DriverArpack.cpp

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///////////////////////////////////////////////////////////////////////////////
//
// File DriverArpack.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
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Description:  Arnoldi solver using Arpack
//
///////////////////////////////////////////////////////////////////////////////

#include <SolverUtils/DriverArpack.h>

namespace Nektar
{
    namespace SolverUtils
    {
        std::string DriverArpack::arpackProblemTypeLookupIds[6] = {
            LibUtilities::SessionReader::RegisterEnumValue("ArpackProblemType","LargestReal"    ,0),
            LibUtilities::SessionReader::RegisterEnumValue("ArpackProblemType","SmallestReal"   ,1),
            LibUtilities::SessionReader::RegisterEnumValue("ArpackProblemType","LargestImag"    ,2),
            LibUtilities::SessionReader::RegisterEnumValue("ArpackProblemType","SmallestImag"   ,3),
            LibUtilities::SessionReader::RegisterEnumValue("ArpackProblemType","LargestMag"     ,4),
            LibUtilities::SessionReader::RegisterEnumValue("ArpackProblemType","SmallestMag"    ,5),
        };
        std::string DriverArpack::arpackProblemTypeDefault = LibUtilities::SessionReader::RegisterDefaultSolverInfo("ArpackProblemType","LargestMag");
        std::string DriverArpack::driverLookupId = LibUtilities::SessionReader::RegisterEnumValue("Driver","Arpack",0);

        std::string DriverArpack::className = GetDriverFactory().RegisterCreatorFunction("Arpack", DriverArpack::create);

        std::string DriverArpack::ArpackProblemTypeTrans[6] =
        { "LR", "SR", "LI", "SI", "LM", "SM" };


        /**
         *
         */
        DriverArpack::DriverArpack(const LibUtilities::SessionReaderSharedPtr pSession)
            : DriverArnoldi(pSession)
        {
        }
    

        /**
         *
         */
        DriverArpack::~DriverArpack()
        {
        }
    
        /**
         *
         */
        void DriverArpack::v_InitObject(ostream &out)
        {
            DriverArnoldi::v_InitObject(out);
        
            //Initialisation of Arnoldi parameters
            m_maxn   = 1000000; // Maximum size of the problem
            m_maxnev = 200;      // maximum number of eigenvalues requested
            m_maxncv = 500;     // Largest number of basis vector used in Implicitly Restarted Arnoldi      
                    
            // Error alerts
            ASSERTL0(m_nvec <= m_maxnev,"NEV is greater than MAXNEV");
            ASSERTL0(m_kdim <= m_maxncv,"NEV is greater than MAXNEV");
            ASSERTL0(2      <= m_kdim-m_nvec,"NCV-NEV is less than 2");
    
            m_equ[0]->PrintSummary(out);
        
            // Print session parameters
            out << "\tArnoldi solver type    : Arpack" << endl;

            out << "\tArpack problem type    : ";
            out << ArpackProblemTypeTrans[m_session->GetSolverInfoAsEnum<int>("ArpackProblemType")] << endl;
            DriverArnoldi::ArnoldiSummary(out);
        
            m_equ[m_nequ - 1]->DoInitialise();
        
            //FwdTrans Initial conditions to be in Coefficient Space
            m_equ[m_nequ-1] ->TransPhysToCoeff();

        }


        void DriverArpack::v_Execute(ostream &out)
        
        {
            Array<OneD, NekDouble> tmpworkd;
            bool random;

            int  nq     = m_equ[0]->UpdateFields()[0]->GetNcoeffs(); // Number of points in the mesh
            int  n      = m_nfields*nq;    // Number of points in eigenvalue calculation
            int lworkl  = 3*m_kdim*(m_kdim+2); // Size of work array
            int       ido ;     //REVERSE COMMUNICATION parameter. At the first call must be initialised at 0
            int       info;     // do not set initial vector (info=0 random initial vector, info=1 read initial vector from session file)
        
            int iparam[11];
            int ipntr[14];
        
            Array<OneD, int> ritzSelect;
            Array<OneD, NekDouble> dr;
            Array<OneD, NekDouble> di;
            Array<OneD, NekDouble> workev;
            Array<OneD, NekDouble> z;
            NekDouble sigmar, sigmai;

            Array<OneD, NekDouble> resid(n);
            Array<OneD, NekDouble> v(n*m_kdim);
            Array<OneD, NekDouble> workl(lworkl);
            Array<OneD, NekDouble> workd(3*n, 0.0);

            ASSERTL0(n <= m_maxn,  "N is greater than   MAXN");

            if(m_session->DefinesFunction("InitialConditions"))
            {
            
                out << "\tInital vector       : input file  " << endl;
                info = 1;
                CopyFieldToArnoldiArray(resid);
            
            }
            else
            {
                out << "\tInital vector       : random  " << endl;
                info = 0;
            }
        
    
            iparam[0] = 1;      // strategy for shift-invert
            iparam[1] = 0;      // (deprecated)
            iparam[2] = m_nits; // maximum number of iterations allowed/taken
            iparam[3] = 1;      // blocksize to be used for recurrence
            iparam[4] = 0;      // number of converged ritz eigenvalues
            iparam[5] = 0;      // (deprecated)
            if((fabs(m_realShift) > NekConstants::kNekZeroTol)|| // use shift if m_realShift > 1e-12
               (fabs(m_imagShift) > NekConstants::kNekZeroTol))        
            {
                iparam[6] = 3;
            }
            else
            {
                iparam[6] = 1;      // computation mode 1=> matrix-vector prod
            }
            iparam[7] = 0;      // (for shift-invert)
            iparam[8] = 0;      // number of MV operations
            iparam[9] = 0;      // number of BV operations
            iparam[10]= 0;      // number of reorthogonalisation steps

