Reference documentation for deal.II version 9.2.0

#include <deal.II/multigrid/mg_base.h>
Public Member Functions  
virtual  ~MGTransferBase () override=default 
virtual void  prolongate (const unsigned int to_level, VectorType &dst, const VectorType &src) const =0 
virtual void  restrict_and_add (const unsigned int from_level, VectorType &dst, const VectorType &src) const =0 
Public Member Functions inherited from Subscriptor  
Subscriptor ()  
Subscriptor (const Subscriptor &)  
Subscriptor (Subscriptor &&) noexcept  
virtual  ~Subscriptor () 
Subscriptor &  operator= (const Subscriptor &) 
Subscriptor &  operator= (Subscriptor &&) noexcept 
void  subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
void  unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
unsigned int  n_subscriptions () const 
template<typename StreamType >  
void  list_subscribers (StreamType &stream) const 
void  list_subscribers () const 
template<class Archive >  
void  serialize (Archive &ar, const unsigned int version) 
Additional Inherited Members  
Static Public Member Functions inherited from Subscriptor  
static ::ExceptionBase &  ExcInUse (int arg1, std::string arg2, std::string arg3) 
static ::ExceptionBase &  ExcNoSubscriber (std::string arg1, std::string arg2) 
Base class used to declare the operations needed by a concrete class implementing prolongation and restriction of vectors in the multigrid context. This class is abstract and has no implementation of these operations.
There are several derived classes, reflecting the fact that vector types and numbering of the finegrid discretization and of the multilevel implementation are independent.
If you use multigrid for a single PDE or for your complete system of equations, you will use MGTransferPrebuilt together with Multigrid. The vector types used on the fine grid as well as for the multilevel operations may be Vector or BlockVector. In both cases, MGTransferPrebuilt will operate on all components of the solution.
For mixed systems, it may be required to do multigrid only for a single component or for some components. The classes MGTransferSelect and MGTransferBlock handle these cases.
MGTransferSelect is used if you use multigrid (on Vector objects) for a single component, possibly grouped using mg_target_component
.
The class MGTransferBlock handles the case where your multigrid method operates on BlockVector objects. These can contain all or a consecutive set of the blocks of the complete system. Since most smoothers cannot operate on block structures, it is not clear whether this case is really useful. Therefore, a tested implementation of this case will be supplied when needed.

overridevirtualdefault 
Destructor. Does nothing here, but needs to be declared virtual anyway.

pure virtual 
Prolongate a vector from level to_level1
to level to_level
. The previous content of dst
is overwritten.
Implemented in MGTransferPrebuilt< VectorType >, MGTransferBlockSelect< number >, MGTransferBlockMatrixFree< dim, Number >, MGTransferSelect< number >, MGTransferBlock< number >, and MGTransferMatrixFree< dim, Number >.

pure virtual 
Restrict a vector from level from_level
to level from_level1
and add this restriction to dst
. If the region covered by cells on level from_level
is smaller than that of level from_level1
(local refinement), then some degrees of freedom in dst
are active and will not be altered. For the other degrees of freedom, the result of the restriction is added.
Implemented in MGTransferPrebuilt< VectorType >, MGTransferBlockMatrixFree< dim, Number >, MGTransferBlockSelect< number >, MGTransferSelect< number >, MGTransferBlock< number >, and MGTransferMatrixFree< dim, Number >.