def METHOD_NAME(doc_terms_file_name="tf_idf_doc_terms_matrix",
             terms_filename="tf_idf_terms",
             timestamp_filename='tf_idf_timestamps'):
    """read the data and return the vocabulary as well as the train, test and validation tests
    Args:
        path ([type]): [description]
    Returns:
        [type]: [description]
    """
    doc_term_matrix = read_mat_file("doc_terms_matrix", doc_terms_file_name)
    terms = read_mat_file("terms", terms_filename)
    times = read_mat_file("timestamps", timestamp_filename)
    vocab = terms
    #  make the time the last row of the doc_terms matrix for better spliting
    times = times.reshape((times.shape[1], 1))
    doc_term_time_matrix = hstack([doc_term_matrix, times])
    train, validation, test_1, test_2, test = split_train_test_matrix(doc_term_time_matrix)
    return vocab, train, validation, test_1, test_2, test