def test_classification_metrics_avg() -> None:
hue1 = "H1"
hue2 = "H2"
m = MetricsDict(hues=[hue1, hue2], is_classification_metrics=True)
m.add_metric("foo", 1.0)
m.add_metric("foo", 2.0)
# Perfect predictions for hue1, should give AUC == 1.0
m.add_predictions(["S1", "S2"],
np.array([0.0, 1.0]),
np.array([0.0, 1.0]),
hue=hue1)
expected_hue1_auc = 1.0
# Worst possible predictions for hue2, should give AUC == 0.0
m.add_predictions(["S1", "S2"],
np.array([1.0, 0.0]),
np.array([0.0, 1.0]),
hue=hue2)
expected_hue2_auc = 0.0
averaged = m.average(across_hues=False)
g1_averaged = averaged.values(hue=hue1)
assert MetricType.AREA_UNDER_ROC_CURVE.value in g1_averaged
assert g1_averaged[MetricType.AREA_UNDER_ROC_CURVE.value] == [
expected_hue1_auc
]
assert MetricType.AREA_UNDER_PR_CURVE.value in g1_averaged
assert MetricType.SUBJECT_COUNT.value in g1_averaged
assert g1_averaged[MetricType.SUBJECT_COUNT.value] == [2.0]
default_averaged = averaged.values()
assert default_averaged == {"foo": [1.5]}
can_enumerate = list(averaged.enumerate_single_values())
assert len(can_enumerate) >= 8
assert can_enumerate[0] == (hue1, MetricType.AREA_UNDER_ROC_CURVE.value,
1.0)
assert can_enumerate[-1] == (MetricsDict.DEFAULT_HUE_KEY, "foo", 1.5)
g2_averaged = averaged.values(hue=hue2)
assert MetricType.AREA_UNDER_ROC_CURVE.value in g2_averaged
assert g2_averaged[MetricType.AREA_UNDER_ROC_CURVE.value] == [
expected_hue2_auc
]
averaged_across_hues = m.average(across_hues=True)
assert averaged_across_hues.get_hue_names() == [
MetricsDict.DEFAULT_HUE_KEY
]
assert MetricType.AREA_UNDER_ROC_CURVE.value in averaged_across_hues.values(
)
expected_averaged_auc = 0.5 * (expected_hue1_auc + expected_hue2_auc)
assert averaged_across_hues.values()[
MetricType.AREA_UNDER_ROC_CURVE.value] == [expected_averaged_auc]
def test_metrics_dict1() -> None:
"""
Test insertion of scalar values into a MetricsDict.
"""
m = MetricsDict()
assert m.get_hue_names() == [MetricsDict.DEFAULT_HUE_KEY]
name = "foo"
v1 = 2.7
v2 = 3.14
m.add_metric(name, v1)
m.add_metric(name, v2)
assert m.values()[name] == [v1, v2]
with pytest.raises(ValueError) as ex:
# noinspection PyTypeChecker
m.add_metric(name, [1.0]) # type: ignore
assert "Expected the metric to be a scalar" in str(ex)
assert m.skip_nan_when_averaging[name] is False
v3 = 3.0
name2 = "bar"
m.add_metric(name2, v3, skip_nan_when_averaging=True)
assert m.skip_nan_when_averaging[name2] is True
# Expected average: Metric "foo" averages over two values v1 and v2. For "bar", we only inserted one value anyhow
average = m.average()
mean_v1_v2 = mean([v1, v2])
assert average.values() == {name: [mean_v1_v2], name2: [v3]}
num_entries = m.num_entries()
assert num_entries == {name: 2, name2: 1}
def test_metrics_dict_flatten(hues: Optional[List[str]]) -> None:
m = MetricsDict(hues=hues)
_hues = hues or [MetricsDict.DEFAULT_HUE_KEY] * 2
m.add_metric("foo", 1.0, hue=_hues[0])
m.add_metric("foo", 2.0, hue=_hues[1])
m.add_metric("bar", 3.0, hue=_hues[0])
m.add_metric("bar", 4.0, hue=_hues[1])
if hues is None:
average = m.average(across_hues=True)
# We should be able to flatten out all the singleton values that the `average` operation returns
all_values = list(average.enumerate_single_values())
assert all_values == [(MetricsDict.DEFAULT_HUE_KEY, "foo", 1.5),
(MetricsDict.DEFAULT_HUE_KEY, "bar", 3.5)]
# When trying to flatten off a dictionary that has two values, this should fail:
with pytest.raises(ValueError) as ex:
list(m.enumerate_single_values())
assert "only hold 1 item" in str(ex)
else:
average = m.average(across_hues=False)
all_values = list(average.enumerate_single_values())
assert all_values == [('A', 'foo', 1.0), ('A', 'bar', 3.0),
('B', 'foo', 2.0), ('B', 'bar', 4.0)]
def test_metrics_dict_average_metrics_averaging() -> None:
"""
Test if averaging metrics avoid NaN as expected.
"""
m = MetricsDict()
metric1 = "foo"
v1 = 1.0
m.add_metric(metric1, v1)
m.add_metric(metric1, np.nan, skip_nan_when_averaging=True)
metric2 = "bar"
v2 = 2.0
m.add_metric(metric2, v2)
m.add_metric(metric2, np.nan, skip_nan_when_averaging=False)
average = m.average()
assert average.values()[metric1] == [v1]
assert np.isnan(average.values()[metric2])
def test_metrics_dict_average_additional_metrics() -> None:
"""
Test if computing the ROC entries and metrics at optimal threshold with MetricsDict.average() works
as expected and returns the correct values.
"""
# Prepare a vector of predictions and labels.
predictions = np.array([0.5, 0.6, 0.1, 0.8, 0.2, 0.9])
labels = np.array([0, 1.0, 0, 0, 1, 1], dtype=np.float)
split_length = [3, 2, 1]
# Get MetricsDict
assert sum(split_length) == len(predictions)
summed = np.cumsum(split_length)
# MetricsDict will get that supplied in 3 chunks.
m = MetricsDict()
for i, end in enumerate(summed):
start = 0 if i == 0 else summed[i - 1]
pred = predictions[start:end]
label = labels[start:end]
subject_ids = list(map(str, range(len(pred))))
m.add_predictions(subject_ids, pred, label)
assert m.has_prediction_entries
# Compute average MetricsDict
averaged = m.average()
# Compute additional expected metrics for the averaged MetricsDict
expected_auc = roc_auc_score(labels, predictions)
expected_fpr, expected_tpr, thresholds = roc_curve(labels, predictions)
expected_optimal_idx = np.argmax(expected_tpr - expected_fpr)
expected_optimal_threshold = float(thresholds[expected_optimal_idx])
expected_accuracy = np.mean(
(predictions > expected_optimal_threshold) == labels)
# Check computed values against expected
assert averaged.values()[MetricType.OPTIMAL_THRESHOLD.value][
0] == pytest.approx(expected_optimal_threshold)
assert averaged.values()[MetricType.ACCURACY_AT_OPTIMAL_THRESHOLD.
value][0] == pytest.approx(expected_accuracy)
assert averaged.values()[MetricType.FALSE_POSITIVE_RATE_AT_OPTIMAL_THRESHOLD.value][0] == \
pytest.approx(expected_fpr[expected_optimal_idx])
assert averaged.values()[MetricType.FALSE_NEGATIVE_RATE_AT_OPTIMAL_THRESHOLD.value][0] == \
pytest.approx(1 - expected_tpr[expected_optimal_idx])
assert averaged.values()[
MetricType.AREA_UNDER_ROC_CURVE.value][0] == pytest.approx(
expected_auc, 1e-6)
