MFEM  v3.1
Finite element discretization library
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mfem::BilinearForm Class Reference

#include <bilinearform.hpp>

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

 BilinearForm (FiniteElementSpace *f)
 Creates bilinear form associated with FE space *f. More...
 
 BilinearForm (FiniteElementSpace *f, BilinearForm *bf, int ps=0)
 
int Size () const
 Get the size of the BilinearForm as a square matrix. More...
 
void EnableStaticCondensation ()
 
bool StaticCondensationIsEnabled () const
 
FiniteElementSpaceSCFESpace () const
 Return the trace FE space associated with static condensation. More...
 
void EnableHybridization (FiniteElementSpace *constr_space, BilinearFormIntegrator *constr_integ, const Array< int > &ess_tdof_list)
 
void UsePrecomputedSparsity (int ps=1)
 
void AllocateMatrix ()
 
Array< BilinearFormIntegrator * > * GetDBFI ()
 
Array< BilinearFormIntegrator * > * GetBBFI ()
 
Array< BilinearFormIntegrator * > * GetFBFI ()
 
Array< BilinearFormIntegrator * > * GetBFBFI ()
 
const double & operator() (int i, int j)
 
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
 Matrix vector multiplication. More...
 
void FullMult (const Vector &x, Vector &y) const
 
virtual void AddMult (const Vector &x, Vector &y, const double a=1.0) const
 
void FullAddMult (const Vector &x, Vector &y) const
 
double InnerProduct (const Vector &x, const Vector &y) const
 
virtual MatrixInverseInverse () const
 Returns a pointer to (approximation) of the matrix inverse. More...
 
virtual void Finalize (int skip_zeros=1)
 Finalizes the matrix initialization. More...
 
const SparseMatrixSpMat () const
 Returns a reference to the sparse matrix. More...
 
SparseMatrixSpMat ()
 
SparseMatrixLoseMat ()
 
void AddDomainIntegrator (BilinearFormIntegrator *bfi)
 Adds new Domain Integrator. More...
 
void AddBoundaryIntegrator (BilinearFormIntegrator *bfi)
 Adds new Boundary Integrator. More...
 
void AddInteriorFaceIntegrator (BilinearFormIntegrator *bfi)
 Adds new interior Face Integrator. More...
 
void AddBdrFaceIntegrator (BilinearFormIntegrator *bfi)
 Adds new boundary Face Integrator. More...
 
void operator= (const double a)
 
void Assemble (int skip_zeros=1)
 Assembles the form i.e. sums over all domain/bdr integrators. More...
 
void ConformingAssemble ()
 
void ConformingAssemble (GridFunction &sol, LinearForm &rhs)
 
void FormLinearSystem (Array< int > &ess_tdof_list, Vector &x, Vector &b, SparseMatrix &A, Vector &X, Vector &B, int copy_interior=0)
 
void RecoverFEMSolution (const Vector &X, const Vector &b, Vector &x)
 
void ComputeElementMatrices ()
 Compute and store internally all element matrices. More...
 
void FreeElementMatrices ()
 Free the memory used by the element matrices. More...
 
void ComputeElementMatrix (int i, DenseMatrix &elmat)
 
void AssembleElementMatrix (int i, const DenseMatrix &elmat, Array< int > &vdofs, int skip_zeros=1)
 
void EliminateEssentialBC (Array< int > &bdr_attr_is_ess, Vector &sol, Vector &rhs, int d=0)
 
void EliminateEssentialBC (Array< int > &bdr_attr_is_ess, int d=0)
 
void EliminateEssentialBCDiag (Array< int > &bdr_attr_is_ess, double value)
 Perform elimination and set the diagonal entry to the given value. More...
 
void EliminateVDofs (Array< int > &vdofs, Vector &sol, Vector &rhs, int d=0)
 Eliminate the given vdofs. NOTE: here, vdofs is a list of DOFs. More...
 
