function tt_product_test ( )

%*****************************************************************************80
%
%% TT_PRODUCT_TEST tests TT_PRODUCT.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license. 
%
%  Modified:
%
%    13 July 2015
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'TT_PRODUCT_TEST:\n' );
  fprintf ( 1, '  TT_PRODUCT(I,J;X) = T(I,X) * T(J,X)\n' );

  r8_lo = -1.0;
  r8_hi = +1.0;
  seed = 123456789;

  fprintf ( 1, '\n' );
  fprintf ( 1, '   I   J      X               TI              TJ              TI*TJ       TT_PRODUCT\n' ); 
  fprintf ( 1, '\n' ); 
  for test = 1 : 10
    [ x, seed ] = r8_uniform_ab ( r8_lo, r8_hi, seed );
    [ i, seed ] = i4_uniform_ab ( 0, 6, seed );
    ti = t_polynomial_value ( i, x );
    [ j, seed ] = i4_uniform_ab ( -1, 4, seed );
    tj = t_polynomial_value ( j, x );
    titj = tt_product ( i, j, x );
    fprintf ( 1, '  %2d  %2d  %14.6g  %14.6g  %14.6g  %14.6g  %14.6g\n', ...
      i, j, x, ti, tj, ti * tj, titj );
  end

  return
end
