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Grid/tests/forces/Test_mobius_force.cc
Peter Boyle 49b0af2c95 Update of tests to compile with the sRNG addition.
Audited the code conventions (again) with the CPS momentum denominator
and added anti periodic in time to the Test_mobius_force.cc and
tested the Test_dwf_gpforce.

Promoted thesee to test full HMC hamiltonian, tr P^2/2 + phidag MdagM phi

with the same pdot and Udot as audited in the Integrator.h etc...

With full comments and sources for factors.
2021-03-18 09:10:02 -04:00

240 lines
8.8 KiB
C++

/*************************************************************************************
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;
MobiusFermionR 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();
}