Eigen 3.0 documentation mentions that if you use an EigenSolver object to compute the Eigen values of a matrix, the eigen values are NOT sorted in any order. When I look at Eigen 2.0 documentation, I see no mention if the eigenvalues are sorted or not. I am guessing there is no order guarantee for 2.0 either. Could someone please confirm if Eigen 2.0 has a sorted order guarantee for the storage/display of eigenvalues?

Thanks

indeed, there is no natural order for complexes so they are not sorted even in Eigen 2.0. (Note that for the self-adjoint case, i.e., SelfAdjointEigenSolver, the eigenvalues are sorted for both Eigen 2 and 3)