P=[-1:0.1:1];
T=[-0.9602 -0.5770 -0.0729 0.3771 0.6405 0.6600 0.4609 0.1336 -0.2013 -0.4344 -0.5000 -0.3930 -0.1647 0.0988 0.3072 0.3960 0.3449 0.1816 -0.0312 -0.2189 -0.3201];
plot(P,T,'+');


    net=newff(minmax(P),[8,1],{'logsig','tansig'},'trainlm');
    net=init(net);
    net.trainParam.epochs=2000;
    net.trainParam.goal=0.001;
    net=train(net,P,T);
 
    y=sim(net,P);
    error=y-T;
    res=norm(error);