Square Operator for imposing essential boundary conditions using only the action, Mult(), of a given unconstrained Operator. More...

#include <operator.hpp>

Inheritance diagram for mfem::ConstrainedOperator:

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Collaboration diagram for mfem::ConstrainedOperator:

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Public Member Functions
	ConstrainedOperator (Operator *A, const Array< int > &list, bool own_A=false)
	Constructor from a general Operator and a list of essential indices/dofs. More...

void	EliminateRHS (const Vector &x, Vector &b) const
	Eliminate "essential boundary condition" values specified in x from the given right-hand side b. More...

virtual void	Mult (const Vector &x, Vector &y) const
	Constrained operator action. More...

virtual	~ConstrainedOperator ()
	Destructor: destroys the unconstrained Operator A if own_A is true. 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 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 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...

Protected Attributes
Array< int >	constraint_list
	List of constrained indices/dofs. More...

Operator *	A
	The unconstrained Operator. More...

bool	own_A
	Ownership flag for A. More...

Vector	z

Vector	w
	Auxiliary vectors. 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...

Additional Inherited Members
Public Types inherited from mfem::Operator
enum	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...

Detailed Description

Square Operator for imposing essential boundary conditions using only the action, Mult(), of a given unconstrained Operator.

Square operator constrained by fixing certain entries in the solution to given "essential boundary condition" values. This class is used by the general, matrix-free system formulation of Operator::FormLinearSystem.

Definition at line 384 of file operator.hpp.

Constructor & Destructor Documentation

mfem::ConstrainedOperator::ConstrainedOperator	(	Operator *	A,
		const Array< int > &	list,
		bool	own_A = `false`
	)

Constructor from a general Operator and a list of essential indices/dofs.

Specify the unconstrained operator *A and a list of indices to constrain, i.e. each entry list[i] represents an essential-dof. If the ownership flag own_A is true, the operator *A will be destroyed when this object is destroyed.

Definition at line 98 of file operator.cpp.

virtual mfem::ConstrainedOperator::~ConstrainedOperator ( )

inlinevirtual

Destructor: destroys the unconstrained Operator A if own_A is true.

Definition at line 424 of file operator.hpp.

Member Function Documentation

void mfem::ConstrainedOperator::EliminateRHS	(	const Vector &	x,
		Vector &	b
	)		const

Eliminate "essential boundary condition" values specified in x from the given right-hand side b.

Performs the following steps:

z = A((0,x_b));  b_i -= z_i;  b_b = x_b;

where the "_b" subscripts denote the essential (boundary) indices/dofs of the vectors, and "_i" – the rest of the entries.

Definition at line 107 of file operator.cpp.

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

virtual

Constrained operator action.

Performs the following steps:

z = A((x_i,0));  y_i = z_i;  y_b = x_b;

where the "_b" subscripts denote the essential (boundary) indices/dofs of the vectors, and "_i" – the rest of the entries.

Implements mfem::Operator.

Definition at line 126 of file operator.cpp.

Member Data Documentation

Operator* mfem::ConstrainedOperator::A

protected

The unconstrained Operator.

Definition at line 388 of file operator.hpp.

Array<int> mfem::ConstrainedOperator::constraint_list

protected

List of constrained indices/dofs.

Definition at line 387 of file operator.hpp.

bool mfem::ConstrainedOperator::own_A

protected

Ownership flag for A.

Definition at line 389 of file operator.hpp.

Vector mfem::ConstrainedOperator::w

mutableprotected

Auxiliary vectors.

Definition at line 390 of file operator.hpp.

Vector mfem::ConstrainedOperator::z

mutableprotected

Definition at line 390 of file operator.hpp.

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

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation