The "real" implementation of the implicit midpoint rule. Implemented by calculation of residuals etc. at half step. This requires non-trivial modifications to the element's residual and Jacobian calculation functions to interpolate values to the midpoint. As such IMRByBDF should be preferred. More...
#include <implicit_midpoint_rule.h>
Inheritance diagram for oomph::IMR:
Public Member Functions | |
| IMR (const bool &adaptive=false) | |
| Common mistakes when using this implementation of midpoint: More... | |
| virtual | ~IMR () |
| Destructor, predictor_pt handled by base. More... | |
| void | set_weights () |
| Setup weights for time derivative calculations. More... | |
| unsigned | nprev_values_for_value_at_evaluation_time () const |
| Number of history values to interpolate over to get the "current" value. More... | |
| Public Member Functions inherited from oomph::IMRBase | |
| IMRBase (const bool &adaptive=false) | |
| Constructor with initialisation. More... | |
| virtual | ~IMRBase () |
| Destructor. More... | |
| unsigned | order () const |
| Actual order (accuracy) of the scheme. More... | |
| unsigned | ndt () const |
| Number of timestep increments that are required by the scheme. More... | |
| unsigned | nprev_values () const |
| ??ds More... | |
| void | shift_time_values (Data *const &data_pt) |
| This function advances the Data's time history so that we can move on 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 | set_error_weights () |
| Set the weights for the error computation. This is not used by midpoint rule. More... | |
| void | set_predictor_weights () |
| Set the weights for the predictor previous timestep. This is not used by midpint rule. More... | |
| void | assign_initial_values_impulsive (Data *const &data_pt) |
| not implemented (??ds TODO) More... | |
| void | assign_initial_positions_impulsive (Node *const &node_pt) |
| Initialiset the positions for the node corresponding to an impulsive start. More... | |
| void | calculate_predicted_positions (Node *const &node_pt) |
| Do the predictor step for the positions at a node (currently empty — overwrite for a specific scheme) More... | |
| double | temporal_error_in_position (Node *const &node_pt, const unsigned &i) |
| Compute the error in the position i at a node zero here – overwrite for specific scheme. More... | |
| void | calculate_predicted_values (Data *const &data_pt) |
| Dummy - just check that the values that problem::calculate_predicted_values() has been called right. More... | |
| double | temporal_error_in_value (Data *const &data_pt, const unsigned &i) |
| Compute the error in the value i in a Data structure zero here – overwrite for specific scheme. 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... | |
| 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... | |
| virtual void | actions_before_timestep (Problem *problem_pt) |
| Interface for any actions that need to be performed before a time step. More... | |
| virtual void | actions_after_timestep (Problem *problem_pt) |
| Interface for any actions that need to be performed after a time step. More... | |
Private Member Functions | |
| IMR (const IMR &dummy) | |
| Inaccessible copy constructor. More... | |
| void | operator= (const IMR &dummy) |
| Inaccessible assignment operator. 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
The "real" implementation of the implicit midpoint rule. Implemented by calculation of residuals etc. at half step. This requires non-trivial modifications to the element's residual and Jacobian calculation functions to interpolate values to the midpoint. As such IMRByBDF should be preferred.
However this class must be used when multiple different time steppers are being used simultaneously for different parts of the problem.
Definition at line 166 of file implicit_midpoint_rule.h.
Constructor & Destructor Documentation
◆ IMR() [1/2]
|
inline |
Common mistakes when using this implementation of midpoint:
- Didn't include the d_u_evaltime_by_du_np1 term in the Jacobian.
- Didn't properly interpolate time/values/x/derivatives in jacobian/residual (all of these MUST be evaluated at the midpoint). Constructor with initialisation
Definition at line 176 of file implicit_midpoint_rule.h.
◆ ~IMR()
|
inlinevirtual |
Destructor, predictor_pt handled by base.
Definition at line 179 of file implicit_midpoint_rule.h.
◆ IMR() [2/2]
|
inlineprivate |
Inaccessible copy constructor.
Definition at line 205 of file implicit_midpoint_rule.h.
Member Function Documentation
◆ nprev_values_for_value_at_evaluation_time()
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inlinevirtual |
Number of history values to interpolate over to get the "current" value.
Implements oomph::IMRBase.
Definition at line 198 of file implicit_midpoint_rule.h.
◆ operator=()
|
inlineprivate |
Inaccessible assignment operator.
Definition at line 208 of file implicit_midpoint_rule.h.
◆ set_weights()
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inlinevirtual |
Setup weights for time derivative calculations.
Implements oomph::IMRBase.
Definition at line 182 of file implicit_midpoint_rule.h.
References oomph::Time::dt(), oomph::TimeStepper::Time_pt, and oomph::TimeStepper::Weight.
The documentation for this class was generated from the following file: