采用“提前停止”方法（抑制过拟合）提高 BP 网络的推广能力，采用训练函数 traingdx和“提前停止”相结合的方法来训练 BP 网络。-Using " early stopping" method (suppression over-fitting) to improve the generalization ability of BP network, using the training function traingdx and " stop ahead