I've come across an irregularity when extracting the eigenvectors when using 
the CISS method to solve the eigenvalue problem.  I'm solving a generalized 
hermitian problem, and it looks like the resulting eigenvectors are 
M-orthogonalized with each other (the M-inner products of different 
eigenvectors are approximately 0, as expected), but are normalized using the 
L2-inner product, not the M-inner product.  Basically, the matrix V'*M*V (V 
being a matrix composed of the extracted eigenvectors) is diagonal, but the 
diagonals are much larger than 1, and the matrix V'*V has non-zero diagonals, 
but the diagonal elements are exactly equal to 1.

This only happens if I use the CISS method.  If I use the Arnoldi method for 
example, the eigenvectors are normalized as expected.  Is there any particular 
reason for this, or is this an error in the implementation?


Reply via email to