MFEM v4.7.0
Finite element discretization library
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mfem::RectangularConstrainedOperator Class Reference

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

#include <operator.hpp>

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

 RectangularConstrainedOperator (Operator *A, const Array< int > &trial_list, const Array< int > &test_list, bool own_A=false)
 Constructor from a general Operator and a list of essential indices/dofs.
 
virtual MemoryClass GetMemoryClass () const
 Returns the type of memory in which the solution and temporaries are stored.
 
void EliminateRHS (const Vector &x, Vector &b) const
 Eliminate columns corresponding to "essential boundary condition" values specified in x from the given right-hand side b.
 
virtual void Mult (const Vector &x, Vector &y) const
 Rectangular-constrained operator action.
 
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.
 
virtual ~RectangularConstrainedOperator ()
 
- 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 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 AddMultTranspose (const Vector &x, Vector &y, const real_t a=1.0) const
 Operator transpose application: y+=A^t(x) (default) or y+=a*A^t(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 OperatorGetGradient (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 OperatorGetProlongation () const
 Prolongation operator from linear algebra (linear system) vectors, to input vectors for the operator. NULL means identity.
 
virtual const OperatorGetRestriction () const
 Restriction operator from input vectors for the operator to linear algebra (linear system) vectors. NULL means identity.
 
virtual const OperatorGetOutputProlongation () const
 Prolongation operator from linear algebra (linear system) vectors, to output vectors for the operator. NULL means identity.
 
virtual const OperatorGetOutputRestrictionTranspose () const
 Transpose of GetOutputRestriction, directly available in this form to facilitate matrix-free RAP-type operators.
 
virtual const OperatorGetOutputRestriction () 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.
 

Protected Attributes

Array< int > trial_constraints
 
Array< int > test_constraints
 
OperatorA
 
bool own_A
 
Vector z
 
Vector w
 
MemoryClass mem_class
 
- 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.
 

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

Detailed Description

Rectangular Operator for imposing essential boundary conditions on the input space using only the action, Mult(), of a given unconstrained Operator.

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

Definition at line 969 of file operator.hpp.

Constructor & Destructor Documentation

◆ RectangularConstrainedOperator()

mfem::RectangularConstrainedOperator::RectangularConstrainedOperator ( Operator * A,
const Array< int > & trial_list,
const Array< int > & test_list,
bool own_A = false )

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

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

Definition at line 667 of file operator.cpp.

◆ ~RectangularConstrainedOperator()

virtual mfem::RectangularConstrainedOperator::~RectangularConstrainedOperator ( )
inlinevirtual

Definition at line 1012 of file operator.hpp.

Member Function Documentation

◆ EliminateRHS()

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

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

Performs the following steps:

b -= A((0,x_b));
b_j = 0

where the "_b" subscripts denote the essential (boundary) indices and the "_j" subscript denotes the essential test indices

Definition at line 686 of file operator.cpp.

◆ GetMemoryClass()

virtual MemoryClass mfem::RectangularConstrainedOperator::GetMemoryClass ( ) const
inlinevirtual

Returns the type of memory in which the solution and temporaries are stored.

Reimplemented from mfem::Operator.

Definition at line 989 of file operator.hpp.

◆ Mult()

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

Rectangular-constrained operator action.

Performs the following steps:

y = A((x_i,0));
y_j = 0

where the "_i" subscripts denote all the nonessential (boundary) trial indices and the "_j" subscript denotes the essential test indices

Implements mfem::Operator.

Definition at line 712 of file operator.cpp.

◆ MultTranspose()

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

Action of the transpose operator: y=A^t(x). The default behavior in class Operator is to generate an error.

Reimplemented from mfem::Operator.

Definition at line 746 of file operator.cpp.

Member Data Documentation

◆ A

Operator* mfem::RectangularConstrainedOperator::A
protected

Definition at line 973 of file operator.hpp.

◆ mem_class

MemoryClass mfem::RectangularConstrainedOperator::mem_class
protected

Definition at line 976 of file operator.hpp.

◆ own_A

bool mfem::RectangularConstrainedOperator::own_A
protected

Definition at line 974 of file operator.hpp.

◆ test_constraints

Array<int> mfem::RectangularConstrainedOperator::test_constraints
protected

Definition at line 972 of file operator.hpp.

◆ trial_constraints

Array<int> mfem::RectangularConstrainedOperator::trial_constraints
protected

Definition at line 972 of file operator.hpp.

◆ w

Vector mfem::RectangularConstrainedOperator::w
protected

Definition at line 975 of file operator.hpp.

◆ z

Vector mfem::RectangularConstrainedOperator::z
mutableprotected

Definition at line 975 of file operator.hpp.


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