调整参数对bp网络的影响

 

调整参数对bp网络的影响，具体如下：

 

 

clc;clear;x=1:1:79;P=rands(1,79);% T=rands(1,79);T=ones(1,79);net=newff(minmax(P),[25,1],{'tansig','purelin'},'trainlm');net.trainParam.show=50;net.trainParam.epochs=200;net.trainParam.goal=0.01;net=train(net,P,T);y=sim(net,P);%%%%%%%%%%%%%%%%%%%%%%调整参数后，epochs变大，goal变小。net2=newff(minmax(P),[25,1],{'tansig','purelin'},'trainlm');net2.trainParam.show=50;net2.trainParam.epochs=200;net2.trainParam.goal=0.00000001;net2=train(net2,P,T);y2=sim(net2,P);%%%%%%%%绘制效果plot(x,T,'r*');hold onplot(x,y,'g*');plot(x,y2,'b*');% axis([0 80 0.999 1.001]);legend('目标值','第一次模拟效果','第二次模拟效果','Location','NorthWest');hold off;