[t,x] = sim('simulink_chua',500);
n = length(t);
n1 = round(n/2);
figure(1);
plot(t(n1:n,1),x(n1:n,1));
xlabel('t','fontsize',20,'fontname','times new roman','FontAngle','italic');
ylabel('x','fontsize',20,'fontname','times new roman','FontAngle','italic');
figure(2);
plot(x(n1:n,1),x(n1:n,2));
xlabel('x','fontsize',20,'fontname','times new roman','FontAngle','italic');
ylabel('z','fontsize',20,'fontname','times new roman','FontAngle','italic');