function [x, iter] = SOR(A, b, omega, max_iter, tol) n = length(b); x = zeros(n, 1); err = inf; k = 0; while err > tol && k < max_iter k = k + 1; x_old = x; for i = 1:n x(i) = (1 - omega) * x_old(i) + omega * (b(i) - A(i, 1:i-1) * x(1:i-1) - A(i, i+1:n) * x_old(i+1:n)) / A(i, i); end err = norm(x - x_old); end iter = k; end 出错 SORm (第 2 行) n = length(b);

看起来你在 SOR 函数中没有使用 function 关键字来定义函数，导致 MATLAB 无法识别该函数。你需要在 SOR 函数的开头加上 function 关键字，比如：

function [x, iter] = SOR(A, b, omega, max_iter, tol)
    n = length(b);
    x = zeros(n, 1);
    err = inf;
    k = 0;
    while err > tol && k < max_iter
        k = k + 1;
        x_old = x;
        for i = 1:n
            x(i) = (1 - omega) * x_old(i) + omega * (b(i) - A(i, 1:i-1) * x(1:i-1) - A(i, i+1:n) * x_old(i+1:n)) / A(i, i);
        end
        err = norm(x - x_old);
    end
    iter = k;
end

这样就可以成功定义 SOR 函数了。