Example #1
0
def test_integration_median_absolute_error_with_output_transform():

    np.random.seed(1)
    size = 105
    np_y_pred = np.random.rand(size, 1)
    np_y = np.random.rand(size, 1)
    np.random.shuffle(np_y)
    np_median_absolute_error = np.median(np.abs(np_y - np_y_pred))

    batch_size = 15

    def update_fn(engine, batch):
        idx = (engine.state.iteration - 1) * batch_size
        y_true_batch = np_y[idx : idx + batch_size]
        y_pred_batch = np_y_pred[idx : idx + batch_size]
        return idx, torch.from_numpy(y_pred_batch), torch.from_numpy(y_true_batch)

    engine = Engine(update_fn)

    m = MedianAbsoluteError(output_transform=lambda x: (x[1], x[2]))
    m.attach(engine, "median_absolute_error")

    data = list(range(size // batch_size))
    median_absolute_error = engine.run(data, max_epochs=1).metrics[
        "median_absolute_error"
    ]

    assert np_median_absolute_error == pytest.approx(median_absolute_error)
    def _test(n_epochs, metric_device):
        metric_device = torch.device(metric_device)
        n_iters = 80
        size = 105
        y_true = torch.rand(size=(size, )).to(device)
        y_preds = torch.rand(size=(size, )).to(device)

        def update(engine, i):
            return (
                y_preds[i * size:(i + 1) * size],
                y_true[i * size:(i + 1) * size],
            )

        engine = Engine(update)

        m = MedianAbsoluteError(device=metric_device)
        m.attach(engine, "mae")

        data = list(range(n_iters))
        engine.run(data=data, max_epochs=n_epochs)

        assert "mae" in engine.state.metrics

        res = engine.state.metrics["mae"]

        np_y_true = y_true.cpu().numpy().ravel()
        np_y_preds = y_preds.cpu().numpy().ravel()

        e = np.abs(np_y_true - np_y_preds)
        np_res = np.median(e)

        assert pytest.approx(res) == np_res