Negativity of eigenvalues to be considered

[anirudt]

Hey!

https://github.com/agyorev/Eigenfaces/blob/master/eigenfaces.py#L89

With respect to the energy wise implementation, ideally the eigenvalues could be even negative, so shouldn't the eigenvalues be chosen according to their energies, and not simply their values? According to this implementation, an influential yet negative eigenvalue also could go unnoticed.