BidomainProblem.cpp

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*/
 
 
#include "BidomainProblem.hpp"
#include "BidomainSolver.hpp"
#include "HeartConfig.hpp"
#include "Exception.hpp"
#include "DistributedVector.hpp"
#include "ReplicatableVector.hpp"
 
template <unsigned DIM>
void BidomainProblem<DIM>::AnalyseMeshForBath()
{
    // Annotate bath notes with correct region code
    if (mHasBath)
    {
        // Initialize all nodes to be bath nodes
        for (typename AbstractTetrahedralMesh<DIM,DIM>::NodeIterator iter=this->mpMesh->GetNodeIteratorBegin();
             iter != this->mpMesh->GetNodeIteratorEnd();
            ++iter)
        {
            (*iter).SetRegion(HeartRegionCode::GetValidBathId());
        }
 
        bool any_bath_element_found = false;
 
        // Set nodes that are part of a heart element to be heart nodes
        //for (unsigned i=0; i<this->mpMesh->GetNumElements(); i++)
        for (typename AbstractTetrahedralMesh<DIM,DIM>::ElementIterator it = this->mpMesh->GetElementIteratorBegin();
             it != this->mpMesh->GetElementIteratorEnd();
             ++it)
        {
            Element<DIM, DIM>& r_element = *it;
 
            if (HeartRegionCode::IsRegionTissue( r_element.GetUnsignedAttribute() ))
            {
                for (unsigned j=0; j<r_element.GetNumNodes(); j++)
                {
                    r_element.GetNode(j)->SetRegion(HeartRegionCode::GetValidTissueId());
                }
            }
            else
            {
                assert(HeartRegionCode::IsRegionBath( r_element.GetUnsignedAttribute() ));
                any_bath_element_found = true;
            }
        }
 
        if (!PetscTools::ReplicateBool(any_bath_element_found))
        {
           EXCEPTION("No bath element found");
        }
    }
    else
    {
        // The problem hasn't been set up with a bath, so check that the user hasn't set any options
        // which would suggest they're expecting there to be a bath!
        std::set<unsigned> bath_identifiers = HeartConfig::Instance()->rGetBathIdentifiers();
        if (!(bath_identifiers.size()==1 && bath_identifiers.find(1)==bath_identifiers.begin())) // IF NOT only 1 in the bath identifiers set
        {
            EXCEPTION("User has set bath identifiers, but the BidomainProblem isn't expecting a bath. Did you mean to use BidomainProblem(..., true)? Or alternatively, BidomainWithBathProblem(...)?");
        }
    }
}
 
template<unsigned DIM>
Vec BidomainProblem<DIM>::CreateInitialCondition()
{
    Vec init_cond = AbstractCardiacProblem<DIM,DIM,2>::CreateInitialCondition();
    if (mHasBath)
    {
        // get the voltage stripe
        DistributedVector ic = this->mpMesh->GetDistributedVectorFactory()->CreateDistributedVector(init_cond);
        DistributedVector::Stripe voltage_stripe = DistributedVector::Stripe(ic,0);
 
        for (DistributedVector::Iterator index = ic.Begin();
             index!= ic.End();
             ++index)
        {
            if (HeartRegionCode::IsRegionBath( this->mpMesh->GetNode( index.Global )->GetRegion() ))
            {
                voltage_stripe[index] = 0.0;
            }
        }
        ic.Restore();
    }
 
    return init_cond;
}
 
template<unsigned DIM>
AbstractCardiacTissue<DIM> * BidomainProblem<DIM>::CreateCardiacTissue()
{
    AnalyseMeshForBath();
    mpBidomainTissue = new BidomainTissue<DIM>(this->mpCellFactory, HeartConfig::Instance()->GetUseStateVariableInterpolation());
    return mpBidomainTissue;
}
 
template<unsigned DIM>
AbstractDynamicLinearPdeSolver<DIM, DIM, 2>* BidomainProblem<DIM>::CreateSolver()
{
    /*
     * NOTE: The this->mpBoundaryConditionsContainer.get() lines below convert a
     * boost::shared_ptr to a normal pointer, as this is what the solvers are
     * expecting. We have to be a bit careful though as boost could decide to delete
     * them whenever it feels like as it won't count the assembers as using them.
     *
     * As long as they are kept as member variables here for as long as they are
     * required in the solvers it should all work OK.
     */
    mpSolver = new BidomainSolver<DIM,DIM>(mHasBath,
                                           this->mpMesh,
                                           mpBidomainTissue,
                                           this->mpBoundaryConditionsContainer.get());
 
