[petsc-users] Solving a linear system with symmetrical matrix

[Longmin RAN]

Hello everyone,


I use superlu inside petsc to solve linear systems with symmetrical
matrix. The solving time is at least twice longer than using superlu
directly. Since I'm new with Petsc, I didn't fine-tune much the petsc
solver, as I had done when using superlu directly. For example, in
superlu there are options like diagonal pivot
threshold(superlu_options_t.DiagPivotThresh), symmetric mode
(superlu_options_t.SymmetricMode), and column
permutation(superlu_options_t.ColPerm). Could anybody inform me about
the corresponding options in petsc? Thanks in advance.

BTW, I tried the following options:
	MatSetOption(A, MAT_SYMMETRIC, PETSC_TRUE);
	MatSetOption(A, MAT_SYMMETRY_ETERNAL, PETSC_TRUE);
But it seems that these options weren't enough to reduce the solving
time sufficiently.


Best regards,

- Longmin Ran