patrate

P = [1,0,-1,0,1;0,1,0,-1,0];
plot(P(1,:),P(2,:),'b');
axis([-5,5,-5,5],"square");
alfa = pi/8;
hold on;
for i=1:3
  T = [cos(alfa) -sin(alfa); sin(alfa) cos(alfa)];
  P = T*P;
  plot(P(1,:),P(2,:),'b');
endfor
figure(2)
axis([-3,3,-3,3],"square");
P = [1,0,-1,0,1;0,1,0,-1,0];
hold on;
for i=1:50
  T = [cos(alfa) -sin(alfa); sin(alfa) cos(alfa)];
  P = T*P;
  P = P*0.9;
  fill(P(1,:),P(2,:),'r');
endfor
figure(3);
P = [1,0,-1,0,1;0,1,0,-1,0];
hold on;
for i=1:50
  T = [cos(alfa) -sin(alfa); sin(alfa) cos(alfa)];
  P = T*P;
  P = P*0.9;
  P = P+[1;2];
  fill(P(1,:),P(2,:),'g');
endfor