function p00_f1_dif_test ( )

%*****************************************************************************80
%
%% p00_f1_dif_test() compares the exact and approximate first derivatives.
%
%  Licensing:
%
%    This code is distributed under the MIT license. 
%
%  Modified:
%
%    06 December 2016
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'P00_F1_DIF_TEST\n' );
  fprintf ( 1, '  P00_F1_DIF approximates the first derivative F1\n' );
  fprintf ( 1, '  by a finite difference F1_DIF.\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Problem               X           F1(X)       F1_DIF(X)\n' );
  fprintf ( 1, '\n' );
%
%  Get the number of problems.
%
  problem_num = p00_problem_num ( );

  for problem = 1 : problem_num

    x = p00_start ( problem );

    f1 = p00_f1 ( problem, x );

    f1_dif = p00_f1_dif ( problem, x );

    fprintf ( 1, '  %7d  %14.6g  %14.6g  %14.6g\n', problem, x, f1, f1_dif );

  end

  return
end
