:
                ax.plot(hi, ji, label='Polarisation')
    ax.set_xlabel('H / kA/m')
    ax.set_ylabel('T')
    if ji or csiz > 1:
        ax.legend(loc='lower right')
    ax.grid()