function [A,W]=Schwarz(n)
% Schwarz算法求高斯-勒让德求积公式的节点和权系数
% Input            - n 是公式中节点个数
% Output           - A 是节点向量，按升序排列
%                  - W 是权系数，按A中对应顺序排列

%  NUMERICAL METHODS: Matlab Programs
% (c) 2007 by Xie Liling
%  Complementary Software to accompany the textbook:
%  Information and Computing Science: A Laboratory Course

beta = (1:n-1)./sqrt(4*(1:n-1).^2-1);
J = diag(beta,-1)+diag(beta,1);
[V,D] = eig(J);
[A,ix]=sort(diag(D));
V(:,1:n)=V(:,ix);
W=2*V(1,ix)'.^2;