    try
    {
        mpSolver->SetFixedExtracellularPotentialNodes(mFixedExtracellularPotentialNodes);
        mpSolver->SetRowForAverageOfPhiZeroed(mRowForAverageOfPhiZeroed);
    }
    catch (const Exception& e)
    {
        delete mpSolver;
        throw e;
    }
 
    return mpSolver;
}
 
template<unsigned DIM>
BidomainProblem<DIM>::BidomainProblem(
            AbstractCardiacCellFactory<DIM>* pCellFactory, bool hasBath)
    : AbstractCardiacProblem<DIM,DIM, 2>(pCellFactory),
      mpBidomainTissue(NULL),
      mRowForAverageOfPhiZeroed(INT_MAX),
      mHasBath(hasBath)
{
    mFixedExtracellularPotentialNodes.resize(0);
}
 
template<unsigned DIM>
BidomainProblem<DIM>::BidomainProblem()
    : AbstractCardiacProblem<DIM, DIM, 2>(),
      mpBidomainTissue(NULL),
      mRowForAverageOfPhiZeroed(INT_MAX)
{
    mFixedExtracellularPotentialNodes.resize(0);
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::SetFixedExtracellularPotentialNodes(std::vector<unsigned> nodes)
{
    mFixedExtracellularPotentialNodes.resize(nodes.size());
    for (unsigned i=0; i<nodes.size(); i++)
    {
        // the solver checks that the nodes[i] is less than
        // the number of nodes in the mesh so this is not done here
        mFixedExtracellularPotentialNodes[i] = nodes[i];
    }
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::SetNodeForAverageOfPhiZeroed(unsigned node)
{
    mRowForAverageOfPhiZeroed = 2*node+1;
}
 
template<unsigned DIM>
BidomainTissue<DIM>* BidomainProblem<DIM>::GetBidomainTissue()
{
    assert(mpBidomainTissue!=NULL);
    return mpBidomainTissue;
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::WriteInfo(double time)
{
    if (PetscTools::AmMaster())
    {
        std::cout << "Solved to time " << time << "\n" << std::flush;
    }
 
    double v_max, v_min, phi_max, phi_min;
 
    VecStrideMax( this->mSolution, 0, PETSC_NULL, &v_max );
    VecStrideMin( this->mSolution, 0, PETSC_NULL, &v_min );
 
    VecStrideMax( this->mSolution, 1, PETSC_NULL, &phi_max );
    VecStrideMin( this->mSolution, 1, PETSC_NULL, &phi_min );
 
    if (PetscTools::AmMaster())
    {
        std::cout << " V; phi_e = " << "[" <<v_min << ", " << v_max << "]" << ";\t"
                  << "[" <<phi_min << ", " << phi_max << "]" << "\n"
                  << std::flush;
    }
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::DefineWriterColumns(bool extending)
{
    AbstractCardiacProblem<DIM,DIM,2>::DefineWriterColumns(extending);
    if (extending)
    {
        mExtracelluarColumnId = this->mpWriter->GetVariableByName("Phi_e");
    }
    else
    {
        mExtracelluarColumnId = this->mpWriter->DefineVariable("Phi_e","mV");
    }
    AbstractCardiacProblem<DIM,DIM,2>::DefineExtraVariablesWriterColumns(extending);
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::WriteOneStep(double time, Vec voltageVec)
{
    this->mpWriter->PutUnlimitedVariable(time);
    std::vector<int> variable_ids;
    variable_ids.push_back(this->mVoltageColumnId);
    variable_ids.push_back(mExtracelluarColumnId);
    this->mpWriter->PutStripedVector(variable_ids, voltageVec);
    AbstractCardiacProblem<DIM,DIM,2>::WriteExtraVariablesOneStep();
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::PreSolveChecks()
{
    AbstractCardiacProblem<DIM,DIM, 2>::PreSolveChecks();
    if (mFixedExtracellularPotentialNodes.empty())
    {
        // We're not pinning any nodes.
        if (mRowForAverageOfPhiZeroed==INT_MAX)
        {
            // We're not using the constrain Average phi_e to 0 method, hence use a null space
            // Check that the KSP solver isn't going to do anything stupid:
            // phi_e is not bounded, so it'd be wrong to use a relative tolerance
            if (HeartConfig::Instance()->GetUseRelativeTolerance())
            {
                EXCEPTION("Bidomain external voltage is not bounded in this simulation - use KSP *absolute* tolerance");
            }
        }
    }
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::SetElectrodes()
{
    if (!mHasBath)
    {
        //Cannot set electrodes when problem has been defined to not have a bath
        return;
    }
 
    assert(this->mpMesh!=NULL);
 
    if (HeartConfig::Instance()->IsElectrodesPresent())
    {
        mpElectrodes = (boost::shared_ptr<Electrodes<DIM> >) new Electrodes<DIM>(*(this->mpMesh));
    }
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::AtBeginningOfTimestep(double time)
{
    if (mpElectrodes && mpElectrodes->SwitchOn(time))
    {
        // At the moment mpBcc and mpDefaultBcc point to a set default BC
        assert(this->mpBoundaryConditionsContainer);
        //assert(this->mpDefaultBoundaryConditionsContainer);
 
