function showcontour ( )
%
%% showcontour() illustrates various contour plots.
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'showcontour()\n' );

  close all

% Set up array of function values.

  x = linspace(-2,2,50)';
  y = linspace(-1.5,1.5,50)';
  F = SampleF(x,y);

% Number of contours set to default value:
  
  figure
  contour(x,y,F)
  axis('equal')
  filename = 'showcontour1.png';
  print ( '-dpng', filename );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );

% Five contours:
  
  figure
  contour(x,y,F,5);
  axis('equal')
  filename = 'showcontour2.png';
  print ( '-dpng', filename );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );

% Five contours with specified values:
  
  figure
  contour(x,y,F,[1 .8  .6  .4  .2])
  axis('equal')
  filename = 'showcontour3.png';
  print ( '-dpng', filename );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );
 
% Four contours with manual labeling:

  figure
  c = contour(x,y,F,4);
% clabel(c,'manual');
  axis('equal')
  filename = 'showcontour4.png';
  print ( '-dpng', filename );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );

  return
end
 
