ProcessC0Projection.cpp

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////////////////////////////////////////////////////////////////////////////////
//
//  File: ProcessC0Projection.cpp
//
//  For more information, please see: http://www.nektar.info/
//
//  The MIT License
//
//  Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
//  Department of Aeronautics, Imperial College London (UK), and Scientific
//  Computing and Imaging Institute, University of Utah (USA).
//
//  License for the specific language governing rights and limitations under
//  Permission is hereby granted, free of charge, to any person obtaining a
//  copy of this software and associated documentation files (the "Software"),
//  to deal in the Software without restriction, including without limitation
//  the rights to use, copy, modify, merge, publish, distribute, sublicense,
//  and/or sell copies of the Software, and to permit persons to whom the
//  Software is furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included
//  in all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
//  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
//  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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//  DEALINGS IN THE SOFTWARE.
//
//  Description: Computes C0 projection.
//
////////////////////////////////////////////////////////////////////////////////

#include <string>
#include <iostream>
using namespace std;

#include "ProcessC0Projection.h"

#include <LibUtilities/BasicUtils/SharedArray.hpp>
#include <LibUtilities/BasicUtils/ParseUtils.hpp>

namespace Nektar
{
namespace Utilities
{

ModuleKey ProcessC0Projection::className =
GetModuleFactory().RegisterCreatorFunction(
    ModuleKey(eProcessModule, "C0Projection"),
    ProcessC0Projection::create, "Computes C0 projection.");

ProcessC0Projection::ProcessC0Projection(FieldSharedPtr f) : ProcessModule(f)
{
    m_config["fields"] = ConfigOption(false,"All","Start field to project");
    m_config["localtoglobalmap"] = ConfigOption(true,"0","Just perform a local to global mapping and back");
    m_config["usexmlbcs"] = ConfigOption(true,"0","Use boundary conditions given in xml file. Requires all projected fields to be defined in xml file");
    m_config["helmsmoothing"] = ConfigOption(false,"Not Set","Use a Helmholtz smoother to remove high frequency components above specified L");

    f->m_declareExpansionAsContField = true;
}

ProcessC0Projection::~ProcessC0Projection()
{
}

void ProcessC0Projection::Process(po::variables_map &vm)
{
    if (m_f->m_verbose)
    {
        if(m_f->m_comm->TreatAsRankZero())
        {
            cout << "ProcessC0Projection: Projecting field into C0 space..."
                 << endl;
        }
    }

    // ensure not using diagonal preconditioner since tends not to converge fo
    // mass matrix
    if(m_f->m_graph->GetMeshDimension() == 3)
    {
        if(boost::iequals(m_f->m_session->GetSolverInfo("GLOBALSYSSOLN"),
                          "IterativeStaticCond"))
        {
            if(boost::iequals(m_f->m_session->GetSolverInfo("PRECONDITIONER"),
                              "Diagonal"))
            {
                m_f->m_session->SetSolverInfo("PRECONDITIONER","LowEnergyBlock");
            }
            if(boost::iequals(m_f->m_session->GetSolverInfo("PRECONDITIONER"),
                              "FullLinearSpaceWithDiagonal"))
            {
                m_f->m_session->SetSolverInfo("PRECONDITIONER","FullLinearSpaceWithLowEnergyBlock");
            }
            
            if(m_f->m_verbose)
            {
                if(m_f->m_comm->GetRank() == 0)
                {
                    cout << "Resetting diagonal precondition to low energy block " << endl;
                }
            }
        }
    }
    bool JustPerformLocToGloMap = m_config["localtoglobalmap"].as<bool>();
    bool HelmSmoother = (boost::iequals(m_config["helmsmoothing"].as<string>(),"Not Set"))? false:true;
    int nfields = m_f->m_exp.size();
    Array<OneD, MultiRegions::ExpListSharedPtr> C0ProjectExp(nfields);
    if(m_config["usexmlbcs"].as<bool>())
    {
        for(int i = 0; i < nfields; ++i)
        {
            C0ProjectExp[i] = m_f->m_exp[i];
        }
    }
    else
    {
        // generate a C0 expansion field with no boundary conditions.
        bool savedef = m_f->m_declareExpansionAsContField;
        bool savedef2 = m_f->m_requireBoundaryExpansion;
        m_f->m_declareExpansionAsContField = true;
        m_f->m_requireBoundaryExpansion    = false;
        C0ProjectExp[0] = m_f->AppendExpList(m_f->m_fielddef[0]->m_numHomogeneousDir,
                                             "DefaultVar",true);
        m_f->m_declareExpansionAsContField = savedef;
        m_f->m_requireBoundaryExpansion    = savedef2;
        for(int i = 1; i < nfields; ++i)
        {
            C0ProjectExp[i] = C0ProjectExp[0];
        }
    }

