[petsc-users] targetting specific eigenvectors

[Nachiket Gokhale]

I am solving a coupled structural-acoustic calculation, and I want to
find the most important "coupled modes", i.e. the modes which transfer
the most energy between the structure and the fluid.  One way to do
this would be to solve the first N modes of the full generalized
eigenproblem (Kx=Mx), and compute a measure of the coupling (
something like \pi = u'Sp ),  where S is the coupling matrix, u is the
displacement and p is there pressure. One could then sort the coupled
modes according to \pi. However, important coupled modes which do not
lie in the first "N" modes may not be found (unless there are matrix
structuring results that I am not aware of).

Are there any algorithms that guarantee that find first N_c important
coupled modes as defined by an user defined criterion, and are there
any code s that implement them?

The only reference I could find was

Alan R. Tackett, Massimiliano Di Ventra, Targeting specific
eigenvectors and eigenvalues of a given Hamiltonian using arbitrary
selection criteria, PHYSICAL REVIEW B 66, 245104  2002.

Sorry for the slightly OT discussion.

Thanks,

Nachiket