petsc_parallel_full_matrix.cc

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// -----------------------------------------------------------------------------
//
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception OR LGPL-2.1-or-later
// Copyright (C) 2004 - 2026 by the deal.II authors
//
// This file is part of the deal.II library.
//
// Detailed license information governing the source code and contributions
// can be found in LICENSE.md and CONTRIBUTING.md at the top level directory.
//
// -----------------------------------------------------------------------------
 
#include <deal.II/lac/petsc_full_matrix.h>
 
#ifdef DEAL_II_WITH_PETSC
 
#  include <deal.II/base/mpi.h>
 
#  include <deal.II/lac/exceptions.h>
#  include <deal.II/lac/petsc_compatibility.h>
#  include <deal.II/lac/petsc_vector.h>
 
 
#endif // DEAL_II_WITH_PETSC
 
DEAL_II_NAMESPACE_OPEN
 
#ifdef DEAL_II_WITH_PETSC
 
namespace PETScWrappers
{
  namespace MPI
  {
    FullMatrix::FullMatrix()
    {
      // just like for vectors and sparse matrices: since we
      // create an empty matrix, we can as
      // well make it sequential
      const PetscInt       m = 0, n = 0;
      const PetscErrorCode ierr =
        MatCreateSeqDense(PETSC_COMM_SELF, m, n, nullptr, &matrix);
      AssertThrow(ierr == 0, ExcPETScError(ierr));
    }
 
 
 
    FullMatrix::FullMatrix(const Mat &A)
      : MatrixBase(A)
    {}
 
 
 
    FullMatrix::~FullMatrix()
    {
      PetscErrorCode ierr = MatDestroy(&matrix);
      AssertNothrow(ierr == 0, ExcPETScError(ierr));
    }
 
 
 
    FullMatrix::FullMatrix(const MPI_Comm  communicator,
                           const size_type m,
                           const size_type n,
                           const size_type local_rows_per_process,
                           const size_type local_columns_per_process)
    {
      do_reinit(
        communicator, m, n, local_rows_per_process, local_columns_per_process);
    }
 
 
 
    void
    FullMatrix::reinit(const MPI_Comm  communicator,
                       const size_type m,
                       const size_type n,
                       const size_type local_rows_per_process,
                       const size_type local_columns_per_process)
    {
      // get rid of old matrix and generate a new one
      const PetscErrorCode ierr = MatDestroy(&matrix);
      AssertThrow(ierr == 0, ExcPETScError(ierr));
 
      do_reinit(
        communicator, m, n, local_rows_per_process, local_columns_per_process);
    }
 
 
 
    FullMatrix &
    FullMatrix::operator=(const value_type d)
    {
      MatrixBase::operator=(d);
      return *this;
    }
 
 
 
    void
    FullMatrix::do_reinit(const MPI_Comm  communicator,
                          const size_type m,
                          const size_type n,
                          const size_type local_rows_per_process,
                          const size_type local_columns_per_process)
    {
      // convert dimensions into PETScInt
      AssertThrowIntegerConversion(static_cast<PetscInt>(m), m);
      AssertThrowIntegerConversion(static_cast<PetscInt>(n), n);
 
      // create a matrix
      // this will create by default a sequential dense matrix(MATSEQDENSE) if
      // constructed with a single process communicator and a distributed dense
      // matrix (MATMPIDENSE) if constructed with more than one.
      PetscErrorCode ierr = MatCreateDense(communicator,
                                           local_rows_per_process,
                                           local_columns_per_process,
                                           m,
                                           n,
                                           nullptr,
                                           &matrix);
      AssertThrow(ierr == 0, ExcPETScError(ierr));
    }
 
 
 
  } // namespace MPI
 
} // namespace PETScWrappers
 
#endif // DEAL_II_WITH_PETSC
DEAL_II_NAMESPACE_CLOSE