Base class for operators that extracts Face degrees of freedom. More...

#include <restriction.hpp>

Inheritance diagram for mfem::FaceRestriction:

Collaboration diagram for mfem::FaceRestriction:

Public Member Functions
	FaceRestriction ()

	FaceRestriction (int h, int w)

virtual	~FaceRestriction ()

void	Mult (const Vector &x, Vector &y) const override=0
	Extract the face degrees of freedom from x into y.

virtual void	AddMultTranspose (const Vector &x, Vector &y, const real_t a=1.0) const override=0
	Add the face degrees of freedom x to the element degrees of freedom y.

virtual void	AddMultTransposeUnsigned (const Vector &x, Vector &y, const real_t a=1.0) const
	Add the face degrees of freedom x to the element degrees of freedom y ignoring the signs from DOF orientation.

virtual void	AddMultTransposeInPlace (Vector &x, Vector &y) const
	Add the face degrees of freedom x to the element degrees of freedom y. Perform the same computation as AddMultTranspose, but x is invalid after calling this method.

void	MultTranspose (const Vector &x, Vector &y) const override
	Set the face degrees of freedom in the element degrees of freedom y to the values given in x.

virtual void	NormalDerivativeMult (const Vector &x, Vector &y) const
	For each face, sets y to the partial derivative of x with respect to the reference coordinate whose direction is perpendicular to the face on the reference element.

virtual void	NormalDerivativeAddMultTranspose (const Vector &x, Vector &y) const
	Add the face reference-normal derivative degrees of freedom in x to the element degrees of freedom in y.

Public Member Functions inherited from mfem::Operator
void	InitTVectors (const Operator Po, const Operator Ri, const Operator *Pi, Vector &x, Vector &b, Vector &X, Vector &B) const
	Initializes memory for true vectors of linear system.

	Operator (int s=0)
	Construct a square Operator with given size s (default 0).

	Operator (int h, int w)
	Construct an Operator with the given height (output size) and width (input size).

int	Height () const
	Get the height (size of output) of the Operator. Synonym with NumRows().

int	NumRows () const
	Get the number of rows (size of output) of the Operator. Synonym with Height().

int	Width () const
	Get the width (size of input) of the Operator. Synonym with NumCols().

int	NumCols () const
	Get the number of columns (size of input) of the Operator. Synonym with Width().

virtual MemoryClass	GetMemoryClass () const
	Return the MemoryClass preferred by the Operator.

virtual void	AddMult (const Vector &x, Vector &y, const real_t a=1.0) const
	Operator application: `y+=A(x)` (default) or `y+=a*A(x)`.

virtual void	ArrayMult (const Array< const Vector * > &X, Array< Vector * > &Y) const
	Operator application on a matrix: `Y=A(X)`.

virtual void	ArrayMultTranspose (const Array< const Vector * > &X, Array< Vector * > &Y) const
	Action of the transpose operator on a matrix: `Y=A^t(X)`.

virtual void	ArrayAddMult (const Array< const Vector * > &X, Array< Vector * > &Y, const real_t a=1.0) const
	Operator application on a matrix: `Y+=A(X)` (default) or `Y+=a*A(X)`.

virtual void	ArrayAddMultTranspose (const Array< const Vector * > &X, Array< Vector * > &Y, const real_t a=1.0) const
	Operator transpose application on a matrix: `Y+=A^t(X)` (default) or `Y+=a*A^t(X)`.

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.

virtual void	AssembleDiagonal (Vector &diag) const
	Computes the diagonal entries into diag. Typically, this operation only makes sense for linear Operators. In some cases, only an approximation of the diagonal is computed.

virtual const Operator *	GetProlongation () const
	Prolongation operator from linear algebra (linear system) vectors, to input vectors for the operator. `NULL` means identity.

virtual const Operator *	GetRestriction () const
	Restriction operator from input vectors for the operator to linear algebra (linear system) vectors. `NULL` means identity.

virtual const Operator *	GetOutputProlongation () const
	Prolongation operator from linear algebra (linear system) vectors, to output vectors for the operator. `NULL` means identity.

virtual const Operator *	GetOutputRestrictionTranspose () const
	Transpose of GetOutputRestriction, directly available in this form to facilitate matrix-free RAP-type operators.

virtual const Operator *	GetOutputRestriction () const
	Restriction operator from output vectors for the operator to linear algebra (linear system) vectors. `NULL` means identity.

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.

void	FormRectangularLinearSystem (const Array< int > &trial_tdof_list, const Array< int > &test_tdof_list, Vector &x, Vector &b, Operator *&A, Vector &X, Vector &B)
	Form a column-constrained linear system using a matrix-free approach.

