Grid/lib/qcd/action/fermion/WilsonCloverFermion.cc

/*************************************************************************************

    Grid physics library, www.github.com/paboyle/Grid

    Source file: ./lib/qcd/action/fermion/WilsonCloverFermion.cc

    Copyright (C) 2017

    Author: paboyle <paboyle@ph.ed.ac.uk>
    Author: Guido Cossu <guido.cossu@ed.ac.uk>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

    See the full license in the file "LICENSE" in the top level distribution directory
    *************************************************************************************/
/*  END LEGAL */
#include <Grid/Grid.h>
#include <Grid/Eigen/Dense>
#include <Grid/qcd/spin/Dirac.h>

namespace Grid
{
namespace QCD
{

// *NOT* EO
template <class Impl>
RealD WilsonCloverFermion<Impl>::M(const FermionField &in, FermionField &out)
{
  // Wilson term
  out.checkerboard = in.checkerboard;
  this->Dhop(in, out, DaggerNo);
  // Clover term
  // apply the sigma and Fmunu
  FermionField temp(out._grid);
  Mooee(in, temp);
  out += temp;
  return axpy_norm(out, 4 + this->mass, in, out);
}

template <class Impl>
RealD WilsonCloverFermion<Impl>::Mdag(const FermionField &in, FermionField &out)
{
  // Wilson term
  out.checkerboard = in.checkerboard;
  this->Dhop(in, out, DaggerYes);
  // Clover term
  // apply the sigma and Fmunu
  FermionField temp(out._grid);
  MooeeDag(in, temp);
  out+=temp;
  return axpy_norm(out, 4 + this->mass, in, out);
}

template <class Impl>
void WilsonCloverFermion<Impl>::ImportGauge(const GaugeField &_Umu)
{
  WilsonFermion<Impl>::ImportGauge(_Umu);
  GridBase *grid = _Umu._grid;
  typename Impl::GaugeLinkField Bx(grid), By(grid), Bz(grid), Ex(grid), Ey(grid), Ez(grid);

  // Compute the field strength terms
  WilsonLoops<Impl>::FieldStrength(Bx, _Umu, Ydir, Zdir);
  WilsonLoops<Impl>::FieldStrength(By, _Umu, Zdir, Xdir);
  WilsonLoops<Impl>::FieldStrength(Bz, _Umu, Xdir, Ydir);
  WilsonLoops<Impl>::FieldStrength(Ex, _Umu, Tdir, Xdir);
  WilsonLoops<Impl>::FieldStrength(Ey, _Umu, Tdir, Ydir);
  WilsonLoops<Impl>::FieldStrength(Ez, _Umu, Tdir, Zdir);

  // Compute the Clover Operator acting on Colour and Spin
  CloverTerm  = fillCloverYZ(Bx);
  CloverTerm += fillCloverXZ(By);
  CloverTerm += fillCloverXY(Bz);
  CloverTerm += fillCloverXT(Ex);
  CloverTerm += fillCloverYT(Ey);
  CloverTerm += fillCloverZT(Ez);
  CloverTerm *= 0.5 * csw; // FieldStrength normalization? should be ( -i/8  ). Is it the anti-symmetric combination? 


  int lvol = _Umu._grid->lSites();
  int DimRep = Impl::Dimension;

  Eigen::MatrixXcd EigenCloverOp = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);
  Eigen::MatrixXcd EigenInvCloverOp = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);

  std::vector<int> lcoor;
  typename SiteCloverType::scalar_object Qx = zero, Qxinv = zero;


  for (int site = 0; site < lvol; site++)
  {
    grid->LocalIndexToLocalCoor(site, lcoor);
    EigenCloverOp = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);
    peekLocalSite(Qx, CloverTerm, lcoor);
    Qxinv = zero;
//if (csw!=0){
    for (int j = 0; j < Ns; j++)
      for (int k = 0; k < Ns; k++)
        for (int a = 0; a < DimRep; a++)
          for (int b = 0; b < DimRep; b++)
            EigenCloverOp(a + j * DimRep, b + k * DimRep) = Qx()(j, k)(a, b);
        //   if (site==0) std::cout << "site =" << site << "\n" << EigenCloverOp << std::endl;  
  
    EigenInvCloverOp = EigenCloverOp.inverse();
    //std::cout << EigenInvCloverOp << std::endl;
    for (int j = 0; j < Ns; j++)
      for (int k = 0; k < Ns; k++)
        for (int a = 0; a < DimRep; a++)
          for (int b = 0; b < DimRep; b++)
            Qxinv()(j, k)(a, b) = EigenInvCloverOp(a + j * DimRep, b + k * DimRep);
        //    if (site==0) std::cout << "site =" << site << "\n" << EigenInvCloverOp << std::endl;
//  }
    pokeLocalSite(Qxinv, CloverTermInv, lcoor);
 }
 


