function hcell_node_display ( node_xy_file_name )

%% HCELL_NODE_DISPLAY displays the nodes in the H-Cell.
%
%  Usage:
%
%    hcell_node_display ( node_xy_file_name )
%
%    A typical invocation might be
%
%      hcell_node_display ( 'xy3.txt' )
%
%    or
%
%      hcell_node_display ( 'xy6.txt' )
%
%    But if you simply say 
%
%      hcell_node_display
%
%    the program will give you a chance to enter the file names
%    interactively.
%
%  Modified:
%
%    22 April 2004
%
%  Author:
%
%    John Burkardt
%
%  Parameters:
%
%    Input, filename NODE_XY_FILE_NAME, the name of a file 
%    containing the XY coordinates of nodes.
%
  timestamp;
  fprintf ( 1, '\n' );
  fprintf ( 1, 'HCELL_NODE_DISPLAY:\n' );
  fprintf ( 1, '  MATLAB version\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Display the nodes in the HCELL problem.\n' );
%
%  Do we have the XY file?
%
  if ( nargin < 1 )

    fprintf ( 1, '\n' );
    fprintf ( 1, 'HCELL_NODE_DISPLAY:\n' );
    node_xy_file_name = input ( 'Enter the name of the XY coordinate file:' );

  end

  node_xy = table_read ( node_xy_file_name );
%
%  Plot the nodes.
%   
  plot ( node_xy(1,:), node_xy(2,:), 'bo' )
%
%  Add the boundary of the region to the plot.
%
  hcell_boundary_add ( 'r' );
%
%  Add the invisible bounding box.
%
  hcell_box_add ( 'w' )

  axis equal
  
  title ( 'Node coordinates' )

  text ( 45.0, 20.0, node_xy_file_name )
  
  fprintf ( 1, '\n' );
  fprintf ( 1, 'HCELL_NODE_DISPLAY:\n' );
  fprintf ( 1, '  Normal end of execution.\n' );
  fprintf ( 1, '\n' );
  timestamp;