subplot(3,2,1)
plot(x,y1,'.k'); hold on
plot (x,f(w,x),'r-'); hold off
xlabel('x');
ylabel('y,f(x)');
title('gauss')

subplot(3,2,3)
plot(x,y2,'.k'); hold on
plot (x,f(w,x),'r-'); hold off
xlabel('x');
ylabel('y,f(x)');
title('uniform')

subplot(3,2,5)
plot(x,y3,'.k'); hold on
plot (x,f(w,x),'r-'); hold off
xlabel('x');
ylabel('y,f(x)');
title('exp')