Trapezoid rule time stepping scheme. More...

#include <trapezoid_rule.h>

Inheritance diagram for oomph::TR:

Public Member Functions
	TR (const bool &adaptive=false)
	Constructor, storage for two history derivatives (one for TR and one for the predictor step), one history value, present value and predicted value. More...

virtual	~TR ()
	Virtual destructor. More...

unsigned	order () const
	Return the actual order of the scheme. More...

void	set_weights ()
	Set the weights. More...

void	set_error_weights ()
	Set the weights for the error computation, (currently empty – overwrite for specific scheme) More...

void	set_predictor_weights ()
	Function to set the predictor weights. More...

unsigned	nprev_values () const
	Number of previous values available. More...

unsigned	derivative_index (const unsigned &t) const
	Location in data of derivatives. More...

unsigned	predicted_value_index () const
	Location of predicted value. More...

unsigned	ndt () const
	Number of timestep increments that need to be stored by the scheme. More...

void	assign_initial_values_impulsive (Data *const &data_pt)
	Initialise the time-history for the Data values, corresponding to an impulsive start. More...

void	assign_initial_positions_impulsive (Node *const &node_pt)
	Initialise the time-history for the nodal positions corresponding to an impulsive start. More...

void	actions_after_timestep (Problem *problem_pt)
	Interface for any actions that need to be performed after a time step. More...

void	actions_before_timestep (Problem *problem_pt)
	Interface for any actions that need to be performed before a time step. More...

void	setup_initial_derivative (Problem *problem_pt)

void	shift_time_values (Data *const &data_pt)
	This function updates the Data's time history so that we can advance to the next timestep. More...

void	shift_time_positions (Node *const &node_pt)
	This function advances the time history of the positions at a node. More...

void	calculate_predicted_positions (Node *const &node_pt)
	Function to calculate predicted positions at a node. More...

void	calculate_predicted_values (Data *const &data_pt)
	Function to calculate predicted data values in a Data object. More...

double	temporal_error_in_position (Node *const &node_pt, const unsigned &i)
	Compute the error in the position i at a node. More...

double	temporal_error_in_value (Data *const &data_pt, const unsigned &i)
	Compute the error in the value i in a Data structure. More...

Public Member Functions inherited from oomph::TimeStepper
	TimeStepper (const unsigned &tstorage, const unsigned &max_deriv)
	Constructor. Pass the amount of storage required by timestepper (present value + history values) and the order of highest time-derivative. More...

	TimeStepper ()
	Broken empty constructor. More...

	TimeStepper (const TimeStepper &)=delete
	Broken copy constructor. More...

void	operator= (const TimeStepper &)=delete
	Broken assignment operator. More...

virtual	~TimeStepper ()
	virtual destructor More...

unsigned	highest_derivative () const
	Highest order derivative that the scheme can compute. More...

double &	time ()
	Return current value of continous time. More...

double	time () const
	Return current value of continous time. More...

virtual unsigned	nprev_values_for_value_at_evaluation_time () const
	Number of previous values needed to calculate the value at the current time. i.e. how many previous values must we loop over to calculate the values at the evaluation time. For most methods this is 1, i.e. just use the value at t_{n+1}. See midpoint method for a counter-example. More...

void	make_steady ()
	Function to make the time stepper temporarily steady. This is trivially achieved by setting all the weights to zero. More...

bool	is_steady () const
	Flag to indicate if a timestepper has been made steady (possibly temporarily to switch off time-dependence) More...

bool	predict_by_explicit_step () const
	Flag: is adaptivity done by taking a separate step using an ExplicitTimeStepper object? More...

ExplicitTimeStepper *	explicit_predictor_pt ()
	Get the pointer to the explicit timestepper to use as a predictor in adaptivity if Predict_by_explicit_step is set. More...

void	set_predictor_pt (ExplicitTimeStepper *_pred_pt)
	Set the pointer to the explicit timestepper to use as a predictor in adaptivity if Predict_by_explicit_step is set. More...

void	update_predicted_time (const double &new_time)
	Set the time that the current predictions apply for, only needed for paranoid checks when doing Predict_by_explicit_step. More...

void	check_predicted_values_up_to_date () const
	Check that the predicted values are the ones we want. More...

unsigned	predictor_storage_index () const
	Return the time-index in each Data where predicted values are stored if the timestepper is adaptive. More...

void	enable_warning_in_assign_initial_data_values ()
	Enable the output of warnings due to possible fct pointer vector size mismatch in assign_initial_data_values (Default) More...

