BP神经网络数据预测matlab代码.rar

%%%%BP Training for MIMO and Multi---samples clear all close all clc xite=0.5; alfa=0.05; w2=rands(6,2); w2_1=w2; w2_2=w2_1; w1=rands(3,6); w1_1=w1; w1_2=w1; dw1=0*w1; I=[0 0 0 0 0 0]'; Iout=[0 0 0 0 0 0]'; FI=[0 0 0 0 0 0]'; OUT=2; k=0; E=1.0; NS=3; while E>=1e-20 k=k+1; times(k)=k; for s=1:NS xs=[1 0 0; 0 1 0; 0 0 1]; ys=[1 0; 0 0.5; 0 1]; x=xs(s,:); for j=1:6 I(j)=x*w1(:,j); Iout(j)=1/(1+exp(-I(j))); end yl=w2'*Iout; yl=yl'; el=0; y=ys(s,:); for l=1:OUT el=el+0.5*(y(l)-yl(l))^2; end % es(s)=el; E=0; if s==NS for s=1:NS E=E+el; end end el=y-yl; w2=w2_1+xite*Iout*el+alfa*(w2_1-w2_2); for j=1:6 S=1/(1+exp(-I(j))); FI(j)=S*(1-S); end for i=1:3 for j=1:6 dw1(i,j)=xite*FI(j)*x(i)*(el(1)*w2(j,1)+el(2)*w2(j,2)); end end w1=w1_1+dw1+alfa*(w1_1-w1_2); w1_2=w1_1; w1_1=w1; w2_2=w2_1; w2_1=w2; end Ek(k)=E; end figure(1) plot(times,Ek,'r') xlabel('k') ylabel('E') save wfile w1 w2;