Tempus_UnitTest_EDIRK_TrapezoidalRule.cpp

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// @HEADER
// ****************************************************************************
//                Tempus: Copyright (2017) Sandia Corporation
//
// Distributed under BSD 3-clause license (See accompanying file Copyright.txt)
// ****************************************************************************
// @HEADER

#include "Tempus_UnitTest_RK_Utils.hpp"

#include "Tempus_StepperRKModifierBase.hpp"

#include "../TestModels/DahlquistTestModel.hpp"


namespace Tempus_Unit_Test {

using Teuchos::RCP;
using Teuchos::rcp;
using Teuchos::rcp_const_cast;
using Teuchos::rcp_dynamic_cast;
using Teuchos::ParameterList;
using Teuchos::sublist;


// ************************************************************
// ************************************************************
TEUCHOS_UNIT_TEST(EDIRK_TrapezoidalRule, Default_Construction)
{
  auto stepper = rcp(new Tempus::StepperEDIRK_TrapezoidalRule<double>());
  testDIRKAccessorsFullConstruction(stepper);

  // Test stepper properties.
  TEUCHOS_ASSERT(stepper->getOrder() == 2);
}


// ************************************************************
// ************************************************************
TEUCHOS_UNIT_TEST(EDIRK_TrapezoidalRule, StepperFactory_Construction)
{
  auto model = rcp(new Tempus_Test::SinCosModel<double>());
  testFactoryConstruction("RK Trapezoidal Rule", model);
}


// ************************************************************
// ************************************************************
TEUCHOS_UNIT_TEST(EDIRK_TrapezoidalRule, AppAction)
{
  auto stepper = rcp(new Tempus::StepperEDIRK_TrapezoidalRule<double>());
  auto model = rcp(new Tempus_Test::SinCosModel<double>());
  testRKAppAction(stepper, model, out, success);
}


// ************************************************************
// ************************************************************

class StepperRKModifierEDIRK_TrapezoidaTest
  : virtual public Tempus::StepperRKModifierBase<double>
{
public:

  StepperRKModifierEDIRK_TrapezoidaTest(Teuchos::FancyOStream &Out, bool &Success)
    : out(Out), success(Success)
  {}

  // FSAL
  virtual ~StepperRKModifierEDIRK_TrapezoidaTest(){}

  virtual void modify(
    Teuchos::RCP<Tempus::SolutionHistory<double> > sh,
    Teuchos::RCP<Tempus::StepperRKBase<double> > stepper,
    const typename Tempus::StepperRKAppAction<double>::ACTION_LOCATION actLoc)
  {
    const double relTol = 1.0e-14;
    auto stageNumber = stepper->getStageNumber();
    Teuchos::SerialDenseVector<int,double> c = stepper->getTableau()->c();

    auto currentState   = sh->getCurrentState();
    auto workingState   = sh->getWorkingState();
    const double dt     = workingState->getTimeStep();
    double time = currentState->getTime();
    if (stageNumber >= 0) time += c(stageNumber)*dt;

    auto x    = workingState->getX();
    auto xDot = workingState->getXDot();
    if (xDot == Teuchos::null) xDot = stepper->getStepperXDot();

    switch (actLoc) {
      case StepperRKAppAction<double>::BEGIN_STEP:
        {
          {
            auto DME = Teuchos::rcp_dynamic_cast<
              const Tempus_Test::DahlquistTestModel<double> > (stepper->getModel());
            TEST_FLOATING_EQUALITY(DME->getLambda(), -1.0, relTol);
          }
          TEST_FLOATING_EQUALITY(dt, 1.0, relTol);

          const double x_0    = get_ele(*(x), 0);
          const double xDot_0 = get_ele(*(xDot), 0);
          TEST_FLOATING_EQUALITY(x_0,     1.0, relTol);      // Should be x_0
          TEST_FLOATING_EQUALITY(xDot_0, -1.0, relTol);      // Should be xDot_0
          TEST_ASSERT(std::abs(time) < relTol);
          TEST_FLOATING_EQUALITY(dt,      1.0, relTol);
          TEST_COMPARE(stageNumber, ==, -1);
          break;
        }
      case StepperRKAppAction<double>::BEGIN_STAGE:
      case StepperRKAppAction<double>::BEFORE_SOLVE:
        {
          const double X_i = get_ele(*(x), 0);
          const double f_i = get_ele(*(xDot), 0);

