ILUDropTolerance is not compatible with Mat re-ordering??

[Rui Wang]

Dr. Zhang,

       Thanks. I definitely will try. 

Best regards,
Rui

---- Original message ----
>Date: Thu, 7 May 2009 21:34:19 -0500 (CDT)
>From: Hong Zhang <hzhang at mcs.anl.gov>  
>Subject: Re: ILUDropTolerance is not compatible with Mat re-ordering??  
>To: ruiwang2 at illinois.edu, PETSc users list <petsc-users at mcs.anl.gov>
>
>
>Rui,
>
>I'm currently working on iludt.
>You can try it from petsc-dev.
>See http://www.mcs.anl.gov/petsc/petsc-as/developers/index.html
>on how to get petsc-dev.
>
>Example: petsc-dev/src/ksp/ksp/examples/tutorials/ex2.c:
>
>./ex2 -pc_type ilu -pc_factor_use_drop_tolerance 0.01,0.0,2
>
>i.e., run ilu with the option
>-pc_factor_use_drop_tolerance <droptol, dtcol,maxrowcount>.
>
>Currently, it only supports sequential aij format.
>dtcol is not implemented.
>
>Send us bug report and
>let us know your need.
>
>Hong
>
>On Thu, 7 May 2009, Rui Wang wrote:
>
>> Thanks a lot. I appreciate your help. Have a nice evening.
>>
>> Rui
>>
>> ---- Original message ----
>>> Date: Thu, 7 May 2009 20:25:25 -0500
>>> From: Barry Smith <bsmith at mcs.anl.gov>
>>> Subject: Re: ILUDropTolerance is not compatible with Mat re-ordering??
>>> To: ruiwang2 at illinois.edu, PETSc users list <petsc-users at mcs.anl.gov>
>>>
>>>
>>>
>>>    PETSc has currently very little support for drop tolerance ILU.
>>> ILU is the bane of any decent mathematicians existence.
>>>
>>>    There isn't support for a reordering.
>>>
>>>    Hong is actually working on much better, more general and more
>>> complete ILUdt that should be ready in a couple of
>>> months. (Yes, Hong has gone over to the dark side of mathematics :-)).
>>>
>>>    Barry
>>>
>>> On May 7, 2009, at 8:19 PM, Rui Wang wrote:
>>>
>>>> Dear All,
>>>>
>>>>      I am trying very hard to use PCILUSetUseDropTolerance()
>>>> together with PCILUSetMatOrdering(), but it does not work, no matter
>>>> what kind of MatOrderingType (RCM, ND...) i choose. The message I got:
>>>>
>>>> -------------------------------------------------------------
>>>> Note: The EXACT line numbers in the stack are not available,
>>>>      INSTEAD the line number of the start of the function
>>>>      is given.
>>>> [0] MatILUDTFactor_SeqAIJ line 66 src/mat/impls/aij/seq/aijfact.c
>>>> [0] MatILUDTFactor line 1362 src/mat/interface/matrix.c
>>>> [0] PCSetUp_ILU line 568 src/sles/pc/impls/ilu/ilu.c
>>>> [0] PCSetUp line 756 src/sles/pc/interface/precon.c
>>>> [0] SLESSolve line 466 src/sles/interface/sles.c
>>>> --------------------------------------------
>>>> [0]PETSC ERROR: unknownfunction() line 0 in  unknown file
>>>> [0] MPI Abort by user Aborting program !
>>>> [0] Aborting program!
>>>> p0_32609:  p4_error: : 59
>>>> ----------------------------------------------------------
>>>>
>>>>    I spent a lot of time on this and still cannot figure it out.
>>>>
>>>>   Actually if I just use PCILUSetUseDropTolerance() itself, it works
>>>> fine. Also,  if I choose other ILU methods such as level-based ILU,
>>>> PCILUSetMatOrdering() works perfectly with them.
>>>>
>>>>    I wonder how to use ILUDropTolerance together with the reordering
>>>> technique (such as RCM)? or they are not compatible?
>>>> BTW, my PETSc version is 2.1.0. Is this because i am using this old
>>>> version?
>>>>
>>>>    Thanks a lot.
>>>>
>>>> Sincerely,
>>>> Rui Wang
>>>>
>>>>
>>>>
>>>>
>>>> --------------------------------------------------
>>>> Rui Wang
>>>> Ph.D. Candidate
>>>> Research Assistant and Predoctoral Fellow
>>>> Department of Electrical and Computer Engineering
>>>> University of Illinois at Urbana-Champaign
>>>
>>
--------------------------------------------------
Rui Wang
Ph.D. Candidate
Research Assistant and Predoctoral Fellow
Department of Electrical and Computer Engineering
University of Illinois at Urbana-Champaign