petsc_shell_matrix.h

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2019 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner
 
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
#ifndef LIBMESH_PETSC_SHELL_MATRIX_H
#define LIBMESH_PETSC_SHELL_MATRIX_H
 
 
#include "libmesh/libmesh_config.h"
#ifdef LIBMESH_HAVE_PETSC
 
 
// Local includes
#include "libmesh/libmesh_common.h"
#include "libmesh/reference_counted_object.h"
#include "libmesh/libmesh.h"
#include "libmesh/shell_matrix.h"
#include "libmesh/petsc_macro.h"
#include "libmesh/petsc_solver_exception.h"
#include "libmesh/petsc_vector.h"
#include "libmesh/libmesh_common.h"
 
// Petsc include files.
#ifdef I
# define LIBMESH_SAW_I
#endif
#include <petscmat.h>
#ifndef LIBMESH_SAW_I
# undef I // Avoid complex.h contamination
#endif
 
namespace libMesh
{
 
template <typename T>
class PetscShellMatrix : public ShellMatrix<T>
{
public:
 
  PetscShellMatrix (const Parallel::Communicator & comm_in);
 
  virtual ~PetscShellMatrix ();
 
  virtual numeric_index_type m () const override;
 
  virtual numeric_index_type n () const override;
 
  virtual numeric_index_type local_m () const;
 
  virtual numeric_index_type local_n () const;
 
  virtual void vector_mult (NumericVector<T> & dest,
                            const NumericVector<T> & arg) const override;
 
  virtual void vector_mult_add (NumericVector<T> & dest,
                                const NumericVector<T> & arg) const override;
 
  virtual void get_diagonal (NumericVector<T> & dest) const override;
 
  virtual void clear () override;
 
  virtual void init () override;
 
  virtual bool initialized() const { return _is_initialized; }
 
  Mat mat() { if (_mat) return _mat; else libmesh_error_msg("A petsc shell matrix is not created yet. Please init() "); }
 
protected:
 
  Mat  _mat;
 
  bool _is_initialized;
};
 
 
//-----------------------------------------------------------------------
// PetscShellMatrix inline members
template <typename T>
inline
PetscShellMatrix<T>::PetscShellMatrix (const Parallel::Communicator & comm_in):
  ShellMatrix<T>(comm_in),
  _mat(nullptr),
  _is_initialized(false)
{}
 
 
 
template <typename T>
inline
PetscShellMatrix<T>::~PetscShellMatrix ()
{
  this->clear();
}
 
 
 
template <typename T>
inline
numeric_index_type PetscShellMatrix<T>::m () const
{
  PetscErrorCode ierr;
  PetscInt m;
 
  ierr = MatGetSize(_mat,&m,nullptr);
  LIBMESH_CHKERR(ierr);
 
  return m;
}
 
 
 
template <typename T>
inline
numeric_index_type PetscShellMatrix<T>::n () const
{
  PetscErrorCode ierr;
  PetscInt n;
 
  ierr = MatGetSize(_mat,nullptr,&n);
  LIBMESH_CHKERR(ierr);
 
  return n;
}
 
 
template <typename T>
inline
numeric_index_type PetscShellMatrix<T>::local_m () const
{
  PetscErrorCode ierr;
  PetscInt m;
 
  ierr = MatGetLocalSize(_mat,&m,nullptr);
  LIBMESH_CHKERR(ierr);
 
  return m;
}
 
 
 
template <typename T>
inline
numeric_index_type PetscShellMatrix<T>::local_n () const
{
  PetscErrorCode ierr;
  PetscInt n;
 
  ierr = MatGetLocalSize(_mat,nullptr,&n);
  LIBMESH_CHKERR(ierr);
 
  return n;
}
 
 
template <typename T>
inline
void PetscShellMatrix<T>::get_diagonal (NumericVector<T> & dest) const
{
  // Make sure the NumericVector passed in is really a PetscVector
  PetscVector<T> & petsc_dest = cast_ref<PetscVector<T> &>(dest);
 
  PetscErrorCode ierr =
    MatGetDiagonal(_mat,petsc_dest.vec()); LIBMESH_CHKERR(ierr);
}
 
 
 
} // namespace libMesh
 
#endif // LIBMESH_HAVE_PETSC
#endif // LIBMESH_SPARSE_SHELL_MATRIX_H