[petsc-users] KSPsolve Problem

[Barry Smith]

  I am guessing that the local solver is ILU(0) and that the ILU(0) factorization is creating a NaN or Inf due to a zero pivot. What happens if you run with the command line option -fp_trap  ?

   Also if this is a small problem you can run with -mat_view to have it display the factored matrix.

  Barry

On Oct 14, 2014, at 2:07 PM, Sharp Stone <thronesf at gmail.com> wrote:

> Dear all,
> 
> I'm trying to solve a linear system with petsc ksp solver. But after I called the kspsolve routine, I always got the "Vec entry at local location 0 is not-a-number or infinite at end of function" errors below. I checked the matrix and the vectors, and they are all numbers (and zeros). Is this a bug or I miss something? Thank you very much in advance!
> 
> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> 
> [0]PETSC ERROR: Floating point exception
> 
> [0]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite at end of function: Parameter number 3
> 
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> 
> [0]PETSC ERROR: Petsc Release Version 3.5.2, Sep, 08, 2014 
> 
> [0]PETSC ERROR: ./pStreamer on a arch-darwin-cxx-debug named host206-47.physci.fit.edu by GPL Tue Oct 14 14:58:05 2014
> 
> [0]PETSC ERROR: Configure options --with-cc=gcc --with-cxx=g++ --with-fc=gfortran --with-clanguage=cxx --download-fblaslapack --download-mpich
> 
> [0]PETSC ERROR: #12 VecValidValues() line 34 in /Users/GPL/local/PETSc/petsc-3.5.2/src/vec/vec/interface/rvector.c
> 
> [0]PETSC ERROR: #13 PCApply() line 442 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/pc/interface/precon.c
> 
> [0]PETSC ERROR: #14 KSP_PCApply() line 230 in /Users/GPL/local/PETSc/petsc-3.5.2/include/petsc-private/kspimpl.h
> 
> [0]PETSC ERROR: #15 KSPSolve_PREONLY() line 26 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/ksp/impls/preonly/preonly.c
> 
> [0]PETSC ERROR: #16 KSPSolve() line 459 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itfunc.c
> 
> [0]PETSC ERROR: #17 PCApply_BJacobi_Singleblock() line 675 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/pc/impls/bjacobi/bjacobi.c
> 
> [0]PETSC ERROR: #18 PCApply() line 440 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/pc/interface/precon.c
> 
> [0]PETSC ERROR: #19 KSP_PCApply() line 230 in /Users/GPL/local/PETSc/petsc-3.5.2/include/petsc-private/kspimpl.h
> 
> [0]PETSC ERROR: #20 KSPInitialResidual() line 56 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itres.c
> 
> [0]PETSC ERROR: #21 KSPSolve_BCGS() line 50 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/ksp/impls/bcgs/bcgs.c
> 
> 
> [0]PETSC ERROR: #22 KSPSolve() line 459 in /Users/GPL/local/PETSc/petsc-3.5.2/src/ksp/ksp/interface/itfunc.c
> 
> 
> -- 
> Best regards,
>