fmifa.m

计算特征值和特征向量的幂法和反幂法以及计算矩阵的minres 算法的matlab程序

function [v,k,toll]=fmifa(A,niu)
[m,n]=size(A);
v(:,1)=ones(m,1);
r=norm(v);
v=v/r;
A1=A-niu*eye(m);
k=1;
tol=1;
while tol>1e-6
    v(:,k+1)=A1\v(:,k);
    c=norm(v(:,k+1));
    v(:,k+1)=v(:,k+1)/c;
    k=k+1;
    a=A*v(:,k)-niu*v(:,k);
    tol=norm(a)/norm(A*v(:,k));
end
v=v(:,k);
k=k-1;
[m,n]=size(tol);
toll=tol(1:n);