Example #1
0
def test_continuous_y():
    # for inference_method in ["lp", "ad3"]:
    for inference_method in ["lp"]:
        X, Y = toy.generate_blocks(n_samples=1)
        x, y = X[0], Y[0]
        w = np.array([1, 1, 0, -4, 0])

        crf = GridCRF(inference_method=inference_method)
        psi = crf.psi(x, y)
        y_cont = np.zeros_like(x)
        gx, gy = np.indices(x.shape[:-1])
        y_cont[gx, gy, y] = 1
        # need to generate edge marginals
        vert = np.dot(y_cont[1:, :, :].reshape(-1, 2).T, y_cont[:-1, :, :].reshape(-1, 2))
        # horizontal edges
        horz = np.dot(y_cont[:, 1:, :].reshape(-1, 2).T, y_cont[:, :-1, :].reshape(-1, 2))
        pw = vert + horz

        psi_cont = crf.psi(x, (y_cont, pw))
        assert_array_almost_equal(psi, psi_cont)

        const = find_constraint(crf, x, y, w, relaxed=False)
        const_cont = find_constraint(crf, x, y, w, relaxed=True)

        # dpsi and loss are equal:
        assert_array_almost_equal(const[1], const_cont[1])
        assert_almost_equal(const[2], const_cont[2])

        # returned y_hat is one-hot version of other
        assert_array_equal(const[0], np.argmax(const_cont[0][0], axis=-1))

        # test loss:
        assert_equal(crf.loss(y, const[0]), crf.continuous_loss(y, const_cont[0][0]))
Example #2
0
def test_loss_augmentation():
    X, Y = toy.generate_blocks(n_samples=1)
    x, y = X[0], Y[0]
    w = np.array([1.0, 1.0, 0.0, -4.0, 0.0])
    unary_params = w[:2]
    pairwise_flat = np.asarray(w[2:])
    pairwise_params = np.zeros((2, 2))
    pairwise_params[np.tri(2, dtype=np.bool)] = pairwise_flat
    pairwise_params = pairwise_params + pairwise_params.T - np.diag(np.diag(pairwise_params))
    crf = GridCRF()
    x_loss_augmented = crf.loss_augment(x, y, w)
    y_hat = crf.inference(x_loss_augmented, w)
    # test that loss_augmented_inference does the same
    y_hat_2 = crf.loss_augmented_inference(x, y, w)
    assert_array_equal(y_hat_2, y_hat)
    energy = compute_energy(x, y_hat, unary_params, pairwise_params)
    energy_loss_augmented = compute_energy(x_loss_augmented, y_hat, unary_params, pairwise_params)

    assert_almost_equal(energy + crf.loss(y, y_hat), energy_loss_augmented)

    # with zero in w:
    unary_params[1] = 0
    assert_raises(ValueError, crf.loss_augment, x, y, w)