    string fields = m_config["fields"].as<string>();
    vector<unsigned int> processFields;

    if(fields.compare("All") == 0)
    {
        for(int i = 0; i < nfields; ++i)
        {
            processFields.push_back(i);
        }
    }
    else
    {
        ASSERTL0(ParseUtils::GenerateOrderedVector(fields.c_str(),
                                                   processFields),
                 "Failed to interpret field string in C0Projection");
    }

    for (int i = 0; i < processFields.size(); ++i)
    {
        ASSERTL0(processFields[i] < nfields,
                 "Attempt to process field that is larger than then number of "
                 "fields available");

        if (m_f->m_verbose)
        {
            if(m_f->m_comm->GetRank() == 0)
            {
                cout << "\t Processing field: " << processFields[i] << endl;
            }
        }

        if(JustPerformLocToGloMap)
        {
            int ncoeffs = m_f->m_exp[0]->GetNcoeffs();
            Vmath::Vcopy(ncoeffs,m_f->m_exp[processFields[i]]->GetCoeffs(),1,
                         C0ProjectExp[processFields[i]]->UpdateCoeffs(),1);
            C0ProjectExp[processFields[i]]->LocalToGlobal();
            C0ProjectExp[processFields[i]]->GlobalToLocal();
            Vmath::Vcopy(ncoeffs,C0ProjectExp[processFields[i]]->GetCoeffs(),1,
                         m_f->m_exp[processFields[i]]->UpdateCoeffs(),1);
        }
        else
        {
            if(HelmSmoother)
            {
                int dim = m_f->m_graph->GetSpaceDimension(); 
                int npoints = m_f->m_exp[0]->GetNpoints();
                NekDouble lambda = m_config["helmsmoothing"].as<NekDouble>();
                lambda = 2*M_PI/lambda;
                lambda = lambda*lambda; 

                if(m_f->m_verbose)
                {
                    cout << "Setting up Helmholtz smoother with lambda = " << lambda << endl;
                }
                
                StdRegions::ConstFactorMap factors; 
                Array<OneD, NekDouble> forcing(npoints);
                factors[StdRegions::eFactorLambda] = -lambda;

                Array<OneD, Array<OneD, NekDouble> > Velocity(dim);
                for(int j =0; j < dim; ++j)
                {
                    Velocity[j] = Array<OneD, NekDouble> (npoints,0.0);
                }
                
                C0ProjectExp[processFields[i]]->BwdTrans(m_f->m_exp[processFields[i]]->GetCoeffs(),
                                                     m_f->m_exp[processFields[i]]->UpdatePhys());

                Vmath::Smul(npoints,-lambda,m_f->m_exp[processFields[i]]->GetPhys(),1,
                             forcing,1);

                // Note we are using the
                // LinearAdvectionDiffusionReaction solver here
                // instead of HelmSolve since lambda is negative and
                // so matrices are not positive definite. Ideally
                // should allow for negative lambda coefficient in
                // HelmSolve
                C0ProjectExp[processFields[i]]->LinearAdvectionDiffusionReactionSolve(Velocity,
                                                   forcing,
                                                   m_f->m_exp[processFields[i]]->UpdateCoeffs(),
                                                                                 -lambda);
            }
            else
            {
                C0ProjectExp[processFields[i]]->BwdTrans(m_f->m_exp[processFields[i]]->GetCoeffs(),
                                                     m_f->m_exp[processFields[i]]->UpdatePhys());
                C0ProjectExp[processFields[i]]->FwdTrans(m_f->m_exp[processFields[i]]->GetPhys(),
                                       m_f->m_exp[processFields[i]]->UpdateCoeffs());
            }
        }
    }

    // reset FieldDef in case of serial input and parallel output
    std::vector<LibUtilities::FieldDefinitionsSharedPtr> FieldDef
        = m_f->m_exp[0]->GetFieldDefinitions();
    // reset up FieldData with new values before projecting
    std::vector<std::vector<NekDouble> > FieldData(FieldDef.size());

    for(int i = 0; i < nfields; ++i)
    {
        for (int j = 0; j < FieldDef.size(); ++j)
        {
            FieldDef[j]->m_fields.push_back(m_f->m_fielddef[0]->m_fields[i]);
            m_f->m_exp[i]->AppendFieldData(FieldDef[j], FieldData[j]);
        }
    }
    
    m_f->m_fielddef = FieldDef;
    m_f->m_data     = FieldData;
}
}
}