Predictions using AUC metrics for multilabel classification

Question

I'm using AUC metrics to do a multilabel classification. Since keras has removed prediction_classes for obtaining the prediction classes, I just use a threshold of 0.5 to get the output classes. However, as I understand, for AUC the threshold should not be 0.5 for an imbalanced data set. How can I get the threshold that was used for training the model?

Besides, I know that AUC is used for binary classification. Can I just use it for multilabel problem? How to calculate the threshold? By taking the average or not.

Answer 1

You can use AUC for the multi-label problem, check this .

import numpy as np 
y_true = np.random.randint(0,2,(100,4))
y_pred = np.random.randint(0,2,(100,4))

m = tf.keras.metrics.AUC(multi_label=True, thresholds=[0, 0.5])
m(y_true, y_pred).numpy()

FYI, from tf 2.5 , it now supports logit predictions.