function f=toro(u)

par = 1;
f(1) = (par-3)*u(1)-0.25*u(2)+u(1)*(u(3)+0.2*(1-u(3)*u(3)));
f(2) = 0.25*u(1)+(par-3)*u(2)+u(2)*(u(3)+0.2*(1-u(3)*u(3)));
f(3) = par*u(3)-(u(1)*u(1)+u(2)*u(2)+u(3)*u(3));
