Mesh refinement operator using an error threshold. More...

#include <mesh_operators.hpp>

Inheritance diagram for mfem::ThresholdRefiner:

Collaboration diagram for mfem::ThresholdRefiner:

Public Member Functions
	ThresholdRefiner (ErrorEstimator &est)
	Construct a ThresholdRefiner using the given ErrorEstimator.

void	SetTotalErrorNormP (real_t norm_p=infinity())
	Set the exponent, p, of the discrete p-norm used to compute the total error from the local element errors.

void	SetTotalErrorGoal (real_t err_goal)
	Set the total error stopping criterion: stop when total_err <= total_err_goal. The default value is zero.

void	SetTotalErrorFraction (real_t fraction)
	Set the total fraction used in the computation of the threshold. The default value is 1/2.

void	SetLocalErrorGoal (real_t err_goal)
	Set the local stopping criterion: stop when local_err_i <= local_err_goal. The default value is zero.

void	SetMaxElements (long long max_elem)
	Set the maximum number of elements stopping criterion: stop when the input mesh has num_elements >= max_elem. The default value is LONG_MAX.

void	PreferNonconformingRefinement ()
	Use nonconforming refinement, if possible (triangles, quads, hexes).

void	PreferConformingRefinement ()
	Use conforming refinement, if possible (triangles, tetrahedra) – this is the default.

void	SetNCLimit (int nc_limit_)
	Set the maximum ratio of refinement levels of adjacent elements (0 = unlimited).

long long	GetNumMarkedElements () const
	Get the number of marked elements in the last Apply() call.

real_t	GetThreshold () const
	Get the threshold used in the last Apply() call.

virtual void	Reset ()
	Reset the associated estimator.

Public Member Functions inherited from mfem::MeshOperator
bool	Apply (Mesh &mesh)
	Perform the mesh operation.

bool	Stop () const
	Check if STOP action is requested, e.g. stopping criterion is satisfied.

bool	Repeat () const
	Check if REPEAT action is requested, i.e. FiniteElementSpaces and GridFunctions need to be updated, and Apply() must be called again.

bool	Continue () const
	Check if CONTINUE action is requested, i.e. FiniteElementSpaces and GridFunctions need to be updated and computations should continue.

bool	Refined () const
	Check if the mesh was refined.

bool	Derefined () const
	Check if the mesh was de-refined.

bool	Rebalanced () const
	Check if the mesh was rebalanced.

int	GetActionInfo () const
	Get the full ActionInfo value generated by the last call to Apply().

virtual	~MeshOperator ()
	The destructor is virtual.

Protected Member Functions
real_t	GetNorm (const Vector &local_err, Mesh &mesh) const

virtual int	ApplyImpl (Mesh &mesh)
	Apply the operator to the mesh.

Protected Member Functions inherited from mfem::MeshOperator
	MeshOperator ()
	Constructor to be used by derived classes.

Protected Attributes
ErrorEstimator &	estimator

AnisotropicErrorEstimator *	aniso_estimator

real_t	total_norm_p

real_t	total_err_goal

real_t	total_fraction

real_t	local_err_goal

long long	max_elements

real_t	threshold

long long	num_marked_elements

Array< Refinement >	marked_elements

long	current_sequence

int	non_conforming

int	nc_limit

Additional Inherited Members
Public Types inherited from mfem::MeshOperator
enum	Action { NONE = 0 , CONTINUE = 1 , STOP = 2 , REPEAT = 3 , MASK_UPDATE = 1 , MASK_ACTION = 3 }
	Action and information constants and masks. More...

enum	Info { REFINED = 41 , DEREFINED = 42 , REBALANCED = 4*3 , MASK_INFO = ~3 }

Detailed Description

Mesh refinement operator using an error threshold.

This class uses the given ErrorEstimator to estimate local element errors and then marks for refinement all elements i such that loc_err_i > threshold. The threshold is computed as

threshold = max(total_err * total_fraction * pow(num_elements,-1.0/p),

local_err_goal);

mfem::ThresholdRefiner::threshold

real_t threshold

Definition mesh_operators.hpp:187

mfem::ThresholdRefiner::local_err_goal

real_t local_err_goal

Definition mesh_operators.hpp:184

mfem::ThresholdRefiner::total_fraction

real_t total_fraction

Definition mesh_operators.hpp:183

p

real_t p(const Vector &x, real_t t)

Definition navier_mms.cpp:53

where p (=total_norm_p), total_fraction, and local_err_goal are settable parameters, total_err = (sum_i local_err_i^p)^{1/p}, when p < inf, or total_err = max_i local_err_i, when p = inf.

Definition at line 175 of file mesh_operators.hpp.

Constructor & Destructor Documentation

◆ ThresholdRefiner()

mfem::ThresholdRefiner::ThresholdRefiner ( ErrorEstimator & est )

Construct a ThresholdRefiner using the given ErrorEstimator.

Definition at line 54 of file mesh_operators.cpp.

Member Function Documentation

◆ ApplyImpl()

int mfem::ThresholdRefiner::ApplyImpl ( Mesh & mesh )

protectedvirtual

Apply the operator to the mesh.

Returns: STOP if a stopping criterion is satisfied or no elements were marked for refinement; REFINED + CONTINUE otherwise.

Implements mfem::MeshOperator.

Definition at line 84 of file mesh_operators.cpp.

◆ GetNorm()

real_t mfem::ThresholdRefiner::GetNorm	(	const Vector &	local_err,
		Mesh &	mesh ) const

protected

Definition at line 72 of file mesh_operators.cpp.

◆ GetNumMarkedElements()

long long mfem::ThresholdRefiner::GetNumMarkedElements ( ) const

inline

Get the number of marked elements in the last Apply() call.

