DAESolverInTime_def.hpp

#ifndef DAESOLVERINTIME_DEF_hpp
#define DAESOLVERINTIME_DEF_hpp
#include "DAESolverInTime_decl.hpp"
 

 
namespace FEDD {
 
 
template<class SC,class LO,class GO,class NO>
DAESolverInTime<SC,LO,GO,NO>::DAESolverInTime( CommConstPtr_Type comm ):
comm_(comm),
verbose_(comm->getRank()==0),
parameterList_(),
isTimeSteppingDefined_(false),
problem_(),
problemTime_(),
timeStepDef_(),
timeSteppingTool_(),
exporter_vector_(),
export_solution_vector_(),
boolExporterSetup_(false)
#ifdef FEDD_TIMER
,solveProblemTimer_ (Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime - Solve Problem"))
#endif
#ifdef FEDD_DETAIL_TIMER
,reassmbleAddInterfaceRHSTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Interface RHS"))
,reassmbleUpdateMeshDisplacementTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Update Mesh Displ."))
,reassmbleSolveGeometryTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Solve Geometry"))
,reassmbleMoveMeshTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Move Mesh"))
,reassmbleSolidMassAndRHSTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Assemble Solid Massmatrix and RHS"))
,reassmbleForTimeTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Assemble Fluid Problem (steady Navier-Stokes)"))
,reassmbleUpdateFluidInTimeTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Update Fluid Solution"))
#endif
{
 
 
}
 
template<class SC,class LO,class GO,class NO>
DAESolverInTime<SC,LO,GO,NO>::DAESolverInTime( ParameterListPtr_Type &parameterList, CommConstPtr_Type comm):
comm_(comm),
verbose_(comm->getRank()==0),
parameterList_(parameterList),
isTimeSteppingDefined_(false),
problem_(),
problemTime_(),
timeStepDef_(),
timeSteppingTool_(),
exporter_vector_(),
export_solution_vector_(),
boolExporterSetup_(false)
#ifdef FEDD_TIMER
,solveProblemTimer_ (Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime - Solve Problem"))
#endif
#ifdef FEDD_DETAIL_TIMER
,reassmbleAddInterfaceRHSTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Interface RHS"))
,reassmbleUpdateMeshDisplacementTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Update Mesh Displ."))
,reassmbleSolveGeometryTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Solve Geometry"))
,reassmbleMoveMeshTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Move Mesh"))
,reassmbleSolidMassAndRHSTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Assemble Solid Massmatrix and RHS"))
,reassmbleForTimeTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Assemble Fluid Problem (steady Navier-Stokes)"))
,reassmbleUpdateFluidInTimeTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Update Fluid Solution"))
#endif
    
{
 
}
 
template<class SC,class LO,class GO,class NO>
DAESolverInTime<SC,LO,GO,NO>::DAESolverInTime( SmallMatrix<int> &timeStepDef, ParameterListPtr_Type &parameterList, CommConstPtr_Type comm):
comm_(comm),
verbose_(comm->getRank()==0),
parameterList_(parameterList),
isTimeSteppingDefined_(false),
problem_(),
problemTime_(),
timeStepDef_(),
timeSteppingTool_(),
exporter_vector_(),
export_solution_vector_(),
boolExporterSetup_(false)
#ifdef FEDD_TIMER
,solveProblemTimer_ (Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime - Solve Problem"))
#endif
#ifdef FEDD_DETAIL_TIMER
,reassmbleAddInterfaceRHSTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Interface RHS"))
,reassmbleUpdateMeshDisplacementTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Update Mesh Displ."))
,reassmbleSolveGeometryTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Solve Geometry"))
,reassmbleMoveMeshTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Move Mesh"))
,reassmbleSolidMassAndRHSTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Assemble Solid Massmatrix and RHS"))
,reassmbleForTimeTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Assemble Fluid Problem (steady Navier-Stokes)"))
,reassmbleUpdateFluidInTimeTimer_(Teuchos::TimeMonitor::getNewCounter("FEDD - DAETime Detail - FSI Update Fluid Solution"))
#endif
    
{
    this->defineTimeStepping(timeStepDef);
}
 
template<class SC,class LO,class GO,class NO>
DAESolverInTime<SC,LO,GO,NO>::~DAESolverInTime(){
 
}
 
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::setProblem(Problem_Type& problem){
 
    problem_ = Teuchos::rcpFromRef(problem); /*now a NON-OWNING TEUCHOS::RCP to the object which was probably constructed in main function */
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::defineTimeStepping(SmallMatrix<int> &timeStepDef){
 
    timeStepDef_ = timeStepDef;
    timeSteppingTool_.reset(new TimeSteppingTools(sublist(parameterList_,"Timestepping Parameter") , comm_));
    isTimeSteppingDefined_ = true;
 
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTime(){
 
    TEUCHOS_TEST_FOR_EXCEPTION(problemTime_.is_null(), std::logic_error, "Mass system is null.");
 
    checkTimeSteppingDef();
 
    if(this->parameterList_->sublist("Parameter").get("FSI",false))
    {
        advanceInTimeFSI();
    }
    else{
        if (!parameterList_->sublist("Timestepping Parameter").get("Class","Singlestep").compare("Loadstepping")) {
            NonLinProbPtr_Type nonLinProb = Teuchos::rcp_dynamic_cast<NonLinProb_Type>(problem_);
            if (nonLinProb.is_null()){ 
                TEUCHOS_TEST_FOR_EXCEPTION(true, std::runtime_error, "Loadstepping only available to nonlinear Problems. (It is a tool to increase Nonlinear Solver convergence.)");
            }
            else{
                advanceWithLoadStepping();
            }
        }
        if (!parameterList_->sublist("Timestepping Parameter").get("Class","Singlestep").compare("Singlestep")) {
            NonLinProbPtr_Type nonLinProb = Teuchos::rcp_dynamic_cast<NonLinProb_Type>(problem_);
            if (nonLinProb.is_null()) {
                advanceInTimeLinear();
            }
            else{
                advanceInTimeNonLinear();
            }
        }
        else if(!parameterList_->sublist("Timestepping Parameter").get("Class","Singlestep").compare("Newmark"))
        {
            NonLinProbPtr_Type nonLinProb = Teuchos::rcp_dynamic_cast<NonLinProb_Type>(problem_);
            if (nonLinProb.is_null()) {
                advanceInTimeLinearNewmark();
            }
            else
            {
                 advanceInTimeNonLinearNewmark();
            }
        }
        else if( !parameterList_->sublist("Timestepping Parameter").get("Class","Singlestep").compare("Multistep")  ){
            NonLinProbPtr_Type nonLinProb = Teuchos::rcp_dynamic_cast<NonLinProb_Type>(problem_);
            if (nonLinProb.is_null()) {
                advanceInTimeLinearMultistep();
            }
            else{
                advanceInTimeNonLinearMultistep();
            }
        }
        else if( !parameterList_->sublist("Timestepping Parameter").get("Class","Singlestep").compare("External")  ){
            NonLinProbPtr_Type nonLinProb = Teuchos::rcp_dynamic_cast<NonLinProb_Type>(problem_);
            if (nonLinProb.is_null()) {
                advanceInTimeLinearExternal();
            }
            else{
                advanceInTimeNonLinearExternal();
            }
        }
        else{
            TEUCHOS_TEST_FOR_EXCEPTION(true, std::runtime_error, "Unknown time discretization type.");
        }
    }
    
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeLinear(){
 
    
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    if (print)
        exportTimestep();
    bool fullImplicitPressure = false;
    int size = timeStepDef_.size();
    double dt = 0.0;
    while (timeSteppingTool_->continueTimeStepping()) {
        problemTime_->updateTime ( timeSteppingTool_->currentTime() );
        dt = timeSteppingTool_->get_dt();
        problemTime_->updateSolutionPreviousStep();
        
