clear all;
clf;
format compact;

nntwarn off;
P=-1:.1:-.5;
T=[-.9602 -.5770 -.0729 .3771 .6405 .6600];
[R,Q]=size(P);
[S1,Q]=size(T);
[W1,B1]=nwtan(S1,R);
disp_freq=100;
max_epoch=20000;
err_goal=0.01;
lr=0.1;

error=[];

A1=tansig(W1*P,B1);

E=T-A1;

SSE=sumsqr(E);

for epoch=1:max_epoch
    if SSE < err_goal,

          epoch=epoch-1;

          break,

end
D1=deltatan(A1,E);

[dW1,dB1]=learnbp(P,D1,lr);

W1=W1+dW1;

B1=B1+dB1;

A1=tansig(W1*P,B1);

E=T-A1;

SSE=sumsqr(E);

error = [error SSE];

    if(rem(epoch,disp_freq)==0)

        epoch

        SSE

        plot(P,T,'r',P,A1,'g')

        pause(1)

    end
end