function orbital_fill_contour ( )

%*****************************************************************************80
%
%% orbital_fill_contour() creates a color contour plot of orbital data.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    02 April 2025
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'orbital_fill_contour():\n' );
  fprintf ( 1, '  MATLAB/Octave version %s\n', version ( ) );
  fprintf ( 1, '  Color contour plot of orbital data using gnuplot().\n' );

  command_filename = 'orbital_fill_contour_commands.txt';
  command_unit = fopen ( command_filename, 'wt' );
  fprintf ( command_unit, '# %s\n', command_filename );
  fprintf ( command_unit, '#\n' );
  fprintf ( command_unit, '# Usage:\n' );
  fprintf ( command_unit, '#  gnuplot < %s\n', command_filename );
  fprintf ( command_unit, '#\n' );
  fprintf ( command_unit, 'set term png\n' );
  fprintf ( command_unit, 'set output "orbital_fill_contour.png"\n' );
  fprintf ( command_unit, 'set xlabel "<--- X --->"\n' );
  fprintf ( command_unit, 'set ylabel "<--- Y --->"\n' );
  fprintf ( command_unit, 'set title "Orbital Data"\n' );
  fprintf ( command_unit, 'set grid\n' );
  fprintf ( command_unit, 'unset surface\n' );
  fprintf ( command_unit, 'set contour base\n' );
  fprintf ( command_unit, 'set view map\n' );
  fprintf ( command_unit, 'set pm3d\n' );
  fprintf ( command_unit, 'splot "orbital_gnuplot_data.txt" with pm3d\n' );
  fprintf ( command_unit, 'quit\n' );
  fclose ( command_unit );
  fprintf ( 1, '  Created command file "%s"\n', command_filename );
%
%  Terminate.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'orbital_fill_contour():\n' );
  fprintf ( 1, '  Normal end of execution.\n' );

  return
end

