by calculation of all possible regressions with mallows' c_p statistic, average prediction mean square error(s_p) and prediction sum of squares (press), the optimum fore-casting model can be obtained.
建立所有可能的回归方程,再根据c_p準则,平均预报均方误差準则(s_p)、预测残差平方和(press)準则等可找到最优预测模型。