I need to compute some metrics for binary classification. I see that many times some people use the probability:
y_pred_proba = clf.fit(X_train, y_train).predict_proba(X_test) roc_auc_score(y_test, y_pred_proba[:,1]) # probability of Class 1
and other times:
y_pred = clf.fit(X_train, y_train).predict(X_test) roc_auc_score(y_test, y_pred) # binary outcome y_pred
if I try both I get completely different results.
Can anyone explain me which one has to be used with metrics score, if predict or predict_proba?