说明：  BP网络实现分类问题；一，问题的提出；根据感知器的的相关理论易知感知器善于解决线性可分；反向传播网络（Back-PropagationN；一个具有r个输入和一个隐含层的神经网络模
(The BP network realization categorizes a problem A, the problem puts forward Knows a machine according to the feeling of of the related theory easy to understand feeling knows that the machine is good at solving line to divide Is anti- to spread a network(Back-PropagationN A nerve network that has one r importation and an implicit layer mold )