MFEM  v4.0
Finite element discretization library
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mfem::BlockLowerTriangularPreconditioner Class Reference

A class to handle Block lower triangular preconditioners in a matrix-free implementation. More...

#include <blockoperator.hpp>

Inheritance diagram for mfem::BlockLowerTriangularPreconditioner:
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Collaboration diagram for mfem::BlockLowerTriangularPreconditioner:
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Public Member Functions

 BlockLowerTriangularPreconditioner (const Array< int > &offsets)
 
void SetDiagonalBlock (int iblock, Operator *op)
 Add block op in the block-entry (iblock, iblock). More...
 
void SetBlock (int iRow, int iCol, Operator *op)
 Add a block op in the block-entry (iblock, jblock). More...
 
virtual void SetOperator (const Operator &op)
 This method is present since required by the abstract base class Solver. More...
 
int NumBlocks () const
 Return the number of blocks. More...
 
OperatorGetBlock (int iblock, int jblock)
 Return a reference to block i,j. More...
 
Array< int > & Offsets ()
 Return the offsets for block starts. More...
 
virtual void Mult (const Vector &x, Vector &y) const
 Operator application. More...
 
virtual void MultTranspose (const Vector &x, Vector &y) const
 Action of the transpose operator. More...
 
 ~BlockLowerTriangularPreconditioner ()
 
- Public Member Functions inherited from mfem::Solver
 Solver (int s=0, bool iter_mode=false)
 Initialize a square Solver with size s. More...
 
 Solver (int h, int w, bool iter_mode=false)
 Initialize a Solver with height h and width w. More...
 
- Public Member Functions inherited from mfem::Operator
 Operator (int s=0)
 Construct a square Operator with given size s (default 0). More...
 
 Operator (int h, int w)
 Construct an Operator with the given height (output size) and width (input size). More...
 
int Height () const
 Get the height (size of output) of the Operator. Synonym with NumRows(). More...
 
int NumRows () const
 Get the number of rows (size of output) of the Operator. Synonym with Height(). More...
 
int Width () const
 Get the width (size of input) of the Operator. Synonym with NumCols(). More...
 
int NumCols () const
 Get the number of columns (size of input) of the Operator. Synonym with Width(). More...
 
virtual MemoryClass GetMemoryClass () const
 Return the MemoryClass preferred by the Operator. More...
 
virtual OperatorGetGradient (const Vector &x) const
 Evaluate the gradient operator at the point x. The default behavior in class Operator is to generate an error. More...
 
virtual const OperatorGetProlongation () const
 Prolongation operator from linear algebra (linear system) vectors, to input vectors for the operator. NULL means identity. More...
 
virtual const OperatorGetRestriction () const
 Restriction operator from input vectors for the operator to linear algebra (linear system) vectors. NULL means identity. More...
 
void FormLinearSystem (const Array< int > &ess_tdof_list, Vector &x, Vector &b, Operator *&A, Vector &X, Vector &B, int copy_interior=0)
 Form a constrained linear system using a matrix-free approach. More...
 
virtual void RecoverFEMSolution (const Vector &X, const Vector &b, Vector &x)
 Reconstruct a solution vector x (e.g. a GridFunction) from the solution X of a constrained linear system obtained from Operator::FormLinearSystem(). More...
 
void PrintMatlab (std::ostream &out, int n=0, int m=0) const
 Prints operator with input size n and output size m in Matlab format. More...
 
virtual ~Operator ()
 Virtual destructor. More...
 
Type GetType () const
 Return the type ID of the Operator class. More...
 

Public Attributes

int owns_blocks
 
- Public Attributes inherited from mfem::Solver
bool iterative_mode
 If true, use the second argument of Mult() as an initial guess. More...
 

Additional Inherited Members

- Public Types inherited from mfem::Operator
enum  Type {
  ANY_TYPE, MFEM_SPARSEMAT, Hypre_ParCSR, PETSC_MATAIJ,
  PETSC_MATIS, PETSC_MATSHELL, PETSC_MATNEST, PETSC_MATHYPRE,
  PETSC_MATGENERIC
}
 Enumeration defining IDs for some classes derived from Operator. More...
 
- Protected Attributes inherited from mfem::Operator
int height
 Dimension of the output / number of rows in the matrix. More...
 
int width
 Dimension of the input / number of columns in the matrix. More...
 

Detailed Description

A class to handle Block lower triangular preconditioners in a matrix-free implementation.

Usage:

If a diagonal block is not set, it is assumed to be an identity block, if an off-diagonal block is not set, it is assumed to be a zero block.

Definition at line 203 of file blockoperator.hpp.

Constructor & Destructor Documentation

mfem::BlockLowerTriangularPreconditioner::BlockLowerTriangularPreconditioner ( const Array< int > &  offsets)

Constructor for BlockLowerTriangularPreconditioners with the same block-structure for rows and columns.

Parameters
offsetsOffsets that mark the start of each row/column block (size nBlocks+1).
Note
BlockLowerTriangularPreconditioner will not own/copy the data contained in offsets.

Definition at line 210 of file blockoperator.cpp.

mfem::BlockLowerTriangularPreconditioner::~BlockLowerTriangularPreconditioner ( )

Definition at line 315 of file blockoperator.cpp.

Member Function Documentation

Operator& mfem::BlockLowerTriangularPreconditioner::GetBlock ( int  iblock,
int  jblock 
)
inline

Return a reference to block i,j.

Definition at line 236 of file blockoperator.hpp.

void mfem::BlockLowerTriangularPreconditioner::Mult ( const Vector x,
Vector y 
) const
virtual

Operator application.

Implements mfem::Operator.

Definition at line 244 of file blockoperator.cpp.

void mfem::BlockLowerTriangularPreconditioner::MultTranspose ( const Vector x,
Vector y 
) const
virtual

Action of the transpose operator.

Reimplemented from mfem::Operator.

Definition at line 280 of file blockoperator.cpp.

int mfem::BlockLowerTriangularPreconditioner::NumBlocks ( ) const
inline

Return the number of blocks.

Definition at line 233 of file blockoperator.hpp.

Array<int>& mfem::BlockLowerTriangularPreconditioner::Offsets ( )
inline

Return the offsets for block starts.

Definition at line 240 of file blockoperator.hpp.

void mfem::BlockLowerTriangularPreconditioner::SetBlock ( int  iRow,
int  iCol,
Operator op 
)

Add a block op in the block-entry (iblock, jblock).

Parameters
iRow,iColThe block will be inserted in location (iRow, iCol).
opThe Operator to be inserted.

Definition at line 232 of file blockoperator.cpp.

void mfem::BlockLowerTriangularPreconditioner::SetDiagonalBlock ( int  iblock,
Operator op 
)

Add block op in the block-entry (iblock, iblock).

Parameters
iblockThe block will be inserted in location (iblock, iblock).
opThe Operator to be inserted.

Definition at line 222 of file blockoperator.cpp.

virtual void mfem::BlockLowerTriangularPreconditioner::SetOperator ( const Operator op)
inlinevirtual

This method is present since required by the abstract base class Solver.

Implements mfem::Solver.

Definition at line 230 of file blockoperator.hpp.

Member Data Documentation

int mfem::BlockLowerTriangularPreconditioner::owns_blocks

Controls the ownership of the blocks: if nonzero, BlockLowerTriangularPreconditioner will delete all blocks that are set (non-NULL); the default value is zero.

Definition at line 253 of file blockoperator.hpp.


The documentation for this class was generated from the following files: