def test_zero_sample():
m = MedianAbsolutePercentageError()
with pytest.raises(
NotComputableError,
match=
r"EpochMetric must have at least one example before it can be computed"
):
m.compute()
def _test(metric_device):
metric_device = torch.device(metric_device)
m = MedianAbsolutePercentageError(device=metric_device)
torch.manual_seed(10 + rank)
size = 105
y_pred = torch.randint(1, 10, size=(size, 1), dtype=torch.double, device=device)
y = torch.randint(1, 10, size=(size, 1), dtype=torch.double, device=device)
m.update((y_pred, y))
# gather y_pred, y
y_pred = idist.all_gather(y_pred)
y = idist.all_gather(y)
np_y_pred = y_pred.cpu().numpy().ravel()
np_y = y.cpu().numpy().ravel()
res = m.compute()
e = np.abs(np_y - np_y_pred) / np.abs(np_y)
# The results between numpy.median() and torch.median() are Inconsistant
# when the length of the array/tensor is even. So this is a hack to avoid that.
# issue: https://github.com/pytorch/pytorch/issues/1837
if np_y_pred.shape[0] % 2 == 0:
e_prepend = np.insert(e, 0, e[0], axis=0)
np_res_prepend = 100.0 * np.median(e_prepend)
assert pytest.approx(res) == np_res_prepend
else:
np_res = 100.0 * np.median(e)
assert pytest.approx(res) == np_res
def test_median_absolute_percentage_error():
# See https://github.com/torch/torch7/pull/182
# For even number of elements, PyTorch returns middle element
# NumPy returns average of middle elements
# Size of dataset will be odd for these tests
size = 51
np_y_pred = np.random.rand(size,)
np_y = np.random.rand(size,)
np_median_absolute_percentage_error = 100.0 * np.median(np.abs(np_y - np_y_pred) / np.abs(np_y))
m = MedianAbsolutePercentageError()
y_pred = torch.from_numpy(np_y_pred)
y = torch.from_numpy(np_y)
m.reset()
m.update((y_pred, y))
assert np_median_absolute_percentage_error == pytest.approx(m.compute())
def test_median_absolute_percentage_error_2():
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_percentage_error = 100.0 * np.median(np.abs(np_y - np_y_pred) / np.abs(np_y))
m = MedianAbsolutePercentageError()
y_pred = torch.from_numpy(np_y_pred)
y = torch.from_numpy(np_y)
m.reset()
batch_size = 16
n_iters = size // batch_size + 1
for i in range(n_iters):
idx = i * batch_size
m.update((y_pred[idx : idx + batch_size], y[idx : idx + batch_size]))
assert np_median_absolute_percentage_error == pytest.approx(m.compute())
