Hi, I followed the Coursera Machine Learning course quite a while ago and I am trying to find out how Mahout implements the Logistic Regression cost function in the code surrounding AbstractOnlineLogisticRegression.
I am looking at the train method in AbstractOnlineLogisticRegression and I see online gradient descent step where the beta matrix is updated but to me its unclear how matches with the cost function described at: http://www.holehouse.org/mlclass/06_Logistic_Regression.html Perhaps Mahout uses an optimized approach for that does not directly map into the formula at that link? Cheers, Frank
