function RJ

R = 1;
J = 1;

for i = 1:10
    
    R(i+1) = .7*R(i) + .5*J(i);
    J(i+1) = -.1*R(i) + .9*J(i);
    
end

plot(R,'o-')
hold on
plot(J,'o-')
xlabel('time')
legend('Romeo','Juliet')
grid

hold off

figure;
plot(R,J,'o-')
xlabel('Romeo')
ylabel('Juliet')
grid