function w = hameig_basic(H)
% w=HAMEIG_BASIC(H) computes the eigenvalues of a Hamiltonian matrix
% using Van Loan's method
% H: Hamiltonian matrix
% w: eigenvalues of H
n = length(H)/2;
T = pvlform(H^2);
v = eig(T(1:n,1:n));
w = [sqrt(v);-sqrt(v)];