ILUDropTolerance is not compatible with Mat re-ordering??

[Rui Wang]

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
>