syssolver_mdagm_eigcg_qdp.h

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// -*- C++ -*-
/*! \file
 *  \brief Solve a M^dag*M*psi=chi linear system by EigCG
 */
 
#ifndef __syssolver_mdagm_eigcg_qdp_h__
#define __syssolver_mdagm_eigcg_qdp_h__
 
#include "handle.h"
#include "syssolver.h"
#include "linearop.h"
#include "lmdagm.h"
#include "named_obj.h"
#include "meas/inline/io/named_objmap.h"
 
#include "actions/ferm/invert/syssolver_mdagm.h"
#include "actions/ferm/invert/syssolver_eigcg_params.h"
#include "actions/ferm/invert/containers.h"
 
namespace Chroma
{
 
  //! Eigenstd::vector accelerated CG system solver namespace
  namespace MdagMSysSolverQDPEigCGEnv
  {
    //! Register the syssolver
    bool registerAll();
  }
 
 
  //! Solve a M*psi=chi linear system by CG2 with eigenvectors
  /*! \ingroup invert
   */
  template<typename T>
  class MdagMSysSolverQDPEigCG : public MdagMSystemSolver<T>
  {
  public:
    //! Constructor
    /*!
     * \param M_         Linear operator ( Read )
     * \param invParam_  inverter parameters ( Read )
     */
    MdagMSysSolverQDPEigCG(Handle< LinearOperator<T> > A_,
                           const SysSolverEigCGParams& invParam_) : 
      MdagM(new MdagMLinOp<T>(A_)), A(A_), invParam(invParam_) 
      {
        // NEED to grab the eignvectors from the named buffer here
        if (! TheNamedObjMap::Instance().check(invParam.eigen_id))
        {
          TheNamedObjMap::Instance().create< LinAlg::RitzPairs<T> >(invParam.eigen_id);
          LinAlg::RitzPairs<T>& GoodEvecs = 
            TheNamedObjMap::Instance().getData< LinAlg::RitzPairs<T> >(invParam.eigen_id);
 
          if(invParam.Neig_max>0 ){
            GoodEvecs.init(invParam.Neig_max);
          }
          else{
            GoodEvecs.init(invParam.Neig);
          }
        }
      }
 
    //! Destructor is automatic
    ~MdagMSysSolverQDPEigCG()
      {
        if (invParam.cleanUpEvecs)
        {
          TheNamedObjMap::Instance().erase(invParam.eigen_id);
        }
      }
 
    //! Return the subset on which the operator acts
    const Subset& subset() const {return A->subset();}
 
    //! Solver the linear system
    /*!
     * \param psi      solution ( Modify )
     * \param chi      source ( Read )
     * \return syssolver results
     *
     * Definitions supplied in the correspond .cc file
     */
    SystemSolverResults_t operator() (T& psi, const T& chi) const;
 
 
    //! Solve the linear system starting with a chrono guess 
    /*! 
     * \param psi solution (Write)
     * \param chi source   (Read)
     * \param predictor   a chronological predictor (Read)
     * \return syssolver results
     */
 
    SystemSolverResults_t operator()(T& psi, const T& chi, 
                                     AbsChronologicalPredictor4D<T>& predictor) const 
    {
      
      START_CODE();
 
      // This solver uses InvCG2, so A is just the matrix.
      // I need to predict with A^\dagger A
      {
        Handle< LinearOperator<T> > MdagM( new MdagMLinOp<T>(A) );
        predictor(psi, (*MdagM), chi);
      }
      // Do solve
      SystemSolverResults_t res=(*this)(psi,chi);
 
      // Store result
      predictor.newVector(psi);
      END_CODE();
      return res;
    }
 
  private:
    // Hide default constructor
    MdagMSysSolverQDPEigCG() {}
 
    Handle< LinearOperator<T> > MdagM;
    Handle< LinearOperator<T> > A;
    SysSolverEigCGParams invParam;
  };
 
} // End namespace
 
#endif