What does it mean if I am getting the same AUC and AUROC value in a CNN?

I am running a Convolutional Neural Network. After it finishes running, I use some metrics to evaluate the performance of the model. 2 of the metrics are the auc and roc_auc_score from sklearn

AUC function: https://scikit-learn.org/stable/modules/generated/sklearn.metrics.auc.html?highlight=auc#sklearn.metrics.auc

AUROC function: https://scikit-learn.org/stable/modules/generated/sklearn.metrics.roc_auc_score.html#sklearn.metrics.roc_auc_score

The code I am using is the following:

print(pred)
fpr, tpr, thresholds = metrics.roc_curve(true_classes, pred, pos_label=1)
print("-----AUC-----")
print(metrics.auc(fpr, tpr))
print("----ROC AUC-----")
print(metrics.roc_auc_score(true_classes, pred))

Where true_classes is a table which is of the form : [0 1 0 1 1 0] where 1 is the positive label and 0 the negative.

And pred is the predictions of the model:

prediction = classifier.predict(test_final)
prediction1 = []
predictions = []
for preds in prediction:
    prediction1.append(preds[0])

pred = prediction1

However I am getting the same AUC and ROC AUC value no matter how many times I run the test (What I mean by that is that AUC and ROC AUC values in each test are the same. Not that they remain the same on all the tests. For example for test 1 I get AUC = 0.987 and ROC_AUC = 0.987 and for test 2 I get AUC = 0.95 and ROC_AUC = 0.95) . Am I doing something wrong? Or is it normal?

Answer

As per documentation linked, metrics.auc is a general case method to calculate area under a curve from points of that curve.

metrics.roc_auc_score is a specific case method used to calculate Area Under Curve for ROC curve.

You would not expect to see different results if you’re using the same data to calculate both, as metrics.roc_auc_score will do the same thing as metrics.auc and, most likely, use the metrics.auc method itself, under the hood (i.e. use the general method for the specific task of calculating Area under ROC curve).