        Teuchos::Array<BlockMatrixPtr_Type> bMatNonLin_vec_allstages;
        BlockMultiVectorPtrArray_Type   solutionRK_stages;
        BlockMultiVectorPtrArray_Type   sourceTermRK_stages;
        
        for (int s=0; s<timeSteppingTool_->getNmbStages(); s++) {
            double time = timeSteppingTool_->currentTime() + dt * timeSteppingTool_->getButcherTableC(s);
            if (verbose_)
                std::cout << "Currently in stage " << s+1 << " of "<< timeSteppingTool_->getNmbStages() << std::endl;
            
            problemTime_->updateRhs();/*apply (mass matrix / dt) to u_t*/
            if ( problemTime_->hasSourceTerm() ){
                TEUCHOS_TEST_FOR_EXCEPTION(true, std::runtime_error, "Fix source term.");
                problemTime_->assembleSourceTerm( time );
            }
            
            if (s==0 && timeSteppingTool_->getButcherTableCoefficient(s , s) == 0.0) {
                /* solution of last time step is later added to rk solution vector */
            }
            else if (s==0 && timeSteppingTool_->getButcherTableCoefficient(s , s) != 0.0) {
                TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "Not implemented butcher table!");
            }
            else{
                for (int s_prior=0; s_prior<s; s_prior++) {
                    SmallMatrix<double> coeff(size);
                    for (int i=0; i<size; i++) {
                        for (int j=0; j<size; j++) {
                            if (timeStepDef_[i][j]>0) {
                                if (i==0 && j==1 && fullImplicitPressure) {
                                    coeff[i][j] = 0;
                                }
                                else{
                                    coeff[i][j] = - timeSteppingTool_->getButcherTableCoefficient(s , s_prior);
                                }
                            }
                        }
                    }
                    if (problemTime_->hasSourceTerm())
                        this->addRhsDAE(coeff, sourceTermRK_stages[s_prior] );
                    
                    this->addRhsDAE( coeff, problemTime_->getSystem(), solutionRK_stages[s_prior] );
                    
                }
                
                SmallMatrix<double> massCoeff(size);
                SmallMatrix<double> problemCoeff(size);
                double coeffSourceTerm = 0.;
                for (int i=0; i<size; i++) {
                    for (int j=0; j<size; j++) {
                        if (timeStepDef_[i][j]>0 && i==j) {
                            massCoeff[i][j] = 1. / dt;
                        }
                        else if (timeStepDef_[i][j]==2) /*force off-diagnonal mass matrix*/
                            massCoeff[i][j] = 1. / dt;
                        else{
                            massCoeff[i][j] = 0.;
                        }
                    }
                }
                for (int i=0; i<size; i++) {
                    for (int j=0; j<size; j++){
                        if (timeStepDef_[i][j]>0){
                            if (i==0 && j==1 && fullImplicitPressure) {
                                problemCoeff[i][j] = 1.;
                                coeffSourceTerm = timeSteppingTool_->getButcherTableCoefficient(s , s); // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT
                            }
                            else{
                                problemCoeff[i][j] = timeSteppingTool_->getButcherTableCoefficient(s , s);
                                coeffSourceTerm = timeSteppingTool_->getButcherTableCoefficient(s , s); // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT DISKRETISIERT WIRD!
                            }
                        }
                        else{
                            problemCoeff[i][j] = 1.;
                        }
                    }
                }
                
                if (problemTime_->hasSourceTerm())
                    addSourceTermToRHS(coeffSourceTerm);
                
                problemTime_->setTimeParameters(massCoeff, problemCoeff);
                problemTime_->combineSystems();
                problemTime_->setBoundaries(time);
                
                problemTime_->solve();
 
            }
            
            if (s+1 == timeSteppingTool_->getNmbStages()) {
                BlockMultiVectorPtr_Type tmpSolution = Teuchos::rcp( new BlockMultiVector_Type ( problemTime_->getSolution() ) );
                solutionRK_stages.push_back(tmpSolution);
                BlockMultiVectorPtr_Type tmpSolutionPtr = problemTime_->getSolution();
                BlockMatrixPtr_Type tmpMassSystem = problemTime_->getMassSystem();
                timeSteppingTool_->calculateSolution( tmpSolutionPtr, solutionRK_stages, tmpMassSystem);
            }
            else{
                solutionRK_stages.push_back( problemTime_->getSolution() );
                if ( problemTime_->hasSourceTerm() )
                    sourceTermRK_stages.push_back( problemTime_->getSourceTerm() );
            }
        }
        
        timeSteppingTool_->advanceTime(true/*output info*/);
        
        if (print)
            exportTimestep();
    }
    
    if (print) {
        closeExporter();
    }
    if (parameterList_->sublist("NSParameter").get("Calculate Coefficients",false)) {
        TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "close txt exporters here.");
    }
 
}
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::getMassCoefficients(SmallMatrix<double> &massCoeff){
    int size = timeStepDef_.size();
    massCoeff.resize(size);
    
    for (int i=0; i<size; i++) {
        for (int j=0; j<size; j++) {
            if (timeStepDef_[i][j]>0 && i==j)
                massCoeff[i][j] = 1.;
            else
                massCoeff[i][j] = 0.;
        }
    }
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::getMultiStageCoefficients(SmallMatrix<double> &problemCoeff, int stage, int stagePrior, bool forRhs){
    int size = timeStepDef_.size();
    problemCoeff.resize(size);
    
    for (int i=0; i<size; i++) {
        for (int j=0; j<size; j++) {
            if (timeStepDef_[i][j]>0)
                problemCoeff[i][j] = timeSteppingTool_->get_dt()* timeSteppingTool_->getButcherTableCoefficient(stage , stagePrior);
            else{
                if (forRhs)
                    problemCoeff[i][j] = 0.;
                else
                    problemCoeff[i][j] = 1.;
            }
        }
    }
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::buildMultiStageRhs( int stage, Teuchos::Array<BlockMatrixPtr_Type>& matrixPrevStages, BlockMultiVectorPtrArray_Type& solutionPrevStages ){
    
    int size = timeStepDef_.size();
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    
    getMassCoefficients(massCoeff);
    
    problemTime_->setTimeParameters(massCoeff, problemCoeff);//problemCoeff not needed here
    problemTime_->updateRhs();/*apply (mass matrix / dt) to u_t*/
    
    bool fullImplicitPressure = parameterList_->sublist("Timestepping Parameter").get("Full implicit pressure",false);
    for (int prevStage=0; prevStage<stage; prevStage++) {
        
        getMultiStageCoefficients(problemCoeff, stage, prevStage, true);
        if (fullImplicitPressure && size>1 )
            problemCoeff[0][1] = 0.;
        
        problemCoeff.scale(-1.);
 
        TEUCHOS_TEST_FOR_EXCEPTION(problemTime_->hasSourceTerm(), std::logic_error, "Using source term must be implemented for single-step methods.");
//                        addRhsDAE(coeff,beNL_vec_allstages.at(s_prior), solutionRK_stages.at(s_prior), sourceTermRK_stages.at(s_prior));
        addRhsDAE( problemCoeff, matrixPrevStages[prevStage], solutionPrevStages[prevStage] );
 
    }
}
 
 
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeNonLinear(){
 
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    BlockMultiVectorPtr_Type solShort;
    if (print){
        if (parameterList_->sublist("Timestepping Parameter").get("Print Solution Short",false)) {
            solShort = Teuchos::rcp(new BlockMultiVector_Type (problemTime_->getSolution()) );
            exportTimestep(solShort);
        }
        else{
            exportTimestep();
        }
    }
    
    // Navier-Stokes treatment of pressure
    bool fullImplicitPressure = parameterList_->sublist("Timestepping Parameter").get("Full implicit pressure",false);
    bool semiImplicitPressure = parameterList_->sublist("Timestepping Parameter").get("Semi implicit pressure",false);
    bool correctPressure = parameterList_->sublist("Timestepping Parameter").get("Correct pressure",false);
    int size = timeStepDef_.size();
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    double dt = 0.0;
    int timeit = 0;
    while (timeSteppingTool_->continueTimeStepping()) {
        
        dt = timeSteppingTool_->get_dt();
        // Which values should we use for extrapolation? u_m and u_m-1 (current implementation) or should we use most recent U_i-1 of multi stages
        if(!parameterList_->sublist("General").get("Linearization","FixedPoint").compare("Extrapolation")) {
            if (timeSteppingTool_->currentTime()!=0.)
                problemTime_->updateSolutionMultiPreviousStep(2); //2nd order
            else
                problemTime_->updateSolutionMultiPreviousStep(1);
        }
        else{
            problemTime_->updateSolutionPreviousStep();
        }
        
        
//        BlockMultiVectorPtrArray_Type sourceTermRK_stages;
 
        TEUCHOS_TEST_FOR_EXCEPTION(timeSteppingTool_->getButcherTableCoefficient(0 , 0) != 0.0, std::logic_error, "Not implemented butchertable! First stage should have 0 diagonal value");
        if (verbose_)
            std::cout << "Currently in stage " << 1 << " of "<< timeSteppingTool_->getNmbStages() <<" (dummy stage)"<< std::endl;
        // Multistage stepping, in general we use at least 2 stages (implicit Euler and Crank-Nicolson)
        Teuchos::Array<BlockMatrixPtr_Type> matrixPrevStages;
        BlockMultiVectorPtrArray_Type       solutionPrevStages;
        
        BlockMatrixPtr_Type blockMatrix = Teuchos::rcp( new BlockMatrix_Type( problemTime_->getSystem()->size() ) );
        problemTime_->reAssembleAndFill( blockMatrix ); // Reassemble FixedPoint
        
        matrixPrevStages.push_back( blockMatrix );
        
