[petsc-users] Petsc has generated inconsistent data!

Fri Aug 26 16:27:49 CDT 2011

Later in the message he only requested that I use "-ksp_norm_type
unpreconditioned". So I did, and the error comes back, now fully
documented below. As I wrote, it works fine with gmres, and the
problem is very simple, diagonal dominant steady state diffusion.

Any hints are highly appreciated.

Dominik

#PETSc Option Table entries:
-ksp_converged_reason
-ksp_converged_use_initial_residual_norm
-ksp_monitor_true_residual
-ksp_norm_type unpreconditioned
-ksp_rtol 1e-3
-ksp_type bcgs
-ksp_view
-log_summary
-pc_type jacobi
#End of PETSc Option Table entries
  0 KSP preconditioned resid norm 1.166190378969e+01 true resid norm
1.166190378969e+01 ||Ae||/||Ax|| 1.000000000000e+00
  1 KSP preconditioned resid norm 5.658835826231e-01 true resid norm
5.658835826231e-01 ||Ae||/||Ax|| 4.852411688762e-02
[0]PETSC ERROR: --------------------- Error Message
------------------------------------
[0]PETSC ERROR: Petsc has generated inconsistent data!
[0]PETSC ERROR: Divide by zero!
[0]PETSC ERROR:
------------------------------------------------------------------------
[2]PETSC ERROR: --------------------- Error Message
------------------------------------
[2]PETSC ERROR: Petsc has generated inconsistent data!
[2]PETSC ERROR: Divide by zero!
[2]PETSC ERROR:
------------------------------------------------------------------------
[2]PETSC ERROR: Petsc Release Version 3.1.0, Patch 8, Thu Mar 17
13:37:48 CDT 2011
[2]PETSC ERROR: See docs/changes/index.html for recent updates.
[2]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
[2]PETSC ERROR: See docs/index.html for manual pages.
[2]PETSC ERROR:
------------------------------------------------------------------------
[2]PETSC ERROR: /home/dsz/build/framework-debug/trunk/bin/cd3t10mpi on
a linux-gnu named tharsis by dsz Fri Aug 26 23:23:47 2011
[2]PETSC ERROR: Libraries linked from
/home/dsz/pack/petsc-3.1-p8/linux-gnu-c-debug/lib
[2]PETSC ERROR: Configure run at Mon Jul 25 14:20:10 2011
[2]PETSC ERROR: Configure options
PETSC_DIR=/home/dsz/pack/petsc-3.1-p8 PETSC_ARCH=linux-gnu-c-debug
--download-f-blas-lapack=CD3T10::SaveSolution()
[0]PETSC ERROR: Petsc Release Version 3.1.0, Patch 8, Thu Mar 17
13:37:48 CDT 2011
[0]PETSC ERROR: See docs/changes/index.html for recent updates.
[0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
[0]PETSC ERROR: See docs/index.html for manual pages.
[0]PETSC ERROR:
------------------------------------------------------------------------
[0]PETSC ERROR: /home/dsz/build/framework-debug/trunk/bin/cd3t10mpi on
a linux-gnu named tharsis by dsz Fri Aug 26 23:23:47 2011
[0]PETSC ERROR: Libraries linked from
/home/dsz/pack/petsc-3.1-p8/linux-gnu-c-debug/lib
[0]PETSC ERROR: Configure run at Mon Jul 25 14:20:10 2011
[0]PETSC ERROR: Configure options
PETSC_DIR=/home/dsz/pack/petsc-3.1-p8 PETSC_ARCH=linux-gnu-c-debug
--download-f-blas-lapack=1 --download-mpich=1 --download-hypre=1
--with-parmetis=1 --download-parmetis=1 --with-x=0 --with-debugging=1
[0]PETSC ERROR:
------------------------------------------------------------------------
[0]PETSC ERROR: KSPSolve_BCGS() line 75 in
src/ksp/ksp/impls/bcgs/[1]PETSC ERROR: --------------------- Error
Message ------------------------------------
[1]PETSC ERROR: Petsc has generated inconsistent data!
[1]PETSC ERROR: Divide by zero!
[1]PETSC ERROR:
------------------------------------------------------------------------
