Hessenberg的Matlab代码

function [G,Q]=Hessenberg(A)
    %10170330 容易
    n=length(A);
    Q=eye(n);
    A_i=A;

    for i=1:n-2
        H_i=eye(n);
        b_i=A_i(i+1:n,i);
        Hi=Householder(b_i);
        H_i(i+1:n,i+1:n)=Hi;
        Q=Q*H_i;
        A_i=H_i*A_i*H_i;
    end
    G=Q.'*A*Q;
    end