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() or Operator::FormRectangularLinearSystem().

void	FormSystemOperator (const Array< int > &ess_tdof_list, Operator *&A)
	Return in A a parallel (on truedofs) version of this square operator.

void	FormRectangularSystemOperator (const Array< int > &trial_tdof_list, const Array< int > &test_tdof_list, Operator *&A)
	Return in A a parallel (on truedofs) version of this rectangular operator (including constraints).

void	FormDiscreteOperator (Operator *&A)
	Return in A a parallel (on truedofs) version of this rectangular operator.

void	PrintMatlab (std::ostream &out, int n, int m=0) const
	Prints operator with input size n and output size m in Matlab format.

virtual void	PrintMatlab (std::ostream &out) const
	Prints operator in Matlab format.

virtual	~Operator ()
	Virtual destructor.

Type	GetType () const
	Return the type ID of the Operator class.

Additional Inherited Members
Public Types inherited from mfem::Operator
enum	DiagonalPolicy { DIAG_ZERO , DIAG_ONE , DIAG_KEEP }
	Defines operator diagonal policy upon elimination of rows and/or columns. More...

enum	Type { ANY_TYPE , MFEM_SPARSEMAT , Hypre_ParCSR , PETSC_MATAIJ , PETSC_MATIS , PETSC_MATSHELL , PETSC_MATNEST , PETSC_MATHYPRE , PETSC_MATGENERIC , Complex_Operator , MFEM_ComplexSparseMat , Complex_Hypre_ParCSR , Complex_DenseMat , MFEM_Block_Matrix , MFEM_Block_Operator }
	Enumeration defining IDs for some classes derived from Operator. More...

Protected Member Functions inherited from mfem::Operator
void	FormConstrainedSystemOperator (const Array< int > &ess_tdof_list, ConstrainedOperator *&Aout)
	see FormSystemOperator()

void	FormRectangularConstrainedSystemOperator (const Array< int > &trial_tdof_list, const Array< int > &test_tdof_list, RectangularConstrainedOperator *&Aout)
	see FormRectangularSystemOperator()

Operator *	SetupRAP (const Operator Pi, const Operator Po)
	Returns RAP Operator of this, using input/output Prolongation matrices Pi corresponds to "P", Po corresponds to "Rt".

Protected Attributes inherited from mfem::Operator
int	height
	Dimension of the output / number of rows in the matrix.

int	width
	Dimension of the input / number of columns in the matrix.

Detailed Description

Base class for operators that extracts Face degrees of freedom.

In order to compute quantities on the faces of a mesh, it is often useful to extract the degrees of freedom on the faces of the elements. This class provides an interface for such operations.

If the FiniteElementSpace is ordered by Ordering::byVDIM, then the expected format for the L-vector is (vdim x ndofs), otherwise if Ordering::byNODES the expected format is (ndofs x vdim), where ndofs is the total number of degrees of freedom. Since FiniteElementSpace can either be continuous or discontinuous, the degrees of freedom on a face can either be single valued or double valued, this is what we refer to as the multiplicity and is represented by the L2FaceValues enum type. The format of the output face E-vector of degrees of freedom is (face_dofs x vdim x multiplicity x nfaces), where face_dofs is the number of degrees of freedom on each face, and nfaces the number of faces of the requested FaceType (see FiniteElementSpace::GetNFbyType).

Note: Objects of this type are typically created and owned by FiniteElementSpace objects, see FiniteElementSpace::GetFaceRestriction().

Definition at line 162 of file restriction.hpp.

Constructor & Destructor Documentation

◆ FaceRestriction() [1/2]

mfem::FaceRestriction::FaceRestriction ( )

inline

Definition at line 165 of file restriction.hpp.

◆ FaceRestriction() [2/2]

mfem::FaceRestriction::FaceRestriction	(	int	h,
		int	w )

inline

Definition at line 167 of file restriction.hpp.

◆ ~FaceRestriction()

virtual mfem::FaceRestriction::~FaceRestriction ( )

inlinevirtual

Definition at line 169 of file restriction.hpp.

Member Function Documentation

◆ AddMultTranspose()

virtual void mfem::FaceRestriction::AddMultTranspose	(	const Vector &	x,
		Vector &	y,
		const real_t	a = 1.0 ) const

overridepure virtual

Add the face degrees of freedom x to the element degrees of freedom y.

Parameters

[in]	x	The face degrees of freedom on the face.
[in,out]	y	The L-vector of degrees of freedom to which we add the face degrees of freedom.
[in]	a	Scalar coefficient for addition.

Reimplemented from mfem::Operator.

