DUNE PDELab (git)
Default class for additional methods in instationary local operators. More...
#include <dune/pdelab/localoperator/idefault.hh>
Public Member Functions | |
void | setTime (R t_) |
set time for subsequent evaluation More... | |
R | getTime () const |
get current time More... | |
void | preStep (RealType time, RealType dt, int stages) |
to be called once before each time step More... | |
void | postStep () |
to be called once at the end of each time step More... | |
void | preStage (RealType time, int r) |
to be called once before each stage More... | |
int | getStage () const |
get current stage More... | |
void | postStage () |
to be called once at the end of each stage | |
RealType | suggestTimestep (RealType dt) const |
to be called after stage 1 More... | |
Detailed Description
class Dune::PDELab::InstationaryLocalOperatorDefaultMethods< R >
Default class for additional methods in instationary local operators.
The algorithm used by the InstationaryGridOperator and the OneStepMethod to advance one step in time is as follows:
- Call the method preStep(start_time_of_step, step_size, nstages) on each localoperator.
-
For each stage1 in [1, nstages]
- Call preStage(time_of_stage1, number_of_stage1) on each localoperator.
-
Assemble constant part of residual: For each stage2 in [0, number_of_stage1-1]
- Call setTime(time_of_stage2) for each local operator.
- Iterate over grid and evaluate the local operator.
- Call setTime(time_of_stage1) for each local operator.
- Apply solver: Iterate over grid (possibly multiple times and evaluate local operator.
- Call postStage() on each local operator.
- Call postStep() on the temporal local operator.
The algorithm used by the InstationaryGridOperator and the ExplicitOneStepMethod to advance one step in time is as follows:
- Call the method preStep(start_time_of_step, step_size, nstages) on each localoperator.
-
For each stage1 in [1, nstages]
- Call preStage(time_of_stage1, number_of_stage1) on each localoperator.
-
Assemble constant part of residual: For each stage2 in [0, number_of_stage1-1]
- Call setTime(time_of_stage2) for each local operator.
- Iterate over grid and evaluate the local operator.
- Call setTime(time_of_stage1) for each local operator.
- Assemble matrices to be solved: Iterate over the grid and evaluate the local operator.
-
If stage1 == 1:
- Possibly call suggestTimeStep() and adjust the time step accordingly.
- Call postStage() on each local operator.
- Call postStep() on the temporal local operator.
The algorithm used by the MultiStepGridOperator and the MultiStepMethod to advance one step in time is as follows:
- Call the method preStep(start_time_of_step, step_size, 1) on each localoperator.
- Call the method preStage(end_time_of_step, 1) on each local operator.
-
Assemble constant part of residual: For each step in [1, number_of_steps]
- Call setTime(end_time_of_step-step_size*number_of_step) for each local operator.
- Iterate over grid and evaluate the local operators.
- Call setTime(end_time_of_step) for each local operator.
- Apply solver: Iterate over grid (possibly multiple times and evaluate local operator.
- Call postStage() on each local operator.
- Call postStep() on each local operator.
- Examples
- recipe-operator-splitting.cc.
Member Function Documentation
◆ getStage()
|
inline |
get current stage
- Returns
- The current stage number previously set by preStage().
◆ getTime()
|
inline |
get current time
- Returns
- The time previously set by setTime().
◆ postStep()
|
inline |
to be called once at the end of each time step
- Note
- With the OneStepMethod and the ExplicitOneStepMetod, for reasons unknown this is only called for temporal but not for spatial local operators. With the MultiStepMethod this is called for all local operators.
◆ preStage()
|
inline |
to be called once before each stage
- Parameters
-
time Time of the stage r Number of the stage, r ∈ [1, nstages] inclusive, where nstages is the number of stage in the step given in the previous call to preStep()
- Note
- For ExplicitOneStepMethod the time given here for stage 1 may be incorrect, since the time step size is only finally determined after the first stage has been assembled.
- For the MultiStepMethod, this is called once after preStep() with r=1.
◆ preStep()
|
inline |
to be called once before each time step
- Parameters
-
time Time at beginning of the step. dt Size of time step. stages Number of stages to do in the step. For the MultiStepMethod this is always 1.
- Note
- For ExplicitOneStepMethod the dt given here may be incorrect, since the time step size is only finally determined after the first stage has been assembled.
-
For the MultiStepMethod the number of stages is given as
- Since there are no times of evaluation in the middle of the step, a multi-step method is similar to a one step method with one stage.
◆ setTime()
|
inline |
set time for subsequent evaluation
This method set the time for subsequent calls to the alpha_*(), lambda_*(), jacobian_*() and jacobian_apply_*() methods.
- Note
- For ExplicitOneStepMethod the time given here in the first stage may be incorrect, since the time step size is only finally determined after the first stage has been assembled.
Referenced by Dune::PDELab::ConvectionDiffusionDG< T, FiniteElementMap >::setTime().
◆ suggestTimestep()
|
inline |
to be called after stage 1
- Note
- Only used by the ExplicitOneStepMethod.
This may be called on the spatial local operator in the case of an explicit one step scheme. It is called after stage 1 has been assembled (so the time given to preStep() may not apply anymore in this case). All the alpha_*() and lambda_*() methods should have been called, so they are a good place to generate the information returned here.
The documentation for this class was generated from the following file:
- dune/pdelab/localoperator/idefault.hh