function bx = bernoulli_poly ( n, x ) %*****************************************************************************80 % %% BERNOULLI_POLY evaluates the Bernoulli polynomial of order N at X. % % Discussion: % % Thanks to Bart Vandewoestyne for pointing out an error in the previous % documentation, 31 January 2008. % % Special values of the Bernoulli polynomial include: % % B(N,0) = B(N,1) = B(N), the N-th Bernoulli number. % % B'(N,X) = N * B(N-1,X) % % B(N,X+1) - B(N,X) = N * X**(N-1) % B(N,X) = (-1)**N * B(N,1-X) % % A formula for the Bernoulli polynomial in terms of the Bernoulli % numbers is: % % B(N,X) = sum ( 0 <= K <= N ) B(K) * C(N,K) * X**(N-K) % % The first few polynomials include: % % B(0,X) = 1 % B(1,X) = X - 1/2 % B(2,X) = X**2 - X + 1/6 % B(3,X) = X**3 - 3/2*X**2 + 1/2*X % B(4,X) = X**4 - 2*X**3 + X**2 - 1/30 % B(5,X) = X**5 - 5/2*X**4 + 5/3*X**3 - 1/6*X % B(6,X) = X**6 - 3*X**5 + 5/2*X**4 - 1/2*X**2 + 1/42 % B(7,X) = X**7 - 7/2*X**6 + 7/2*X**5 - 7/6*X**3 + 1/6*X % B(8,X) = X**8 - 4*X**7 + 14/3*X**6 - 7/3*X**4 + 2/3*X**2 - 1/30 % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 31 January 2008 % % Author: % % John Burkardt % % Parameters: % % Input, integer N, the order of the Bernoulli polynomial to % be evaluated. N must be 0 or greater. % % Input, real X, the value of X at which the polynomial is to % be evaluated. % % Output, real BX, the value of B(N,X). % b = bernoulli_number ( n ); ido = 0; row = comb_row ( ido, n ); bx = 1.0; for i = 1 : n bx = bx * x + b(i+1) * row(i+1); end return end