void EliminateVDofs (Array< int > &vdofs, int d=0)
 
void EliminateEssentialBCFromDofs (Array< int > &ess_dofs, Vector &sol, Vector &rhs, int d=0)
 
void EliminateEssentialBCFromDofs (Array< int > &ess_dofs, int d=0)
 
void EliminateEssentialBCFromDofsDiag (Array< int > &ess_dofs, double value)
 Perform elimination and set the diagonal entry to the given value. More...
 
void EliminateVDofsInRHS (Array< int > &vdofs, const Vector &x, Vector &b)
 
double FullInnerProduct (const Vector &x, const Vector &y) const
 
virtual void Update (FiniteElementSpace *nfes=NULL)
 
FiniteElementSpaceGetFES ()
 Return the FE space associated with the BilinearForm. More...
 
virtual ~BilinearForm ()
 Destroys bilinear form. More...
 
- 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=std::cout, 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)
 
int Height () const
 Get the height (size of output) of the Operator. Synonym with NumRows. More...
 
int NumRows () const
 
int Width () const
 Get the width (size of input) of the Operator. Synonym with NumCols. More...
 
int NumCols () const
 
virtual void MultTranspose (const Vector &x, Vector &y) const
 Action of the transpose operator. More...
 
virtual OperatorGetGradient (const Vector &x) const
 Evaluate the gradient operator at the point x. More...
 
void PrintMatlab (std::ostream &out, int n=0, int m=0)
 Prints operator with input size n and output size m in matlab format. More...
 
virtual ~Operator ()
 

Protected Member Functions

void AllocMat ()
 
 BilinearForm ()
 

Protected Attributes

SparseMatrixmat
 Sparse matrix to be associated with the form. More...
 
SparseMatrixmat_e
 
FiniteElementSpacefes
 FE space on which the form lives. More...
 
int extern_bfs
 
Array< BilinearFormIntegrator * > dbfi
 Set of Domain Integrators to be applied. More...
 
Array< BilinearFormIntegrator * > bbfi
 Set of Boundary Integrators to be applied. More...
 
Array< BilinearFormIntegrator * > fbfi
 Set of interior face Integrators to be applied. More...
 
Array< BilinearFormIntegrator * > bfbfi
 Set of boundary face Integrators to be applied. More...
 
DenseMatrix elemmat
 
Array< int > vdofs
 
DenseTensorelement_matrices
 
StaticCondensationstatic_cond
 
Hybridizationhybridization
 
int precompute_sparsity
 
- Protected Attributes inherited from mfem::Operator
int height
 
int width
 

Detailed Description

Class for bilinear form - "Matrix" with associated FE space and BLFIntegrators.

Definition at line 29 of file bilinearform.hpp.

Constructor & Destructor Documentation

mfem::BilinearForm::BilinearForm ( )
inlineprotected

Definition at line 68 of file bilinearform.hpp.

mfem::BilinearForm::BilinearForm ( FiniteElementSpace f)

Creates bilinear form associated with FE space *f.

Definition at line 64 of file bilinearform.cpp.

mfem::BilinearForm::BilinearForm ( FiniteElementSpace f,
BilinearForm bf,
int  ps = 0 
)

Definition at line 76 of file bilinearform.cpp.

mfem::BilinearForm::~BilinearForm ( )
virtual

Destroys bilinear form.

Definition at line 754 of file bilinearform.cpp.

Member Function Documentation

void mfem::BilinearForm::AddBdrFaceIntegrator ( BilinearFormIntegrator bfi)

Adds new boundary Face Integrator.

Definition at line 191 of file bilinearform.cpp.

void mfem::BilinearForm::AddBoundaryIntegrator ( BilinearFormIntegrator bfi)

Adds new Boundary Integrator.

Definition at line 181 of file bilinearform.cpp.

void mfem::BilinearForm::AddDomainIntegrator ( BilinearFormIntegrator bfi)

Adds new Domain Integrator.

Definition at line 176 of file bilinearform.cpp.

void mfem::BilinearForm::AddInteriorFaceIntegrator ( BilinearFormIntegrator bfi)

Adds new interior Face Integrator.

