[petsc-users] access suitesparse from petsc

[Barry Smith]

  For UMFPack you can control a great deal of the solver behavior:

 MATSOLVERUMFPACK = "umfpack" - A matrix type providing direct solvers (LU) for sequential matrices
  via the external package UMFPACK.

  ./configure --download-suitesparse to install PETSc to use UMFPACK

  Consult UMFPACK documentation for more information about the Control parameters
  which correspond to the options database keys below.

  Options Database Keys:
+ -mat_umfpack_ordering                - CHOLMOD, AMD, GIVEN, METIS, BEST, NONE
. -mat_umfpack_prl                     - UMFPACK print level: Control[UMFPACK_PRL]
. -mat_umfpack_strategy <AUTO>         - (choose one of) AUTO UNSYMMETRIC SYMMETRIC 2BY2
. -mat_umfpack_dense_col <alpha_c>     - UMFPACK dense column threshold: Control[UMFPACK_DENSE_COL]
. -mat_umfpack_dense_row <0.2>         - Control[UMFPACK_DENSE_ROW]
. -mat_umfpack_amd_dense <10>          - Control[UMFPACK_AMD_DENSE]
. -mat_umfpack_block_size <bs>         - UMFPACK block size for BLAS-Level 3 calls: Control[UMFPACK_BLOCK_SIZE]
. -mat_umfpack_2by2_tolerance <0.01>   - Control[UMFPACK_2BY2_TOLERANCE]
. -mat_umfpack_fixq <0>                - Control[UMFPACK_FIXQ]
. -mat_umfpack_aggressive <1>          - Control[UMFPACK_AGGRESSIVE]
. -mat_umfpack_pivot_tolerance <delta> - UMFPACK partial pivot tolerance: Control[UMFPACK_PIVOT_TOLERANCE]
. -mat_umfpack_sym_pivot_tolerance <0.001> - Control[UMFPACK_SYM_PIVOT_TOLERANCE]
. -mat_umfpack_scale <NONE>           - (choose one of) NONE SUM MAX
. -mat_umfpack_alloc_init <delta>      - UMFPACK factorized matrix allocation modifier: Control[UMFPACK_ALLOC_INIT]
. -mat_umfpack_droptol <0>            - Control[UMFPACK_DROPTOL]
- -mat_umfpack_irstep <maxit>          - UMFPACK maximum number of iterative refinement steps: Control[UMFPACK_IRSTEP]

  For Cholmod we don't seem to have currently the ability. If there are some you would like added you can try yourself or let us know what you need.

  Barry


> On Feb 24, 2015, at 11:43 AM, Manav Bhatia <bhatiamanav at gmail.com> wrote:
> 
> 
>> On Feb 24, 2015, at 11:40 AM, Jed Brown <jed at jedbrown.org> wrote:
>> 
>> Manav Bhatia <bhatiamanav at gmail.com> writes:
>> 
>>> Greetings! 
>>> 
>>>  What are the command line options to access suitesparse from petsc? I was not able to find any specification in the manual. 
>> 
>> Presumably you mean Umfpack or Cholmod.
>> 
>> -pc_type lu -pc_factor_mat_solver_package umfpack
>> 
>> -pc_type cholesky -pc_factor_mat_solver_package cholmod
> 
> Aha!
> 
> I was thinking that there would be something that would read like suitesparse. Thanks for the info.
> 
> Also, the suitesparse website talks of different orderings available (AMD, CAMD, COLAMD, and CCOLAMD). Are any of these accessible by command line options as well? 
> 
> Thanks,
> Manav