///////////////////////////////////////////////////////////////////////////////
//
// File DriverModifiedArnoldi.h
//
// 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: Driver class for eigenvalue analysis using the modified Arnoldi
//              method.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef NEKTAR_SOLVERUTILS_DRIVERMODIFIEDARNOLDI_H
#define NEKTAR_SOLVERUTILS_DRIVERMODIFIEDARNOLDI_H

#include <SolverUtils/DriverArnoldi.h>

namespace Nektar
{
    namespace SolverUtils
    {
        class DriverModifiedArnoldi: public DriverArnoldi
        {
        public:
            friend class MemoryManager<DriverModifiedArnoldi>;
        
            /// Creates an instance of this class
            static DriverSharedPtr create(const LibUtilities::SessionReaderSharedPtr& pSession) {
                DriverSharedPtr p = MemoryManager<DriverModifiedArnoldi>::AllocateSharedPtr(pSession);
                p->InitObject();
                return p;
            }
	
            ///Name of the class
            static std::string className;
        
	protected:
        
            /// Constructor
            DriverModifiedArnoldi(const LibUtilities::SessionReaderSharedPtr pSession);

            /// Destructor
            virtual ~DriverModifiedArnoldi();

            /// Virtual function for initialisation implementation.
            virtual void v_InitObject(ostream &out = cout );

            /// Virtual function for solve implementation.
            virtual void v_Execute(ostream &out = cout);

        private:
            /// Generates a new vector in the sequence by applying the linear operator.
            void EV_update(Array<OneD, NekDouble> &src,
                           Array<OneD, NekDouble> &tgt);

            /// Generates the upper Hessenberg matrix H and computes its eigenvalues.
            void EV_small(Array<OneD, Array<OneD, NekDouble> > &Kseq,
                          const int ntot,
                          const Array<OneD, NekDouble> &alpha,
                          const int kdim,
                          Array<OneD, NekDouble> &zvec,
                          Array<OneD, NekDouble> &wr,
                          Array<OneD, NekDouble> &wi,
                          NekDouble &resnorm);

            /// Tests for convergence of eigenvalues of H.
            int EV_test(const int itrn,
                        const int kdim,
                        Array<OneD, NekDouble> &zvec,
                        Array<OneD, NekDouble> &wr,
                        Array<OneD, NekDouble> &wi,
                        const NekDouble resnorm,
                        const int nvec,
                        ofstream &evlout,
                        NekDouble &resid0);


            /// Sorts a sequence of eigenvectors/eigenvalues by magnitude.
            void EV_sort(Array<OneD, NekDouble> &evec,
                         Array<OneD, NekDouble> &wr,
                         Array<OneD, NekDouble> &wi,
                         Array<OneD, NekDouble> &test,
                         const int dim);

            void EV_post(Array<OneD, Array<OneD, NekDouble> > &Tseq,
                         Array<OneD, Array<OneD, NekDouble> > &Kseq,
                         const int ntot,
                         const int kdim,
                         const int nvec,
                         Array<OneD, NekDouble> &zvec,
                         Array<OneD, NekDouble> &wr,
                         Array<OneD, NekDouble> &wi,
                         const int icon);

            void EV_big(Array<OneD, Array<OneD, NekDouble> > &bvecs,
                        Array<OneD, Array<OneD, NekDouble> > &evecs,
                        const int ntot,
                        const int kdim,
                        const int nvec,
                        Array<OneD, NekDouble> &zvec,
                        Array<OneD, NekDouble> &wr,
                        Array<OneD, NekDouble> &wi);

            static std::string driverLookupId;
        };
    }	
} //end of namespace

#endif //NEKTAR_SOLVERS_AUXILIARY_ADRBASE_H

