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

Extension of Multigrid object to algebraically generated coarse spaces. More...

#include <algebraic.hpp>

Inheritance diagram for mfem::ceed::AlgebraicMultigrid:
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Collaboration diagram for mfem::ceed::AlgebraicMultigrid:
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Public Member Functions

 AlgebraicMultigrid (AlgebraicSpaceHierarchy &hierarchy, BilinearForm &form, const Array< int > &ess_tdofs)
 Constructs multigrid solver based on existing space hierarchy.
 
virtual void SetOperator (const mfem::Operator &op) override
 Not supported for multigrid.
 
 ~AlgebraicMultigrid ()
 
- Public Member Functions inherited from mfem::GeometricMultigrid
MFEM_DEPRECATED GeometricMultigrid (const FiniteElementSpaceHierarchy &fespaces_)
 Deprecated.
 
 GeometricMultigrid (const FiniteElementSpaceHierarchy &fespaces_, const Array< int > &ess_bdr)
 Construct a geometric multigrid object for the given finite element space hierarchy fespaces_, where ess_bdr is a list of mesh boundary element attributes that define the essential DOFs.
 
virtual ~GeometricMultigrid ()
 Destructor.
 
void FormFineLinearSystem (Vector &x, Vector &b, OperatorHandle &A, Vector &X, Vector &B)
 
void RecoverFineFEMSolution (const Vector &X, const Vector &b, Vector &x)
 Recover the solution of a linear system formed with FormFineLinearSystem()
 
- Public Member Functions inherited from mfem::Multigrid
 Multigrid ()=default
 Constructs an empty multigrid hierarchy.
 
 Multigrid (const Array< Operator * > &operators_, const Array< Solver * > &smoothers_, const Array< Operator * > &prolongations_, const Array< bool > &ownedOperators_, const Array< bool > &ownedSmoothers_, const Array< bool > &ownedProlongations_)
 Constructs a multigrid hierarchy from the given inputs.
 
virtual ~Multigrid ()
 Destructor.
 
- Public Member Functions inherited from mfem::MultigridBase
 MultigridBase ()
 Constructs an empty multigrid hierarchy.
 
 MultigridBase (const Array< Operator * > &operators_, const Array< Solver * > &smoothers_, const Array< bool > &ownedOperators_, const Array< bool > &ownedSmoothers_)
 Constructs a multigrid hierarchy from the given inputs.
 
virtual ~MultigridBase ()
 Destructor.
 
void AddLevel (Operator *op, Solver *smoother, bool ownOperator, bool ownSmoother)
 Adds a level to the multigrid operator hierarchy.
 
int NumLevels () const
 Returns the number of levels.
 
int GetFinestLevelIndex () const
 Returns the index of the finest level.
 
const OperatorGetOperatorAtLevel (int level) const
 Returns operator at given level.
 
OperatorGetOperatorAtLevel (int level)
 
const OperatorGetOperatorAtFinestLevel () const
 Returns operator at finest level.
 
OperatorGetOperatorAtFinestLevel ()
 
const SolverGetSmootherAtLevel (int level) const
 Returns smoother at given level.
 
SolverGetSmootherAtLevel (int level)
 
void SetCycleType (CycleType cycleType_, int preSmoothingSteps_, int postSmoothingSteps_)
 Set cycle type and number of pre- and post-smoothing steps used by Mult.
 
virtual void Mult (const Vector &x, Vector &y) const override
 Application of the multigrid as a preconditioner.
 
virtual void ArrayMult (const Array< const Vector * > &X_, Array< Vector * > &Y_) const override
 Operator application on a matrix: Y=A(X).
 
- Public Member Functions inherited from mfem::Solver
 Solver (int s=0, bool iter_mode=false)
 Initialize a square Solver with size s.
 
 Solver (int h, int w, bool iter_mode=false)
 Initialize a Solver with height h and width w.
 
- 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 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 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 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.
 

Additional Inherited Members

- Public Types inherited from mfem::MultigridBase
enum class  CycleType { VCYCLE , WCYCLE }
 
- 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...
 
- Public Attributes inherited from mfem::Solver
bool iterative_mode
 If true, use the second argument of Mult() as an initial guess.
 
- 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".
 
- Protected Attributes inherited from mfem::GeometricMultigrid
const FiniteElementSpaceHierarchyfespaces
 
Array< Array< int > * > essentialTrueDofs
 
Array< BilinearForm * > bfs
 
- Protected Attributes inherited from mfem::Multigrid
Array< Operator * > prolongations
 
Array< bool > ownedProlongations
 
- Protected Attributes inherited from mfem::MultigridBase
Array< Operator * > operators
 
Array< Solver * > smoothers
 
Array< bool > ownedOperators
 
Array< bool > ownedSmoothers
 
CycleType cycleType
 
int preSmoothingSteps
 
int postSmoothingSteps
 
Array2D< Vector * > X
 
Array2D< Vector * > Y
 
Array2D< Vector * > R
 
Array2D< Vector * > Z
 
int nrhs
 
- 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

Extension of Multigrid object to algebraically generated coarse spaces.

Definition at line 155 of file algebraic.hpp.

Constructor & Destructor Documentation

◆ AlgebraicMultigrid()

mfem::ceed::AlgebraicMultigrid::AlgebraicMultigrid ( AlgebraicSpaceHierarchy & hierarchy,
BilinearForm & form,
const Array< int > & ess_tdofs )

Constructs multigrid solver based on existing space hierarchy.

This only works if the Ceed device backend is enabled.

Parameters
[in]hierarchyHierarchy of (algebraic) spaces
[in]formpartially assembled BilinearForm on finest level
[in]ess_tdofsList of essential true dofs on finest level

Definition at line 304 of file algebraic.cpp.

◆ ~AlgebraicMultigrid()

mfem::ceed::AlgebraicMultigrid::~AlgebraicMultigrid ( )

Definition at line 369 of file algebraic.cpp.

Member Function Documentation

◆ SetOperator()

virtual void mfem::ceed::AlgebraicMultigrid::SetOperator ( const mfem::Operator & op)
inlineoverridevirtual

Not supported for multigrid.

Reimplemented from mfem::MultigridBase.

Definition at line 171 of file algebraic.hpp.


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