y = R;
x = 1;
delta_E = 2*x+3;
delta_SE = 2*(x-y)+5;
decision = (x+1)*(x+1)+(y+0.5)*(y+0.5)-R*R;
circle_tab(x,y) = 1;

while(y>x)

   if(decision < 0)
       decision = decision + delta_E;
       delta_E = delta_E + 2;
       delta_SE = delta_SE + 2;
   else
       y=y-1;
       decision = decision + delta_SE;
       delta_E = delta_E + 2;
       delta_SE = delta_SE + 4;
   end
   x = x +1;
   circle_tab(x,y) = 1;
end