function BPnet3()
X=-1:0.1:1;T=sin(pi*X);
plot(X,T,'+');
S1=5;
[W1,b1,W2,b2]=initff(X,S1,'tansig',T,'purelin');

disp_freq=10;
max_epoch=8000;
err_goal=0.02;


tp=[disp_freq max_epoch err_goal];
[W1,b1,W2,b2,te,tr]=trainlm(W1,b1,'tansig',W2,b2,'purelin',X,T,tp);
X1=0.5;
[y1,y2]=simuff(X1,W1,b1,'tansig',W2,b2,'purelin');
y2