def test_view_of_view_modification():
    adata = ad.AnnData(np.zeros((10, 10)))
    adata[0, :][:, 5:].X = np.ones(5)
    assert np.all(adata.X[0, 5:] == np.ones(5))
    adata[[1, 2], :][:, [1, 2]].X = np.ones((2, 2))
    assert np.all(adata.X[1:3, 1:3] == np.ones((2, 2)))

    adata.X = sparse.csr_matrix(adata.X)
    adata[0, :][:, 5:].X = np.ones(5) * 2
    assert np.all(asarray(adata.X)[0, 5:] == np.ones(5) * 2)
    adata[[1, 2], :][:, [1, 2]].X = np.ones((2, 2)) * 2
    assert np.all(asarray(adata.X)[1:3, 1:3] == np.ones((2, 2)) * 2)
def forcedens(title, pos, fdens, ax=0):
    """plot force densities"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title(title)
    ax.grid(True)

    ax.plot(pos, [1e-3*ft for ft in fdens[0]], label='F tang')
    ax.plot(pos, [1e-3*fn for fn in fdens[1]], label='F norm')
    ax.legend()
    ax.set_xlabel('Pos / deg')
    ax.set_ylabel('Force Density / kN/m²')