MFEM  v3.4
Finite element discretization library
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mfem::BlockOperator Class Reference

A class to handle Block systems in a matrix-free implementation. More...

#include <blockoperator.hpp>

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

 BlockOperator (const Array< int > &offsets)
 
 BlockOperator (const Array< int > &row_offsets, const Array< int > &col_offsets)
 Constructor for general BlockOperators. More...
 
void SetDiagonalBlock (int iblock, Operator *op, double c=1.0)
 Add block op in the block-entry (iblock, iblock). More...
 
void SetBlock (int iRow, int iCol, Operator *op, double c=1.0)
 Add a block op in the block-entry (iblock, jblock). More...
 
int NumRowBlocks () const
 Return the number of row blocks. More...
 
int NumColBlocks () const
 Return the number of column blocks. More...
 
int IsZeroBlock (int i, int j) const
 Check if block (i,j) is a zero block. More...
 
OperatorGetBlock (int i, int j)
 Return a reference to block i,j. More...
 
double GetBlockCoef (int i, int j) const
 Return the coefficient for block i,j. More...
 
void SetBlockCoef (int i, int j, double c)
 Set the coefficient for block i,j. More...
 
Array< int > & RowOffsets ()
 Return the row offsets for block starts. More...
 
Array< int > & ColOffsets ()
 Return the columns 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...
 
 ~BlockOperator ()
 
- 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 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
 

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 systems in a matrix-free implementation.

Usage:

If a block is not set, it is assumed to be a zero block.

Definition at line 34 of file blockoperator.hpp.

Constructor & Destructor Documentation

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

Constructor for BlockOperators with the same block-structure for rows and columns. offsets: offsets that mark the start of each row/column block (size nRowBlocks+1). Note: BlockOperator will not own/copy the data contained in offsets.

Definition at line 21 of file blockoperator.cpp.

mfem::BlockOperator::BlockOperator ( const Array< int > &  row_offsets,
const Array< int > &  col_offsets 
)

Constructor for general BlockOperators.

row_offsets: offsets that mark the start of each row block (size nRowBlocks+1). col_offsets: offsets that mark the start of each column block (size nColBlocks+1). Note: BlockOperator will not own/copy the data contained in offsets.

Definition at line 36 of file blockoperator.cpp.

mfem::BlockOperator::~BlockOperator ( )

Definition at line 117 of file blockoperator.cpp.

Member Function Documentation

Array<int>& mfem::BlockOperator::ColOffsets ( )
inline

Return the columns offsets for block starts.

Definition at line 89 of file blockoperator.hpp.

Operator& mfem::BlockOperator::GetBlock ( int  i,
int  j 
)
inline

Return a reference to block i,j.

Definition at line 77 of file blockoperator.hpp.

double mfem::BlockOperator::GetBlockCoef ( int  i,
int  j 
) const
inline

Return the coefficient for block i,j.

Definition at line 80 of file blockoperator.hpp.

int mfem::BlockOperator::IsZeroBlock ( int  i,
int  j 
) const
inline

Check if block (i,j) is a zero block.

Definition at line 75 of file blockoperator.hpp.

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

Operator application.

Implements mfem::Operator.

Definition at line 68 of file blockoperator.cpp.

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

Action of the transpose operator.

Reimplemented from mfem::Operator.

Definition at line 92 of file blockoperator.cpp.

int mfem::BlockOperator::NumColBlocks ( ) const
inline

Return the number of column blocks.

Definition at line 72 of file blockoperator.hpp.

int mfem::BlockOperator::NumRowBlocks ( ) const
inline

Return the number of row blocks.

Definition at line 70 of file blockoperator.hpp.

Array<int>& mfem::BlockOperator::RowOffsets ( )
inline

Return the row offsets for block starts.

Definition at line 87 of file blockoperator.hpp.

void mfem::BlockOperator::SetBlock ( int  iRow,
int  iCol,
Operator op,
double  c = 1.0 
)

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

irow, icol: The block will be inserted in location (irow, icol). op: the Operator to be inserted. c: optional scalar multiple for this block.

Definition at line 57 of file blockoperator.cpp.

void mfem::BlockOperator::SetBlockCoef ( int  i,
int  j,
double  c 
)
inline

Set the coefficient for block i,j.

Definition at line 83 of file blockoperator.hpp.

void mfem::BlockOperator::SetDiagonalBlock ( int  iblock,
Operator op,
double  c = 1.0 
)

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

iblock: The block will be inserted in location (iblock, iblock). op: the Operator to be inserted. c: optional scalar multiple for this block.

Definition at line 52 of file blockoperator.cpp.

Member Data Documentation

int mfem::BlockOperator::owns_blocks

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

Definition at line 101 of file blockoperator.hpp.


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