  // Separate the even and odd parts.
  pickCheckerboard(Even, CloverTermEven, CloverTerm);
  pickCheckerboard( Odd,  CloverTermOdd, CloverTerm);


  pickCheckerboard(Even, CloverTermDagEven, adj(CloverTerm));
  pickCheckerboard( Odd,  CloverTermDagOdd, adj(CloverTerm));


  pickCheckerboard(Even, CloverTermInvEven, CloverTermInv);
  pickCheckerboard( Odd,  CloverTermInvOdd, CloverTermInv);
  

  pickCheckerboard(Even, CloverTermInvDagEven, adj(CloverTermInv));
  pickCheckerboard( Odd,  CloverTermInvDagOdd, adj(CloverTermInv));

}

template <class Impl>
void WilsonCloverFermion<Impl>::Mooee(const FermionField &in, FermionField &out)
{
  conformable(in,out);
  this->MooeeInternal(in, out, DaggerNo, InverseNo);
}

template <class Impl>
void WilsonCloverFermion<Impl>::MooeeDag(const FermionField &in, FermionField &out)
{
  this->MooeeInternal(in, out, DaggerYes, InverseNo);
}

template <class Impl>
void WilsonCloverFermion<Impl>::MooeeInv(const FermionField &in, FermionField &out)
{
  this->MooeeInternal(in, out, DaggerNo, InverseYes);
}

template <class Impl>
void WilsonCloverFermion<Impl>::MooeeInvDag(const FermionField &in, FermionField &out)
{
  this->MooeeInternal(in, out, DaggerYes, InverseYes);
}

template <class Impl>
void WilsonCloverFermion<Impl>::MooeeInternal(const FermionField &in, FermionField &out, int dag, int inv)
{
  out.checkerboard = in.checkerboard;
  CloverFieldType *Clover;
  assert(in.checkerboard == Odd || in.checkerboard == Even);




 if (dag){ 
  if (in._grid->_isCheckerBoarded){
    if (in.checkerboard == Odd){
//      std::cout << "Calling clover term adj Odd" << std::endl;
      Clover = (inv) ? &CloverTermInvDagOdd : &CloverTermDagOdd;

/* test 
       int DimRep = Impl::Dimension;
  Eigen::MatrixXcd A = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);
  std::vector<int> lcoor;
  typename SiteCloverType::scalar_object Qx2 = zero;
  GridBase *grid = in._grid;
    int site = 0 ;
    grid->LocalIndexToLocalCoor(site, lcoor);
    peekLocalSite(Qx2, *Clover, lcoor);
    for (int j = 0; j < Ns; j++)
      for (int k = 0; k < Ns; k++)
        for (int a = 0; a < DimRep; a++)
          for (int b = 0; b < DimRep; b++)
            A(a + j * DimRep, b + k * DimRep) = Qx2()(j, k)(a, b);
    std::cout << "adj Odd =" << site << "\n" << A << std::endl;
 end test */



    } else {
//      std::cout << "Calling clover term adj Even" << std::endl;
      Clover = (inv) ? &CloverTermInvDagEven : &CloverTermDagEven;

/* test 
       int DimRep = Impl::Dimension;
  Eigen::MatrixXcd A = Eigen::MatrixXcd::Zero(Ns * DimRep, Ns * DimRep);
  std::vector<int> lcoor;
  typename SiteCloverType::scalar_object Qx2 = zero;
  GridBase *grid = in._grid;
    int site = 0 ;
    grid->LocalIndexToLocalCoor(site, lcoor);
    peekLocalSite(Qx2, *Clover, lcoor);
    for (int j = 0; j < Ns; j++)
      for (int k = 0; k < Ns; k++)
        for (int a = 0; a < DimRep; a++)
          for (int b = 0; b < DimRep; b++)
            A(a + j * DimRep, b + k * DimRep) = Qx2()(j, k)(a, b);
    std::cout << "adj Odd =" << site << "\n" << A << std::endl;
 end test */


    }
 //   std::cout << GridLogMessage << "*Clover.checkerboard "  << (*Clover).checkerboard << std::endl;
    out = *Clover * in;
  } else { 
  Clover = (inv) ? &CloverTermInv : &CloverTerm; 
  out = adj(*Clover) * in;
  }

  


 } else {
  if (in._grid->_isCheckerBoarded){
   
    if (in.checkerboard == Odd){
    //  std::cout << "Calling clover term Odd" << std::endl;
      Clover = (inv) ? &CloverTermInvOdd : &CloverTermOdd;
    } else {
    //  std::cout << "Calling clover term Even" << std::endl;
      Clover = (inv) ? &CloverTermInvEven : &CloverTermEven;
    }    
    out = *Clover * in;
  //  std::cout << GridLogMessage << "*Clover.checkerboard "  << (*Clover).checkerboard << std::endl; 
  } else { 
    Clover = (inv) ? &CloverTermInv : &CloverTerm; 
    out = *Clover * in;
  }
 }

} // MooeeInternal

// Derivative parts
template <class Impl>
void WilsonCloverFermion<Impl>::MDeriv(GaugeField &mat, const FermionField &U, const FermionField &V, int dag)
{


