Reference documentation for deal.II version Git 5ef709c 20150703 17:04:49 +0200

#include <deal.II/lac/trilinos_precondition.h>
Classes  
struct  AdditionalData 
Public Member Functions  
void  initialize (const SparseMatrix &matrix, const AdditionalData &additional_data=AdditionalData()) 
Public Member Functions inherited from TrilinosWrappers::PreconditionBase  
PreconditionBase ()  
PreconditionBase (const PreconditionBase &)  
~PreconditionBase ()  
void  clear () 
virtual void  vmult (VectorBase &dst, const VectorBase &src) const 
virtual void  Tvmult (VectorBase &dst, const VectorBase &src) const 
virtual void  vmult (::Vector< double > &dst, const ::Vector< double > &src) const 
virtual void  Tvmult (::Vector< double > &dst, const ::Vector< double > &src) const 
virtual void  vmult (::parallel::distributed::Vector< double > &dst, const ::parallel::distributed::Vector< double > &src) const 
virtual void  Tvmult (::parallel::distributed::Vector< double > &dst, const ::parallel::distributed::Vector< double > &src) const 
DeclException1 (ExcNonMatchingMaps, std::string,<< "The sparse matrix the preconditioner is based on "<< "uses a map that is not compatible to the one in vector "<< arg1<< ". Check preconditioner and matrix setup.")  
Public Member Functions inherited from Subscriptor  
Subscriptor ()  
Subscriptor (const Subscriptor &)  
virtual  ~Subscriptor () 
Subscriptor &  operator= (const Subscriptor &) 
void  subscribe (const char *identifier=0) const 
void  unsubscribe (const char *identifier=0) const 
unsigned int  n_subscriptions () const 
void  list_subscribers () const 
DeclException3 (ExcInUse, int, char *, std::string &,<< "Object of class "<< arg2<< " is still used by "<< arg1<< " other objects."<< "\n\n"<< "(Additional information: "<< arg3<< ")\n\n"<< "See the entry in the Frequently Asked Questions of "<< "deal.II (linked to from http://www.dealii.org/) for "<< "a lot more information on what this error means and "<< "how to fix programs in which it happens.")  
DeclException2 (ExcNoSubscriber, char *, char *,<< "No subscriber with identifier <"<< arg2<< "> subscribes to this object of class "<< arg1<< ". Consequently, it cannot be unsubscribed.")  
template<class Archive >  
void  serialize (Archive &ar, const unsigned int version) 
Additional Inherited Members  
Public Types inherited from TrilinosWrappers::PreconditionBase  
typedef ::types::global_dof_index  size_type 
Protected Attributes inherited from TrilinosWrappers::PreconditionBase  
std_cxx11::shared_ptr< Epetra_Operator >  preconditioner 
Epetra_MpiComm  communicator 
std_cxx11::shared_ptr< Epetra_Map >  vector_distributor 
A wrapper class for an incomplete Cholesky factorization (IC) preconditioner for symmetric Trilinos matrices. This preconditioner works both in serial and in parallel, depending on the matrix it is based on. In general, an incomplete factorization does not take all fillin elements that would appear in a full factorization (that is the basis for a direct solve). Trilinos allows to set the amount of fillin elements, governed by the additional data argument ic_fill
, so one can gradually choose between a factorization on the sparse matrix structure only (ic_fill=0
) to a full factorization (ic_fill
in the range of 10 to 50, depending on the spatial dimension of the PDE problem and the degree of the finite element basis functions; generally, more required fillin elements require this parameter to be set to a higher integer value).
The AdditionalData data structure allows to set preconditioner options. Besides the fillin argument, these options are some options for perturbations (see the documentation of the AdditionalData structure for details), and a parameter overlap
that determines if and how much overlap there should be between the matrix partitions on the various MPI processes. The default settings are 0 for the additional fillin, 0 for the absolute augmentation tolerance, 1 for the relative augmentation tolerance, 0 for the overlap.
Note that a parallel application of the IC preconditioner is actually a blockJacobi preconditioner with block size equal to the local matrix size. Spoken more technically, this parallel operation is an additive Schwarz method with an IC approximate solve as inner solver, based on the (outer) parallel partitioning.
Definition at line 814 of file trilinos_precondition.h.
void TrilinosWrappers::PreconditionIC::initialize  (  const SparseMatrix &  matrix, 
const AdditionalData &  additional_data = AdditionalData() 

) 
Initialize function. Takes the matrix the preconditioner should be computed of, and additional flags if there are any.