function c = roots_to_r8poly ( n, x ) %*****************************************************************************80 % %% ROOTS_TO_R8POLY converts polynomial roots to polynomial coefficients. % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 16 April 2005 % % Author: % % John Burkardt % % Parameters: % % Input, integer N, the number of roots specified. % % Input, real X(N), the roots. % % Output, real C(1:N+1), the coefficients of the polynomial. % % % Initialize C to (0, 0, ..., 0, 1). % Essentially, we are setting up a divided difference table. % c(1:n) = 0.0; c(n+1) = 1.0; % % Convert to standard polynomial form by shifting the abscissas % of the divided difference table to 0. % for j = 1 : n for i = 1 : n+1-j c(n-i+1) = c(n-i+1) - x(n+1-i-j+1) * c(n-i+1+1); end end return end