  GaugeField tmp(mat._grid);

  conformable(U._grid, V._grid);
  conformable(U._grid, mat._grid);

  mat.checkerboard = U.checkerboard;
  tmp.checkerboard = U.checkerboard;

  this->DhopDeriv(mat, U, V, dag);
  MooDeriv(tmp, U, V, dag);
  mat += tmp;
}

// Derivative parts
template <class Impl>
void WilsonCloverFermion<Impl>::MooDeriv(GaugeField &mat, const FermionField &X, const FermionField &Y, int dag)
{
  
GridBase *grid = mat._grid;

//GaugeLinkField Lambdaodd(grid), Lambdaeven(grid), tmp(grid);
//Lambdaodd  = zero; //Yodd*dag(Xodd)+Xodd*dag(Yodd);                   // I have to peek spin and decide the color structure
//Lambdaeven = zero; //Teven*dag(Xeven)+Xeven*dag(Yeven) + 2*(Dee^-1)

GaugeLinkField Lambda(grid), tmp(grid);
Lambda=zero;

conformable(mat._grid, X._grid);
conformable(Y._grid, X._grid);

std::vector<GaugeLinkField> C1p(Nd,grid), C2p(Nd,grid), C3p(Nd,grid), C4p(Nd,grid);
std::vector<GaugeLinkField> C1m(Nd,grid), C2m(Nd,grid), C3m(Nd,grid), C4m(Nd,grid);
std::vector<GaugeLinkField> U(Nd, mat._grid);

for (int mu = 0; mu < Nd; mu++) {
 U[mu] = PeekIndex<LorentzIndex>(mat, mu);   
 C1p[mu]=zero; C2p[mu]=zero; C3p[mu]=zero; C4p[mu]=zero; 
 C1m[mu]=zero; C2m[mu]=zero; C3m[mu]=zero; C4m[mu]=zero;
}

/*
  PARALLEL_FOR_LOOP
    for (int i = 0; i < CloverTerm._grid->oSites(); i++)
    {
      T._odata[i]()(0, 1) = timesMinusI(F._odata[i]()());
      T._odata[i]()(1, 0) = timesMinusI(F._odata[i]()());
      T._odata[i]()(2, 3) = timesMinusI(F._odata[i]()());
      T._odata[i]()(3, 2) = timesMinusI(F._odata[i]()());
    }
*/  

for (int i=0;i<4;i++){  //spin
  for(int j=0;j<4;j++){  //spin

for (int mu=0;mu<4;mu++){  //color
  for (int nu=0;nu<4;nu++){  //color

// insertion in upper staple
    tmp = Lambda * U[nu];
    C1p[mu]+=Impl::ShiftStaple(Impl::CovShiftForward(tmp, nu, Impl::CovShiftBackward(U[mu], mu, Impl::CovShiftIdentityBackward(U[nu], nu))), mu);

    tmp = Lambda * U[mu];    
    C2p[mu]+= Impl::ShiftStaple(Impl::CovShiftForward(U[nu], nu, Impl::CovShiftBackward(tmp, mu, Impl::CovShiftIdentityBackward(U[nu], nu))), mu);

    tmp = Impl::CovShiftIdentityForward(Lambda, nu) * U[nu];    
    C3p[mu]+= Impl::ShiftStaple(Impl::CovShiftForward(U[nu], nu, Impl::CovShiftBackward(U[mu], mu, Impl::CovShiftIdentityBackward(tmp, nu))), mu);
   
    tmp = Lambda;    
    C4p[mu]+= Impl::ShiftStaple(Impl::CovShiftForward(U[nu], nu, Impl::CovShiftBackward(U[mu], mu, Impl::CovShiftIdentityBackward(U[nu], nu))),mu) * tmp;

// insertion in lower staple               
    tmp = Lambda * U[nu];
    C1m[mu]+= Impl::ShiftStaple(Impl::CovShiftBackward(tmp, nu, Impl::CovShiftBackward(U[mu], mu, U[nu])), mu);

    tmp = Lambda * U[mu];
    C2m[mu]+= Impl::ShiftStaple(Impl::CovShiftBackward(U[nu], nu, Impl::CovShiftBackward(tmp, mu, U[nu])), mu);

    tmp = Lambda * U[nu];
    C3m[mu]+= Impl::ShiftStaple(Impl::CovShiftBackward(U[nu], nu, Impl::CovShiftBackward(U[mu], mu, tmp)), mu);

    tmp = Lambda;
    C4m[mu]+= Impl::ShiftStaple(Impl::CovShiftBackward(U[nu], nu, Impl::CovShiftBackward(U[mu], mu, U[nu])), mu)* tmp;
  }
}

}
}

//Still implementing. Have to be tested, and understood how to project EO




}

// Derivative parts
template <class Impl>
void WilsonCloverFermion<Impl>::MeeDeriv(GaugeField &mat, const FermionField &U, const FermionField &V, int dag)
{
  assert(0); // not implemented yet
}

FermOpTemplateInstantiate(WilsonCloverFermion); // now only for the fundamental representation
//AdjointFermOpTemplateInstantiate(WilsonCloverFermion);
//TwoIndexFermOpTemplateInstantiate(WilsonCloverFermion);
//GparityFermOpTemplateInstantiate(WilsonCloverFermion);
}
}