        BlockMultiVectorPtr_Type sol =
            Teuchos::rcp( new BlockMultiVector_Type( problemTime_->getSolution() ) );
        solutionPrevStages.push_back( sol );
        
        for (int stage=1; stage<timeSteppingTool_->getNmbStages(); stage++) {
            double time = timeSteppingTool_->currentTime() + dt * timeSteppingTool_->getButcherTableC(stage);
            problemTime_->updateTime( time );
            if (verbose_)
                std::cout << "Currently in stage " << stage+1 << " of "<< timeSteppingTool_->getNmbStages() << std::endl;
            
            buildMultiStageRhs( stage, matrixPrevStages, solutionPrevStages );
                                    
            TEUCHOS_TEST_FOR_EXCEPTION(problemTime_->hasSourceTerm(), std::logic_error, "Using source term must be implemented for single-step methods.");
//                problemTime_->AssembleSourceTerm(time);
            
 
            SmallMatrix<double> massCoeff(size);
            SmallMatrix<double> problemCoeff(size);
                        
            getMassCoefficients(massCoeff);
            getMultiStageCoefficients(problemCoeff, stage, stage, false);
            if (fullImplicitPressure && size>1 )
                problemCoeff[0][1] = timeSteppingTool_->get_dt();
                                                       
            problemTime_->setTimeParameters(massCoeff, problemCoeff);
 
            NonLinearSolver<SC, LO, GO, NO> nlSolver(parameterList_->sublist("General").get("Linearization","FixedPoint"));
            nlSolver.solve(*problemTime_,time);
            
            if (correctPressure) {
                TEUCHOS_TEST_FOR_EXCEPTION( !fullImplicitPressure && !semiImplicitPressure, std::logic_error,"There is no pressure that can be corrected." );
                
                MultiVectorPtr_Type sol = problemTime_->getSolution()->getBlockNonConst(1);
                MultiVectorConstPtr_Type solLast = problemTime_->getSolutionPreviousTimestep()->getBlock(1);
                timeSteppingTool_->correctPressure( sol, solLast );
                if (verbose_)
                    std::cout << "Pressure corrected." << std::endl;
            }
            
            if (stage+1 == timeSteppingTool_->getNmbStages()) {
                // save last solution
                BlockMultiVectorPtr_Type tmpSolution = Teuchos::rcp( new BlockMultiVector_Type ( problemTime_->getSolution() ) );
                
                solutionPrevStages.push_back( tmpSolution );
                BlockMultiVectorPtr_Type tmpSolutionPtr = problemTime_->getSolution();
                BlockMatrixPtr_Type tmpMassSystem = problemTime_->getMassSystem();
                timeSteppingTool_->calculateSolution( tmpSolutionPtr, solutionPrevStages, tmpMassSystem, solShort);
            }
            else{
                BlockMatrixPtr_Type blockMatrix = Teuchos::rcp( new BlockMatrix_Type( problemTime_->getSystem()->size() ) );
                problemTime_->reAssembleAndFill( blockMatrix );
                matrixPrevStages.push_back( blockMatrix );
                
                BlockMultiVectorPtr_Type sol =
                    Teuchos::rcp( new BlockMultiVector_Type( problemTime_->getSolution() ) );
                solutionPrevStages.push_back( sol );
                
                TEUCHOS_TEST_FOR_EXCEPTION(problemTime_->hasSourceTerm(), std::logic_error, "Using source term must be implemented for single-step methods.");
//                    sourceTermRK_stages.push_back(*problemTime_->GetSourceTerm());
            }
        }
        timeSteppingTool_->advanceTime(true/*output info*/);
        timeit++;
        if (print) {
            exportTimestep();
        }
        if (parameterList_->sublist("NSParameter").get("Calculate Coefficients",false)) {
            vec_dbl_ptr_Type values(new vec_dbl_Type(4));
            TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "Drag and Lift are not implemented.");
//            nonLinearProblem_->ComputeDragLift(values);
        }
    }
 
    if (print) {
        closeExporter();
    }
    if (parameterList_->sublist("NSParameter").get("Calculate Coefficients",false)) {
        TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "close txt exporters here.");
    }
 
}
 
// TODO: Irgendwann einmal fuer St. Venant-Kirchoff oder so programmieren.
// Erstmal nicht wichtig
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceWithLoadStepping()
{
    
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    bool printExtraData = parameterList_->sublist("General").get("Export Extra Data",false);
    bool printData = parameterList_->sublist("General").get("Export Data",false);
    if (print)
    {
        exportTimestep();
    }
    
    vec_dbl_ptr_Type its = Teuchos::rcp(new vec_dbl_Type ( 2, 0. ) ); //0:linear iterations, 1: nonlinear iterations
    ExporterTxtPtr_Type exporterTimeTxt;
    ExporterTxtPtr_Type exporterIterations;
    ExporterTxtPtr_Type exporterNewtonIterations;
    if (printData) {
        std::string suffix = parameterList_->sublist("General").get("Export Suffix","");
        
        exporterTimeTxt = Teuchos::rcp(new ExporterTxt());
        exporterTimeTxt->setup( "time" + suffix, this->comm_ );
        
        exporterNewtonIterations = Teuchos::rcp(new ExporterTxt());
        exporterNewtonIterations->setup( "newtonIterations" + suffix, this->comm_ );
        
        exporterIterations = Teuchos::rcp(new ExporterTxt());
        exporterIterations->setup( "linearIterations" + suffix, this->comm_ );
    }
    // Groesse des Problems, Zeitschrittweite und Newmark-Parameter
    int size = timeStepDef_.size();
    TEUCHOS_TEST_FOR_EXCEPTION( size>1, std::runtime_error, "Loadstepping only implemented or sensible for 1x1 Systems.");
    double dt = timeSteppingTool_->get_dt();
   
 
    // Koeffizienten vor der Massematrix und vor der Systemmatrix des steady-Problems
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    double coeffSourceTerm = 0.0; // Koeffizient fuer den Source-Term (= rechte Seite der DGL); mit Null initialisieren
 
    // Koeffizient vor der Massematrix
    massCoeff[0][0] = 0.;
    problemCoeff[0][0] =  1.0;
    // Der Source Term ist schon nach der Assemblierung mit der Dichte \rho skaliert worden
    coeffSourceTerm = 1.0; // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT DISKRETISIERT WIRD!
 
    // Temporaerer Koeffizienten fuer die Skalierung der Massematrix in der rechten Seite des Systems in UpdateNewmarkRhs()
    vec_dbl_Type coeffTemp(1);
    coeffTemp.at(0) = 1.0;
 
    // Uebergebe die Parameter fuer Masse- und steady-Problemmatrix an TimeProblem
    // Wegen moeglicher Zeitschrittweitensteuerung, rufe CombineSystems()
    // in jedem Zeitschritt auf, um LHS neu aufzustellen.
    // Bei AdvanceInTimeNonLinear... wird das in ReAssemble() gemacht!!!
    problemTime_->setTimeParameters(massCoeff, problemCoeff);
    // Der Source Term ist schon nach der Assemblierung mit der Dichte \rho skaliert worden
   
    // ######################
    // "Time" loop
    // ######################
    while(timeSteppingTool_->continueTimeStepping())
    {
        // Stelle (massCoeff*M + problemCoeff*A) auf
        //problemTime_->combineSystems();
        
       
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( time );
          
        NonLinearSolver<SC, LO, GO, NO> nlSolver(parameterList_->sublist("General").get("Linearization","Newton"));
        nlSolver.solve( *problemTime_, time, its );
        
        timeSteppingTool_->advanceTime(true/*output info*/);
        if (printData) {
            exporterTimeTxt->exportData( timeSteppingTool_->currentTime() );
            exporterIterations->exportData( (*its)[0] );
            exporterNewtonIterations->exportData( (*its)[1] );
        }
        if (print) {
            exportTimestep();
        }
        this->problemTime_->assemble("UpdateTime"); // Updates to next timestep
 
    }
    
    comm_->barrier();
    if (print)
    {
        closeExporter();
    }
}
 
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeLinearNewmark()
{
    // problemCoeff vor A (= kompletes steady-System)
    // massCoeff vor M (= Massematrix)
    // coeffSourceTerm vor f (= rechte Seite der DGL)
 
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    if (print)
    {
        exportTimestep();
    }
 
    // Groesse des Problems, Zeitschrittweite und Newmark-Parameter
    int size = timeStepDef_.size();
    TEUCHOS_TEST_FOR_EXCEPTION( size>1, std::runtime_error, "Newmark only implemented for systems of size 1x1.");
    double dt = timeSteppingTool_->get_dt();
    double beta = timeSteppingTool_->get_beta();
    double gamma = timeSteppingTool_->get_gamma();
 
    // Koeffizienten vor der Massematrix und vor der Systemmatrix des steady-Problems
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    double coeffSourceTerm = 0.0; // Koeffizient fuer den Source-Term (= rechte Seite der DGL); mit Null initialisieren
 
    // Koeffizient vor der Massematrix
    massCoeff[0][0] = 1.0/(dt*dt*beta);
    problemCoeff[0][0] =  1.0;
    // Der Source Term ist schon nach der Assemblierung mit der Dichte \rho skaliert worden
    coeffSourceTerm = 1.0; // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT DISKRETISIERT WIRD!
 
