invgreville.m

矩阵的广义逆计算

%利用Greville法求广义逆矩阵
A=[0 2j j 0 4+2j 1 3 5j 0 1-j 3 0 j 3-2j 5 7 3 -2 6-9j 0;
    0 0 0 -3 -6 -3-j 7 0 1 3 2 7j 1-j 2 3 j 6 -3-6j 1 7;
    0 2 1 1 4-4j 1 j 1 2 2+j j 9 2+2j 1 9 4 1+j 8 4 9-11j;
    1 4j 3 7 1 8 -j 2 0 2j 0 11 3 3+j 10j 11 0 3 5+7j 2;
    j 9 2j 1 0 -3 -4j 2 6 7 8 4 7+j 0 11j 9 10 2-2j j 3];
[m n]=size(A);
AA=A(:,1);
if AA==0
    X=zeros(1,m);
else
    X=AA'/(AA'*AA);
end
for i=2:n
    d=X*A(:,i);
    c=A(:,i)-AA*d;
    if c==0
        b=d'*X/(1+d'*d);
    else
        b=c'/(c'*c);
    end
    X=[X-d*b ;b];
    AA=[AA A(:,i)];
end