Definition at line 251 of file mesh_operators.hpp.

◆ GetThreshold()

real_t mfem::ThresholdRefiner::GetThreshold ( ) const

inline

Get the threshold used in the last Apply() call.

Definition at line 254 of file mesh_operators.hpp.

◆ PreferConformingRefinement()

void mfem::ThresholdRefiner::PreferConformingRefinement ( )

inline

Use conforming refinement, if possible (triangles, tetrahedra) – this is the default.

Definition at line 240 of file mesh_operators.hpp.

◆ PreferNonconformingRefinement()

void mfem::ThresholdRefiner::PreferNonconformingRefinement ( )

inline

Use nonconforming refinement, if possible (triangles, quads, hexes).

Definition at line 236 of file mesh_operators.hpp.

◆ Reset()

void mfem::ThresholdRefiner::Reset ( )

virtual

Reset the associated estimator.

Implements mfem::MeshOperator.

Definition at line 140 of file mesh_operators.cpp.

◆ SetLocalErrorGoal()

void mfem::ThresholdRefiner::SetLocalErrorGoal ( real_t err_goal )

inline

Set the local stopping criterion: stop when local_err_i <= local_err_goal. The default value is zero.

Note: If local_err_goal == 0, it is essentially ignored in the threshold computation.

Definition at line 228 of file mesh_operators.hpp.

◆ SetMaxElements()

void mfem::ThresholdRefiner::SetMaxElements ( long long max_elem )

inline

Set the maximum number of elements stopping criterion: stop when the input mesh has num_elements >= max_elem. The default value is LONG_MAX.

Definition at line 233 of file mesh_operators.hpp.

◆ SetNCLimit()

void mfem::ThresholdRefiner::SetNCLimit ( int nc_limit_ )

inline

Set the maximum ratio of refinement levels of adjacent elements (0 = unlimited).

Definition at line 244 of file mesh_operators.hpp.

◆ SetTotalErrorFraction()

void mfem::ThresholdRefiner::SetTotalErrorFraction ( real_t fraction )

inline

Set the total fraction used in the computation of the threshold. The default value is 1/2.

Note: If fraction == 0, total_err is essentially ignored in the threshold computation, i.e. threshold = local error goal.

Definition at line 222 of file mesh_operators.hpp.

◆ SetTotalErrorGoal()

void mfem::ThresholdRefiner::SetTotalErrorGoal ( real_t err_goal )

inline

Set the total error stopping criterion: stop when total_err <= total_err_goal. The default value is zero.

Definition at line 216 of file mesh_operators.hpp.

◆ SetTotalErrorNormP()

void mfem::ThresholdRefiner::SetTotalErrorNormP ( real_t norm_p = infinity() )

inline

Set the exponent, p, of the discrete p-norm used to compute the total error from the local element errors.

Definition at line 211 of file mesh_operators.hpp.

Member Data Documentation

◆ aniso_estimator

AnisotropicErrorEstimator* mfem::ThresholdRefiner::aniso_estimator

protected

Definition at line 179 of file mesh_operators.hpp.

◆ current_sequence

long mfem::ThresholdRefiner::current_sequence

protected

Definition at line 191 of file mesh_operators.hpp.

◆ estimator

ErrorEstimator& mfem::ThresholdRefiner::estimator

protected

Definition at line 178 of file mesh_operators.hpp.

◆ local_err_goal

real_t mfem::ThresholdRefiner::local_err_goal

protected

Definition at line 184 of file mesh_operators.hpp.

◆ marked_elements

Array<Refinement> mfem::ThresholdRefiner::marked_elements

protected

Definition at line 190 of file mesh_operators.hpp.

◆ max_elements

long long mfem::ThresholdRefiner::max_elements

protected

Definition at line 185 of file mesh_operators.hpp.

◆ nc_limit

int mfem::ThresholdRefiner::nc_limit

protected

Definition at line 194 of file mesh_operators.hpp.

◆ non_conforming

int mfem::ThresholdRefiner::non_conforming

protected

Definition at line 193 of file mesh_operators.hpp.

◆ num_marked_elements

long long mfem::ThresholdRefiner::num_marked_elements

protected

Definition at line 188 of file mesh_operators.hpp.

◆ threshold

real_t mfem::ThresholdRefiner::threshold

protected

Definition at line 187 of file mesh_operators.hpp.

◆ total_err_goal

real_t mfem::ThresholdRefiner::total_err_goal

protected

Definition at line 182 of file mesh_operators.hpp.

◆ total_fraction

real_t mfem::ThresholdRefiner::total_fraction

protected

Definition at line 183 of file mesh_operators.hpp.

◆ total_norm_p

real_t mfem::ThresholdRefiner::total_norm_p

protected

Definition at line 181 of file mesh_operators.hpp.

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

mesh/mesh_operators.hpp
mesh/mesh_operators.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ThresholdRefiner()

Member Function Documentation

◆ ApplyImpl()

◆ GetNorm()

◆ GetNumMarkedElements()

◆ GetThreshold()

◆ PreferConformingRefinement()

◆ PreferNonconformingRefinement()

◆ Reset()

◆ SetLocalErrorGoal()

◆ SetMaxElements()

◆ SetNCLimit()

◆ SetTotalErrorFraction()

◆ SetTotalErrorGoal()

◆ SetTotalErrorNormP()

Member Data Documentation

◆ aniso_estimator

◆ current_sequence

◆ estimator

◆ local_err_goal

◆ marked_elements

◆ max_elements

◆ nc_limit

◆ non_conforming

◆ num_marked_elements

◆ threshold

◆ total_err_goal

◆ total_fraction

◆ total_norm_p