Tempus Version of the Day
Time Integration
Loading...
Searching...
No Matches
Tempus_StepperIMEX_RK_decl.hpp
Go to the documentation of this file.
1// @HEADER
2// ****************************************************************************
3// Tempus: Copyright (2017) Sandia Corporation
4//
5// Distributed under BSD 3-clause license (See accompanying file Copyright.txt)
6// ****************************************************************************
7// @HEADER
8
9#ifndef Tempus_StepperIMEX_RK_decl_hpp
10#define Tempus_StepperIMEX_RK_decl_hpp
11
12#include "Tempus_config.hpp"
14#include "Tempus_StepperImplicit.hpp"
15#include "Tempus_WrapperModelEvaluatorPairIMEX_Basic.hpp"
16
17
18namespace Tempus {
19
288template<class Scalar>
289class StepperIMEX_RK : virtual public Tempus::StepperImplicit<Scalar>,
290 virtual public Tempus::StepperRKBase<Scalar>
291{
292public:
293
299 StepperIMEX_RK(std::string stepperType = "IMEX RK SSP2");
300
303 const Teuchos::RCP<const Thyra::ModelEvaluator<Scalar> >& appModel,
304 const Teuchos::RCP<Thyra::NonlinearSolverBase<Scalar> >& solver,
305 bool useFSAL,
306 std::string ICConsistency,
307 bool ICConsistencyCheck,
308 bool zeroInitialGuess,
309 const Teuchos::RCP<StepperRKAppAction<Scalar> >& stepperRKAppAction,
310 std::string stepperType,
311 Teuchos::RCP<const RKButcherTableau<Scalar> > explicitTableau,
312 Teuchos::RCP<const RKButcherTableau<Scalar> > implicitTableau,
313 Scalar order);
314
315
317
318
319 virtual Teuchos::RCP<const RKButcherTableau<Scalar> > getTableau() const
320 { return getExplicitTableau(); }
321
323 virtual void setTableaus( std::string stepperType = "",
324 Teuchos::RCP<const RKButcherTableau<Scalar> > explicitTableau = Teuchos::null,
325 Teuchos::RCP<const RKButcherTableau<Scalar> > implicitTableau = Teuchos::null);
326
327 virtual void setTableaus(
328 Teuchos::RCP<Teuchos::ParameterList> stepperPL,
329 std::string stepperType);
330
332 virtual Teuchos::RCP<const RKButcherTableau<Scalar> > getExplicitTableau() const
333 { return explicitTableau_; }
334
336 virtual void setExplicitTableau(
337 Teuchos::RCP<const RKButcherTableau<Scalar> > explicitTableau);
338
340 virtual Teuchos::RCP<const RKButcherTableau<Scalar> > getImplicitTableau() const
341 { return implicitTableau_; }
342
344 virtual void setImplicitTableau(
345 Teuchos::RCP<const RKButcherTableau<Scalar> > implicitTableau);
346
347 virtual void setModel(
348 const Teuchos::RCP<const Thyra::ModelEvaluator<Scalar> >& appModel);
349
350 virtual Teuchos::RCP<const Thyra::ModelEvaluator<Scalar> > getModel() const
351 { return this->wrapperModel_; }
352
353 virtual void setModelPair(
354 const Teuchos::RCP<WrapperModelEvaluatorPairIMEX_Basic<Scalar> >& mePair);
355
356 virtual void setModelPair(
357 const Teuchos::RCP<const Thyra::ModelEvaluator<Scalar> >& explicitModel,
358 const Teuchos::RCP<const Thyra::ModelEvaluator<Scalar> >& implicitModel);
359
361 virtual void initialize();
362
364 virtual void setInitialConditions (
365 const Teuchos::RCP<SolutionHistory<Scalar> >& solutionHistory);
366
368 virtual void takeStep(
369 const Teuchos::RCP<SolutionHistory<Scalar> >& solutionHistory);
370
371 virtual Teuchos::RCP<Tempus::StepperState<Scalar> >getDefaultStepperState();
372 virtual Scalar getOrder()const { return order_; }
373 virtual Scalar getOrderMin()const { return order_; }
374 virtual Scalar getOrderMax()const { return order_; }
375
376 virtual bool isExplicit() const {return true;}
377 virtual bool isImplicit() const {return true;}
378 virtual bool isExplicitImplicit() const
379 {return isExplicit() && isImplicit();}
380 virtual bool isOneStepMethod() const {return true;}
381 virtual bool isMultiStepMethod() const {return !isOneStepMethod();}
382 virtual OrderODE getOrderODE() const {return FIRST_ORDER_ODE;}
384
385 std::vector<Teuchos::RCP<Thyra::VectorBase<Scalar> > >& getStageF() {return stageF_;}
386 std::vector<Teuchos::RCP<Thyra::VectorBase<Scalar> > >& getStageG() {return stageG_;}
387 Teuchos::RCP<Thyra::VectorBase<Scalar> >& getXTilde() {return xTilde_;}
388
390 virtual Scalar getAlpha(const Scalar dt) const
391 {
392 const Teuchos::SerialDenseMatrix<int,Scalar> & A = implicitTableau_->A();
393 return Scalar(1.0)/(dt*A(0,0)); // Getting the first diagonal coeff!