        // Note, no point calling this->SetBoundaryConditionsContainer() as the
        // solver has already been created..
        mpSolver->ResetBoundaryConditionsContainer(mpElectrodes->GetBoundaryConditionsContainer().get());
 
        // ..but we set mpBcc anyway, so the local mpBcc is
        // the same as the one being used in the solver...
        this->mpBoundaryConditionsContainer = mpElectrodes->GetBoundaryConditionsContainer();
 
        this->mpDefaultBoundaryConditionsContainer = this->mpBoundaryConditionsContainer;
 
        // At t==0 or after checkpointing we won't have a system assembled at this stage: BCs will be applied once the matrix
        // is assembled. Dirichlet BCs will be present at the time of assembly and no null space will be created either.
        if (mpSolver->GetLinearSystem() != NULL)
        {
            // System matrix is assembled once at the beginning of the simulation. After that, nobody will take care
            // of applying new BC to the system matrix. Must be triggered explicitly.
            if (mpElectrodes->HasGroundedElectrode())
            {
                this->mpBoundaryConditionsContainer->ApplyDirichletToLinearProblem( *(mpSolver->GetLinearSystem()),
                                                                                   true, false);
            }
 
            // If a grounded electrode is switched on, the linear system is not singular anymore. Remove the null space.
            if (mpElectrodes->HasGroundedElectrode())
            {
                mpSolver->GetLinearSystem()->RemoveNullSpace();
            }
        }
    }
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::OnEndOfTimestep(double time)
{
    if (mpElectrodes && mpElectrodes->SwitchOff(time))
    {
        // At the moment mpBcc should exist and therefore
        // mpDefaultBcc should be empty (not if electrodes switched on after 0ms)
        assert(this->mpBoundaryConditionsContainer);
        //assert(! this->mpDefaultBoundaryConditionsContainer);
 
        // Set up default boundary conditions container - no Neumann fluxes
        // or Dirichlet fixed nodes
        this->mpDefaultBoundaryConditionsContainer.reset(new BoundaryConditionsContainer<DIM,DIM,2>);
        for (unsigned problem_index=0; problem_index<2; problem_index++)
        {
            this->mpDefaultBoundaryConditionsContainer->DefineZeroNeumannOnMeshBoundary(this->mpMesh, problem_index);
        }
 
        // If there's a grounded electrode, we must remove BC from linear system. At the moment, we don't
        // have a sensible way of doing this, therefore we reassemble the system.
        if (mpElectrodes->HasGroundedElectrode())
        {
            delete mpSolver;
            AbstractCardiacProblem<DIM,DIM,2>::mpSolver = CreateSolver();
            mpSolver->SetTimeStep(HeartConfig::Instance()->GetPdeTimeStep());
        }
 
        // Note, no point calling this->SetBoundaryConditionsContainer() as the
        // solver has already been created..
        mpSolver->ResetBoundaryConditionsContainer(this->mpDefaultBoundaryConditionsContainer.get());
        // ..but we set mpBcc to be mpDefaultBcc anyway, so the local mpBcc is
        // the same as the one being used in the solver...
        this->mpBoundaryConditionsContainer = this->mpDefaultBoundaryConditionsContainer;
    }
}
 
template<unsigned DIM>
void BidomainProblem<DIM>::SetUpAdditionalStoppingTimes(std::vector<double>& rAdditionalStoppingTimes)
{
    if (mpElectrodes)
    {
        rAdditionalStoppingTimes.push_back(mpElectrodes->GetSwitchOnTime());
        rAdditionalStoppingTimes.push_back(mpElectrodes->GetSwitchOffTime());
    }
}
 
template<unsigned DIM>
bool BidomainProblem<DIM>::GetHasBath()
{
    return mHasBath;
}
 
// Explicit instantiation
template class BidomainProblem<1>;
template class BidomainProblem<2>;
template class BidomainProblem<3>;
 
 
// Serialization for Boost >= 1.36
#include "SerializationExportWrapperForCpp.hpp"
EXPORT_TEMPLATE_CLASS_SAME_DIMS(BidomainProblem)