function points_01_plot ( input_file_name )

%% POINTS_01_PLOT plots a set of points that lie in the unit square.
%
%  Discussion:
%
%    The input data is assumed to be a set of points in the unit square.
%
%    The input data is assumed to be stored in an ASCII file named 
%    INPUT_FILE_NAME, with one pair of coordinates per line of text.
%  
%  Modified:
%
%    17 November 2006
%
%  Author:
%
%    John Burkardt
%
%  Parameters:
%
%    Input, string INPUT_FILE_NAME, the name of the file.
%
  fprintf ( 1, '\n' );
  timestamp;

  fprintf ( 1, '\n' );
  fprintf ( 1, 'POINTS_01_PLOT:\n' );
  fprintf ( 1, '  Read a set of points in the unit square,\n' );
  fprintf ( 1, '  plot them.\n' );

  p = load ( input_file_name );

  clf

  axes_handle = axes;
%
%  Make a scatter plot of the points, using filled circles.
%
  handle = scatter ( p(:,1), p(:,2), 'b', 'filled' );
%
%  Force the plotting region to be square, not rectangular.
%
  axis square
%
%  Request grid lines.
%
  grid on
%
%  Specify the location of the grid lines, and suppress labeling.
%
  set ( axes_handle, 'xtick', [ 0, .25, .50, .75, 1] );
  set ( axes_handle, 'xticklabel', [] );
  set ( axes_handle, 'ytick', [ 0, .25, .50, .75, 1] );
  set ( axes_handle, 'yticklabel', [] );
%
%  Make the plotting region slightly bigger than the data.
%
  axis ( [ -0.1, 1.1, -0.1, 1.1 ] )
%
%  Title
%
  title ( input_file_name );

  fprintf ( 1, '\n' );
  fprintf ( 1, 'POINTS_01_PNG\n' );
  fprintf ( 1, '  The input data "%s" was read in, and plotted.\n', ...
    input_file_name );

  fprintf ( 1, '\n' );
  timestamp;