          if (stageNumber == 0) {
            TEST_FLOATING_EQUALITY(X_i,      1.0, relTol);
            TEST_ASSERT(std::abs(f_i) < relTol);
            TEST_ASSERT(std::abs(time) < relTol);
          } else if (stageNumber == 1) {
            TEST_FLOATING_EQUALITY(X_i,      1.0, relTol);
            TEST_FLOATING_EQUALITY(f_i,     -1.0, relTol);
            TEST_FLOATING_EQUALITY(time,     1.0, relTol);
          } else {
            TEUCHOS_TEST_FOR_EXCEPT( !(-1 < stageNumber && stageNumber < 2));
          }

          break;
        }
      case StepperRKAppAction<double>::AFTER_SOLVE:
      case StepperRKAppAction<double>::BEFORE_EXPLICIT_EVAL:
      case StepperRKAppAction<double>::END_STAGE:
        {
          const double X_i = get_ele(*(x), 0);
          const double f_i = get_ele(*(xDot), 0);

          if (stageNumber == 0) {
            // X_i = 1, f_1 = 0
            TEST_FLOATING_EQUALITY(X_i,      1.0, relTol);
            TEST_FLOATING_EQUALITY(f_i,     -1.0, relTol);
            TEST_ASSERT(std::abs(time) < relTol);
          } else if (stageNumber == 1) {
            // X_i = , f_i =
            TEST_FLOATING_EQUALITY(X_i,     1.0/3.0, relTol);
            TEST_FLOATING_EQUALITY(f_i,    -1.0/3.0, relTol);
            TEST_FLOATING_EQUALITY(time,    1.0, relTol);
          } else {
            TEUCHOS_TEST_FOR_EXCEPT( !(-1 < stageNumber && stageNumber < 2));
          }

          break;
        }
      case StepperRKAppAction<double>::END_STEP:
        {
          const double x_1 = get_ele(*(x), 0);
          time = workingState->getTime();
          TEST_FLOATING_EQUALITY(x_1,  1.0/3.0, relTol);   // Should be x_1
          TEST_FLOATING_EQUALITY(time,     1.0, relTol);
          TEST_FLOATING_EQUALITY(dt,       1.0, relTol);
          TEST_COMPARE(stageNumber, ==, -1);

          if (stepper->getUseEmbedded() == true) {
            TEST_FLOATING_EQUALITY(workingState->getTolRel(), 1.0, relTol);
            TEST_ASSERT(std::abs(workingState->getTolAbs()) < relTol);
            // e = 0 from doxygen above.
            TEST_ASSERT(std::abs(workingState->getErrorRel()) < relTol);
          }

        }

    }


  }

private:

  Teuchos::FancyOStream & out;
  bool & success;
};


// ************************************************************
// ************************************************************
TEUCHOS_UNIT_TEST(DIRK, EDIRK_Trapezoida_Modifier)
{
  auto stepper = rcp(new Tempus::StepperEDIRK_TrapezoidalRule<double>());
  Teuchos::RCP<const Thyra::ModelEvaluator<double> >
    model = rcp(new Tempus_Test::DahlquistTestModel<double>());

  auto modifier = rcp(new StepperRKModifierEDIRK_TrapezoidaTest(out, success));

  stepper->setModel(model);
  stepper->setAppAction(modifier);
  stepper->setICConsistency("Consistent");
  stepper->setUseFSAL(false);
  stepper->initialize();

  // Create a SolutionHistory.
  auto solutionHistory = Tempus::createSolutionHistoryME(model);

  // Take one time step.
  stepper->setInitialConditions(solutionHistory);
  solutionHistory->initWorkingState();
  double dt = 1.0;
  solutionHistory->getWorkingState()->setTimeStep(dt);
  solutionHistory->getWorkingState()->setTime(dt);
  stepper->takeStep(solutionHistory);           // Primary testing occurs in
                                                // modifierX during takeStep().
  // Test stepper properties.
  TEUCHOS_ASSERT(stepper->getOrder() == 2);
}
} // namespace Tempus_Unit_Test