    // Temporaerer Koeffizienten fuer die Skalierung der Massematrix in der rechten Seite des Systems in UpdateNewmarkRhs()
    vec_dbl_Type coeffTemp(1);
    coeffTemp.at(0) = 1.0;
 
    // Uebergebe die Parameter fuer Masse- und steady-Problemmatrix an TimeProblem
    // Wegen moeglicher Zeitschrittweitensteuerung, rufe CombineSystems()
    // in jedem Zeitschritt auf, um LHS neu aufzustellen.
    // Bei AdvanceInTimeNonLinear... wird das in ReAssemble() gemacht!!!
    problemTime_->setTimeParameters(massCoeff, problemCoeff);
 
    // ######################
    // Time loop
    // ######################
    while(timeSteppingTool_->continueTimeStepping())
    {
        // Stelle (massCoeff*M + problemCoeff*A) auf
        problemTime_->combineSystems();
 
        // Update u und berechne u' und u'' mit Hilfe der Newmark-Vorschrift
        problemTime_->updateSolutionNewmarkPreviousStep(dt, beta, gamma);
 
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( timeSteppingTool_->currentTime() );
        // Stelle die rechte Seite des zeitdiskretisierten Systems auf (ohne f_{n+1}).
        // Bei Newmark lautet dies:
        // M*[\frac{1}{dt^2*beta}*u_n + \frac{1}{dt*beta}*u'_n + \frac{0.5 - beta}{beta}*u''_n],
        // wobei u' = v (velocity) und u'' = w (acceleration).
        problemTime_->updateNewmarkRhs(dt, beta, gamma, coeffTemp);
 
        // TODO: SourceTerm wird in jedem Zeitschritt neu berechnet; auch wenn konstant!!!
        // if(time == 0){nur dann konstanten SourceTerm berechnen}
        if ( problemTime_->hasSourceTerm() )
        {
//            TEUCHOS_TEST_FOR_EXCEPTION(true, std::runtime_error, "Fix source term.");
            problemTime_->assembleSourceTerm(time);
 
            // Fuege die rechte Seite der DGL (f bzw. f_{n+1}) der rechten Seite hinzu (skaliert mit coeffSourceTerm)
            // Die Skalierung mit der Dichte erfolgt schon in der Assemblierungsfunktion!
            addSourceTermToRHS(coeffSourceTerm);
        }
 
        // Uebergabeparameter fuer BC noch hinzu nehmen!
        problemTime_->setBoundaries(time);
        problemTime_->solve();
 
        timeSteppingTool_->advanceTime(true/*output info*/);
 
        if (print) {
            exportTimestep();
        }
 
    }
 
    comm_->barrier();
    if (print)
    {
        closeExporter();
    }
}
 
 
// TODO: Irgendwann einmal fuer St. Venant-Kirchoff oder so programmieren.
// Erstmal nicht wichtig
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeNonLinearNewmark()
{
    
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    bool printExtraData = parameterList_->sublist("General").get("Export Extra Data",false);
    bool printData = parameterList_->sublist("General").get("Export Data",false);
    if (print)
    {
        exportTimestep();
    }
    
    vec_dbl_ptr_Type its = Teuchos::rcp(new vec_dbl_Type ( 2, 0. ) ); //0:linear iterations, 1: nonlinear iterations
    ExporterTxtPtr_Type exporterTimeTxt;
    ExporterTxtPtr_Type exporterIterations;
    ExporterTxtPtr_Type exporterNewtonIterations;
    if (printData) {
        std::string suffix = parameterList_->sublist("General").get("Export Suffix","");
        
        exporterTimeTxt = Teuchos::rcp(new ExporterTxt());
        exporterTimeTxt->setup( "time" + suffix, this->comm_ );
        
        exporterNewtonIterations = Teuchos::rcp(new ExporterTxt());
        exporterNewtonIterations->setup( "newtonIterations" + suffix, this->comm_ );
        
        exporterIterations = Teuchos::rcp(new ExporterTxt());
        exporterIterations->setup( "linearIterations" + suffix, this->comm_ );
    }
    // Groesse des Problems, Zeitschrittweite und Newmark-Parameter
    int size = timeStepDef_.size();
    TEUCHOS_TEST_FOR_EXCEPTION( size>1, std::runtime_error, "Newmark only implemented for systems of size 1x1.");
    double dt = timeSteppingTool_->get_dt();
    double beta = timeSteppingTool_->get_beta();
    double gamma = timeSteppingTool_->get_gamma();
    
    // Koeffizienten vor der Massematrix und vor der Systemmatrix des steady-Problems
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    double coeffSourceTerm = 0.0; // Koeffizient fuer den Source-Term (= rechte Seite der DGL); mit Null initialisieren
    
    // Koeffizient vor der Massematrix
    massCoeff[0][0] = 1.0/(dt*dt*beta);
    problemCoeff[0][0] =  1.0;
    // Der Source Term ist schon nach der Assemblierung mit der Dichte \rho skaliert worden
    coeffSourceTerm = 1.0; // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT DISKRETISIERT WIRD!
    
    // Temporaerer Koeffizienten fuer die Skalierung der Massematrix in der rechten Seite des Systems in UpdateNewmarkRhs()
    vec_dbl_Type coeffTemp(1);
    coeffTemp.at(0) = 1.0;
    
    // Uebergebe die Parameter fuer Masse- und steady-Problemmatrix an TimeProblem
    // Wegen moeglicher Zeitschrittweitensteuerung, rufe CombineSystems()
    // in jedem Zeitschritt auf, um LHS neu aufzustellen.
    problemTime_->setTimeParameters(massCoeff, problemCoeff);
    
    // ######################
    // Time loop
    // ######################
    while(timeSteppingTool_->continueTimeStepping())
    {
        // Stelle (massCoeff*M + problemCoeff*A) auf
        problemTime_->combineSystems();
        
        // Update u und berechne u' und u'' mit Hilfe der Newmark-Vorschrift
        problemTime_->updateSolutionNewmarkPreviousStep(dt, beta, gamma);
        
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( time );
        // Stelle die rechte Seite des zeitdiskretisierten Systems auf (ohne f_{n+1}).
        // Bei Newmark lautet dies:
        // M*[\frac{1}{dt^2*beta}*u_n + \frac{1}{dt*beta}*u'_n + \frac{0.5 - beta}{beta}*u''_n],
        // wobei u' = v (velocity) und u'' = w (acceleration).
        problemTime_->updateNewmarkRhs(dt, beta, gamma, coeffTemp);
        
        // TODO: SourceTerm wird in jedem Zeitschritt neu berechnet; auch wenn konstant!!!
        // if(time == 0){nur dann konstanten SourceTerm berechnen}
        if (problemTime_->hasSourceTerm())
        {
//            TEUCHOS_TEST_FOR_EXCEPTION(true, std::runtime_error, "Fix source term.");
            problemTime_->assembleSourceTerm(time);
            
            // Fuege die rechte Seite der DGL (f bzw. f_{n+1}) der rechten Seite hinzu (skaliert mit coeffSourceTerm)
            // Die Skalierung mit der Dichte erfolgt schon in der Assemblierungsfunktion!
            // This is done in  calculateNonLinResidualVec for this nonlinear problem
            addSourceTermToRHS(coeffSourceTerm);
        }
        
        // Uebergabeparameter fuer BC noch hinzu nehmen!
//        problemTime_->setBoundaries(time);
        
        NonLinearSolver<SC, LO, GO, NO> nlSolver(parameterList_->sublist("General").get("Linearization","Newton"));
        nlSolver.solve( *problemTime_, time, its );
        
        timeSteppingTool_->advanceTime(true/*output info*/);
        if (printData) {
            exporterTimeTxt->exportData( timeSteppingTool_->currentTime() );
            exporterIterations->exportData( (*its)[0] );
            exporterNewtonIterations->exportData( (*its)[1] );
        }
        if (print) {
            exportTimestep();
        }
        
    }
    
    comm_->barrier();
    if (print)
    {
        closeExporter();
    }
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeFSI()
{
    // problemCoeff vor A (= komplettes steady-System)
    // massCoeff vor M (= Massematrix)
    // coeffSourceTerm vor f (= rechte Seite der DGL)
    
    
    FSIProblemPtr_Type fsi = Teuchos::rcp_dynamic_cast<FSIProblem_Type>( this->problemTime_->getUnderlyingProblem() );
    
