Integrators::Theta< dim > Class Template Reference

#include <integrator.h>

Inheritance diagram for Integrators::Theta< dim >:

Collaboration diagram for Integrators::Theta< dim >:

Public Member Functions
	Theta (AmandusIntegrator< dim > &client, bool implicit, dealii::BlockMask blocks=dealii::BlockMask(), bool enforce_homogenity=false)
virtual void	extract_data (const dealii::AnyData &data)
	Extract data independent of the cell. More...
Public Member Functions inherited from AmandusIntegrator< dim >
	AmandusIntegrator ()
unsigned int	n_errors () const
unsigned int	error_type (unsigned int i) const
std::string	error_name (unsigned int i) const
dealii::UpdateFlags	update_flags () const
	Returns the update flags to be used. More...
dealii::UpdateFlags	update_flags_face () const
	Returns the update flags to be used on boundary and interior faces. More...
void	add_flags (const dealii::UpdateFlags flags)
	Add update flags on all objects. More...
void	add_flags_face (const dealii::UpdateFlags flags)
	Add update flags on boundary and internal faces. More...

Private Member Functions
virtual void	cell (dealii::MeshWorker::DoFInfo< dim > &dinfo, dealii::MeshWorker::IntegrationInfo< dim > &info) const
virtual void	boundary (dealii::MeshWorker::DoFInfo< dim > &dinfo, dealii::MeshWorker::IntegrationInfo< dim > &info) const
virtual void	face (dealii::MeshWorker::DoFInfo< dim > &dinfo1, dealii::MeshWorker::DoFInfo< dim > &dinfo2, dealii::MeshWorker::IntegrationInfo< dim > &info1, dealii::MeshWorker::IntegrationInfo< dim > &info2) const

Private Attributes
dealii::SmartPointer< AmandusIntegrator< dim >, Theta< dim > >	client
bool	is_implicit
dealii::BlockMask	block_mask
bool	enforce_homogenity

Additional Inherited Members
Public Attributes inherited from AmandusIntegrator< dim >
double	timestep
	Current timestep if applicable. More...
dealii::SmartPointer< dealii::Quadrature< dim > >	cell_quadrature
	Quadrature rule used on cells. More...
dealii::SmartPointer< dealii::Quadrature< dim-1 > >	boundary_quadrature
	Quadrature rule used on boundary faces. More...
dealii::SmartPointer< dealii::Quadrature< dim-1 > >	face_quadrature
	Quadrature rule used on faces. More...
Protected Attributes inherited from AmandusIntegrator< dim >
std::vector< unsigned int >	error_types
std::vector< std::string >	error_names

Detailed Description

template<int dim>
class Integrators::Theta< dim >

The local integrator for the two residuals in dealii::ThetaTimestepping, namely the explicit part and the Newton-residual of the implicit part.

Constructor & Destructor Documentation

template<int dim>

Integrators::Theta< dim >::Theta ( AmandusIntegrator< dim > &  client, bool  implicit, dealii::BlockMask  blocks = dealii::BlockMask(), bool  enforce_homogenity = false  )

inline

Constructor setting the integrator for the stationary problem and optionally a BlockMask, which for DAE identifies which blocks are subject to timestepping. Given a stationary operator \( F(u) \) and a weighted timestep \( \omega \), the local integral computed is

\[ Mu \pm \omega F(u), \]

where the sign is positive for the implicit operator and negative for the explicit.

Parameters

client	is the integrator for the stationary problem. Copied into the dealii::SmartPointer client.
implicit	selects whether the Newton residual of the implicit side (true) or the explicit side of the theta scheme is integrated. Copied into the variable is_implicit.
blocks	If the system is a DAE, for instance the Stokes equations, then the timestepping applies only to some parts of the system, for instance only the velocities. Thus, the mass matrix in the fomula above would have empty blocks.
enforce_homogenity	Set all components corresponding to blocks which are not timestepped to zero. If the initial system satisfies the algebraic constraints then this will be true anyway but setting it allows us to choose arbitrary initial values for non-timestepped blocks.

Warning

Requires that dealii::MeshWorker::LoopControl::cells_first is false! This integrator has to modify the results of the stationary integrator. In part, for face integration, this modification can be applied in face(). But since the matrix coupling only interior degrees of freedom is accumulated through all interior and boundary faces, the modification of scaling the stationary matrix and then adding the mass matrix must be applied after all these contributions have been assembled. Setting dealii::MeshWorker::LoopControl::cells_first to false accomplishes this.

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Member Function Documentation

template<int dim>

void Integrators::Theta< dim >::boundary ( dealii::MeshWorker::DoFInfo< dim > &  dinfo, dealii::MeshWorker::IntegrationInfo< dim > &  info  ) const

privatevirtual

template<int dim>

void Integrators::Theta< dim >::cell ( dealii::MeshWorker::DoFInfo< dim > &  dinfo, dealii::MeshWorker::IntegrationInfo< dim > &  info  ) const

privatevirtual

template<int dim>

void Integrators::Theta< dim >::extract_data ( const dealii::AnyData &  data )

inlinevirtual

Extract data independent of the cell.

Extract data which does not depend on the current cell from AnyData, before the loop over cells and faces is run. By default, get the current time step if we are in a timestepping scheme.

Reimplemented from AmandusIntegrator< dim >.

template<int dim>

void Integrators::Theta< dim >::face ( dealii::MeshWorker::DoFInfo< dim > &  dinfo1, dealii::MeshWorker::DoFInfo< dim > &  dinfo2, dealii::MeshWorker::IntegrationInfo< dim > &  info1, dealii::MeshWorker::IntegrationInfo< dim > &  info2  ) const

privatevirtual

Member Data Documentation

template<int dim>

dealii::BlockMask Integrators::Theta< dim >::block_mask

private

template<int dim>

dealii::SmartPointer<AmandusIntegrator<dim>, Theta<dim> > Integrators::Theta< dim >::client

private

template<int dim>

bool Integrators::Theta< dim >::enforce_homogenity

private

template<int dim>

bool Integrators::Theta< dim >::is_implicit

private

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

• integrator.h