ptems::Preconditioner< T > Struct Template Reference

Defines the interface for a left, right, or split preconditioner. More...

#include <ptems/solvers/gmres.hpp>

Inheritance diagram for ptems::Preconditioner< T >:

Public Types
typedef T	value_type
	The entry types of the matrix to precondition. More...

Public Member Functions
virtual void	Initialise (const ParallelComm &comm, const std::vector< SparseMatrixEntry< T >> &mat, std::size_t firstRow, std::size_t size, const std::vector< std::size_t > rowOffset)=0
	Initialise the preconditioner for the specified matrix. More...
virtual void	ApplyLeft (const ParallelComm &comm, std::vector< T > &rhs)=0
	Apply the left preconditioner to the specified vector overriding the vector with the result. More...
virtual void	ApplyRight (const ParallelComm &comm, std::vector< T > &rhs)=0
	Apply the right preconditioner to the specified vector overriding the vector with the result. More...
virtual PreconditionerType	Type () const =0
	Gets the type of the preconditioner. More...

Detailed Description

template<typename T>
struct ptems::Preconditioner< T >

Defines the interface for a left, right, or split preconditioner.

For a preconditioner \(M\) to the matrix \(A\) we define left, right, and split preconditioners as follows:

• Left preconditioned system: \( M^{-1}Ax = M^{-1}b \)
• Right preconditioned system: \( AM^{-1}u = b\), where \(u=Mx\)
• Split preconditioned system: \( L^{-1}AU^{-1}x = L^{-1}b \), where \(u=Ux\) and \(M=LU\).

Template Parameters

The	type of the matrix entries the pre-conditioner is for

Member Typedef Documentation

value_type

template<typename T >

typedef T ptems::Preconditioner< T >::value_type

The entry types of the matrix to precondition.

Member Function Documentation

ApplyLeft()

template<typename T >

virtual void ptems::Preconditioner< T >::ApplyLeft ( const ParallelComm &  comm, std::vector< T > &  rhs  )

pure virtual

Apply the left preconditioner to the specified vector overriding the vector with the result.

Attention

If the preconditioner is a right preconditioner this method must perform a no-op (return vector unchanged)

Parameters

comm	MPI communicator for parallel preconditioning
rhs	Vector to precondition (contains complete vector NOT slice). Update with the preconditioned vector

Implemented in ptems::ILUPreconditioner< T >, and ptems::RightPreconditioner< T >.

ApplyRight()

template<typename T >

virtual void ptems::Preconditioner< T >::ApplyRight ( const ParallelComm &  comm, std::vector< T > &  rhs  )

pure virtual

Apply the right preconditioner to the specified vector overriding the vector with the result.

Attention

If the preconditioner is a left preconditioner this method must perform a no-op (return vector unchanged)

Parameters

comm	MPI communicator for parallel preconditioning
rhs	Vector to precondition (contains complete vector NOT slice). Update with the preconditioned vector

Implemented in ptems::ILUPreconditioner< T >, and ptems::LeftPreconditioner< T >.

Initialise()

template<typename T >

virtual void ptems::Preconditioner< T >::Initialise ( const ParallelComm &  comm, const std::vector< SparseMatrixEntry< T >> &  mat, std::size_t  firstRow, std::size_t  size, const std::vector< std::size_t >  rowOffset  )

pure virtual

Initialise the preconditioner for the specified matrix.

The preconditioner can be called with a "slice" if using MPI (different processors get different slices)

Attention

If the linear solver is reused (for example in non-linear solvers) this method may be called multiply times with different matrices. The underlying implementation must, therefore, treat each call as a complete new initialisation (essentially construction) of the preconditioner.

Parameters

comm	MPI communicator for parallel preconditioning
mat	The slice of the matrix for the current process as a sparse matrix. Entries are ordered by row, then column
firstRow	The row index of the first row in the slice
size	The number of rows (and columns) of the FULL matrix
rowOffset	The offset into mat for each row in the slice (the offset with index 0 is for firstRow (and will always by 0), 1 for firstRow+1 etc.)

Implemented in ptems::ILUPreconditioner< T >.

Type()

template<typename T >

virtual PreconditionerType ptems::Preconditioner< T >::Type ( ) const

pure virtual

Gets the type of the preconditioner.

Implemented in ptems::ILUPreconditioner< T >, ptems::SplitPreconditioner< T >, ptems::RightPreconditioner< T >, and ptems::LeftPreconditioner< T >.

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The documentation for this struct was generated from the following file:

• ptems/solvers/gmres.hpp