function [lambda,y,g] =Potenze(A,Nmax,tol)
%METODO DELLE POTENZE

y=ones(size(A,1),1);
k=1;
m=1;
flag=false;
lambda(1)=1;
g(1)=lambda(1);

while (~flag)&(m<Nmax)
    m=m+1;
    w=A*y;
    [M,k]=max(abs(w));
    lambda(m)=w(k)/y(k);
    g(m)=lambda(m);
    y=w/norm(w,Inf);%W/M
    flag=abs(lambda(m)-lambda(m-1))/abs(lambda(m))<tol;  
end

end