clear all;

L=15; U=15;
figure(3);
axis([-L U -L U]);
axis manual;
A=[-L U; 0 0];
B=[0 0; -L U];
plot(A(1,:),A(2,:));
hold on;
plot(B(1,:),B(2,:));
grid;

B =[0.5 -0.75; 0.75 0.5];


A=inv(B)    %    r= 4/sqrt(13) ? 1.1094  > 1 


x=ones(2,1)+ rand(2,1);

for k=1:15

  plot(x(1),x(2),'or');
  hold on;pause(0.3)

  x=A*x;

end