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    bool printData = parameterList_->sublist("General").get("Export Data",false);
    bool printExtraData = parameterList_->sublist("General").get("Export Extra Data",false);
        
    if (print)
    {
        exportTimestep();
    }
 
 
    vec_dbl_ptr_Type its = Teuchos::rcp(new vec_dbl_Type ( 2, 0. ) ); //0:linear iterations, 1: nonlinear iterations
    ExporterTxtPtr_Type exporterTimeTxt;
    ExporterTxtPtr_Type exporterDisplXTxt;
    ExporterTxtPtr_Type exporterDisplYTxt;
    ExporterTxtPtr_Type exporterIterations;
    ExporterTxtPtr_Type exporterNewtonIterations;
    
    if (printData) {
        exporterTimeTxt = Teuchos::rcp(new ExporterTxt());
        exporterDisplXTxt = Teuchos::rcp(new ExporterTxt());
        exporterDisplYTxt = Teuchos::rcp(new ExporterTxt());
        exporterTimeTxt->setup( "time", this->comm_ );
 
        std::string suffix = parameterList_->sublist("General").get("Export Suffix","");
        
        exporterNewtonIterations = Teuchos::rcp(new ExporterTxt());
        exporterNewtonIterations->setup( "newtonIterations" + suffix, this->comm_ );
        
        exporterIterations = Teuchos::rcp(new ExporterTxt());
        exporterIterations->setup( "linearIterations" + suffix, this->comm_ );
    }
    if (printExtraData) {
 
        vec_dbl_Type v(3,-9999.);
        this->problemTime_->getValuesOfInterest(v);
        vec_dbl_Type vGathered(this->comm_->getSize());
        Teuchos::gatherAll<int,double>( *this->comm_, 1, &v[0], vGathered.size(), &vGathered[0] );
        int targetRank=0;
        while (vGathered[targetRank] < 0){
            targetRank++;
            TEUCHOS_TEST_FOR_EXCEPTION( targetRank == vGathered.size(), std::runtime_error, "No targetRank for export of displacements was found!" );
        }
        
        std::string suffix = parameterList_->sublist("General").get("Export Suffix","");
        
        exporterDisplXTxt->setup( "displ_x" + suffix, this->comm_ , targetRank);
        exporterDisplYTxt->setup( "displ_y" + suffix, this->comm_ , targetRank);
        
    }
    
    // Notwendige Parameter
    bool geometryExplicit = this->parameterList_->sublist("Parameter").get("Geometry Explicit",true);
    int sizeFSI = timeStepDef_.size();
 
    // ACHTUNG
    int sizeFluid = 2; // u_f  + p
    int sizeStructure = 1; // d_s
 
    double dt = timeSteppingTool_->get_dt();
    double beta = timeSteppingTool_->get_beta();
    double gamma = timeSteppingTool_->get_gamma();
    int nmbBDF = timeSteppingTool_->getBDFNumber();
 
    // ######################
    // Fluid: Mass-, Problem, SourceTerm Koeffizienten
    // ######################
    SmallMatrix<double> massCoeffFluid(sizeFluid);
    SmallMatrix<double> problemCoeffFluid(sizeFluid);
    double coeffSourceTermFluid = 0.0;
 
    for (int i=0; i<sizeFluid; i++) {
        for (int j=0; j<sizeFluid; j++) {
            if (timeStepDef_[i][j]>0 && i==j) {
                massCoeffFluid[i][j] = timeSteppingTool_->getInformationBDF(0) / dt;
            }
            else{
                massCoeffFluid[i][j] = 0.0;
            }
        }
    }
    for (int i=0; i<sizeFluid; i++) {
        for (int j=0; j<sizeFluid; j++){
            if (timeStepDef_[i][j]>0){
                problemCoeffFluid[i][j] = timeSteppingTool_->getInformationBDF(1);
                coeffSourceTermFluid = timeSteppingTool_->getInformationBDF(1);
            }
            else{
                problemCoeffFluid[i][j] = 1.;
            }
        }
    }
 
 
    // ######################
    // Struktur: Mass-, Problem, SourceTerm Koeffizienten
    // ######################
    // Koeffizienten vor der Massematrix und vor der Systemmatrix des steady-Problems
    SmallMatrix<double> massCoeffStructure(sizeStructure);
    SmallMatrix<double> problemCoeffStructure(sizeStructure);
    double coeffSourceTermStructure = 0.0; // Koeffizient fuer den Source-Term (= rechte Seite der DGL); mit Null initialisieren
 
    // Koeffizient vor der Massematrix
    for(int i = 0; i < sizeStructure; i++)
    {
        for(int j = 0; j < sizeStructure; j++)
        {
            // Falls in dem Block von timeStepDef_ zeitintegriert werden soll.
            // i == j, da vektorwertige Massematrix blockdiagonal ist
            if(timeStepDef_[i + sizeFluid][j + sizeFluid] > 0  && i == j) // Weil: (u_f, p, d_s,...) und timeStepDef_ von FSI
            {
               // Vorfaktor der Massematrix in der LHS
                massCoeffStructure[i][j] = 1.0/(dt*dt*beta);
            }
            else
            {
                massCoeffStructure[i][j] = 0.;
            }
        }
    }
 
    
    // Die anderen beiden Koeffizienten
    for(int i = 0; i < sizeStructure; i++)
    {
        for(int j = 0; j < sizeStructure; j++)
        {
            if(timeStepDef_[i + sizeFluid][j + sizeFluid] > 0 )
            {
                problemCoeffStructure[i][j] =  1.0;
                // Der Source Term ist schon nach der Assemblierung mit der Dichte \rho skaliert worden
                coeffSourceTermStructure = 1.0; // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT DISKRETISIERT WIRD!
            }
            else // Die steady-Systemmatrix ist nicht zwingend blockdiagonal
            {
                problemCoeffStructure[i][j] = 1.0;
            }
        }
    }
 
 
    // ######################
    // FSI: Mass-, Problem-Koeffizienten
    // ######################
    SmallMatrix<double> massCoeffFSI(sizeFSI);
    SmallMatrix<double> problemCoeffFSI(sizeFSI);
    for (int i = 0; i < sizeFluid; i++)
    {
        for (int j = 0; j < sizeFluid; j++)
        {
            massCoeffFSI[i][j] = massCoeffFluid[i][j];
            problemCoeffFSI[i][j] = problemCoeffFluid[i][j];
        }
    }
 
    for (int i = 0; i < sizeStructure; i++)
    {
        for (int j = 0; j < sizeStructure; j++)
        {
            massCoeffFSI[i + sizeFluid][j + sizeFluid] = massCoeffStructure[i][j];
            problemCoeffFSI[i + sizeFluid][j + sizeFluid] = problemCoeffStructure[i][j];
        }
    }
 
    // Setze noch Einsen an die Stellen, wo Eintraege (Kopplungsbloecke) vorhanden sind.
    problemCoeffFSI[0][3] = 1.0; // C1_T
    problemCoeffFSI[2][3] = 1.0; // C3_T
    problemCoeffFSI[3][0] = 1.0; // C1
    problemCoeffFSI[3][2] = 1.0; // C2
    if(!geometryExplicit)
    {
        problemCoeffFSI[4][2] = 1.0; // C4
        problemCoeffFSI[4][4] = 1.0; // H (Geometrie)
        std::string linearization = this->parameterList_->sublist("General").get("Linearization","Extrapolation");
        if(linearization == "Newton" || linearization == "NOX")
        {
            problemCoeffFSI[0][4] = 1.0; // Shape-Derivatives Velocity
            problemCoeffFSI[1][4] = 1.0; // Shape-Derivatives Div-Nebenbedingung
        }
    }
 
    this->problemTime_->setTimeParameters(massCoeffFSI, problemCoeffFSI);
    
    if (printExtraData) {
        exporterTimeTxt->exportData( timeSteppingTool_->currentTime() );
        vec_dbl_Type v(3,0.);
        this->problemTime_->getValuesOfInterest( v );
 
        exporterDisplXTxt->exportData( v[0] );
        exporterDisplYTxt->exportData( v[1] );
    }
 
//    {
//        // Initialize mass matrix for fluid problem
//        MatrixPtr_Type massmatrix;
//        TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "Fix reassembly of mass matrix for FSI.");
//        MatrixPtr_Type massmatrix;
//        fsi->setSolidMassmatrix( massmatrix );
//    }
    // ######################
    // Time loop
    // ######################
#ifdef FEDD_TIMER
    TimeMonitor_Type solveTM(*solveProblemTimer_);
#endif
    while(timeSteppingTool_->continueTimeStepping())
    {
        problemTime_->updateTime ( timeSteppingTool_->currentTime() );
 
        std::string linearization = this->parameterList_->sublist("General").get("Linearization","Extrapolation");
 
