[petsc-users] questions about contour integration solvers in SLEPc

[Jose E. Roman]

El 02/12/2013, a las 18:47, Michael Povolotskyi escribió:

> Dear Developers of SLEPc,
> I have found that SLEPc has now two eigenvalues solver that are based on contour integration, rather than on Krylov space method.
> They are EPSFEAST and EPSCISS.
> 
> I'm eager to try these solvers in my code both for Hermitian and non-Hermitian problems.
> My questions are as follows:
> 1) Are there any tutorial examples for those solvers?

No. For EPSFEAST you specify an interval -eps_interval a,b and for EPSCISS you specify an ellipse containing the wanted eigenvalues, with -eps_ciss_center c -eps_ciss_radius r
See more options in ciss.c

> 2) How is the algorithm of EPSCISS is different from EPSFEAST algorithm?
> Is it similar to one from http://prb.aps.org/abstract/PRB/v86/i7/e075103, where FEAST is extended to the non-Hermitian matrices?

As far as I know FEAST does not support non-Hermitian problems. CISS does. See references cited at the top of ciss.c
We will continue to improve CISS in the next SLEPc versions. If you want help trying it, send us an email to slepc-maint and we will guide you.

> 3) Will I be able to configure SLEPC to use FEAST algorithm from MKL?

I haven't tried this. Send errors/problems to slepc-maint.

Jose


> 
> Thank you,
> Michael.