[1]PETSC ERROR: Petsc Release Version 3.1.0, Patch 8, Thu Mar 17
13:37:48 CDT 2011
[1]PETSC ERROR: See docs/changes/index.html for recent updates.
[1]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
[1]PETSC ERROR: See docs/index.html for manual pages.
[1]PETSC ERROR:
------------------------------------------------------------------------
[1]PETSC ERROR: /home/dsz/build/framework-debug/trunk/bin/cd3t10mpi on
a linux-gnu named tharsis by dsz Fri Aug 26 23:23:47 2011
[1]PETSC ERROR: Libraries linked from
/home/dsz/pack/petsc-3.1-p8/linux-gnu-c-debug/lib
[1]PETSC ERROR: Configure run at Mon Jul 25 14:20:10 2011
[1]PETSC ERROR: Configure options
PETSC_DIR=/home/dsz/pack/petsc-3.1-p8 PETSC_ARCH=linux-gnu-c-debug
--download-f-blas-lapack=1 --download-mpich=1 --download-hypre=1
--with-parmetis=1 --download-parmetis=1 --with-x=0 --with-debugging=1
[2]PETSC ERROR:
------------------------------------------------------------------------
[2]PETSC ERROR: KSPSolve_BCGS() line 75 in src/ksp/ksp/impls/bcgs/bcgs.c
[2]PETSC ERROR: KSPSolve() line 396 in src/ksp/ksp/interface/itfunc.c
[2]PETSC ERROR: User provided function() line 1215 in
"unknowndirectory/"/home/dsz/src/framework/trunk/solve/PetscSolver.cxx
[3]PETSC ERROR: --------------------- Error Message
------------------------------------
[3]PETSC ERROR: Petsc has generated inconsistent data!
[3]PETSC ERROR: Divide by zero!
[3]PETSC ERROR:
------------------------------------------------------------------------
[3]PETSC ERROR: Petsc Release Version 3.1.0, Patch 8, Thu Mar 17
13:37:48 CDT 2011
[3]PETSC ERROR: See docs/changes/index.html for recent updates.
[3]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
[3]PETSC ERROR: See docs/index.html for manual pages.
[3]PETSC ERROR:
------------------------------------------------------------------------
[3]PETSC ERROR: /home/dsz/build/framework-debug/trunk/bin/cd3t10mpi on
a linux-gnu named tharsis by dsz Fri Aug 26 23:23:47 2011
[3]PETSC ERROR: Libraries linked from
/home/dsz/pack/petsc-3.1-p8/linux-gnu-c-debug/lib
[3]PETSC ERROR: Configure run at Mon Jul 25 14:20:10 2011
[3]PETSC ERROR: Configure options
PETSC_DIR=/home/dsz/pack/petsc-3.1-p8 PETSC_ARCH=linux-gnu-c-debug
--download-f-blas-lapack=bcgs.c
[0]PETSC ERROR: KSPSolve() line 396 in src/ksp/ksp/interface/itfunc.c
[0]PETSC ERROR: User provided function() line 1215 in
"unknowndirectory/"/home/dsz/src/framework/trunk/solve/PetscSolver.cxx
1 --download-mpich=1 --download-hypre=1 --with-parmetis=1
--download-parmetis=1 --with-x=0 --with-debugging=1
[1]PETSC ERROR:
------------------------------------------------------------------------
[1]PETSC ERROR: KSPSolve_BCGS() line 75 in src/ksp/ksp/impls/bcgs/bcgs.c
[1]PETSC ERROR: KSPSolve() line 396 in src/ksp/ksp/interface/itfunc.c
[1]PETSC ERROR: User provided function() line 1215 in
"unknowndirectory/"/home/dsz/src/framework/trunk/solve/PetscSolver.cxx
1 --download-mpich=1 --download-hypre=1 --with-parmetis=1
--download-parmetis=1 --with-x=0 --with-debugging=1
[3]PETSC ERROR:
------------------------------------------------------------------------
[3]PETSC ERROR: KSPSolve_BCGS() line 75 in src/ksp/ksp/impls/bcgs/bcgs.c
[3]PETSC ERROR: KSPSolve() line 396 in src/ksp/ksp/interface/itfunc.c
[3]PETSC ERROR: User provided function() line 1215 in
"unknowndirectory/"/home/dsz/src/framework/trunk/solve/PetscSolver.cxx
PetscSolver::Finalize()
PetscSolver::FinalizePetsc()

