[petsc-users] Solving a simpler PDE results in error while solving the original equation works in snes/tutorials/ex13.c
Matthew Knepley
knepley at gmail.com
Mon Jul 10 18:29:02 CDT 2023
On Mon, Jul 10, 2023 at 5:02 PM Tony Wu <wutony0408 at gmail.com> wrote:
> In snes/tutorials/ex13.c,
> there is a function SetupPrimalProblem(), which sets up the f_0 and f_1 in
> PetscDSSetResidual() as described in
> https://petsc.org/release/manualpages/DT/PetscDSSetResidual/#petscdssetresidual
> ,
> and also the boundary conditions using the exact solution
> trig_inhomogeneous_u().
>
> Now, I am trying to modify f_0, f_1, and the boundary conditions in order
> to solve the 2D equation
> u+\Delta u=f,
> where f(x,y)=x and the boundary conditions are determined by the exact
> solution u(x,y)=x.
>
> In order to do this, I defined the following point-wise functions:
>
> static void f00(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt
> uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar
> u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt
> aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar
> a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const
> PetscScalar constants[], PetscScalar f0[])
> {
> f0[0] -= u[0];
> f0[0] += x[0];
> }
>
> static void f11(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt
> uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar
> u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt
> aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar
> a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const
> PetscScalar constants[], PetscScalar f1[])
> {
> PetscInt d;
> for (d = 0; d < dim; ++d)
> {
> f1[d] = u_x[d];
> }
> }
>
> static void u_exact(PetscInt dim, PetscReal time, const PetscReal x[],
> PetscInt Nc, PetscScalar *u, void *ctx)
>
This function is declared "void" but should be "PetscErrorCode". There must
have been a warning on compile.
Thanks,
Matt
> {
> *u = 0.0;
> *u += x[0];
> return PETSC_SUCCESS;
> }
>
> I then replaced the f0, f1_u and ex in SetupPrimalProblem()
> by the corresponding f00, f11, and u_exact.
> .
>
> However, I got the following error message:
>
> [0]PETSC ERROR: --------------------- Error Message
> --------------------------------------------------------------
> [0]PETSC ERROR:
> [0]PETSC ERROR: See https://petsc.org/release/faq/ for trouble shooting.
> [0]PETSC ERROR: Petsc Release Version 3.19.3, unknown
> [0]PETSC ERROR: ./ex13 on a arch-linux-c-debug named LAPTOP by user Tue
> Jul 11 04:06:13 2023
> [0]PETSC ERROR: Configure options --COPTFLAGS=-O3 --CXXOPTFLAGS=-O3
> --FOPTFLAGS=-O3 --with-shared-libraries --with-cxx-dialect=C++11
> --with-make-np=8 --download-hdf5=yes --download-mumps=yes
> --download-parmetis=yes --download-metis=yes --download-superlu=yes
> --download-hypre=yes --download-superlu_dist=yes --download-scalapack=yes
> --download-triangle=yes
> [0]PETSC ERROR: #1 DMProjectPoint_Func_Private() at
> /home/user/petsc/src/dm/impls/plex/plexproject.c:128
> [0]PETSC ERROR: #2 DMProjectPoint_Private() at
> /home/user/petsc/src/dm/impls/plex/plexproject.c:395
> [0]PETSC ERROR: #3 DMProjectLocal_Generic_Plex() at
> /home/user/petsc/src/dm/impls/plex/plexproject.c:852
> [0]PETSC ERROR: #4 DMProjectFunctionLabelLocal_Plex() at
> /home/user/petsc/src/dm/impls/plex/plexproject.c:921
> [0]PETSC ERROR: #5 DMProjectFunctionLabelLocal() at
> /home/user/petsc/src/dm/interface/dm.c:8071
> [0]PETSC ERROR: #6 DMPlexInsertBoundaryValuesEssential() at
> /home/user/petsc/src/dm/impls/plex/plexfem.c:795
> [0]PETSC ERROR: #7 DMPlexInsertBoundaryValues_Plex() at
> /home/user/petsc/src/dm/impls/plex/plexfem.c:1046
> [0]PETSC ERROR: #8 DMPlexInsertBoundaryValues() at
> /home/user/petsc/src/dm/impls/plex/plexfem.c:1154
> [0]PETSC ERROR: #9 DMPlexSNESComputeBoundaryFEM() at
> /home/user/petsc/src/snes/utils/dmplexsnes.c:1372
> [0]PETSC ERROR: #10 SNESComputeFunction_DMLocal() at
> /home/user/petsc/src/snes/utils/dmlocalsnes.c:63
> [0]PETSC ERROR: #11 SNESComputeFunction() at
> /home/user/petsc/src/snes/interface/snes.c:2389
> [0]PETSC ERROR: #12 SNESSolve_NEWTONLS() at
> /home/user/petsc/src/snes/impls/ls/ls.c:172
> [0]PETSC ERROR: #13 SNESSolve() at
> /home/user/petsc/src/snes/interface/snes.c:4644
> [0]PETSC ERROR: #14 PetscConvEstGetConvRateSNES_Private() at
> /home/user/petsc/src/snes/utils/convest.c:369
> [0]PETSC ERROR: #15 PetscConvEstGetConvRate() at
> /home/user/petsc/src/snes/utils/convest.c:468
> [0]PETSC ERROR: #16 SNESSolve() at
> /home/user/petsc/src/snes/interface/snes.c:4561
> [0]PETSC ERROR: #17 main() at ex13.c:431
> [0]PETSC ERROR: Reached the main program with an out-of-range error code
> 584475600. This should never happen
> [0]PETSC ERROR: PETSc Option Table entries:
> [0]PETSC ERROR: -convest_num_refine 2 (source: command line)
> [0]PETSC ERROR: -potential_petscspace_degree 1 (source: command line)
> [0]PETSC ERROR: -snes_convergence_estimate (source: command line)
> [0]PETSC ERROR: -snes_monitor (source: command line)
> [0]PETSC ERROR: ----------------End of Error Message -------send entire
> error message to petsc-maint at mcs.anl.gov----------
> --------------------------------------------------------------------------
> MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_SELF
> with errorcode 584475600.
>
> NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
> You may or may not see output from other processes, depending on
> exactly when Open MPI kills them.
> --------------------------------------------------------------------------
>
>
> I have no idea why the program solves the original, more complicated,
> equation successfully while not being able to solve a simpler one.
> Any help or reference would be much appreciated!
>
--
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20230710/e462477c/attachment-0001.html>
More information about the petsc-users
mailing list