Yes ex13 works for me. Could you let me know where can I download the program and how can I add options at the runtime? Thank you so much.
Jifeng On Thu, Jul 3, 2014 at 12:13 PM, murat keçeli <[email protected]> wrote: > Hi Jifeng, > > You can start with ex13 in SLEPc to see how it works for your case. You > would need MUMPS as a direct solver. Section 3.4.5 is the relevant section > in SLEPc manual (Campos and Roman 2012 paper would be very helpful if you > need more details). Let me know if it works for you and we can continue > from there. > > Thanks, > Murat > > > On Thu, Jul 3, 2014 at 12:18 AM, jifeng zhao < > [email protected]> wrote: > >> Hi Murat, >> >> Yes, that sounds great. I would like to have a try. Would you let me know >> how to use it on top of SLEPC and PETSC in more details? >> >> Cheers, >> Jifeng Zhao >> >> >> On Wed, Jul 2, 2014 at 9:41 PM, murat keçeli <[email protected]> wrote: >> >>> Hi Jifeng, >>> >>> I think your application is suitable for the SIPs method, see attached >>> paper. We have improved it recently, so that it can handle very >>> large (500k by 500k with more than 3.e7 nonzeros) sparse matrices.Current >>> version of SIPs is basically adding a second layer of parallelism on top of >>> SLEPc's shift and invert method. Let me or Hong Zhang (cc, the developer of >>> SIPs) know, if you would like to give it a try. >>> >>> Murat Keceli >>> >>> >>> On Wed, Jul 2, 2014 at 4:46 PM, jifeng zhao < >>> [email protected]> wrote: >>> >>>> Hello all, >>>> >>>> I am working on solving a generalized eigenvalue problem with SLEPC and >>>> PETSC. >>>> >>>> *K* x = lamda *M* x >>>> >>>> I attached the sparsity pattern of matrix *M* (*K* is the same). It is >>>> a FEM model. It is so sparse is because of constraints. >>>> >>>> I have tried two things: >>>> >>>> 1. Krylov-Schur and exact shift-and-invert (I will try MUMPS in >>>> future). It works. But I am worrying that it is less parrallelable, when >>>> the problem contains millions of degree of freedom. >>>> >>>> 2. JD with Jacobi preconditioner. It could work, but a lot of tuning >>>> needs to be done in terms of RTOL, max_iteration_number. And sometimes I >>>> suffer from a stagnated solution, and can't obtain accurate result. >>>> >>>> Does anybody know that for my specific case of matrix sparsity, is >>>> there any thing I can do to speed up my direct solver (Krylov-Schur)? >>>> >>>> Is there any recommended preconditioners I could try on, for the case >>>> of JD? There are a lot of preconditioners in HYPRE library. >>>> >>>> Thank you in advance! >>>> [image: Inline image 1] >>>> -- >>>> Jifeng Zhao >>>> PhD candidate at Northwestern University, US >>>> Theoretical and Applied Mechanics Program >>>> >>> >>> >> >> >> -- >> Jifeng Zhao >> PhD candidate at Northwestern University, US >> Theoretical and Applied Mechanics Program >> > > -- Jifeng Zhao PhD candidate at Northwestern University, US Theoretical and Applied Mechanics Program
