Dear All,
I use PCFactorSetLevels for ILU and PCFactorSetFill for other
preconditioning in my code to help solve the problems that the default
option is hard to solve. However, I found the latter one,
PCFactorSetFill does not take effect for my problem. The matrices and
rhs as well as the solutions are attached from the link below. I obtain
the solution using hypre preconditioner and it takes 7 and 38 iterations
for matrix 1 and matrix 2. However, if I use other preconditioner, the
solver just failed at the first matrix. I have tested this matrix using
the native sequential solver (not PETSc) with ILU preconditioning. If I
set the incomplete factorization level to 0, this sequential solver will
take more than 100 iterations. If I increase the factorization level to
1 or more, it just takes several iterations. This remind me that the PC
factor for this matrices should be increased. However, when I tried it
in PETSc, it just does not work.
Matrix and rhs can be obtained from the link below.
https://eilinator.eos.ubc.ca:8443/index.php/s/CalUcq9CMeblk4R
Would anyone help to check if you can make this work by increasing the
PC factor level or fill?
Thanks and regards,
Danyang