void	disable_warning_in_assign_initial_data_values ()
	Disable the output of warnings due to possible fct pointer vector size mismatch in assign_initial_data_values. More...

const DenseMatrix< double > *	weights_pt () const
	Get a (const) pointer to the weights. More...

virtual void	undo_make_steady ()
	Reset the is_steady status of a specific TimeStepper to its default and re-assign the weights. More...

std::string	type () const
	Return string that indicates the type of the timestepper (e.g. "BDF", "Newmark", etc.) More...

void	time_derivative (const unsigned &i, Data *const &data_pt, Vector< double > &deriv)
	Evaluate i-th derivative of all values in Data and return in Vector deriv[]. More...

double	time_derivative (const unsigned &i, Data *const &data_pt, const unsigned &j)
	Evaluate i-th derivative of j-th value in Data. More...

void	time_derivative (const unsigned &i, Node *const &node_pt, Vector< double > &deriv)
	Evaluate i-th derivative of all values in Node and return in Vector deriv[] (this can't be simply combined with time_derivative(.., Data, ...) because of differences with haning nodes). More...

double	time_derivative (const unsigned &i, Node *const &node_pt, const unsigned &j)
	Evaluate i-th derivative of j-th value in Node. Note the use of the node's value() function so that hanging nodes are taken into account (this is why the functions for Data and Node cannot be combined through simple polymorphism: value is not virtual). More...

Time *const &	time_pt () const
	Access function for the pointer to time (const version) More...

Time *&	time_pt ()
	Access function for the pointer to time (can't have a paranoid test for null pointers because this is used as a set function). More...

virtual double	weight (const unsigned &i, const unsigned &j) const
	Access function for j-th weight for the i-th derivative. More...

unsigned	ntstorage () const
	Return the number of doubles required to represent history (one for steady) More...

bool	adaptive_flag () const
	Function to indicate whether the scheme is adaptive (false by default) More...

Public Attributes
bool	Initial_derivative_set

bool	Shift_f

Private Member Functions
	TR (const TR &dummy)=delete
	Broken copy constructor. More...

void	operator= (const TR &dummy)=delete
	Broken assignment operator. More...

Private Attributes
Vector< double >	Predictor_weight
	Private data for the predictor weights. More...

double	Error_weight
	Private data for the error weight. More...

Additional Inherited Members
Protected Attributes inherited from oomph::TimeStepper
Time *	Time_pt
	Pointer to discrete time storage scheme. More...

DenseMatrix< double >	Weight
	Storage for the weights associated with the timestepper. More...

std::string	Type
	String that indicates the type of the timestepper (e.g. "BDF", "Newmark", etc.) More...

bool	Adaptive_Flag
	Boolean variable to indicate whether the timestepping scheme can be adaptive. More...

bool	Is_steady
	Bool to indicate if the timestepper is steady, i.e. its time-derivatives evaluate to zero. This status may be achieved temporarily by calling make_steady(). It can be reset to the appropriate default by the function undo_make_steady(). More...

bool	Shut_up_in_assign_initial_data_values
	Boolean to indicate if the timestepper will output warnings when setting possibly an incorrect number of initial data values from function pointers. More...

bool	Predict_by_explicit_step
	Flag: is adaptivity done by taking a separate step using an ExplicitTimeStepper object? More...

ExplicitTimeStepper *	Explicit_predictor_pt
	Pointer to explicit time stepper to use as predictor if Predict_by_explicit_step is set. ??ds merge the two? predict by explicit if pointer is set? More...

double	Predicted_time
	Store the time that the predicted values currently stored are at, to compare for paranoid checks. More...

int	Predictor_storage_index
	The time-index in each Data object where predicted values are stored. -1 if not set. More...

Detailed Description

Trapezoid rule time stepping scheme.

This method requires a value of dy/dt at the initial time. The implementation of this calculation is exactly the same as is used for explicit time stepping.

The function setup_initial_derivative(Problem* problem_pt) should be called after the initial conditions have been set, but before beginning time stepping, to compute this initial value of dy/dt.

Warning: moving nodes not implemented (I have no test case).

Definition at line 45 of file trapezoid_rule.h.

Constructor & Destructor Documentation

◆ TR() [1/2]

oomph::TR::TR ( const bool & adaptive = false )

inline

Constructor, storage for two history derivatives (one for TR and one for the predictor step), one history value, present value and predicted value.

