/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./tests/Test_gpdwf_force.cc
Copyright (C) 2015
Author: paboyle <paboyle@ph.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.h>
using namespace std;
using namespace Grid;
using namespace Grid::QCD;
#define parallel_for PARALLEL_FOR_LOOP for
int main (int argc, char ** argv)
{
Grid_init(&argc,&argv);
std::vector<int> latt_size = GridDefaultLatt();
std::vector<int> simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
std::vector<int> mpi_layout = GridDefaultMpi();
const int Ls=8;
GridCartesian * UGrid = SpaceTimeGrid::makeFourDimGrid(GridDefaultLatt(), GridDefaultSimd(Nd,vComplex::Nsimd()),GridDefaultMpi());
GridRedBlackCartesian * UrbGrid = SpaceTimeGrid::makeFourDimRedBlackGrid(UGrid);
GridCartesian * FGrid = SpaceTimeGrid::makeFiveDimGrid(Ls,UGrid);
GridRedBlackCartesian * FrbGrid = SpaceTimeGrid::makeFiveDimRedBlackGrid(Ls,UGrid);
std::vector<int> seeds4({1,2,3,4});
std::vector<int> seeds5({5,6,7,8});
GridParallelRNG RNG5(FGrid); RNG5.SeedFixedIntegers(seeds5);
GridParallelRNG RNG4(UGrid); RNG4.SeedFixedIntegers(seeds4);
int threads = GridThread::GetThreads();
std::cout<<GridLogMessage << "Grid is setup to use "<<threads<<" threads"<<std::endl;
typedef typename GparityDomainWallFermionR::FermionField FermionField;
FermionField phi (FGrid); gaussian(RNG5,phi);
FermionField Mphi (FGrid);
FermionField MphiPrime (FGrid);
LatticeGaugeField U(UGrid);
SU3::HotConfiguration(RNG4,U);
////////////////////////////////////
// Unmodified matrix element
////////////////////////////////////
RealD mass=0.01;
RealD M5=1.8;
const int nu = 3;
std::vector<int> twists(Nd,0); twists[nu] = 1;
GparityDomainWallFermionR::ImplParams params; params.twists = twists;
GparityDomainWallFermionR Ddwf(U,*FGrid,*FrbGrid,*UGrid,*UrbGrid,mass,M5,params);
Ddwf.M (phi,Mphi);
ComplexD S = innerProduct(Mphi,Mphi); // pdag MdagM p
// get the deriv of phidag MdagM phi with respect to "U"
LatticeGaugeField UdSdU(UGrid);
LatticeGaugeField tmp(UGrid);
Ddwf.MDeriv(tmp , Mphi, phi,DaggerNo ); UdSdU=tmp;
Ddwf.MDeriv(tmp , phi, Mphi,DaggerYes ); UdSdU=(UdSdU+tmp);
FermionField Ftmp (FGrid);
////////////////////////////////////
// Modify the gauge field a little
////////////////////////////////////
RealD dt = 0.001;
LatticeColourMatrix mommu(UGrid);
LatticeColourMatrix forcemu(UGrid);
LatticeGaugeField mom(UGrid);
LatticeGaugeField Uprime(UGrid);
for(int mu=0;mu<Nd;mu++){
SU3::GaussianFundamentalLieAlgebraMatrix(RNG4, mommu); // Traceless antihermitian momentum; gaussian in lie alg
PokeIndex<LorentzIndex>(mom,mommu,mu);
// fourth order exponential approx
parallel_for(auto i=mom.begin();i<mom.end();i++){
Uprime[i](mu) =
U[i](mu)
+ mom[i](mu)*U[i](mu)*dt
+ mom[i](mu) *mom[i](mu) *U[i](mu)*(dt*dt/2.0)
+ mom[i](mu) *mom[i](mu) *mom[i](mu) *U[i](mu)*(dt*dt*dt/6.0)
+ mom[i](mu) *mom[i](mu) *mom[i](mu) *mom[i](mu) *U[i](mu)*(dt*dt*dt*dt/24.0)
+ mom[i](mu) *mom[i](mu) *mom[i](mu) *mom[i](mu) *mom[i](mu) *U[i](mu)*(dt*dt*dt*dt*dt/120.0)
+ mom[i](mu) *mom[i](mu) *mom[i](mu) *mom[i](mu) *mom[i](mu) *mom[i](mu) *U[i](mu)*(dt*dt*dt*dt*dt*dt/720.0)
;
}
}
Ddwf.ImportGauge(Uprime);
Ddwf.M (phi,MphiPrime);
ComplexD Sprime = innerProduct(MphiPrime ,MphiPrime);
//////////////////////////////////////////////
// Use derivative to estimate dS
//////////////////////////////////////////////
LatticeComplex dS(UGrid); dS = zero;
for(int mu=0;mu<Nd;mu++){
mommu = PeekIndex<LorentzIndex>(UdSdU,mu);
mommu=Ta(mommu)*2.0;
PokeIndex<LorentzIndex>(UdSdU,mommu,mu);
}
for(int mu=0;mu<Nd;mu++){
forcemu = PeekIndex<LorentzIndex>(UdSdU,mu);
mommu = PeekIndex<LorentzIndex>(mom,mu);
// Update PF action density
dS = dS+trace(mommu*forcemu)*dt;
}
Complex dSpred = sum(dS);
// From TwoFlavourPseudoFermion:
//////////////////////////////////////////////////////
// dS/du = - phi^dag (Mdag M)^-1 [ Mdag dM + dMdag M ] (Mdag M)^-1 phi
// = - phi^dag M^-1 dM (MdagM)^-1 phi - phi^dag (MdagM)^-1 dMdag dM (Mdag)^-1 phi
//
// = - Ydag dM X - Xdag dMdag Y
//
//////////////////////////////////////////////////////
// Our conventions really make this UdSdU; We do not differentiate wrt Udag here.
// So must take dSdU - adj(dSdU) and left multiply by mom to get dS/dt.
//
// When we have Gparity -- U and Uconj enter.
//
// dU/dt = p U
// dUc/dt = p* Uc // Is p real, traceless, etc..
//
// dS/dt = dUdt dSdU = p U dSdU
//
// Gparity --- deriv is pc Uc dSdUc + p U dSdU
//
// Pmu = zero;
// for(int mu=0;mu<Nd;mu++){
// SU<Ncol>::GaussianFundamentalLieAlgebraMatrix(pRNG, Pmu);
// PokeIndex<LorentzIndex>(P, Pmu, mu);
// }
//
//
// GridBase *grid = out._grid;
// LatticeReal ca (grid);
// LatticeMatrix la (grid);
// Complex ci(0.0,scale);
// Matrix ta;
// out=zero;
// for(int a=0;a<generators();a++){
// gaussian(pRNG,ca);
// generator(a,ta);
// la=toComplex(ca)*ci*ta; // i t_a Lambda_a c_a // c_a is gaussian
// out += la;
// }
// p = sum_a i gauss_a t_a
//
// dU = p U dt
//
// dUc = p^c Uc dt = -i gauss_a t_a^c Uc
//
//
// For Gparity the dS /dt from Uc links
//
std::cout << GridLogMessage << " S "<<S<<std::endl;
std::cout << GridLogMessage << " Sprime "<<Sprime<<std::endl;
std::cout << GridLogMessage << "dS "<<Sprime-S<<std::endl;
std::cout << GridLogMessage << "predict dS "<< dSpred <<std::endl;
std::cout<< GridLogMessage << "Done" <<std::endl;
Grid_finalize();
}