394 }
396 virtual Scalar getBeta (const Scalar ) const { return Scalar(1.0); }
397
398 Teuchos::RCP<const Teuchos::ParameterList> getValidParameters() const;
399
401
402 virtual void describe(Teuchos::FancyOStream & out,
403 const Teuchos::EVerbosityLevel verbLevel) const;
405
406 virtual bool isValidSetup(Teuchos::FancyOStream & out) const;
407
409 const Teuchos::RCP<const Thyra::VectorBase<Scalar> > & X,
410 Scalar time, Scalar stepSize, Scalar stageNumber,
411 const Teuchos::RCP<Thyra::VectorBase<Scalar> > & G) const;
412
414 const Teuchos::RCP<const Thyra::VectorBase<Scalar> > & X,
415 Scalar time, Scalar stepSize, Scalar stageNumber,
416 const Teuchos::RCP<Thyra::VectorBase<Scalar> > & F) const;
417
418 void setOrder(Scalar order) { order_ = order; }
419
420protected:
421
422 Teuchos::RCP<const RKButcherTableau<Scalar> > explicitTableau_;
423 Teuchos::RCP<const RKButcherTableau<Scalar> > implicitTableau_;
424
425 Scalar order_;
426
427 std::vector<Teuchos::RCP<Thyra::VectorBase<Scalar> > > stageF_;
428 std::vector<Teuchos::RCP<Thyra::VectorBase<Scalar> > > stageG_;
429
430 Teuchos::RCP<Thyra::VectorBase<Scalar> > xTilde_;
431
432};
433
434
447template <typename Scalar>
449 : virtual public Tempus::TimeDerivative<Scalar>
450{
451public:
452
455 Scalar s, Teuchos::RCP<const Thyra::VectorBase<Scalar> > xTilde)
456 { initialize(s, xTilde); }
457
460
462 virtual void compute(
463 Teuchos::RCP<const Thyra::VectorBase<Scalar> > x,
464 Teuchos::RCP< Thyra::VectorBase<Scalar> > xDot,
465 Teuchos::RCP< Thyra::VectorBase<Scalar> > xDotDot = Teuchos::null)
466 {
467 xDotDot = Teuchos::null;
468
469 // ith stage
470 // s = 1/(dt*a_ii)
471 // xOld = solution at beginning of time step
472 // xTilde = xOld + dt*(Sum_{j=1}^{i-1} a_ij x_dot_j)
473 // xDotTilde = - (s*x_i - s*xTilde)
474 Thyra::V_StVpStV(xDot.ptr(),s_,*x,-s_,*xTilde_);
475 }
476
477 virtual void initialize(Scalar s,
478 Teuchos::RCP<const Thyra::VectorBase<Scalar> > xTilde)
479 { s_ = s; xTilde_ = xTilde; }
480
481private:
482
483 Teuchos::RCP<const Thyra::VectorBase<Scalar> > xTilde_;
484 Scalar s_; // = 1/(dt*a_ii)
485};
486
487
489// ------------------------------------------------------------------------
490template<class Scalar>
491Teuchos::RCP<StepperIMEX_RK<Scalar> >
493 const Teuchos::RCP<const Thyra::ModelEvaluator<Scalar> >& model,
494 std::string stepperType,
495 Teuchos::RCP<Teuchos::ParameterList> pl);
496
497
498} // namespace Tempus
499#endif // Tempus_StepperIMEX_RK_decl_hpp
Time-derivative interface for IMEX RK.
StepperIMEX_RKTimeDerivative(Scalar s, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xTilde)
Constructor.
virtual void compute(Teuchos::RCP< const Thyra::VectorBase< Scalar > > x, Teuchos::RCP< Thyra::VectorBase< Scalar > > xDot, Teuchos::RCP< Thyra::VectorBase< Scalar > > xDotDot=Teuchos::null)
Compute the time derivative.
