Hi Fande, Thanks very much for your comments and suggestions!
I use the solutions of the linear system later on within an eigenvalue problem. The eigenvalues of the latter seem to be very sensitive regarding the accuracy of the solutions of the linear system of equations. Thanks, Kathrin Am 08.12.2016 um 12:03 schrieb Kong, Fande <[email protected]<mailto:[email protected]>>: On Thu, Dec 8, 2016 at 10:44 AM, Kathrin Smetana <[email protected]<mailto:[email protected]>> wrote: Dear libmesh users/developers, I have to solve a linear system of equations (system size approximately 10^6) very often (about 5000 times). The linear system of equations is the result of a FEM discretization of 3D linear elasticity. I thought about using a sparse Cholesky decomposition as the matrix is symmetric or a sparse LU decomposition, depending on availability. I have had a look at the Eigen package and their direct LU factorization for instance with Umfpack or SuperLU support looks very promising to me. I was wondering why you are going to use a direct solver? Because the resulting system is highly ill-conditioned due to a challenging physics configuration? If this is not the case, I think you could use a AMG (hypre or pcamg in petsc). AMG should work with the linear elasticity equation. You can also try ASM (additive Schwarz method). All those solvers are available in petsc or through petsc. Fande, Do you think that is a good option or do you have any other recommendations for me? Thanks, Kathrin ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today.http://sdm.link/xeonphi _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
