function walker_1d_plot ( n, track )

  l = length ( track );
  clf
  hold on
  plot ( [-n,-n], [1,l], 'r-', 'LineWidth', 5 );
  plot ( [ n, n], [1,l], 'r-', 'LineWidth', 5 );
  plot ( track, 1:l, 'b.-', 'LineWidth', 3, 'Markersize', 40 )
  hold off

  return
end