Implemented in mfem::ConformingFaceRestriction, mfem::L2FaceRestriction, mfem::NCL2FaceRestriction, mfem::ParNCH1FaceRestriction, and mfem::ParNCL2FaceRestriction.

◆ AddMultTransposeInPlace()

virtual void mfem::FaceRestriction::AddMultTransposeInPlace	(	Vector &	x,
		Vector &	y ) const

inlinevirtual

Add the face degrees of freedom x to the element degrees of freedom y. Perform the same computation as AddMultTranspose, but x is invalid after calling this method.

Parameters

[in,out]	x	The face degrees of freedom on the face.
[in,out]	y	The L-vector of degrees of freedom to which we add the face degrees of freedom.

Note: This method is an optimization of AddMultTranspose where the x Vector is used and modified to avoid memory allocation and memcpy.

Reimplemented in mfem::ConformingFaceRestriction, mfem::NCL2FaceRestriction, mfem::ParNCH1FaceRestriction, and mfem::ParNCL2FaceRestriction.

Definition at line 209 of file restriction.hpp.

◆ AddMultTransposeUnsigned()

virtual void mfem::FaceRestriction::AddMultTransposeUnsigned	(	const Vector &	x,
		Vector &	y,
		const real_t	a = 1.0 ) const

inlinevirtual

Add the face degrees of freedom x to the element degrees of freedom y ignoring the signs from DOF orientation.

Reimplemented in mfem::ConformingFaceRestriction.

Definition at line 192 of file restriction.hpp.

◆ Mult()

void mfem::FaceRestriction::Mult	(	const Vector &	x,
		Vector &	y ) const

overridepure virtual

Extract the face degrees of freedom from x into y.

Parameters

[in]	x	The L-vector of degrees of freedom.
[out]	y	The degrees of freedom on the face, corresponding to a face E-vector.

Implements mfem::Operator.

Implemented in mfem::ConformingFaceRestriction, mfem::L2FaceRestriction, mfem::NCL2FaceRestriction, mfem::ParL2FaceRestriction, mfem::ParNCH1FaceRestriction, and mfem::ParNCL2FaceRestriction.

◆ MultTranspose()

void mfem::FaceRestriction::MultTranspose	(	const Vector &	x,
		Vector &	y ) const

inlineoverridevirtual

Set the face degrees of freedom in the element degrees of freedom y to the values given in x.

Parameters

[in]	x	The face degrees of freedom on the face.
[in,out]	y	The L-vector of degrees of freedom to which we add the face degrees of freedom.

Reimplemented from mfem::Operator.

Definition at line 221 of file restriction.hpp.

◆ NormalDerivativeAddMultTranspose()

virtual void mfem::FaceRestriction::NormalDerivativeAddMultTranspose	(	const Vector &	x,
		Vector &	y ) const

inlinevirtual

Add the face reference-normal derivative degrees of freedom in x to the element degrees of freedom in y.

see NormalDerivativeMult.

Parameters

[in]	x	The degrees of freedom of the face reference-normal derivative. Is E-vector like.
[in,out]	y	The L-vector degrees of freedom.

Reimplemented in mfem::L2FaceRestriction.

Definition at line 261 of file restriction.hpp.

◆ NormalDerivativeMult()

virtual void mfem::FaceRestriction::NormalDerivativeMult	(	const Vector &	x,
		Vector &	y ) const

inlinevirtual

For each face, sets y to the partial derivative of x with respect to the reference coordinate whose direction is perpendicular to the face on the reference element.

This is not the normal derivative in physical coordinates, but can be mapped to the physical normal derivative using the element Jacobian and the tangential derivatives (in reference coordinates) which can be computed from the face values (provided by Mult).

Note that due to the polynomial degree of the element mapping, the physical normal derivative may be a higher degree polynomial than the restriction of the values to the face. However, the normal derivative in reference coordinates has degree-1, and therefore can be exactly represented with the degrees of freedom of a face E-vector.

Parameters

[in]	x	The L-vector degrees of freedom.
[in,out]	y	The reference normal derivative degrees of freedom. Is E-vector like.

Reimplemented in mfem::L2FaceRestriction.

Definition at line 247 of file restriction.hpp.

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

fem/restriction.hpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ FaceRestriction() [1/2]

◆ FaceRestriction() [2/2]

◆ ~FaceRestriction()

Member Function Documentation

◆ AddMultTranspose()

◆ AddMultTransposeInPlace()

◆ AddMultTransposeUnsigned()

◆ Mult()

◆ MultTranspose()

◆ NormalDerivativeAddMultTranspose()

◆ NormalDerivativeMult()