function a = r8poly_f2p ( n, a ) %*****************************************************************************80 % %% R8POLY_F2P converts a real polynomial from factorial form to power sum form. % % Discussion: % % The (falling) factorial form is % % p(x) = a(1) % + a(2) * x % + a(3) * x*(x-1) % ... % + a(n) * x*(x-1)*...*(x-(n-2)) % % The power sum form is % % p(x) = a(1) + a(2)*x + a(3)*x**2 + ... + a(n)*x**(n-1) % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 09 July 2004 % % Author: % % John Burkardt % % Parameters: % % Input, integer N, the dimension of A. % % Input, real A(N), the polynomial coefficients in factorial form. % % Output, real A(N), the polynomial coefficients in power sum form. % w = -n; for m = 1 : n val = 0.0; z = w; for i = m : n z = z + 1.0; val = a(n+m-i) + z * val; a(n+m-i) = val; end w = w + 1.0; end return end