        // Ist noetig, falls wir extrapolieren, damit wir
        // immer die korrekten previousSolution_ haben.
        // TODO: Vermutlich reicht lediglich (da erstmal nur BDF2):
        // this->problemTime_->updateSolutionMultiPreviousStep(nmbBDF);
        if(nmbBDF<2 && !parameterList_->sublist("General").get("Linearization","FixedPoint").compare("Extrapolation"))
        {// we need the last two solution for a second order extrapolation.
            if (timeSteppingTool_->currentTime() != 0.0)
            {
                this->problemTime_->updateSolutionMultiPreviousStep(2);
            }
            else
            {
                this->problemTime_->updateSolutionMultiPreviousStep(1);
            }
        }
        else
        {
            this->problemTime_->updateSolutionMultiPreviousStep(nmbBDF);
        }
        {
#ifdef FEDD_DETAIL_TIMER
            TimeMonitor_Type reassmbleTM(*reassmbleAddInterfaceRHSTimer_);
#endif
            // Den Block C2*d_s^n in der RHS im Interface-Block setzen.
            this->problemTime_->assemble("AddInterfaceBlockRHS");
        }
        {
#ifdef FEDD_DETAIL_TIMER
            TimeMonitor_Type reassmbleTM(*reassmbleUpdateMeshDisplacementTimer_);
#endif
            // Alte Gitterbewegung mit der Geometrieloesung ueberschreiben.
            this->problemTime_->assemble("UpdateMeshDisplacement");
        }
        // Das Geometry-Problem separat loesen, falls GE.
        if(geometryExplicit)
        {
            {
#ifdef FEDD_DETAIL_TIMER
                TimeMonitor_Type reassmbleTM(*reassmbleSolveGeometryTimer_);
#endif
                this->problemTime_->assemble("SolveGeometryProblem");
            }
#ifdef FEDD_DETAIL_TIMER
            TimeMonitor_Type reassmbleTM(*reassmbleMoveMeshTimer_);
#endif
            this->problemTime_->assemble("MoveMesh");
        }
 
 
        // ######################
        // Struktur Zeitsystem
        // ######################
        // In jedem Zeitschritt die RHS der Struktur holen.
        // Die Massematrix wird in FSI jedoch nur fuer t = 0 berechnet, da Referenzkonfiguration
        // in der Struktur.
        {
            
            
#ifdef FEDD_DETAIL_TIMER
            TimeMonitor_Type reassmbleTM(*reassmbleSolidMassAndRHSTimer_);
#endif
            // Hier wird auch direkt ein Update der Loesung bei der Struktur gemacht.
            // Aehnlich zu "UpdateFluidInTime".
            
            if(timeSteppingTool_->currentTime() == 0.0)
            {
                // We extract the underlying FSI problem
                MatrixPtr_Type massmatrix;
                fsi->setSolidMassmatrix( massmatrix );
                this->problemTime_->systemMass_->addBlock( massmatrix, 2, 2 );
            }
            // this should be done automatically rhs will not be used here
//            this->problemTime_->getRhs()->addBlock( Teuchos::rcp_const_cast<MultiVector_Type>(rhs->getBlock(0)), 2 );
            this->problemTime_->assemble("ComputeSolidRHSInTime");
        }
 
 
        if(geometryExplicit) //  && linearization != "Extrapolation"
        {
#ifdef FEDD_DETAIL_TIMER
            TimeMonitor_Type reassmbleTM(*reassmbleForTimeTimer_);
#endif
            this->problemTime_->assemble("ForTime");
        }
 
        // ######################
        // Fluid Zeitsystem
        // ######################
        // Fluid-Loesung aktualisieren fuer die naechste(n) BDF2-Zeitintegration(en)
        // in diesem Zeitschritt.
        {
#ifdef FEDD_DETAIL_TIMER
            TimeMonitor_Type reassmbleTM(*reassmbleUpdateFluidInTimeTimer_);
#endif
            //Do we need this, if BDF for FSI is used correctly? We still need it to save the mass matrices
            this->problemTime_->assemble("UpdateFluidInTime");
        }
        // Aktuelle Massematrix auf dem Gitter fuer BDF2-Integration und
        // fuer das FSI-System (bei GI wird die Massematrix weiterhin in TimeProblem.reAssemble() assembliert).
        // In der ersten nichtlinearen Iteration wird bei GI also die Massematrix zweimal assembliert.
        // Massematrix fuer FSI holen und fuer timeProblemFluid setzen (fuer BDF2)
        MatrixPtr_Type massmatrix;
        fsi->setFluidMassmatrix( massmatrix );
        this->problemTime_->systemMass_->addBlock( massmatrix, 0, 0 );
        
 
        // RHS nach BDF2
        this->problemTime_->assemble( "ComputeFluidRHSInTime" ); // hier ist massmatrix nicht relevant
//        this->problemTime_->getRhs()->addBlock( Teuchos::rcp_const_cast<MultiVector_Type>(rhs->getBlock(0)), 0 );
 
 
        // ######################
        // System loesen
        // ######################
        // Use BDF1 Parameters for first system
        if (timeSteppingTool_->currentTime() == 0.) {
            for (int i = 0; i < sizeFluid; i++)
            {
                for (int j = 0; j < sizeFluid; j++){
                    if (massCoeffFSI[i][j] != 0.)
                        massCoeffFSI[i][j] = 1./dt ;
                }
            }
            this->problemTime_->setTimeParameters(massCoeffFSI, problemCoeffFSI);
        }
        
        
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( time );        
        NonLinearSolver<SC, LO, GO, NO> nlSolver(parameterList_->sublist("General").get("Linearization","FixedPoint"));
 
        nlSolver.solve(*this->problemTime_, time, its);
        
        if (timeSteppingTool_->currentTime() <= dt+1.e-10) {
            for (int i = 0; i < sizeFluid; i++)
            {
                for (int j = 0; j < sizeFluid; j++){
                    massCoeffFSI[i][j] = massCoeffFluid[i][j];
                }
            }
            this->problemTime_->setTimeParameters(massCoeffFSI, problemCoeffFSI);
        }
        
        this->problemTime_->computeValuesOfInterestAndExport();
 
        timeSteppingTool_->advanceTime(true/*output info*/);
        this->problemTime_->assemble("UpdateTime"); // Zeit in FSI inkrementieren
        if (printData) {
            exporterTimeTxt->exportData( timeSteppingTool_->currentTime() );
            exporterIterations->exportData( (*its)[0] );
            exporterNewtonIterations->exportData( (*its)[1] );
        }
        if (printExtraData) {
            vec_dbl_Type v(3,-9999.);
            this->problemTime_->getValuesOfInterest(v);
            
            exporterDisplXTxt->exportData( v[0] );
            exporterDisplYTxt->exportData( v[1] );
        }
        if (print)
        {
            exportTimestep();
        }
 
    }
 
    comm_->barrier();
    if (printExtraData) {
        exporterTimeTxt->closeExporter();
        exporterIterations->closeExporter();
        exporterNewtonIterations->closeExporter();
    }
    if (printExtraData) {
        exporterDisplXTxt->closeExporter();
        exporterDisplYTxt->closeExporter();        
    }
    if (print)
    {
        closeExporter();
    }
}
 
 
/* UEBERARBEITEN!!!!!!!!!!!!!!!!! */
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeLinearMultistep(){
 
    //TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "advanceInTimeLinearMultistep rework.");
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    if (print) {
        exportTimestep();
    }
    int size = timeStepDef_.size();
    double dt = timeSteppingTool_->get_dt();
    int nmbBDF = timeSteppingTool_->getBDFNumber();
    vec_dbl_Type coeffPrevSteps(nmbBDF);
    for (int i=0; i<coeffPrevSteps.size(); i++) {
       coeffPrevSteps.at(i) = timeSteppingTool_->getInformationBDF(i+2) / dt;
    }
 
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    double coeffSourceTerm = 0.;
 
    for (int i=0; i<size; i++) {
        for (int j=0; j<size; j++) {
            if (timeStepDef_[i][j]==1 && i==j) {
                massCoeff[i][j] = timeSteppingTool_->getInformationBDF(0) / dt;
            }
            else{
                massCoeff[i][j] = 0.;
            }
        }
    }
    for (int i=0; i<size; i++) {
        for (int j=0; j<size; j++){
            if (timeStepDef_[i][j]==1){
                problemCoeff[i][j] =  timeSteppingTool_->getInformationBDF(1);
                coeffSourceTerm = timeSteppingTool_->getInformationBDF(1); // ACHTUNG FUER SOURCE TERM, DER NICHT IN DER ZEIT DISKRETISIERT WIRD!
            }
            else{
                problemCoeff[i][j] = 1.;
            }
        }
    }
    problemTime_->setTimeParameters(massCoeff, problemCoeff);
 
