function r8poly_deriv_value_test ( )

%*****************************************************************************80
%
%% r8poly_deriv_value_test() tests r8poly_deriv_value().
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    17 November 2019
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'r8poly_deriv_value_test():\n' );
  fprintf ( 1, '  r8poly_deriv_value() evaluates the derivative of a polynomial.\n' );

  d = 4;
  x = 1:d;
  c = roots_to_r8poly ( d, x );
  r8poly_print ( c, '  The polynomial' );

  fprintf ( 1, '\n' );
  fprintf ( 1, '  A table of derivative values:\n' );
  fprintf ( 1, '\n' );
  x = linspace ( 0.0, 4.0, 9 );
  for i = 1 : 9
    y = r8poly_deriv_value ( d, c, x(i) );
    fprintf ( 1, '  %8.4f  %8.4f\n', x(i), y );
  end

  return
end
