learnbp

clear all
nntwarn off
format compact

P = -1:.1:-.5;
T = [-.9602 -.5770 -.0729 .3771 .6405 .6600];

[R,Q] = size(P);
[S1,Q] = size(T);
[S2,Q] = size(T);
[S3,Q] = size(T);
[W1,B1] = nwtan(S1,R);
[W2,B2] = nwtan(S2,S1);
[W3,B3] = rands(S3,S2);

disp_freq = 100;
max_epoch = 10000;
err_goal = 0.01;
lr = 0.001;
error = [];
A1 = tansig(W1*P,B1);
A2 = tansig(W2*A1,B2);
A3 = purelin(W3*A2,B3);
E = T - A3;
SSE = sumsqr(E);
save wagi

for (epoch=1:max_epoch)
    if (SSE < err_goal)
        epoch = epoch - 1;
        break
    end

    D3 = deltalin(A3,E);
    D2 = deltatan(A2,D3,W3);
    D1 = deltatan(A1,D2,W2);
    [dW1,dB1] = learnbp(P,D1,lr);
    [dW2,dB2] = learnbp(A1,D2,lr);
    [dW3,dB3] = learnbp(A2,D3,lr);
    W1 = W1 + dW1;
    B1 = B1 + dB1;
    W2 = W2 + dW2;
    B2 = B2 + dB2;
    W3 = W3 + dW3;
    B3 = B3 + dB3;

    A1 = tansig(W1*P,B1);
    A2 = tansig(W2*A1,B2);
    A3 = purelin(W3*A2,B3);

    E = T-A3;
    SSE = sumsqr(E);
    error = [error SSE];

    if (rem(epoch,disp_freq)==0)
        epoch
        SSE
        plot(P,T,'r',P,A3,'g')
        pause(1e-5)
    end
end
epoch
SSE