title: how to decide the forecasting method from the ME, MAD, MSE, SDE?
body: <p>how to decide the forecasting method from the ME, MAD, MSE, SDE?
  for example, there is 4 methods that will be decide.
  but, the value won't be always greater or smaller among the error of each other.
  so, how can I decide the method of that forecast methods?</p>