function [u,result,num]=fisher(M,V,X)
[m,n]=size(M);
I=eye(m);
J=ones(m);
B=M'*(I-J./m)*M;
E=m*V;
[U,D]=eig(inv(E)*B);
[lamda,index]=max(sum(D));
u=U(:,index);
result=abs(X*u-M*u);
[minu,num]=min(result);