About Cost

[winfieldcw]

Hi，Kat
why do you define the average_error:
cost = tf.div(tf.add(base_cost, regularizer), num_ratings_tr * 2, name="average_error"
but not
cost = tf.div(tf.add(base_cost, regularizer), num_ratings_tr, name="average_error"

num_ratings_tr * 2 mean ?