BP的训练方法.删除init_wj_hid_output与init_wj_input_hid可以进行新的学习!不然只是按老方式学习!这是一个最简单的BP算法异或问题!没有阈值，学习速度不可改变!下次会改进!如果同或只需改变输入的方式就可以!-BP's training methods. Delete init_wj_hid_output with init_wj _input_hid can conduct new learning! Otherwise, only the old way by learning! This is a very simple BP Algorithm differences or problems! no threshold, learning speed irrevocable! The next will improve! If the same or just change the labor on the way!