20 #ifndef LIBMESH_PETSC_PRECONDITIONER_H    21 #define LIBMESH_PETSC_PRECONDITIONER_H    23 #include "libmesh/libmesh_config.h"    25 #ifdef LIBMESH_HAVE_PETSC    28 #include "libmesh/preconditioner.h"    29 #include "libmesh/libmesh_common.h"    30 #include "libmesh/reference_counted_object.h"    31 #include "libmesh/libmesh.h"    32 #include "libmesh/petsc_macro.h"    33 #include "libmesh/wrapped_petsc.h"    42 template <
typename T> 
class SparseMatrix;
    43 template <
typename T> 
class NumericVector;
    44 template <
typename T> 
class ShellMatrix;
    69   virtual void clear () 
override;
    71   virtual void init () 
override;
   100 #endif // #ifdef LIBMESH_HAVE_PETSC   101 #endif // LIBMESH_PETSC_PRECONDITIONER_H 
This class provides an interface to the suite of preconditioners available from PETSc. 
Mat _mat
PETSc Mat pulled out of the _matrix object during init(). 
virtual void init() override
Initialize data structures if not done so already. 
Provides a uniform interface to vector storage schemes for different linear algebra libraries...
The libMesh namespace provides an interface to certain functionality in the library. 
virtual void apply(const NumericVector< T > &x, NumericVector< T > &y) override
Computes the preconditioned vector y based on input vector x. 
This class provides a uniform interface for preconditioners. 
WrappedPetsc< PC > _pc
Preconditioner context. 
PetscPreconditioner(const libMesh::Parallel::Communicator &comm_in)
Constructor. 
virtual void clear() override
Release all memory and clear data structures. 
static void set_petsc_preconditioner_type(const PreconditionerType &preconditioner_type, PC &pc)
Tells PETSc to use the user-specified preconditioner. 
PreconditionerType
Defines an enum for preconditioner types. 
virtual ~PetscPreconditioner()=default
void ErrorVector unsigned int