I tried to use SGDRegressor to train data incrementally because I have newer data everyday. But I found when I train with data for 30 days, and then predict the result of 1st day. The result is very different. Then I predict from 1st to 14th day, I found the result are all the same value. But result of each day are all different and have multiple patterns. Is that correct? or just the size of training data too small? thx