    //#########
    //time loop
    //#########
    while (timeSteppingTool_->continueTimeStepping()) {
 
        problemTime_->updateSolutionMultiPreviousStep(nmbBDF);
 
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateMultistepRhs(coeffPrevSteps,nmbBDF);/*apply mass matrix to u_t*/
        if (problemTime_->hasSourceTerm()) {
            problemTime_->assembleSourceTerm(time);
            addSourceTermToRHS(coeffSourceTerm);
        }
 
        problemTime_->combineSystems();
        // Uebergabeparameter fuer BC noch hinzunehmen!
        problemTime_->setBoundaries(time);
        problemTime_->solve();
 
        timeSteppingTool_->advanceTime(true/*output info*/);
 
        if (print) {
            exportTimestep();
        }
 
    }
    comm_->barrier();
    if (print) {
        closeExporter();
    }
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeNonLinearMultistep(){
 
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    if (print) {
        exportTimestep();
    }
 
    int size = timeStepDef_.size();
    double dt = timeSteppingTool_->get_dt();
    int nmbBDF = timeSteppingTool_->getBDFNumber();
 
    vec_dbl_Type coeffPrevSteps(nmbBDF);
    for (int i=0; i<coeffPrevSteps.size(); i++) {
        coeffPrevSteps.at(i) = timeSteppingTool_->getInformationBDF(i+2) / dt;
    }
 
    SmallMatrix<double> massCoeff(size);
    SmallMatrix<double> problemCoeff(size);
    double coeffSourceTerm = 0.;
 
    for (int i=0; i<size; i++) {
        for (int j=0; j<size; j++) {
            if (timeStepDef_[i][j]>0 && i==j) {
                massCoeff[i][j] = timeSteppingTool_->getInformationBDF(0) / dt;
            }
            else{
                massCoeff[i][j] = 0.;
            }
        }
    }
    for (int i=0; i<size; i++) {
        for (int j=0; j<size; j++){
            if (timeStepDef_[i][j]>0){
                problemCoeff[i][j] = timeSteppingTool_->getInformationBDF(1);
                coeffSourceTerm = timeSteppingTool_->getInformationBDF(1);
            }
            else{
                problemCoeff[i][j] = 1.;
            }
        }
    }
    problemTime_->setTimeParameters(massCoeff, problemCoeff);
    //#########
    //time loop
    //#########
    while (timeSteppingTool_->continueTimeStepping()) {
 
        // For the first time step we use BDF1
        if (timeSteppingTool_->currentTime()==0.) {
            SmallMatrix<double> tmpmassCoeff(size);
            SmallMatrix<double> tmpproblemCoeff(size);
            for (int i=0; i<size; i++) {
                for (int j=0; j<size; j++) {
                    if (timeStepDef_[i][j]>0 && i==j) {
                        tmpmassCoeff[i][j] = 1. / dt;
                    }
                    else{
                        tmpmassCoeff[i][j] = 0.;
                    }
                }
            }
            for (int i=0; i<size; i++) {
                for (int j=0; j<size; j++){
                    if (timeStepDef_[i][j]>0){
                        tmpproblemCoeff[i][j] =  1.; // ist das richtig? Vermutlich schon, da BDF so geschrieben ist, dass zu berechnende Lsg den Koeffizienten 1 hat
                    }
                    else{
                        tmpproblemCoeff[i][j] = 1.;
                    }
                }
            }
            problemTime_->setTimeParameters(tmpmassCoeff, tmpproblemCoeff);
        }
        if(nmbBDF<2 && !parameterList_->sublist("General").get("Linearization","FixedPoint").compare("Extrapolation")) {
            if (timeSteppingTool_->currentTime()!=0.){
                problemTime_->updateSolutionMultiPreviousStep(2);
            }
            else{
                problemTime_->updateSolutionMultiPreviousStep(1);
            }
        }
        else{
            problemTime_->updateSolutionMultiPreviousStep(nmbBDF);
        }
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( time );
        
        if (timeSteppingTool_->currentTime()==0.) {
            vec_dbl_Type tmpcoeffPrevSteps(1, 1. / dt);
            problemTime_->updateMultistepRhs(tmpcoeffPrevSteps,1);/*apply (mass matrix / dt) to u_t*/
        }
        else{
            problemTime_->updateMultistepRhs(coeffPrevSteps,nmbBDF);/*apply (mass matrix / dt) to u_t*/
        }
        if (problemTime_->hasSourceTerm()) {
            TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "Check sourceterm.");
//            problemTime_->AssembleSourceTerm(time);
//            if (timeSteppingTool_->CurrentTime()==0.) {
//               AddSourceTermToRHS(1.);
//            }
//            else{
//                AddSourceTermToRHS(coeffSourceTerm); //ACHTUNG
//            }
        }
 
        NonLinearSolver<SC, LO, GO, NO> nlSolver(parameterList_->sublist("General").get("Linearization","FixedPoint"));
        nlSolver.solve(*problemTime_,time);
 
        // After the first time step we can use the desired BDF Parameters
        if (timeSteppingTool_->currentTime()==0.) {
            problemTime_->setTimeParameters(massCoeff, problemCoeff);
        }
 
        timeSteppingTool_->advanceTime(true/*output info*/);
 
        if (print) {
            exportTimestep();
        }
    }
 
    if (print) {
        closeExporter();
    }
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeLinearExternal(){
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    if (print) {
        exportTimestep();
    }
    
    double dt = timeSteppingTool_->get_dt();
    int counter=0;
    //#########
    //time loop
    //#########
    while (timeSteppingTool_->continueTimeStepping()) {
        
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( time );
 
        problemTime_->assemble( "Assemble" );
        
        if (problemTime_->hasSourceTerm()){
            problemTime_->assembleSourceTerm(time); // assemble source term and add to rhs
            problemTime_->addToRhs( problemTime_->getSourceTerm() );
        }
        
        problemTime_->setBoundaries( time );
        
        BlockMultiVectorPtr_Type tmpSol = Teuchos::rcp(new BlockMultiVector_Type(problemTime_->getSolution()) );
        
        //problemTime_->getSystemCombined()->print();
        //problemTime_->getRhs()->print();
        
        problemTime_->solve();
        
        //AceGen systems and solutions are always for a Newton method, i.e., we solve for an update even in the linear case.
                    // ?? Alpha a + beta this?
        problemTime_->getSolution()->update( 1., tmpSol, -1. );
        
        problemTime_->assemble( "SetSolutionNewton" ); // Newton solution is actually the solution at t+1 and time solution is still at time t
    
        problemTime_->assemble( "OnlyUpdate" ); // updates AceGEN history
        
        problemTime_->assemble( "SetSolutionInTime" ); // Here, we update the time solution with the Newton solution, which basically means that we can go to the next timestep
        
        timeSteppingTool_->advanceTime(true/*output info*/);
        counter++;
        if (print)
            exportTimestep();
    }
    
    if (print) {
        closeExporter();
    }
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::advanceInTimeNonLinearExternal(){
        
    bool print = parameterList_->sublist("General").get("ParaViewExport",false);
    if (print) {
        exportTimestep();
    }
    
    double dt = timeSteppingTool_->get_dt();
    int counter=0;
    //#########
    //time loop
    //#########
    while (timeSteppingTool_->continueTimeStepping()) {
        
        double time = timeSteppingTool_->currentTime() + dt;
        problemTime_->updateTime ( time );
            
        if (problemTime_->hasSourceTerm()){
            problemTime_->assembleSourceTerm(time); // assemble source term; added to residual vector in calculateNonLinResidualVec()
        }
        NonLinearSolver<SC, LO, GO, NO> nlSolver(parameterList_->sublist("General").get("Linearization","Newton"));
        nlSolver.solve(*problemTime_,time);
        problemTime_->assemble( "OnlyUpdate" ); // updates AceGEN history
        
        problemTime_->assemble( "SetSolutionInTime" ); // Here, we update the time solution with the Newton solution, which basically means that we can go to the next timestep
        
        timeSteppingTool_->advanceTime(true/*output info*/);
        counter++;
        if (print) {
            exportTimestep();
        }
    }
    
    if (print) {
        closeExporter();
    }
}
    
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::addRhsDAE(SmallMatrix<double> coeff, BlockMatrixPtr_Type bMat, BlockMultiVectorPtr_Type vec){
 
    BlockMultiVectorPtr_Type mv = Teuchos::rcp( new BlockMultiVector_Type( vec ) );    
    bMat->apply( *vec, *mv , coeff );
    problemTime_->getRhs()->update( 1., *mv, 1. );
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::addRhsDAE(SmallMatrix<double> coeff, BlockMultiVectorPtr_Type vec){
    TEUCHOS_TEST_FOR_EXCEPTION(true, std::logic_error, "Is this correct? addRhsDAE!");
    for (int i=0; i<vec->size(); i++)
        problemTime_->getRhs()->getBlockNonConst(i)->update( coeff[i][i], vec->getBlock(i), 1. );
}
    