Definition at line 186 of file bilinearform.cpp.

virtual void mfem::BilinearForm::AddMult ( const Vector x,
Vector y,
const double  a = 1.0 
) const
inlinevirtual

Definition at line 137 of file bilinearform.hpp.

void mfem::BilinearForm::AllocateMatrix ( )
inline

Pre-allocate the internal SparseMatrix before assembly. If the flag 'precompute sparsity' is set, the matrix is allocated in CSR format (i.e. finalized) and the entries are initialized with zeros.

Definition at line 113 of file bilinearform.hpp.

void mfem::BilinearForm::AllocMat ( )
protected

Definition at line 20 of file bilinearform.cpp.

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

Assembles the form i.e. sums over all domain/bdr integrators.

Definition at line 246 of file bilinearform.cpp.

void mfem::BilinearForm::AssembleElementMatrix ( int  i,
const DenseMatrix elmat,
Array< int > &  vdofs,
int  skip_zeros = 1 
)

Definition at line 224 of file bilinearform.cpp.

void mfem::BilinearForm::ComputeElementMatrices ( )

Compute and store internally all element matrices.

Definition at line 563 of file bilinearform.cpp.

void mfem::BilinearForm::ComputeElementMatrix ( int  i,
DenseMatrix elmat 
)

Definition at line 196 of file bilinearform.cpp.

void mfem::BilinearForm::ConformingAssemble ( )

For partially conforming FE spaces, complete the assembly process by performing A := P^t A P where A is the internal sparse matrix and P is the conforming prolongation of the FE space. After this call the BilinearForm becomes an operator on the conforming FE space.

Definition at line 386 of file bilinearform.cpp.

void mfem::BilinearForm::ConformingAssemble ( GridFunction sol,
LinearForm rhs 
)
inline

A shortcut for converting the whole linear system to conforming DOFs.

Definition at line 185 of file bilinearform.hpp.

double & mfem::BilinearForm::Elem ( int  i,
int  j 
)
virtual

Returns reference to a_{ij}.

Implements mfem::Matrix.

Definition at line 148 of file bilinearform.cpp.

const double & mfem::BilinearForm::Elem ( int  i,
int  j 
) const
virtual

Returns constant reference to a_{ij}.

Implements mfem::Matrix.

Definition at line 153 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateEssentialBC ( Array< int > &  bdr_attr_is_ess,
Vector sol,
Vector rhs,
int  d = 0 
)

Eliminate essential boundary DOFs from the system. The array 'bdr_attr_is_ess' marks boundary attributes that constitute the essential part of the boundary. If d == 0, the diagonal at the essential DOFs is set to 1.0, otherwise it is left the same.

Definition at line 605 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateEssentialBC ( Array< int > &  bdr_attr_is_ess,
int  d = 0 
)

Definition at line 622 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateEssentialBCDiag ( Array< int > &  bdr_attr_is_ess,
double  value 
)

Perform elimination and set the diagonal entry to the given value.

Definition at line 638 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateEssentialBCFromDofs ( Array< int > &  ess_dofs,
Vector sol,
Vector rhs,
int  d = 0 
)

Similar to EliminateVDofs but here ess_dofs is a marker (boolean) array on all vdofs (ess_dofs[i] < 0 is true).

Definition at line 693 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateEssentialBCFromDofs ( Array< int > &  ess_dofs,
int  d = 0 
)

Similar to EliminateVDofs but here ess_dofs is a marker (boolean) array on all vdofs (ess_dofs[i] < 0 is true).

Definition at line 707 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateEssentialBCFromDofsDiag ( Array< int > &  ess_dofs,
double  value 
)

Perform elimination and set the diagonal entry to the given value.

Definition at line 718 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateVDofs ( Array< int > &  vdofs,
Vector sol,
Vector rhs,
int  d = 0 
)

Eliminate the given vdofs. NOTE: here, vdofs is a list of DOFs.

Definition at line 655 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateVDofs ( Array< int > &  vdofs,
int  d = 0 
)

Eliminate the given vdofs storing the eliminated part internally; this method works in conjunction with EliminateVDofsInRHS and allows elimination of boundary conditions in multiple right-hand sides. In this method, vdofs is a list of DOFs.

