Barry and Jed, Nice to know that! Is there a corresponding function call to set RCM? Thanks, Qin
On Friday, February 14, 2014 10:20 AM, Jed Brown <[email protected]> wrote: Qin Lu <[email protected]> writes: > Hello, > > Is the RCM reordering available for ILU preconditioner in PETSc? The manual > says RCM works with LU factorization, but it does not mention it for > preconditioners. It works for all factorization preconditioners (ILU, ICC, LU, Cholesky). ~/petsc/src/ksp/ksp/examples/tutorials$ ./ex2 -m 100 -n 100 -ksp_view -pc_type ilu -pc_factor_mat_ordering_type rcm KSP Object: 1 MPI processes type: gmres GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement GMRES: happy breakdown tolerance 1e-30 maximum iterations=10000, initial guess is zero tolerances: relative=9.80296e-07, absolute=1e-50, divergence=10000 left preconditioning using PRECONDITIONED norm type for convergence test PC Object: 1 MPI processes type: ilu ILU: out-of-place factorization 0 levels of fill tolerance for zero pivot 2.22045e-14 using diagonal shift on blocks to prevent zero pivot [INBLOCKS] matrix ordering: rcm factor fill ratio given 1, needed 1 Factored matrix follows: Mat Object: 1 MPI processes type: seqaij rows=10000, cols=10000 package used to perform factorization: petsc total: nonzeros=49600, allocated nonzeros=49600 total number of mallocs used during MatSetValues calls =0 not using I-node routines linear system matrix = precond matrix: Mat Object: 1 MPI processes type: seqaij rows=10000, cols=10000 total: nonzeros=49600, allocated nonzeros=50000 total number of mallocs used during MatSetValues calls =0 not using I-node routines Norm of error 0.00314611 iterations 84
