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Grid/tests/forces/Test_mobius_force.cc
Peter Boyle e51eaedc56 Making tests compile
2022-11-15 22:58:30 -05:00

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/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./tests/Test_dwf_force.cc
Copyright (C) 2015
Author: Peter Boyle <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/Grid.h>
using namespace std;
using namespace Grid;
;
int main (int argc, char ** argv)
{
Grid_init(&argc,&argv);
Coordinate latt_size = GridDefaultLatt();
Coordinate simd_layout = GridDefaultSimd(Nd,vComplex::Nsimd());
Coordinate 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;
LatticeFermion phi (FGrid); gaussian(RNG5,phi);
LatticeFermion Mphi (FGrid);
LatticeFermion MphiPrime (FGrid);
LatticeGaugeField U(UGrid);
SU<Nc>::HotConfiguration(RNG4,U);
////////////////////////////////////
// Unmodified matrix element
////////////////////////////////////
RealD mass=0.01;
RealD M5=1.8;
RealD b=0.5;
RealD c=0.5;
WilsonImplParams p;
p.boundary_phases[0] = 1.0;
p.boundary_phases[1] = 1.0;
p.boundary_phases[2] = 1.0;
p.boundary_phases[3] =- 1.0;
MobiusFermionD Ddwf(U,*FGrid,*FrbGrid,*UGrid,*UrbGrid,mass,M5,b,c,p);
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);
// *****************************************************************************************
// *** There is a funny negative sign in all derivatives. This is - UdSdU. ***
// *** ***
// *** Deriv in both Wilson gauge action and the TwoFlavour.h seems to miss a minus sign ***
// *** UdSdU is negated relative to what I think - call what is returned mUdSdU, ***
// *** and insert minus sign ***
// *****************************************************************************************
UdSdU = - UdSdU ; // Follow sign convention of actions in Grid. Seems crazy.
LatticeFermion Ftmp (FGrid);
////////////////////////////////////
// Modify the gauge field a little
////////////////////////////////////
RealD dt = 0.001;
RealD Hmom = 0.0;
RealD Hmomprime = 0.0;
LatticeColourMatrix mommu(UGrid);
LatticeColourMatrix mUdSdUmu(UGrid);
LatticeGaugeField mom(UGrid);
LatticeGaugeField Uprime(UGrid);
for(int mu=0;mu<Nd;mu++){
SU<Nc>::GaussianFundamentalLieAlgebraMatrix(RNG4, mommu); // Traceless antihermitian momentum; gaussian in lie alg
PokeIndex<LorentzIndex>(mom,mommu,mu);
// Momentum Hamiltonian is - trace(p^2)/HMC_MOM_DENOMINATOR
//
// Integrator.h: RealD H = - FieldImplementation::FieldSquareNorm(P)/HMC_MOMENTUM_DENOMINATOR; // - trace (P*P)/denom // GaugeImplTypes.h: Hloc += trace(Pmu * Pmu);
// Sign comes from a sneaky multiply by "i" in GaussianFundemantalLie algebra
// P is i P^a_\mu T^a, not Pa Ta
//
// Integrator.h: H = Hmom + sum S(action)
Hmom -= real(sum(trace(mommu*mommu)))/ HMC_MOMENTUM_DENOMINATOR;
// fourth order exponential approx
autoView( U_v , U, CpuRead);
autoView( mom_v, mom, CpuRead);
autoView(Uprime_v, Uprime, CpuWrite);
thread_foreach(i,mom_v,{
Uprime_v[i](mu) = U_v[i](mu)
+ mom_v[i](mu)*U_v[i](mu)*dt
+ mom_v[i](mu) *mom_v[i](mu) *U_v[i](mu)*(dt*dt/2.0)
+ mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *U_v[i](mu)*(dt*dt*dt/6.0)
+ mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *U_v[i](mu)*(dt*dt*dt*dt/24.0)
+ mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *U_v[i](mu)*(dt*dt*dt*dt*dt/120.0)
+ mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *mom_v[i](mu) *U_v[i](mu)*(dt*dt*dt*dt*dt*dt/720.0)
;
});
}
std::cout << GridLogMessage <<"Initial mom hamiltonian is "<< Hmom <<std::endl;
Ddwf.ImportGauge(Uprime);
Ddwf.M (phi,MphiPrime);
ComplexD Sprime = innerProduct(MphiPrime ,MphiPrime);
//////////////////////////////////////////////
// Use derivative to estimate dS
//////////////////////////////////////////////
LatticeComplex dS(UGrid); dS = Zero();
LatticeComplex dSmom(UGrid); dSmom = Zero();
LatticeComplex dSmom2(UGrid); dSmom2 = Zero();
for(int mu=0;mu<Nd;mu++){
mommu = PeekIndex<LorentzIndex>(UdSdU,mu);
mommu=Ta(mommu);
PokeIndex<LorentzIndex>(UdSdU,mommu,mu);
}
for(int mu=0;mu<Nd;mu++){
mUdSdUmu= PeekIndex<LorentzIndex>(UdSdU,mu);
mommu = PeekIndex<LorentzIndex>(mom,mu);
//
// Derive HMC eom:
//
// Sdot = - 2 trace( p p^dot ) / D - trace( p [ mUdSdU - h.c. ] ) = 0
//
//
// Sdot = 0 = - 2 trace( p p^dot ) / D - 2 trace( p Ta( mUdSdU ) = 0
//
// EOM:
//
// pdot = - D Ta( mUdSdU ) -- source of sign is the "funny sign" above
//
// dSqcd_dt = - 2.0*trace(mommu* Ta(mUdSdU) )*dt -- i.e. mUdSdU with adjoint term -> force has a 2x implicit
//
// dH_mom/dt = - 2 trace (p pdot)/Denom
//
// dH_tot / dt = 0 <= pdot = - Denom * mUdSdU
//
// dH_mom/dt = 2 trace (p mUdSdU )
//
// True Momentum delta H has a dt^2 piece
//
// dSmom = [ trace mom*mom - trace ( (mom-Denom*f*dt)(mom-Denom*f*dt) ) ] / Denom
// = 2*trace(mom*f) dt - Denom*dt*dt * trace(f*f).
// = dSmom + dSmom2
//
dS = dS - 2.0*trace(mommu*mUdSdUmu)*dt; // U and Udagger derivs hence 2x.
dSmom = dSmom + 2.0*trace(mommu*mUdSdUmu) * dt; // this 2.0 coms from derivative of p^2
dSmom2 = dSmom2 - trace(mUdSdUmu*mUdSdUmu) * dt*dt* HMC_MOMENTUM_DENOMINATOR; // Remnant
mommu = mommu - mUdSdUmu * dt* HMC_MOMENTUM_DENOMINATOR;;
Hmomprime -= real(sum(trace(mommu*mommu))) / HMC_MOMENTUM_DENOMINATOR;
}
ComplexD dSpred = sum(dS);
ComplexD dSm = sum(dSmom);
ComplexD dSm2 = sum(dSmom2);
std::cout << GridLogMessage <<"dSm "<< dSm<<std::endl;
std::cout << GridLogMessage <<"dSm2 "<< dSm2<<std::endl;
std::cout << GridLogMessage <<"Initial mom hamiltonian is "<< Hmom <<std::endl;
std::cout << GridLogMessage <<"Final mom hamiltonian is "<< Hmomprime <<std::endl;
std::cout << GridLogMessage <<"Delta mom hamiltonian is "<< Hmomprime-Hmom <<std::endl;
std::cout << GridLogMessage <<"predict Delta mom hamiltonian is "<< dSm+dSm2 <<std::endl;
std::cout << GridLogMessage << "Initial S "<<S<<std::endl;
std::cout << GridLogMessage << "Final S "<<Sprime<<std::endl;
std::cout << GridLogMessage << "Delta S "<<Sprime-S<<std::endl;
std::cout << GridLogMessage << "predict delta S"<< dSpred <<std::endl;
std::cout << GridLogMessage << "defect "<< Sprime-S-dSpred <<std::endl;
std::cout << GridLogMessage << "Total dS "<< Hmomprime - Hmom + Sprime - S <<std::endl;
std::cout << GridLogMessage << "dS - dt^2 term "<< Hmomprime - Hmom + Sprime - S - dSm2 <<std::endl;
assert( fabs(real(Sprime-S-dSpred)) < 1.0 ) ;
std::cout<< GridLogMessage << "Done" <<std::endl;
Grid_finalize();
}
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