说明：  遗传算法优化BP神经网络的参考程序，缺少的code函数应该可以用gadecod（）函数补上，是很好的范例，很清楚，可以帮助学习
(Genetic algorithm optimization BP neural network reference program, the missing code function should be able to use the gadecod () function, is a good example, very clear, can help to learn)