Definition at line 63 of file trapezoid_rule.h.

References oomph::TimeStepper::Adaptive_Flag, Error_weight, Initial_derivative_set, Predictor_weight, Shift_f, and oomph::TimeStepper::Weight.

◆ ~TR()

virtual oomph::TR::~TR ( )

inlinevirtual

Virtual destructor.

Definition at line 80 of file trapezoid_rule.h.

◆ TR() [2/2]

oomph::TR::TR ( const TR & dummy )

privatedelete

Broken copy constructor.

Member Function Documentation

◆ actions_after_timestep()

void oomph::TR::actions_after_timestep ( Problem * problem_pt )

inlinevirtual

Interface for any actions that need to be performed after a time step.

Reimplemented from oomph::TimeStepper.

Definition at line 171 of file trapezoid_rule.h.

References Shift_f.

◆ actions_before_timestep()

void oomph::TR::actions_before_timestep ( Problem * problem_pt )

inlinevirtual

Interface for any actions that need to be performed before a time step.

Reimplemented from oomph::TimeStepper.

Definition at line 177 of file trapezoid_rule.h.

References Initial_derivative_set, and oomph::Global_string_for_annotation::string().

◆ assign_initial_positions_impulsive()

void oomph::TR::assign_initial_positions_impulsive ( Node *const & node_pt )

inlinevirtual

Initialise the time-history for the nodal positions corresponding to an impulsive start.

Implements oomph::TimeStepper.

Definition at line 164 of file trapezoid_rule.h.

◆ assign_initial_values_impulsive()

void oomph::TR::assign_initial_values_impulsive ( Data *const & data_pt )

inlinevirtual

Initialise the time-history for the Data values, corresponding to an impulsive start.

Implements oomph::TimeStepper.

Definition at line 155 of file trapezoid_rule.h.

◆ calculate_predicted_positions()

void oomph::TR::calculate_predicted_positions ( Node *const & node_pt )

inlinevirtual

Function to calculate predicted positions at a node.

Reimplemented from oomph::TimeStepper.

Definition at line 264 of file trapezoid_rule.h.

References i, oomph::Node::ndim(), oomph::Node::position_is_a_copy(), predicted_value_index(), Predictor_weight, and oomph::Node::x().

◆ calculate_predicted_values()

void oomph::TR::calculate_predicted_values ( Data *const & data_pt )

inlinevirtual

Function to calculate predicted data values in a Data object.

Reimplemented from oomph::TimeStepper.

Definition at line 290 of file trapezoid_rule.h.

References i, oomph::Data::is_a_copy(), oomph::Data::nvalue(), predicted_value_index(), Predictor_weight, oomph::Data::set_value(), and oomph::Data::value().

◆ derivative_index()

unsigned oomph::TR::derivative_index ( const unsigned & t ) const

inline

Location in data of derivatives.

Definition at line 128 of file trapezoid_rule.h.

References oomph::Global_string_for_annotation::string(), and t.

Referenced by predicted_value_index(), set_predictor_weights(), set_weights(), setup_initial_derivative(), and shift_time_values().

◆ ndt()

unsigned oomph::TR::ndt ( ) const

inlinevirtual

Number of timestep increments that need to be stored by the scheme.

Implements oomph::TimeStepper.

Definition at line 148 of file trapezoid_rule.h.

◆ nprev_values()

unsigned oomph::TR::nprev_values ( ) const

inlinevirtual

Number of previous values available.

Implements oomph::TimeStepper.

Definition at line 122 of file trapezoid_rule.h.

◆ operator=()

void oomph::TR::operator= ( const TR & dummy )

privatedelete

Broken assignment operator.

◆ order()

unsigned oomph::TR::order ( ) const

inlinevirtual

Return the actual order of the scheme.

Reimplemented from oomph::TimeStepper.

Definition at line 83 of file trapezoid_rule.h.

◆ predicted_value_index()

unsigned oomph::TR::predicted_value_index ( ) const

inline

Location of predicted value.

Definition at line 142 of file trapezoid_rule.h.

References derivative_index().

Referenced by calculate_predicted_positions(), calculate_predicted_values(), temporal_error_in_position(), and temporal_error_in_value().

◆ set_error_weights()

void oomph::TR::set_error_weights ( )

inlinevirtual

Set the weights for the error computation, (currently empty – overwrite for specific scheme)

Reimplemented from oomph::TimeStepper.

Definition at line 97 of file trapezoid_rule.h.

