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_dict_roc() -> None:
"""
Test if adding ROC entries to a MetricsDict instance works, and returns the correct AUC.
"""
# Prepare a vector of predictions and labels. We can compute AUC off those to compare.
# MetricsDict will get that supplied in 3 chunks, and should return the same AUC value.
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]
assert sum(split_length) == len(predictions)
summed = np.cumsum(split_length)
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(range(len(pred)))
m.add_predictions(subject_ids, pred, label)
assert m.has_prediction_entries
actual_auc = m.get_roc_auc()
expected_auc = roc_auc_score(labels, predictions)
assert actual_auc == pytest.approx(expected_auc, 1e-6)
actual_pr_auc = m.get_pr_auc()
expected_pr_auc = 0.7111111
assert actual_pr_auc == pytest.approx(expected_pr_auc, 1e-6)
def test_metrics_dict_roc_degenerate() -> None:
"""
Test if adding ROC entries to a MetricsDict instance works, if there is only 1 class present.
"""
# Prepare a vector of predictions and labels. We can compute AUC off those to compare.
# MetricsDict will get that supplied in 3 chunks, and should return the same AUC value.
predictions = np.array([0.5, 0.6, 0.1, 0.8, 0.2, 0.9])
m = MetricsDict()
subject_ids = list(range(len(predictions)))
m.add_predictions(subject_ids, predictions, np.ones_like(predictions))
assert m.has_prediction_entries
assert m.get_roc_auc() == 1.0
assert m.get_pr_auc() == 1.0
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(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)
