BP网络范例 MATLAB

clc
clear
cd C:\Users\ASUS1\Desktop
A=xlsread('第二题数据.xls');
p=A(:,1:4)';
t=A(:,5)';
[pn,minp,maxp,tn,mint,maxt]=premnmx(p,t);%原始数据归一化?
net=newff(pn,tn,[9],{'tansig','purelin'},'traingdx');%设置网络,建立相应的BP网络?
net=init(net);%初始化
net.trainParam.show=2000;%?训练网络?
net.trainParam.lr=0.01;
net.trainParam.epochs=1000;
net.trainParam.goal=1e-5;
net.trainParam.max_fail = 20;
net=train(net,pn,tn);%调用TRAINGDM算法训练BP网络?
%??对BP网络进行仿真
net
a=sim(net,pn);%??计算仿真误差
E=tn-a;
MSE=mse(E)