The PETSc matrix fix is easy: You don't do a sparsity pattern then copy with PETSc and Trilinos matrices You should've had a SparsityTools::dsitribute_sparsity_pattern call after the make sparsity pattern call. This is a standard. Look at step40.
Abbas On Saturday, November 29, 2025 at 12:19:23 AM UTC+1 [email protected] wrote: > Hi everyone, > > I am using MatrixFree framework with geometric multigrid in dealii. I am > trying to implement a matrix-based coarse grid solver that uses PETSc AMG > as a preconditioner. However, I have encountered a problem: under certain > conditions (which I describe below), > the MatrixFreeTools::compute_matrix() function fails to compute the coarse > system matrix. I reproduced the same error using a modified version of the > tutorial code of step-75. The error is as follows: > > ``` > [3]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > [3]PETSC ERROR: Argument out of range > [3]PETSC ERROR: Inserting a new nonzero at global row/column (30, 35) into > matrix > [3]PETSC ERROR: See https://petsc.org/release/faq/ for trouble shooting. > [3]PETSC ERROR: Petsc Release Version 3.21.4, Jul 30, 2024 > [3]PETSC ERROR: step-75 on a arch-linux-c-opt named paragon by dg615 Fri > Nov 28 22:32:54 2025 > [3]PETSC ERROR: Configure options --with-cc=mpicc --with-cxx=mpicxx > --with-fc=mpif90 --with-debugging=0 COPTFLAGS="-O3 -march=native > -mtune=native" CXXOPTFLAGS="-O3 -march=native -mtune=native" FOPTFLAGS="-O3 > -march=native -mtune=native" --with-blaslapack-dir=/opt/intel/mkl > --download-superlu_dist --download-superlu --download-metis > --download-parmetis --download-mumps --download-scalapack --download-hypre > --download-hdf5 --download-fftw --download-suitesparse --download-cmake > [3]PETSC ERROR: #1 MatSetValues_MPIAIJ() at > /home/dg615/proj/petsc/petsc-3.21.4/src/mat/impls/aij/mpi/mpiaij.c:592 > [3]PETSC ERROR: #2 MatAssemblyEnd_MPIAIJ() at > /home/dg615/proj/petsc/petsc-3.21.4/src/mat/impls/aij/mpi/mpiaij.c:777 > [3]PETSC ERROR: #3 MatAssemblyEnd() at > /home/dg615/proj/petsc/petsc-3.21.4/src/mat/interface/matrix.c:5820 > ``` > > The block of code that produces the error is the following: > > ``` > template <int dim, typename number> > const PETScWrappers::MPI::SparseMatrix & > LaplaceOperator<dim, number>::get_system_matrix() const > { > if (system_matrix.m() == 0 && system_matrix.n() == 0) > { > const auto &dof_handler = this->matrix_free.get_dof_handler(); > > // MODIFIED starts > // > ======================================================================= > const IndexSet &owned_dofs = dof_handler.locally_owned_dofs(); > const IndexSet &relevant_dofs = DoFTools:: > extract_locally_relevant_dofs(dof_handler); > const IndexSet &used_dofs = owned_dofs; // using relevant_dofs > here gives an error > DynamicSparsityPattern dsp(used_dofs); > > DoFTools::make_sparsity_pattern(dof_handler, dsp, this-> > constraints); > > SparsityPattern sp; > sp.copy_from(dsp); > system_matrix.reinit( > used_dofs, > used_dofs, > sp, > dof_handler.get_triangulation().get_mpi_communicator() > ); > // > ======================================================================= > // MODIFIED ends > > // The error is thrown from the function below > MatrixFreeTools::compute_matrix( > matrix_free, > constraints, > system_matrix, > &LaplaceOperator::do_cell_integral_local, > this); > } > > return this->system_matrix; > } > ``` > I've also attached the modified step-75.cc file. You can find the modified > area of the code by searching MODIFIED keyword. I also changed the code to > run with PETSc (originally Trilinos; NOTE: you might have to modify the > CMakeLists.txt file not to require Trilinos if you don't have Trilinos > installed (I don't) and are pasting the step-75.cc file into the tutorial > folder). > > Error condition: in my code the coarse grid is a cuboid with some number > of global refinements, the error occurs when the number of those > refinements is > 2. In step-75 modified code the error occurs when the > variable `minLevel` is set to anything above 0. > > I have tried using locally_relevant_dofs instead of locally_owned_dofs but > in that case i get a different error: > > ``` > An error occurred in line <203> of file > </home/dg615/proj/petsc/dealii-9.7.0/source/lac/petsc_parallel_sparse_matrix.cc> > > in function > void dealii::PETScWrappers::MPI::SparseMatrix::do_reinit(MPI_Comm, > const dealii::IndexSet&, const dealii::IndexSet&, const > SparsityPatternType&) [with SparsityPatternType = dealii::SparsityPattern; > MPI_Comm = ompi_communicator_t*] > The violated condition was: > local_rows.is_contiguous() && local_columns.is_contiguous() > Additional information: > PETSc only supports contiguous row/column ranges > ``` > > Can someone please let me know how I can fix this issue? Is it internal to > dealii/PETSc or is it something I've missed? I know I could assemble the > coarse matrices using the standard matrix-based assembly logic, but I was > wondering if it could be done entirely in the MF infrastructure. > > Thank you. > > Best wishes, > Davit Gyulamiryan > > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/dealii/01bc320f-9994-4487-b48c-6b756e861680n%40googlegroups.com.
