BPSAN

说明：  通过BP神经网络学习一个3维的函数的源代码，为加快速度，程序初始化的为已经经过学习的得到结点权值，如果预设为随机值，将重新学习。(BP neural network through a three-dimensional study of the function of the source code to speed up, the initialization procedure for the study has already been node weights, if limited to random value, re-learn.)