mfem::DiscreteLinearOperator Class Reference

#include <bilinearform.hpp>

Inheritance diagram for mfem::DiscreteLinearOperator:

Collaboration diagram for mfem::DiscreteLinearOperator:

Public Member Functions
	DiscreteLinearOperator (FiniteElementSpace *domain_fes, FiniteElementSpace *range_fes)
void	AddDomainInterpolator (DiscreteInterpolator *di)
void	AddTraceFaceInterpolator (DiscreteInterpolator *di)
Array< BilinearFormIntegrator * > *	GetDI ()
virtual void	Assemble (int skip_zeros=1)
Public Member Functions inherited from mfem::MixedBilinearForm
	MixedBilinearForm (FiniteElementSpace *tr_fes, FiniteElementSpace *te_fes)
virtual double &	Elem (int i, int j)
	Returns reference to a_{ij}. More...
virtual const double &	Elem (int i, int j) const
	Returns constant reference to a_{ij}. More...
virtual void	Mult (const Vector &x, Vector &y) const
	Operator application: y=A(x). More...
virtual void	AddMult (const Vector &x, Vector &y, const double a=1.0) const
virtual void	AddMultTranspose (const Vector &x, Vector &y, const double a=1.0) const
virtual void	MultTranspose (const Vector &x, Vector &y) const
	Action of the transpose operator: y=A^t(x). The default behavior in class Operator is to generate an error. More...
virtual MatrixInverse *	Inverse () const
	Returns a pointer to (an approximation) of the matrix inverse. More...
virtual void	Finalize (int skip_zeros=1)
	Finalizes the matrix initialization. More...
void	GetBlocks (Array2D< SparseMatrix * > &blocks) const
const SparseMatrix &	SpMat () const
SparseMatrix &	SpMat ()
SparseMatrix *	LoseMat ()
void	AddDomainIntegrator (BilinearFormIntegrator *bfi)
void	AddBoundaryIntegrator (BilinearFormIntegrator *bfi)
void	AddTraceFaceIntegrator (BilinearFormIntegrator *bfi)
Array< BilinearFormIntegrator * > *	GetDBFI ()
Array< BilinearFormIntegrator * > *	GetBBFI ()
Array< BilinearFormIntegrator * > *	GetTFBFI ()
void	operator= (const double a)
void	Assemble (int skip_zeros=1)
void	ConformingAssemble ()
void	EliminateTrialDofs (Array< int > &bdr_attr_is_ess, const Vector &sol, Vector &rhs)
void	EliminateEssentialBCFromTrialDofs (Array< int > &marked_vdofs, const Vector &sol, Vector &rhs)
virtual void	EliminateTestDofs (Array< int > &bdr_attr_is_ess)
void	Update ()
virtual	~MixedBilinearForm ()
Public Member Functions inherited from mfem::Matrix
	Matrix (int s)
	Creates a square matrix of size s. More...
	Matrix (int h, int w)
	Creates a matrix of the given height and width. More...
virtual void	Print (std::ostream &out=mfem::out, int width_=4) const
	Prints matrix to stream out. More...
virtual	~Matrix ()
	Destroys matrix. 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 Operator &	GetGradient (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 Operator *	GetProlongation () const
	Prolongation operator from linear algebra (linear system) vectors, to input vectors for the operator. NULL means identity. More...
virtual const Operator *	GetRestriction () 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...

Additional Inherited Members
Public Types inherited from mfem::Matrix
enum	DiagonalPolicy { DIAG_ZERO, DIAG_ONE, DIAG_KEEP }
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::MixedBilinearForm
SparseMatrix *	mat
FiniteElementSpace *	trial_fes
FiniteElementSpace *	test_fes
Array< BilinearFormIntegrator * >	dom
Array< BilinearFormIntegrator * >	bdr
Array< BilinearFormIntegrator * >	skt
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

Class for constructing the matrix representation of a linear operator, v = L u, from one FiniteElementSpace (domain) to another FiniteElementSpace (range). The constructed matrix A is such that

V = A U

where U and V are the vectors of degrees of freedom representing the functions u and v, respectively. The dimensions of A are

number of rows of A = dimension of the range space and
number of cols of A = dimension of the domain space.

This class is very similar to MixedBilinearForm. One difference is that the linear operator L is defined using a special kind of BilinearFormIntegrator (we reuse its functionality instead of defining a new class). The other difference with the MixedBilinearForm class is that the "assembly" process overwrites the global matrix entries using the local element matrices instead of adding them.

Note that if we define the bilinear form b(u,v) := (Lu,v) using an inner product in the range space, then its matrix representation, B, is

B = M A, (since V^t B U = b(u,v) = (Lu,v) = V^t M A U)

where M denotes the mass matrix for the inner product in the range space: V1^t M V2 = (v1,v2). Similarly, if c(u,w) := (Lu,Lw) then

C = A^t M A.

Definition at line 506 of file bilinearform.hpp.

Constructor & Destructor Documentation

mfem::DiscreteLinearOperator::DiscreteLinearOperator ( FiniteElementSpace *  domain_fes, FiniteElementSpace *  range_fes  )

inline

Definition at line 509 of file bilinearform.hpp.

Member Function Documentation

void mfem::DiscreteLinearOperator::AddDomainInterpolator ( DiscreteInterpolator *  di )

inline

Definition at line 513 of file bilinearform.hpp.

void mfem::DiscreteLinearOperator::AddTraceFaceInterpolator ( DiscreteInterpolator *  di )

inline

Definition at line 516 of file bilinearform.hpp.

void mfem::DiscreteLinearOperator::Assemble ( int  skip_zeros = 1 )

virtual

Definition at line 1189 of file bilinearform.cpp.

Array<BilinearFormIntegrator*>* mfem::DiscreteLinearOperator::GetDI ( )

inline

Definition at line 519 of file bilinearform.hpp.

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

• fem/bilinearform.hpp
• fem/bilinearform.cpp