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::addSourceTermToRHS(double coeff)
{
   BlockMultiVectorPtr_Type tmpMV = problemTime_->getSourceTerm();
    
   problemTime_->getRhs()->update(coeff, *tmpMV, 1.);
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::exportTimestep(){
 
    if (!boolExporterSetup_) {
        setupExporter();
    }
    if (verbose_) {
        std::cout << "-- Exporting..."<< std::flush;
    }
    for (int i=0; i<exporter_vector_.size(); i++) {
        
        exporter_vector_[i]->save( timeSteppingTool_->currentTime() );
 
    }
 
    if (verbose_) {
        std::cout << "done! --"<< std::endl;
    }
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::exportTimestep(BlockMultiVectorPtr_Type& solShort){
 
    if (!boolExporterSetup_) {
        setupExporter(solShort);
    }
    if (verbose_) {
        std::cout << "-- Exporting..."<< std::flush;
    }
    for (int i=0; i<exporter_vector_.size(); i++) {
        
        exporter_vector_[i]->save( timeSteppingTool_->currentTime() );
 
    }
 
    if (verbose_) {
        std::cout << "done! --"<< std::endl;
    }
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::closeExporter(){
 
    if (boolExporterSetup_) {
        for (int i=0; i<exporter_vector_.size(); i++)
            exporter_vector_[i]->closeExporter();
    }
}
 
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::setupExporter(){
    for (int i=0; i<timeStepDef_.size(); i++) {
        // \lambda in FSI, koennen wir nicht exportieren, weil keine Elementliste dafuer vorhanden
        bool exportThisBlock  = true;
        if(this->parameterList_->sublist("Parameter").get("FSI",false) == true  )
            exportThisBlock = (i != 3);
       else if(this->parameterList_->sublist("Parameter").get("FSCI",false) == true)
            exportThisBlock = (i != 4);
 
        if(exportThisBlock)
        {
            ExporterPtr_Type exporterPtr(new Exporter_Type());
            MultiVectorConstPtr_Type exportVector = problemTime_->getSolution()->getBlock(i);
 
            DomainConstPtr_Type dom = problemTime_->getDomain(i);
 
            int exportEveryXTimesteps = parameterList_->sublist("Exporter").get( "Export every X timesteps", 1 );
            std::string plSuffix = "Suffix variable" + std::to_string(i+1);
            std::string suffix = parameterList_->sublist("Exporter").get(plSuffix, "" );
            std::string varName = problemTime_->getVariableName(i) + suffix;
            MeshPtr_Type meshNonConst = Teuchos::rcp_const_cast<Mesh_Type>(dom->getMesh());
            exporterPtr->setup(varName, meshNonConst, dom->getFEType(), parameterList_);
            
//            exporterPtr->setup(dom->getDimension(), dom->getNumElementsGlobal(), dom->getElements(), dom->getPointsUnique(), dom->getMapUnique(), dom->getMapRepeated(), dom->getFEType(), varName, exportEveryXTimesteps, comm_ , parameterList_);
 
            UN dofsPerNode = problemTime_->getDofsPerNode(i);
            
            if (dofsPerNode == 1)
                exporterPtr->addVariable( exportVector, varName, "Scalar", dofsPerNode, dom->getMapUnique() );
            else
                exporterPtr->addVariable( exportVector, varName, "Vector", dofsPerNode, dom->getMapUnique() );
 
            exporter_vector_.push_back(exporterPtr);
            export_solution_vector_.push_back(exportVector);
        }
    }
    boolExporterSetup_ = true;
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::setupExporter(BlockMultiVectorPtr_Type& solShort){
    for (int i=0; i<timeStepDef_.size(); i++) {
        // \lambda in FSI, koennen wir nicht exportieren, weil keine Elementliste dafuer vorhanden
        bool exportThisBlock  = true;
        exportThisBlock = !(this->parameterList_->sublist("Parameter").get("FSI",false) && i == 3);
        if(exportThisBlock)
        {
            ExporterPtr_Type exporterPtr(new Exporter_Type());
            MultiVectorConstPtr_Type exportVector = problemTime_->getSolution()->getBlock(i);
            MultiVectorConstPtr_Type exportVectorShort = solShort->getBlock(i);
 
            DomainConstPtr_Type dom = problemTime_->getDomain(i);
 
            int exportEveryXTimesteps = parameterList_->sublist("Exporter").get( "Export every X timesteps", 1 );
            std::string plSuffix = "Suffix variable" + std::to_string(i+1);
            std::string suffix = parameterList_->sublist("Exporter").get(plSuffix, "" );
            std::string varName = problemTime_->getVariableName(i) + suffix;
            std::string varNameShort = problemTime_->getVariableName(i) + "_short_" + suffix;
            
            MeshPtr_Type meshNonConst = Teuchos::rcp_const_cast<Mesh_Type>(dom->getMesh());
            exporterPtr->setup(varName, meshNonConst, dom->getFEType(), parameterList_);
            
//            exporterPtr->setup(dom->getDimension(), dom->getNumElementsGlobal(), dom->getElements(), dom->getPointsUnique(), dom->getMapUnique(), dom->getMapRepeated(), dom->getFEType(), varName, exportEveryXTimesteps, comm_ , parameterList_);
 
            UN dofsPerNode = problemTime_->getDofsPerNode(i);
            
            if (dofsPerNode == 1){
                exporterPtr->addVariable( exportVector, varName, "Scalar", dofsPerNode, dom->getMapUnique() );
                exporterPtr->addVariable( exportVectorShort, varNameShort, "Scalar", dofsPerNode, dom->getMapUnique() );
            }
            else {
                exporterPtr->addVariable( exportVector, varName, "Vector", dofsPerNode, dom->getMapUnique() );
                exporterPtr->addVariable( exportVectorShort, varNameShort, "Vector", dofsPerNode,     dom->getMapUnique() );
            }
 
 
            exporter_vector_.push_back(exporterPtr);
            export_solution_vector_.push_back(exportVector);
        }
    }
    boolExporterSetup_ = true;
 
}
 
 
   //ch 21.03.19: Funktion aendern!
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::setupTimeStepping(){
 
    int size = this->problem_->getSystem()->size();
    
    problemTime_.reset(new TimeProblem<SC,LO,GO,NO>(*this->problem_,comm_));
    
    // Fuer FSI
    if(this->parameterList_->sublist("Parameter").get("FSI",false) || this->parameterList_->sublist("Parameter").get("SCI",false) || this->parameterList_->sublist("Parameter").get("FSCI",false))
    {
        // Beachte: Massematrix ist schon vektorwertig!
        // Reset auf Massesystem von problemTime_ (=FSI), da auf problemTime_ kein assemble() bzw. assembleMassSystem() aufgerufen wird.
        this->problemTime_->systemMass_.reset(new BlockMatrix_Type(this->problemTime_->getSystem()->size()));
        this->problemTime_->systemCombined_.reset( new BlockMatrix_Type( this->problemTime_->getSystem()->size() ));
    }
    else
    {
        size = timeStepDef_.size();
        SmallMatrix<double> massCoeff(size);
        SmallMatrix<double> problemCoeff(size); //hier egal, nur Massenmatrix wichtig. Deswegen auf Null belassen
 
        for (int i=0; i<size; i++) {
            for (int j=0; j<size; j++) {
                if (timeStepDef_[i][j]>1 && i==j) {
                    massCoeff[i][j] = 1.0;
                }
                else{
                    massCoeff[i][j] = 0.;
                }
            }
        }
 
        // Setze massCoeff und problemCoeff in TimeProblem
        // ACHTUNG: problemCoeff ist Null. Es wird also nur die Massematrix in systemCombined_ geschrieben.        
        problemTime_->setTimeParameters(massCoeff,problemCoeff);
 
        // Assembliere Massematrix -> ggf. ReAssemble() falls nichtlinear ->
        // -> das linearProblem (bzw. nonlinearProblem) von oben mit der Massematrix verbinden
        problemTime_->setTimeDef( timeStepDef_ );
        problemTime_->assemble( "MassSystem" );
    }
 
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::setTimeStep(double dt){
 
    checkTimeSteppingDef();
 
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::setFinalTime(double T){
 
    checkTimeSteppingDef();
 
}
 
template<class SC,class LO,class GO,class NO>
void DAESolverInTime<SC,LO,GO,NO>::checkTimeSteppingDef(){
#ifdef ASSERTS_WARNINGS
    MYASSERT(isTimeSteppingDefined_,"Time stepping not defined!");
#endif
 
}
}
#endif