Definition at line 672 of file bilinearform.cpp.

void mfem::BilinearForm::EliminateVDofsInRHS ( Array< int > &  vdofs,
const Vector x,
Vector b 
)

Use the stored eliminated part of the matrix (see EliminateVDofs) to modify r.h.s.; vdofs is a list of DOFs (non-directional, i.e. >= 0).

Definition at line 730 of file bilinearform.cpp.

void mfem::BilinearForm::EnableHybridization ( FiniteElementSpace constr_space,
BilinearFormIntegrator constr_integ,
const Array< int > &  ess_tdof_list 
)

Enable hybridization; for details see the description for class Hybridization in fem/hybridization.hpp. This method should be called before assembly.

Definition at line 138 of file bilinearform.cpp.

void mfem::BilinearForm::EnableStaticCondensation ( )

Enable the use of static condensation. For details see the description for class StaticCondensation in fem/staticcond.hpp This method should be called before assembly. If the number of unknowns after static condensation is not reduced, it is not enabled.

Definition at line 121 of file bilinearform.cpp.

void mfem::BilinearForm::Finalize ( int  skip_zeros = 1)
virtual

Finalizes the matrix initialization.

Reimplemented from mfem::Matrix.

Definition at line 168 of file bilinearform.cpp.

void mfem::BilinearForm::FormLinearSystem ( Array< int > &  ess_tdof_list,
Vector x,
Vector b,
SparseMatrix A,
Vector X,
Vector B,
int  copy_interior = 0 
)

Form the linear system A X = B, corresponding to the current bilinear form and b(.), by applying any necessary transformations such as: eliminating boundary conditions; applying conforming constraints for non-conforming AMR; static condensation; hybridization.

The GridFunction-size vector x must contain the essential b.c. The BilinearForm and the LinearForm-size vector b must be assembled.

The vector X is initialized with a suitable initial guess: when using hybridization, the vector X is set to zero; otherwise, the essential entries of X are set to the corresponding b.c. and all other entries are set to zero (copy_interior == 0) or copied from x (copy_interior != 0).

This method can be called multiple times (with the same ess_tdof_list array) to initialize different right-hand sides and boundary condition values.

After solving the linear system, the finite element solution x can be recovered by calling RecoverFEMSolution (with the same vectors X, b, and x).

Definition at line 421 of file bilinearform.cpp.

void mfem::BilinearForm::FreeElementMatrices ( )
inline

Free the memory used by the element matrices.

Definition at line 225 of file bilinearform.hpp.

void mfem::BilinearForm::FullAddMult ( const Vector x,
Vector y 
) const
inline

Definition at line 140 of file bilinearform.hpp.

double mfem::BilinearForm::FullInnerProduct ( const Vector x,
const Vector y 
) const
inline

Definition at line 267 of file bilinearform.hpp.

void mfem::BilinearForm::FullMult ( const Vector x,
Vector y 
) const
inline

Definition at line 134 of file bilinearform.hpp.

Array<BilinearFormIntegrator*>* mfem::BilinearForm::GetBBFI ( )
inline

Definition at line 117 of file bilinearform.hpp.

Array<BilinearFormIntegrator*>* mfem::BilinearForm::GetBFBFI ( )
inline

Definition at line 121 of file bilinearform.hpp.

Array<BilinearFormIntegrator*>* mfem::BilinearForm::GetDBFI ( )
inline

Definition at line 115 of file bilinearform.hpp.

Array<BilinearFormIntegrator*>* mfem::BilinearForm::GetFBFI ( )
inline

Definition at line 119 of file bilinearform.hpp.

FiniteElementSpace* mfem::BilinearForm::GetFES ( )
inline

Return the FE space associated with the BilinearForm.

Definition at line 273 of file bilinearform.hpp.

double mfem::BilinearForm::InnerProduct ( const Vector x,
const Vector y 
) const
inline

Definition at line 143 of file bilinearform.hpp.

MatrixInverse * mfem::BilinearForm::Inverse ( ) const
virtual

Returns a pointer to (approximation) of the matrix inverse.

Implements mfem::Matrix.

Definition at line 163 of file bilinearform.cpp.

