test_ranking.py 文件源码

def test_score_scale_invariance():
    # Test that average_precision_score and roc_auc_score are invariant by
    # the scaling or shifting of probabilities
    y_true, _, probas_pred = make_prediction(binary=True)

    roc_auc = roc_auc_score(y_true, probas_pred)
    roc_auc_scaled = roc_auc_score(y_true, 100 * probas_pred)
    roc_auc_shifted = roc_auc_score(y_true, probas_pred - 10)
    assert_equal(roc_auc, roc_auc_scaled)
    assert_equal(roc_auc, roc_auc_shifted)

    pr_auc = average_precision_score(y_true, probas_pred)
    pr_auc_scaled = average_precision_score(y_true, 100 * probas_pred)
    pr_auc_shifted = average_precision_score(y_true, probas_pred - 10)
    assert_equal(pr_auc, pr_auc_scaled)
    assert_equal(pr_auc, pr_auc_shifted)