A = [4 -1 0 0 0; -1 4 -1 0 0; 0 -1 4 -1 0; 0 0 -1 4 -1; 0 0 0 -1 4]; b = [2;4;6;8;16]; max_iter = 30; tol = 1.0e-6; x0=[0,0,0,0]';[x,iter] = GS(A,b,x0,max_iter,tol);function [x,iter] = GS(A,b,x0,max_iter,tol) n = size(A,1); x = x0; iter = 0; while iter < max_iter for i = 1:n x(i) = b(i); for j = 1:i-1 x(i) = x(i) - A(i,j)*x(j); end for j = i+1:n x(i) = x(i) - A(i,j)*x(j); end %x(i) = x(i) + A(i,i)* x(i); x(i) = x(i) / A(i,i); end err = norm(A*x-b,Inf); fprintf('Step %d Error = %.2e\n',iter, err); if err < tol break; end iter = iter +1 ; end end出错 Demo3_Jacobi>GS (第 62 行) x(i) = x(i) - A(i,j)*x(j); 出错 Demo3_Jacobi (第 15 行) [x,iter] = GS(A,b,x0,max_iter,tol);

这段代码使用了高斯-塞德尔迭代法求解线性方程组Ax=b，但是在第62行出现了错误。这是因为在高斯-塞德尔迭代法中，需要使用已经更新过的x的值来计算下一个x的值，而在第62行中，却使用了未更新过的x的值，导致计算结果出错。建议在第62行之前加上一行代码x(i) = x(i) / A(i,i)，将已经更新过的x的值代入计算。