Multigrid Class Reference

The Multigrid hierarchy including meshes, vectors and matrices, prolongations is stored. More...

#include <jacsolve.h>

Public Member Functions
	Multigrid (Mesh const &cmesh, int nlevel)
	Multigrid (Multigrid const &)=delete
Multigrid &	operator= (Multigrid const &)=delete
	~Multigrid ()
size_t	Nlevels () const
int	Ndofs () const
Mesh const &	GetMesh (int lev) const
std::vector< double > const &	GetSolution (int lev) const
void	DefineOperators ()
void	DefineOperator (size_t lev)
void	JacobiSolve (size_t lev)
void	MG_Step (size_t lev, int pre_smooth=1, bool const bzero=false, int nu=1)
void	MG_Solve (int pre_smooth=1, double eps=1e-6, int nu=1)

Private Attributes
gMesh_Hierarchy	_meshes
	mesh hierarchy from coarse (level 0) to fine. More...
std::vector< FEM_Matrix >	_SK
	Sparse matrix on each level. More...
std::vector< std::vector< double > >	_u
	Solution vector on each level. More...
std::vector< std::vector< double > >	_f
	Right hand side vector on each level. More...
std::vector< std::vector< double > >	_d
	Defect vector on each level. More...
std::vector< std::vector< double > >	_w
	Correction vector on each level. More...
std::vector< BisectIntDirichlet >	_Pc2f
	Interpolation to level from next coarser level. More...

Detailed Description

The Multigrid hierarchy including meshes, vectors and matrices, prolongations is stored.

Definition at line 57 of file jacsolve.h.

Constructor & Destructor Documentation

Multigrid() [1/2]

Multigrid::Multigrid	(	Mesh const &	cmesh,
		int	nlevel
	)

    Generates the mesh hierachy with @p nlevel meshes starting from coarse mesh @p cmesg .

The refined meshes are generated by edge bisection. All memory is allocated but stiffness matrices are yet not calculated

    @param[in] cmesh          initial coarse mesh
    @param[in] nlevel  number of meshes in hierarchy, including the initial coarse mesh

Definition at line 104 of file jacsolve.cpp.

Multigrid() [2/2]

Multigrid::Multigrid ( Multigrid const &  )

delete

~Multigrid()

Multigrid::~Multigrid

(

)

Definition at line 134 of file jacsolve.cpp.

Member Function Documentation

DefineOperator()

void Multigrid::DefineOperator

(

size_t

lev

)

    Calculates PDE matrix for level @p lev.

Parameters

[in]

lev

level in hierachy

Definition at line 146 of file jacsolve.cpp.

DefineOperators()

void Multigrid::DefineOperators

(

)

Calculates PDE matrices for all levels.

Definition at line 137 of file jacsolve.cpp.

GetMesh()

Mesh const& Multigrid::GetMesh ( int  lev ) const

inline

Returns

Meshes number lev .

Definition at line 92 of file jacsolve.h.

GetSolution()

std::vector<double> const& Multigrid::GetSolution ( int  lev ) const

inline

Returns

Solution vector at level lev .

Definition at line 98 of file jacsolve.h.

JacobiSolve()

void Multigrid::JacobiSolve

(

size_t

lev

)

    Solves the system of equations at level @p lev via Jacobi iterations

Parameters

[in]

lev

level in hierachy

Definition at line 164 of file jacsolve.cpp.

MG_Solve()

void Multigrid::MG_Solve	(	int	pre_smooth = 1,
		double	eps = 1e-6,
		int	nu = 1
	)

    Solves the system of equations at finest level via multigrid

Parameters

[in]	pre_smooth	number of pre/post-smoothing sweeps
[in]	eps	stopping criteria (relative error)
[in]	nu	defines the multigrid cycle (1/2 = V/W)

Definition at line 207 of file jacsolve.cpp.

MG_Step()

void Multigrid::MG_Step	(	size_t	lev,
		int	pre_smooth = 1,
		bool const	bzero = false,
		int	nu = 1
	)

    Peformes one multigrid step at level @p lev .

Parameters

[in]	lev	level in hierachy
[in]	pre_smooth	number of pre/post-smoothing sweeps
[in]	bzero	start with zero-vector as solution
[in]	nu	defines the multigrid cycle (1/2 = V/W)

Definition at line 170 of file jacsolve.cpp.

Ndofs()

int Multigrid::Ndofs ( ) const

inline

Returns

Number of Unknowns.

Definition at line 86 of file jacsolve.h.

Nlevels()

size_t Multigrid::Nlevels ( ) const

inline

Returns

Number of meshes in hierarchy.

Definition at line 80 of file jacsolve.h.

operator=()

Multigrid& Multigrid::operator= ( Multigrid const &  )

delete

Member Data Documentation

_d

std::vector<std::vector<double> > Multigrid::_d

private

Defect vector on each level.

Definition at line 145 of file jacsolve.h.

_f

std::vector<std::vector<double> > Multigrid::_f

private

Right hand side vector on each level.

Definition at line 144 of file jacsolve.h.

_meshes

gMesh_Hierarchy Multigrid::_meshes

private

mesh hierarchy from coarse (level 0) to fine.

Definition at line 141 of file jacsolve.h.

_Pc2f

std::vector<BisectIntDirichlet> Multigrid::_Pc2f

private

Interpolation to level from next coarser level.

Definition at line 147 of file jacsolve.h.

_SK

std::vector<FEM_Matrix> Multigrid::_SK

private

Sparse matrix on each level.

Definition at line 142 of file jacsolve.h.

_u

std::vector<std::vector<double> > Multigrid::_u

private

Solution vector on each level.

Definition at line 143 of file jacsolve.h.

_w

std::vector<std::vector<double> > Multigrid::_w

private

Correction vector on each level.

Definition at line 146 of file jacsolve.h.

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

• jacsolve.h
• jacsolve.cpp