function [x] = Linf_ball(rho)

t = 0:.01:4;
[m,n] = size(t);

for i=1:n
  if t(i) <= 1 
    x(1,i) = rho;
    x(2,i) = -rho + t(i)*2*rho;
  elseif t(i) <= 2  
    x(1,i) = rho + (1-t(i))*2*rho;
    x(2,i) = rho;
  elseif t(i) <= 3
    x(1,i) = -rho;
    x(2,i) = rho + (2-t(i))*2*rho;
  else 
    x(1,i) = -rho - (3-t(i))*2*rho;
    x(2,i) = -rho;
  end
end