code: def calcMse(predTst, yTest, axis=0):
      
      return np.mean((yTest - predTst) ** 2, axis=axis)
docs: calculate mean squared error. Assumes that axis=0 is time
  
          Parameters
          ----------
          predTst : np.array, predicted reponse for yTest
          yTest : np.array, acxtually observed response for yTest
          Returns
          -------
          aryFunc : np.array
              MSE