function geyser_scatter ( )

%*****************************************************************************80
%
%% GEYSER_SCATTER uses MATLAB to make a scatter plot.
%
%  Discussion:
%
%    The data includes records of the length in minutes of eruptions
%    and pauses at the Old Faithful geyser.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    25 April 2018
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'GEYSER_SCATTER\n' );
  fprintf ( 1, '  MATLAB version\n' );
  fprintf ( 1, '  Create a scatter plot of eruption length versus\n' );
  fprintf ( 1, '  subsequent pause length at the Old Faithful geyser.\n' );
%
%  Load the data.
%  It's in CSV format.
%  Skip the first row, of labels.
%  Skip the first column, of indices.
%
  data = csvread ( 'faithful_data.csv', 1, 1 );

  scatter ( data(:,1), data(:,2), 'filled' );

  grid ( 'on' )
  title ( 'Duration of Eruption / Pause at Old Faithful' )
  xlabel ( '<-- Eruption Duration (minutes)-->' )
  ylabel ( '<-- Pause Duration (minutes) -->' )
%
%  Save a copy of the plot as a PNG file.
%
  filename = 'geyser_scatter.png';
  print ( '-dpng', filename );
%
%  Terminate.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'GEYSER_SCATTER:\n' );
  fprintf ( 1, '  Normal end of execution.\n' );

  return
end
