Hello, I am a new user to Petsc + Slepc. I am trying to extract natural frequency of a finite element model using Slepc. The way I do is
1. Use other software (Abaqus) to assembly the stiffness and mass matrix. 2. Use Slepc to solve a generalized eigenvalue problem. K x = lamda M x with K, M being stiffness and mass matrix. I wrote my petsc/slepc code based on the examples on slepc web. They all compiled and working correctly. The question I am raising here is what solvers (solver combinations) should I use to be most efficient? Right now I am using "bcgsl" (BiCGSTAB) solver for KSP linear solvers, "JD" jacobian-davison for eigen solver, and "bjacobi" (block jacobian) for my preconditioner. It works, but I need it to be more efficient to solver big problem (millions of degrees of freedom). I am not an expert on knowing how these solvers are different at all! Is there anybody who has extracted eigenvalues of a Finite element model using Slepc? How can I possibly improve the performance? Thank you! PS: my running command reads like: ./eigen_solver -f1 petsc_stiff1.dat -f2 petsc_mass1.dat -eps_nev 40 -eps_target 0.0 -eps_type jd -st_type precond -st_ksp_type bcgsl -st_pc_type bjacobi -st_ksp_rtol 0.001 -eps_tol 1e-5 -eps_harmonic -- Jifeng Zhao PhD candidate at Northwestern University, US Theoretical and Applied Mechanics Program