            int cycle = 0;
            const char* problem = ArpackProblemTypeTrans[m_session->GetSolverInfoAsEnum<int>("ArpackProblemType")].c_str();
        
            std::string name = m_session->GetFilename().substr(0,m_session->GetFilename().find_last_of('.'))+".evl";
            ofstream pFile(name.c_str());
        
            ido     = 0;    //At the first call must be initialisedat 0
        
            while(ido != 99)//ido==-1 || ido==1 || ido==0)
            {
                //Routine for eigenvalue evaluation for non-symmetric operators
                Arpack::Dnaupd( ido, "I",       // B='I' for std eval problem
                                n, problem,  m_nvec,
                                m_evtol, &resid[0], m_kdim, 
                                &v[0], n, iparam, ipntr, &workd[0],
                                &workl[0], lworkl, info);
            
                //Plotting of real and imaginary part of the eigenvalues from workl
                out << "\rIteration " << cycle << ", output: " << info << ", ido=" << ido << " " << std::flush;

                if(!((cycle-1)%m_kdim)&&(cycle> m_kdim))
                {
                    pFile << "Krylov spectrum at iteration: " <<  cycle << endl;

                    if(m_timeSteppingAlgorithm)
                    {
                        pFile << "EV  Magnitude   Angle       Growth      Frequency   Residual"    << endl;
                    }
                    else
                    {
                        pFile << "EV  Real        Imaginary   inverse real  inverse imag  Residual"   << endl;
                    }

                    out << endl;
                    for(int k=0; k<=m_kdim-1; ++k)
                    {                    
                        // write m_nvec eigs to screen
                        if(m_kdim-1-k < m_nvec)
                        {
                            WriteEvs(out,k, workl[ipntr[5]-1+k],workl[ipntr[6]-1+k]);
                        }
                        // write m_kdim eigs to screen
                        WriteEvs(pFile,k, workl[ipntr[5]-1+k],workl[ipntr[6]-1+k]);
                    }
                }
            
                cycle++;
            
                if (ido == 99) break;
                        
                ASSERTL0(ido == 1, "Unexpected reverse communication request.");
   
                //workd[inptr[0]-1] copied into operator fields
                CopyArnoldiArrayToField(tmpworkd = workd + (ipntr[0]-1));

            m_equ[0]->TransCoeffToPhys();

                m_equ[0]->DoSolve();

                if(!(cycle%m_infosteps))
                {
                    out << endl;
                    m_equ[0]->Output();
                }

                if(m_EvolutionOperator == eTransientGrowth)
                {
                    //start Adjoint with latest fields of direct 
                    CopyFwdToAdj();
        
                    m_equ[1]->TransCoeffToPhys();
                    m_equ[1]->DoSolve();
                }
            
                // operated fields are copied into workd[inptr[1]-1] 
                CopyFieldToArnoldiArray(tmpworkd = workd + (ipntr[1]-1));
            
            }
        
            out<< endl << "Converged in " << iparam[8] << " iterations" << endl;
    
            ASSERTL0(info >= 0," Error with Dnaupd");
    
            ritzSelect = Array<OneD, int>       (m_kdim,0);
            dr         = Array<OneD, NekDouble> (m_nvec+1,0.0);
            di         = Array<OneD, NekDouble> (m_nvec+1,0.0);
            workev     = Array<OneD, NekDouble> (3*m_kdim);
            z          = Array<OneD, NekDouble> (n*(m_nvec+1));
        
            sigmar     = m_realShift; 
            sigmai     = m_imagShift;
    
            //Setting 'A', Ritz vectors are computed. 'S' for Shur vectors
            Arpack::Dneupd(1, "A", ritzSelect.get(), dr.get(), di.get(), z.get(), n, sigmar, sigmai, workev.get(), "I", n, problem, m_nvec, m_evtol, resid.get(), m_kdim, v.get(), n, iparam, ipntr, workd.get(), workl.get(),lworkl,info);
        
            ASSERTL0(info == 0, " Error with Dneupd");
            int nconv=iparam[4];
            Array<OneD, MultiRegions::ExpListSharedPtr>  fields = m_equ[0]->UpdateFields();
        
            out << "Converged Eigenvalues: " << nconv << endl;
            pFile << "Converged Eigenvalues:"<< nconv << endl;

            if(m_timeSteppingAlgorithm)
            {
                pFile << "EV  Magnitude   Angle       Growth      Frequency" << endl;
            }
            else
            {
                pFile << "EV  Real        Imaginary   inverse real  inverse imag" << endl;
            }

        
            for(int i= 0; i< nconv; ++i)
            {
                WriteEvs(out,i,dr[i],di[i]);
                WriteEvs(pFile,i,dr[i],di[i]);
            
                std::string file = m_session->GetFilename().substr(0,m_session->GetFilename().find_last_of('.')) + "_eig_" + boost::lexical_cast<std::string>(i);
            
                WriteFld(file,z + i*nq);
            }
        
            m_real_evl = dr;
            m_imag_evl = di;
       
            pFile.close();
        
            for(int j = 0; j < m_equ[0]->GetNvariables(); ++j)
            {
                NekDouble vL2Error = m_equ[0]->L2Error(j,false);
                NekDouble vLinfError = m_equ[0]->LinfError(j);
                if (m_comm->GetRank() == 0)
                {
                    out << "L 2 error (variable " << m_equ[0]->GetVariable(j) << ") : " << vL2Error << endl;
                    out << "L inf error (variable " << m_equ[0]->GetVariable(j) << ") : " << vLinfError << endl;
                }   
            }
        }
    }
}