Example #1
0
def test_model(num_classes):
    bounds = (0, 255)
    channels = num_classes

    def mean_brightness_net(images):
        logits = mx.symbol.mean(images, axis=(2, 3))
        return logits

    images = mx.symbol.Variable('images')
    logits = mean_brightness_net(images)

    model = MXNetModel(
        images,
        logits,
        {},
        ctx=mx.cpu(),
        num_classes=num_classes,
        bounds=bounds,
        channel_axis=1)

    test_images = np.random.rand(2, channels, 5, 5).astype(np.float32)
    test_label = 7

    # Tests
    assert model.batch_predictions(test_images).shape \
        == (2, num_classes)

    test_logits = model.predictions(test_images[0])
    assert test_logits.shape == (num_classes,)

    test_gradient = model.gradient(test_images[0], test_label)
    assert test_gradient.shape == test_images[0].shape

    np.testing.assert_almost_equal(
        model.predictions_and_gradient(test_images[0], test_label)[0],
        test_logits)
    np.testing.assert_almost_equal(
        model.predictions_and_gradient(test_images[0], test_label)[1],
        test_gradient)

    assert model.num_classes() == num_classes
Example #2
0
def test_model(num_classes):
    bounds = (0, 255)
    channels = num_classes

    def mean_brightness_net(images):
        logits = mx.symbol.mean(images, axis=(2, 3))
        return logits

    images = mx.symbol.Variable('images')
    logits = mean_brightness_net(images)

    model = MXNetModel(
        images,
        logits,
        {},
        device=mx.cpu(),
        num_classes=num_classes,
        bounds=bounds,
        channel_axis=1)

    test_images = np.random.rand(2, channels, 5, 5).astype(np.float32)
    test_label = 7

    # Tests
    assert model.batch_predictions(test_images).shape \
        == (2, num_classes)

    test_logits = model.predictions(test_images[0])
    assert test_logits.shape == (num_classes,)

    test_gradient = model.gradient(test_images[0], test_label)
    assert test_gradient.shape == test_images[0].shape

    np.testing.assert_almost_equal(
        model.predictions_and_gradient(test_images[0], test_label)[0],
        test_logits)
    np.testing.assert_almost_equal(
        model.predictions_and_gradient(test_images[0], test_label)[1],
        test_gradient)

    assert model.num_classes() == num_classes
Example #3
0
def test_model_gradient(num_classes):
    bounds = (0, 255)
    channels = num_classes

    def mean_brightness_net(images):
        logits = mx.symbol.mean(images, axis=(2, 3))
        return logits

    images = mx.symbol.Variable('images')
    logits = mean_brightness_net(images)

    preprocessing = (np.arange(num_classes)[:, None, None],
                     np.random.uniform(size=(channels, 5, 5)) + 1)

    model = MXNetModel(
        images,
        logits,
        {},
        ctx=mx.cpu(),
        num_classes=num_classes,
        bounds=bounds,
        preprocessing=preprocessing,
        channel_axis=1)

    test_images = np.random.rand(2, channels, 5, 5).astype(np.float32)
    test_image = test_images[0]
    test_label = 7

    epsilon = 1e-2
    _, g1 = model.predictions_and_gradient(test_image, test_label)
    l1 = model._loss_fn(test_image - epsilon / 2 * g1, test_label)
    l2 = model._loss_fn(test_image + epsilon / 2 * g1, test_label)

    assert 1e4 * (l2 - l1) > 1

    # make sure that gradient is numerically correct
    np.testing.assert_array_almost_equal(
        1e4 * (l2 - l1),
        1e4 * epsilon * np.linalg.norm(g1)**2,
        decimal=1)
Example #4
0
def test_model_gradient(num_classes):
    bounds = (0, 255)
    channels = num_classes

    def mean_brightness_net(images):
        logits = mx.symbol.mean(images, axis=(2, 3))
        return logits

    images = mx.symbol.Variable('images')
    logits = mean_brightness_net(images)

    preprocessing = (np.arange(num_classes)[:, None, None],
                     np.random.uniform(size=(channels, 5, 5)) + 1)

    model = MXNetModel(images,
                       logits, {},
                       ctx=mx.cpu(),
                       num_classes=num_classes,
                       bounds=bounds,
                       preprocessing=preprocessing,
                       channel_axis=1)

    test_images = np.random.rand(2, channels, 5, 5).astype(np.float32)
    test_image = test_images[0]
    test_label = 7

    epsilon = 1e-2
    _, g1 = model.predictions_and_gradient(test_image, test_label)
    l1 = model._loss_fn(test_image - epsilon / 2 * g1, test_label)
    l2 = model._loss_fn(test_image + epsilon / 2 * g1, test_label)

    assert 1e4 * (l2 - l1) > 1

    # make sure that gradient is numerically correct
    np.testing.assert_array_almost_equal(1e4 * (l2 - l1),
                                         1e4 * epsilon * np.linalg.norm(g1)**2,
                                         decimal=1)