Question

Matlab 共轭梯度法求解任意线性方程组！求详细解释如下程序

function x = cg(A,b)
tol=1e-10;
r = b + A*b;
w = -r;
z = A*w;
s = w'*z;
t = (r'*w)/s;
x = -b + t*w;
for k = 1:numel(b);
r = r - t*z;
if( norm(r) < tol )
return;
end
B = (r'*z)/s;
w = -r + B*w;
z = A*w;
s = w'*z;
t = (r'*w)/s;
x = x + t*w;
end

Answer 1

你这样问不解决问题的，共轭梯度法虽然是最简单的Krylov子空间方法，但是对一般的本科生而言仍然比较困难，你得找本教材来慢慢看，把整个推导过程自己算一遍，这样才能搞明白程序的原理。

Answer 2

...

Answer 3

晕