References oomph::Time::dt(), Error_weight, and oomph::TimeStepper::Time_pt.

◆ set_predictor_weights()

void oomph::TR::set_predictor_weights ( )

inlinevirtual

Function to set the predictor weights.

Reimplemented from oomph::TimeStepper.

Definition at line 105 of file trapezoid_rule.h.

References derivative_index(), oomph::Time::dt(), Predictor_weight, and oomph::TimeStepper::Time_pt.

◆ set_weights()

void oomph::TR::set_weights ( )

inlinevirtual

Set the weights.

Implements oomph::TimeStepper.

Definition at line 89 of file trapezoid_rule.h.

References derivative_index(), oomph::Time::dt(), oomph::TimeStepper::Time_pt, and oomph::TimeStepper::Weight.

◆ setup_initial_derivative()

void oomph::TR::setup_initial_derivative ( Problem * problem_pt )

inline

Definition at line 189 of file trapezoid_rule.h.

References derivative_index(), oomph::Problem::get_dvaluesdt(), Initial_derivative_set, oomph::oomph_info, oomph::Problem::set_dofs(), and Shift_f.

◆ shift_time_positions()

void oomph::TR::shift_time_positions ( Node *const & node_pt )

inlinevirtual

This function advances the time history of the positions at a node.

Implements oomph::TimeStepper.

Definition at line 257 of file trapezoid_rule.h.

◆ shift_time_values()

void oomph::TR::shift_time_values ( Data *const & data_pt )

inlinevirtual

This function updates the Data's time history so that we can advance to the next timestep.

Implements oomph::TimeStepper.

Definition at line 210 of file trapezoid_rule.h.

References derivative_index(), oomph::Time::dt(), oomph::Data::is_a_copy(), oomph::Data::nvalue(), oomph::Data::set_value(), Shift_f, oomph::TimeStepper::time_pt(), and oomph::Data::value().

◆ temporal_error_in_position()

double oomph::TR::temporal_error_in_position	(	Node *const &	node_pt,
		const unsigned &	i
	)

inlinevirtual

Compute the error in the position i at a node.

Reimplemented from oomph::TimeStepper.

Definition at line 315 of file trapezoid_rule.h.

References Error_weight, i, predicted_value_index(), and oomph::Node::x().

◆ temporal_error_in_value()

double oomph::TR::temporal_error_in_value	(	Data *const &	data_pt,
		const unsigned &	i
	)

inlinevirtual

Compute the error in the value i in a Data structure.

Reimplemented from oomph::TimeStepper.

Definition at line 322 of file trapezoid_rule.h.

References Error_weight, i, predicted_value_index(), and oomph::Data::value().

Member Data Documentation

◆ Error_weight

double oomph::TR::Error_weight

private

Private data for the error weight.

Definition at line 334 of file trapezoid_rule.h.

Referenced by set_error_weights(), temporal_error_in_position(), temporal_error_in_value(), and TR().

◆ Initial_derivative_set

bool oomph::TR::Initial_derivative_set

Definition at line 251 of file trapezoid_rule.h.

Referenced by actions_before_timestep(), setup_initial_derivative(), and TR().

◆ Predictor_weight

Vector<double> oomph::TR::Predictor_weight

private

Private data for the predictor weights.

Definition at line 331 of file trapezoid_rule.h.

Referenced by calculate_predicted_positions(), calculate_predicted_values(), set_predictor_weights(), and TR().

◆ Shift_f

bool oomph::TR::Shift_f

Definition at line 253 of file trapezoid_rule.h.

Referenced by actions_after_timestep(), setup_initial_derivative(), shift_time_values(), and TR().

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

trapezoid_rule.h

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TR() [1/2]

◆ ~TR()

◆ TR() [2/2]

Member Function Documentation

◆ actions_after_timestep()

◆ actions_before_timestep()

◆ assign_initial_positions_impulsive()

◆ assign_initial_values_impulsive()

◆ calculate_predicted_positions()

◆ calculate_predicted_values()

◆ derivative_index()

◆ ndt()

◆ nprev_values()

◆ operator=()

◆ order()

◆ predicted_value_index()

◆ set_error_weights()

◆ set_predictor_weights()

◆ set_weights()

◆ setup_initial_derivative()

◆ shift_time_positions()

◆ shift_time_values()

◆ temporal_error_in_position()

◆ temporal_error_in_value()

Member Data Documentation

◆ Error_weight

◆ Initial_derivative_set

◆ Predictor_weight

◆ Shift_f