function i4_gpf_test ( )

%*****************************************************************************80
%
%% i4_gpf_test() tests i4_gpf().
%
%  Licensing:
%
%    This code is distributed under the MIT license. 
%
%  Modified:
%
%    16 November 2022
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'i4_gpf_test()\n' );
  fprintf ( 1, '  i4_gpf() evaluates the greatest prime factor function.\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '         N      Exact         I4_gpf(N)\n' );

  n_data = 0;

  while ( true )

    [ n_data, n, gpf1 ] = i4_gpf_values ( n_data );

    if ( n_data == 0 )
      break
    end

    gpf2 = i4_gpf ( n );

    fprintf ( 1, '  %8d  %12d  %12d\n', n, gpf1, gpf2 );

  end
 
  return
end
