unprec_ovdwf_linop_array_w.cc

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/*! \file
 *  \brief Unpreconditioned Overlap-DWF (Borici) linear operator
 */
 
#include "chromabase.h"
#include "actions/ferm/linop/unprec_ovdwf_linop_array_w.h"
 
using namespace QDP::Hints;
 
namespace Chroma 
{ 
  //! Creation routine
  /*! \ingroup fermact
   *
   * \param u_            gauge field   (Read)
   * \param WilsonMass_   DWF height    (Read)
   * \param m_q_          quark mass    (Read)
   */
  void 
  UnprecOvDWLinOpArray::create(Handle< FermState<T,P,Q> > state,
                               const Real& WilsonMass_, const Real& m_q_, int N5_)
  {
    WilsonMass = WilsonMass_;
    m_q = m_q_;
    a5  = 1.0;
    N5  = N5_;
 
    D.create(state);
//    CoeffWilsr_s = (AnisoP) ? Wilsr_s / xiF_0 : 1;
  }
 
 
  //! Apply the operator onto a source std::vector
  /*!
   * The operator acts on the entire lattice
   *
   * \param psi           Pseudofermion field                  (Read)
   * \param isign   Flag ( PLUS | MINUS )              (Read)
   */
  void
  UnprecOvDWLinOpArray::operator() (multi1d<LatticeFermion>& chi,
                                    const multi1d<LatticeFermion>& psi, 
                                    enum PlusMinus isign) const
  {
    START_CODE();
 
    if( chi.size() != N5 )  chi.resize(N5);
 
    //
    //  Chi   =  D' Psi
    //
    Real fact1 = a5*(Nd - WilsonMass);
    Real fact2 = -0.5*a5;
 
    if (isign == PLUS)
    {
      LatticeFermion  tmp1, tmp2;
      moveToFastMemoryHint(tmp1);
      moveToFastMemoryHint(tmp2);
 
      for(int n=0; n < N5; ++n)
      {
        if (n == 0)
        {
          tmp1   = psi[n] - m_q*chiralProjectPlus(psi[N5-1]) + chiralProjectMinus(psi[1]);
          D(tmp2, tmp1, isign);
          chi[n] = fact1*tmp1 + fact2*tmp2 + psi[n] 
            + m_q*chiralProjectPlus(psi[N5-1]) - chiralProjectMinus(psi[1]);
        }
        else if (n == N5-1)
        {
          tmp1   = psi[n] + chiralProjectPlus(psi[N5-2]) - m_q*chiralProjectMinus(psi[0]);
          D(tmp2, tmp1, isign);
          chi[n] = fact1*tmp1 + fact2*tmp2 + psi[n] 
            - chiralProjectPlus(psi[N5-2]) + m_q*chiralProjectMinus(psi[0]);
        }
        else
        {
          tmp1   = psi[n] + chiralProjectPlus(psi[n-1]) + chiralProjectMinus(psi[n+1]);
          D(tmp2, tmp1, isign);
          chi[n] = fact1*tmp1 + fact2*tmp2 + psi[n] 
            - chiralProjectPlus(psi[n-1]) - chiralProjectMinus(psi[n+1]);
        }
      }          
    }
    else   // isign = MINUS   case
    {
      multi1d<LatticeFermion>  tmp(N5);   // should be more clever and reduce temporaries
      LatticeFermion  tmp1;
      moveToFastMemoryHint(tmp);
      moveToFastMemoryHint(tmp1);
 
      for(int n=0; n < N5; ++n)
      {
        D(tmp1, psi[n], isign);
        tmp[n] = fact1*psi[n] + fact2*tmp1;
      }
 
      for(int n=0; n < N5; ++n)
      {
        if (n == 0)
        {
          chi[0] = tmp[0] + psi[0] + chiralProjectPlus(tmp[1]) - chiralProjectPlus(psi[1])
            - m_q*(chiralProjectMinus(tmp[N5-1]) - chiralProjectMinus(psi[N5-1]));
        }
        else if (n == N5-1)
        {
          chi[n] = tmp[n] + psi[n] + chiralProjectMinus(tmp[N5-2]) - chiralProjectMinus(psi[N5-2])
            - m_q*(chiralProjectPlus(tmp[0]) - chiralProjectPlus(psi[0]));
        }
        else
        {
          chi[n] = tmp[n] + psi[n] + chiralProjectMinus(tmp[n-1]) - chiralProjectMinus(psi[n-1])
            + chiralProjectPlus(tmp[n+1]) - chiralProjectPlus(psi[n+1]);
        }
      }          
    }
 
    getFermBC().modifyF(chi);
 
    END_CODE();
  }
 
  //! Apply the Dminus operator on a lattice fermion. See my notes ;-)
  void 
  UnprecOvDWLinOpArray::Dminus(LatticeFermion& chi,
                               const LatticeFermion& psi,
                               enum PlusMinus isign,
                               int s5) const
  {
    LatticeFermion tt ; moveToFastMemoryHint(tt);
    D.apply(tt,psi,isign,0);
    D.apply(tt,psi,isign,1);
    chi = (1.0 - (Nd-WilsonMass))*psi +0.5*tt ; //really -(-.5)D
  }
  
 
} // End Namespace Chroma