Teuchos::RCP< const Thyra::VectorBase< Scalar > > xTilde_
virtual void initialize(Scalar s, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xTilde)
Implicit-Explicit Runge-Kutta (IMEX-RK) time stepper.
virtual void setInitialConditions(const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
Set the initial conditions and make them consistent.
virtual Teuchos::RCP< const RKButcherTableau< Scalar > > getTableau() const
Returns the explicit tableau!
virtual Teuchos::RCP< const RKButcherTableau< Scalar > > getImplicitTableau() const
Return implicit tableau.
std::vector< Teuchos::RCP< Thyra::VectorBase< Scalar > > > stageG_
Teuchos::RCP< const Teuchos::ParameterList > getValidParameters() const
virtual Scalar getBeta(const Scalar) const
Return beta = d(x)/dx.
virtual void setExplicitTableau(Teuchos::RCP< const RKButcherTableau< Scalar > > explicitTableau)
Set the explicit tableau from tableau.
Teuchos::RCP< const RKButcherTableau< Scalar > > explicitTableau_
virtual void initialize()
Initialize during construction and after changing input parameters.
virtual bool isValidSetup(Teuchos::FancyOStream &out) const
virtual void setTableaus(std::string stepperType="", Teuchos::RCP< const RKButcherTableau< Scalar > > explicitTableau=Teuchos::null, Teuchos::RCP< const RKButcherTableau< Scalar > > implicitTableau=Teuchos::null)
Set both the explicit and implicit tableau from ParameterList.
virtual void setImplicitTableau(Teuchos::RCP< const RKButcherTableau< Scalar > > implicitTableau)
Set the implicit tableau from tableau.
virtual void describe(Teuchos::FancyOStream &out, const Teuchos::EVerbosityLevel verbLevel) const
std::vector< Teuchos::RCP< Thyra::VectorBase< Scalar > > > stageF_
std::vector< Teuchos::RCP< Thyra::VectorBase< Scalar > > > & getStageF()
virtual void takeStep(const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
Take the specified timestep, dt, and return true if successful.
virtual Teuchos::RCP< Tempus::StepperState< Scalar > > getDefaultStepperState()
Provide a StepperState to the SolutionState. This Stepper does not have any special state data,...
virtual Scalar getAlpha(const Scalar dt) const
Return alpha = d(xDot)/dx.
Teuchos::RCP< const RKButcherTableau< Scalar > > implicitTableau_
void evalExplicitModel(const Teuchos::RCP< const Thyra::VectorBase< Scalar > > &X, Scalar time, Scalar stepSize, Scalar stageNumber, const Teuchos::RCP< Thyra::VectorBase< Scalar > > &F) const
Teuchos::RCP< Thyra::VectorBase< Scalar > > xTilde_
std::vector< Teuchos::RCP< Thyra::VectorBase< Scalar > > > & getStageG()
virtual void setModelPair(const Teuchos::RCP< WrapperModelEvaluatorPairIMEX_Basic< Scalar > > &mePair)
Create WrapperModelPairIMEX from user-supplied ModelEvaluator pair.
virtual void setModel(const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &appModel)
Set the model.
StepperIMEX_RK(std::string stepperType="IMEX RK SSP2")
Default constructor.
Teuchos::RCP< Thyra::VectorBase< Scalar > > & getXTilde()
virtual Teuchos::RCP< const RKButcherTableau< Scalar > > getExplicitTableau() const
Return explicit tableau.
virtual Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > getModel() const
virtual OrderODE getOrderODE() const
void evalImplicitModelExplicitly(const Teuchos::RCP< const Thyra::VectorBase< Scalar > > &X, Scalar time, Scalar stepSize, Scalar stageNumber, const Teuchos::RCP< Thyra::VectorBase< Scalar > > &G) const
Thyra Base interface for implicit time steppers.
Teuchos::RCP< WrapperModelEvaluator< Scalar > > wrapperModel_
Base class for Runge-Kutta methods, ExplicitRK, DIRK and IMEX.
This interface defines the time derivative connection between an implicit Stepper and WrapperModelEva...
Teuchos::RCP< StepperIMEX_RK< Scalar > > createStepperIMEX_RK(const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &model, std::string stepperType, Teuchos::RCP< Teuchos::ParameterList > pl)
Nonmember constructor - ModelEvaluator and ParameterList.
@ FIRST_ORDER_ODE
Stepper integrates first-order ODEs.