function price_plots ( )

%*****************************************************************************80
%
%% PRICE_PLOTS reads price data and plots 3 prices on one display.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    19 July 2018
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'PRICE_PLOTS:\n' );
  fprintf ( 1, '  Octave version\n' );
  fprintf ( 1, '  Plot prices of bananas, gas and milk over time.\n' );
%
%  Read the items of data.
%
  data = load ( 'price_data.txt' );
%
%  Create a vector X.
%
  x = linspace ( 1, 241, 241 );
  size ( x )
  size ( data )
%
%  Plot 3 curves together.
%
  plot ( x, data(:,3), x, data(:,10), x, data(:,13), 'LineWidth', 3 );
  legend ( 'Bananas', 'Gas', 'Milk' );
  grid on
  xlabel ( 'Month Index', 'Fontsize', 16 );
  ylabel ( 'Price in Dollars', 'Fontsize', 16 );
  title ( 'Bananas / Gas / Milk prices, Feb 2008-Feb 2018', 'Fontsize', 16 );

  pause ( 5 )
%
%  Save graphics to a file.
%
  filename = 'price_plots.png';
  print ( '-dpng', filename );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Graphics file saved as "%s"\n', filename );
%
%  Terminate.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'PRICE_PLOTS:\n' );
  fprintf ( 1, '  Normal end of execution.\n' );

  return
end

