[Python] Correctly invoke TorchEval AUC calculation for two tensors

Discussão em 'Python' iniciado por Stack, Março 14, 2025.

  1. Stack

    Stack Membro Participativo

    I am new to torcheval and trying to measure the AUC of my binary classifier (doc).

    I notice that while classifier accuracy is decent, the AUC metric evaluates to below 0.5, which is incorrect (given that accuracy is better than 50/50 and my classes are balanced). The AUC also differs from sklearn.metrics.roc_auc_score. For a simple example:

    from torcheval.metrics.aggregation.auc import AUC
    from torcheval.metrics import BinaryAccuracy

    from sklearn.metrics import roc_auc_score, accuracy_score

    p_pred = torch.tensor([0.2, 0.3, 0.4, 0.6, 0.7, 0.8]) # model est likelihood of target class
    y_true = torch.tensor([0.0, 0.0, 1.0, 0.0, 1.0, 1.0]) # ground truth, 1 = target class

    # TorchEval Metrics
    auc_metric = AUC()
    accuracy_metric = BinaryAccuracy(threshold=0.5)
    auc_metric.reset()
    accuracy_metric.reset()
    auc_metric.update(p_pred,y_true)
    accuracy_metric.update(input=p_pred,target=y_true)

    print(f"TorchEval Accuracy = {accuracy_metric.compute().item():.3}")
    print(f"Sklearn Accuracy = {accuracy_score(y_true=y_true,y_pred=p_pred.round()):.3}")
    print(f"TorchEval AUC = {auc_metric.compute().item():.3}")
    print(f"Sklearn AUC = {roc_auc_score(y_true=y_true,y_score=p_pred):.3}")


    Return an unexpected value of TorchEval AUC:

    TorchEval Accuracy = 0.667
    Sklearn Accuracy = 0.667
    TorchEval AUC = 0.3
    Sklearn AUC = 0.889


    How can I correctly invoke TorchEval AUC to get the expected value of ~0.9?

    Continue reading...

Compartilhe esta Página