clear all
nntwarn off
format compact

P = [-1:.1:-.5];
T = [-.9602 -.5770 -0.0729 .3771 .6405 .6600] ;

[R,Q] = size(P);
[S3,Q] = size(T);

S1 = 7;
S2 = 7;

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

load wagi;

disp_freq = 100;
max_epoch = 10000;
err_goal = 0.001;
lr = 0.01;
error = [];

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

E = T - A3;
SSE = sumsqr(E);

for epoch = 1:max_epoch
    if SSE < err_goal, epoch = epoch-1;
        break
    end
    D3 = deltalin(A3,E);
    [dW3,dB3] = learnbp(A2,D3,lr);
    D2 = deltatan(A2,D3,W3);
    [dW2,dB2] = learnbp(A1,D2,lr);
    D1 = deltatan(A1,D2,W2);
    [dW1,dB1] = learnbp(P,D1,lr);

    W1 = W1+dW1; B1 = B1+dB1;
    A1 = tansig(W1*P,B1);

    W2 = W2+dW2; B2 = B2+dB2;
    A2 = tansig(W2*A1,B2);

    W3 = W3+dW3; B3 = B3+dB3;
    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-100);
    end
end
SSE
epoch