On Fri, Aug 26, 2011 at 11:17 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>
>  Are you sure that is the entire error message. It should print the routine and the line number where this happens.
>
>   Likely it is at
>
>  do {
>    ierr = VecDot(R,RP,&rho);CHKERRQ(ierr);       /*   rho <- (r,rp)      */
>    beta = (rho/rhoold) * (alpha/omegaold);
>    ierr = VecAXPBYPCZ(P,1.0,-omegaold*beta,beta,R,V);CHKERRQ(ierr);  /* p <- r - omega * beta* v + beta * p */
>    ierr = KSP_PCApplyBAorAB(ksp,P,V,T);CHKERRQ(ierr);  /*   v <- K p           */
>    ierr = VecDot(V,RP,&d1);CHKERRQ(ierr);
>    if (d1 == 0.0) SETERRQ(((PetscObject)ksp)->comm,PETSC_ERR_PLIB,"Divide by zero");
>    alpha = rho / d1;                 /*   a <- rho / (v,rp)  */
>
>  Which means bi-cg-stab has broken down. You'll need to consult references to Bi-CG-stab to see why this might happen (it can happen while GMRES is happy). It may be KSPBCGSL can proceed past this point with a problem values for
>   Options Database Keys:
> +  -ksp_bcgsl_ell <ell> Number of Krylov search directions
> -  -ksp_bcgsl_cxpol Use a convex function of the MR and OR polynomials after the BiCG step
> -  -ksp_bcgsl_xres <res> Threshold used to decide when to refresh computed residuals
>
> but most likely the preconditioner or matrix is bogus in some way since I think Bi-CG-stab rarely breaks down in practice.
>
>
>  Barry
>
>
>
> On Aug 26, 2011, at 4:05 PM, Dominik Szczerba wrote:
>
>> When solving my linear system with -ksp_type bcgs I get:
>>
>>  0 KSP preconditioned resid norm 1.166190378969e+01 true resid norm
>> 1.166190378969e+01 ||Ae||/||Ax|| 1.000000000000e+00
>>  1 KSP preconditioned resid norm 5.658835826231e-01 true resid norm
>> 5.658835826231e-01 ||Ae||/||Ax|| 4.852411688762e-02
>> [1]PETSC ERROR: --------------------- Error Message
>> ------------------------------------
>> [1]PETSC ERROR: Petsc has generated inconsistent data!
>> [1]PETSC ERROR: Divide by zero!
>> [1]PETSC ERROR:
>> ------------------------------------------------------------------------
>> [1]PETSC ERROR: Petsc Release Version 3.1.0, Patch 8, Thu Mar 17
>> 13:37:48 CDT 2011
>> [1]PETSC ERROR: See docs/changes/index.html for recent updates.
>> [1]PETSC ERROR: [3]PETSC ERROR: --------------------- Error Message
>> ------------------------------------
>> [3]PETSC ERROR: Petsc has generated inconsistent data!
>> [3]PETSC ERROR: Divide by zero!
>>
>> PETSc Option Table entries:
>> -ksp_converged_reason
>> -ksp_monitor
>> -ksp_monitor_true_residual
>> -ksp_norm_type unpreconditioned
>> -ksp_right_pc
>> -ksp_rtol 1e-3
>> -ksp_type bcgs
>> -ksp_view
>> -log_summary
>> -pc_type jacobi
>>
>> When solving the same system with GMRES all works fine. This is a
>> simple test diffusion problem. How can I find out what the problem is?
>>
>> Dominik
>
>