function playfair_plot ( )

  data = load ( 'playfair.txt' );
  r = data(:,2) ./ data(:,3);

  plot ( data(:,1), r, 'r-o', 'linewidth', 3 );
  grid ( 'on' )
  xlabel ( '<-- Year -->' );
  ylabel ( '<-- Weeks of Labor-->' );
  title ( '<-- Weeks of Labor to Buy Measure of Wheat-->' );
  filename = 'playfair.png';
  print ( '-dpng', filename );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );

  return
end

