function temperature_scatter3d ( )

%*****************************************************************************80
%
%% temperature_scatter3d makes a 3D scatter plot.
%
%  Discussion:
%
%    Plot the longitude, latitude, and January temperature for various
%    cities in US.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    08 May 2018
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'temperature_scatter3d\n' );
  fprintf ( 1, '  MATLAB version\n' );
  fprintf ( 1, '  Create a 3D scatter plot of logintude,\n' );
  fprintf ( 1, '  latitude, and January temperature.\n' );
%
%  Load the data.
%
  tll = load ( 'temperature_data.txt' );

  scatter3 ( tll(:,2), tll(:,3), tll(:,1), 'r', 'filled' );

  grid ( 'on' )
  title ( 'January Temperatures in US Cities', 'Fontsize', 16 )
  xlabel ( '<-- Longitude -->', 'Fontsize', 16 )
  ylabel ( '<-- Latitude -->', 'Fontsize', 16 )
  zlabel ( '<-- Temperature -->', 'Fontsize', 16 )

  view ( 3 )
%
%  Save a copy of the plot as a PNG file.
%
  filename = 'temperature_scatter3d.png';
  print ( '-dpng', filename );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );
%
%  Terminate.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'temperature_scatter3d:\n' );
  fprintf ( 1, '  Normal end of execution.\n' );

  return
end
