TheEdoardo93

def probabilistic_matrix_factorization_technique(ratings_matrix):
    random_state = RandomState(0) # generates a casual number given by the Mersenne Twister pseudo-random number generator
    number_of_users = max(ratings_matrix[:, 0]) # max value in the first column (e.g., users)
    number_of_items = max(ratings_matrix[:, 1]) # max value in the second column (e.g., items)

    # Shift user_id and item_id by 1, in order to let user_id and item_id start from 0
    ratings_matrix[:, (0, 1)] -= 1

    # Delete all the rows in the ratings matrix which have 0 as rating value
    final_ratings_matrix = delete_all_rows_in_the_ratings_matrix_which_have_0_as_rating_value(ratings_matrix)