SparseMatrix* mfem::BilinearForm::LoseMat ( )
inline

Definition at line 155 of file bilinearform.hpp.

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

Matrix vector multiplication.

Implements mfem::Operator.

Definition at line 158 of file bilinearform.cpp.

const double& mfem::BilinearForm::operator() ( int  i,
int  j 
)
inline

Definition at line 123 of file bilinearform.hpp.

void mfem::BilinearForm::operator= ( const double  a)
inline

Definition at line 169 of file bilinearform.hpp.

void mfem::BilinearForm::RecoverFEMSolution ( const Vector X,
const Vector b,
Vector x 
)

Call this method after solving a linear system constructed using the FormLinearSystem method to recover the solution as a GridFunction-size vector in x.

Definition at line 515 of file bilinearform.cpp.

FiniteElementSpace* mfem::BilinearForm::SCFESpace ( ) const
inline

Return the trace FE space associated with static condensation.

Definition at line 95 of file bilinearform.hpp.

int mfem::BilinearForm::Size ( ) const
inline

Get the size of the BilinearForm as a square matrix.

Definition at line 82 of file bilinearform.hpp.

const SparseMatrix& mfem::BilinearForm::SpMat ( ) const
inline

Returns a reference to the sparse matrix.

Definition at line 153 of file bilinearform.hpp.

SparseMatrix& mfem::BilinearForm::SpMat ( )
inline

Definition at line 154 of file bilinearform.hpp.

bool mfem::BilinearForm::StaticCondensationIsEnabled ( ) const
inline

Check if static condensation was actually enabled by a previous call to EnableStaticCondensation.

Definition at line 92 of file bilinearform.hpp.

void mfem::BilinearForm::Update ( FiniteElementSpace nfes = NULL)
virtual

Reimplemented in mfem::ParBilinearForm.

Definition at line 737 of file bilinearform.cpp.

void mfem::BilinearForm::UsePrecomputedSparsity ( int  ps = 1)
inline

For scalar FE spaces, precompute the sparsity pattern of the matrix (assuming dense element matrices) based on the types of integrators present in the bilinear form.

Definition at line 108 of file bilinearform.hpp.

Member Data Documentation

Array<BilinearFormIntegrator*> mfem::BilinearForm::bbfi
protected

Set of Boundary Integrators to be applied.

Definition at line 47 of file bilinearform.hpp.

Array<BilinearFormIntegrator*> mfem::BilinearForm::bfbfi
protected

Set of boundary face Integrators to be applied.

Definition at line 53 of file bilinearform.hpp.

Array<BilinearFormIntegrator*> mfem::BilinearForm::dbfi
protected

Set of Domain Integrators to be applied.

Definition at line 44 of file bilinearform.hpp.

DenseTensor* mfem::BilinearForm::element_matrices
protected

Definition at line 58 of file bilinearform.hpp.

DenseMatrix mfem::BilinearForm::elemmat
protected

Definition at line 55 of file bilinearform.hpp.

int mfem::BilinearForm::extern_bfs
protected

Definition at line 41 of file bilinearform.hpp.

Array<BilinearFormIntegrator*> mfem::BilinearForm::fbfi
protected

Set of interior face Integrators to be applied.

Definition at line 50 of file bilinearform.hpp.

FiniteElementSpace* mfem::BilinearForm::fes
protected

FE space on which the form lives.

Definition at line 39 of file bilinearform.hpp.

Hybridization* mfem::BilinearForm::hybridization
protected

Definition at line 61 of file bilinearform.hpp.

SparseMatrix* mfem::BilinearForm::mat
protected

Sparse matrix to be associated with the form.

Definition at line 33 of file bilinearform.hpp.

SparseMatrix* mfem::BilinearForm::mat_e
protected

Definition at line 36 of file bilinearform.hpp.

int mfem::BilinearForm::precompute_sparsity
protected

Definition at line 63 of file bilinearform.hpp.

StaticCondensation* mfem::BilinearForm::static_cond
protected

Definition at line 60 of file bilinearform.hpp.

Array<int> mfem::BilinearForm::vdofs
protected

Definition at line 56 of file bilinearform.hpp.


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