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Grid/lib/qcd/hmc/integrators/Integrator.h
Guido Cossu 49b5c49851 Checked the hermiticity of the op in derivative, ok 
Still CG fails to converge
2016-07-31 12:37:33 +01:00

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/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/qcd/hmc/integrators/Integrator.h
Copyright (C) 2015
Author: Azusa Yamaguchi <ayamaguc@staffmail.ed.ac.uk>
Author: Peter Boyle <paboyle@ph.ed.ac.uk>
Author: neo <cossu@post.kek.jp>
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 */
//--------------------------------------------------------------------
/*! @file Integrator.h
* @brief Classes for the Molecular Dynamics integrator
*
* @author Guido Cossu
* Time-stamp: <2015-07-30 16:21:29 neo>
*/
//--------------------------------------------------------------------
#ifndef INTEGRATOR_INCLUDED
#define INTEGRATOR_INCLUDED
// class Observer;
#include <memory>
namespace Grid {
namespace QCD {
struct IntegratorParameters {
int Nexp;
int MDsteps; // number of outer steps
RealD trajL; // trajectory length
RealD stepsize;
IntegratorParameters(int MDsteps_, RealD trajL_ = 1.0, int Nexp_ = 12)
: Nexp(Nexp_),
MDsteps(MDsteps_),
trajL(trajL_),
stepsize(trajL / MDsteps){
// empty body constructor
};
};
/*! @brief Class for Molecular Dynamics management */
template <class GaugeField, class SmearingPolicy, class RepresentationPolicy>
class Integrator {
protected:
typedef IntegratorParameters ParameterType;
IntegratorParameters Params;
const ActionSetHirep<GaugeField, RepresentationPolicy> as;
int levels; //
double t_U; // Track time passing on each level and for U and for P
std::vector<double> t_P; //
GaugeField P;
SmearingPolicy& Smearer;
RepresentationPolicy Representations;
// Should match any legal (SU(n)) gauge field
// Need to use this template to match Ncol to pass to SU<N> class
template <int Ncol, class vec>
void generate_momenta(Lattice<iVector<iScalar<iMatrix<vec, Ncol> >, Nd> >& P,
GridParallelRNG& pRNG) {
typedef Lattice<iScalar<iScalar<iMatrix<vec, Ncol> > > > GaugeLinkField;
GaugeLinkField Pmu(P._grid);
Pmu = zero;
for (int mu = 0; mu < Nd; mu++) {
SU<Ncol>::GaussianFundamentalLieAlgebraMatrix(pRNG, Pmu);
PokeIndex<LorentzIndex>(P, Pmu, mu);
}
}
// ObserverList observers; // not yet
// typedef std::vector<Observer*> ObserverList;
// void register_observers();
// void notify_observers();
void update_P(GaugeField& U, int level, double ep) {
t_P[level] += ep;
update_P(P, U, level, ep);
std::cout << GridLogIntegrator << "[" << level << "] P "
<< " dt " << ep << " : t_P " << t_P[level] << std::endl;
}
// to be used by the actionlevel class to iterate
// over the representations
struct _updateP {
template <class FieldType, class GF, class Repr>
void operator()(std::vector<Action<FieldType>*> repr_set, Repr& Rep,
GF& Mom, GF& U, double ep) {
for (int a = 0; a < repr_set.size(); ++a) {
FieldType forceR(U._grid);
// Implement smearing only for the fundamental representation now
repr_set.at(a)->deriv(Rep.U, forceR);
GF force =
Rep.RtoFundamentalProject(forceR); // Ta for the fundamental rep
std::cout << GridLogIntegrator << "Hirep Force average: "
<< norm2(force) / (U._grid->gSites()) << std::endl;
Mom -= force * ep;
}
}
} update_P_hireps{};
void update_P(GaugeField& Mom, GaugeField& U, int level, double ep) {
// input U actually not used in the fundamental case
// Fundamental updates, include smearing
for (int a = 0; a < as[level].actions.size(); ++a) {
GaugeField force(U._grid);
GaugeField& Us = Smearer.get_U(as[level].actions.at(a)->is_smeared);
as[level].actions.at(a)->deriv(Us, force); // deriv should NOT include Ta
std::cout << GridLogIntegrator
<< "Smearing (on/off): " << as[level].actions.at(a)->is_smeared
<< std::endl;
if (as[level].actions.at(a)->is_smeared) Smearer.smeared_force(force);
force = Ta(force);
std::cout << GridLogIntegrator
<< "Force average: " << norm2(force) / (U._grid->gSites())
<< std::endl;
Mom -= force * ep;
}
// Force from the other representations
as[level].apply(update_P_hireps, Representations, Mom, U, ep);
}
void update_U(GaugeField& U, double ep) {
update_U(P, U, ep);
t_U += ep;
int fl = levels - 1;
std::cout << GridLogIntegrator << " "
<< "[" << fl << "] U "
<< " dt " << ep << " : t_U " << t_U << std::endl;
}
void update_U(GaugeField& Mom, GaugeField& U, double ep) {
// rewrite exponential to deal automatically with the lorentz index?
for (int mu = 0; mu < Nd; mu++) {
auto Umu = PeekIndex<LorentzIndex>(U, mu);
auto Pmu = PeekIndex<LorentzIndex>(Mom, mu);
Umu = expMat(Pmu, ep, Params.Nexp) * Umu;
PokeIndex<LorentzIndex>(U, ProjectOnGroup(Umu), mu);
}
// Update the smeared fields, can be implemented as observer
Smearer.set_GaugeField(U);
// Update the higher representations fields
Representations.update(U); // void functions if fundamental representation
}
virtual void step(GaugeField& U, int level, int first, int last) = 0;
public:
Integrator(GridBase* grid, IntegratorParameters Par,
ActionSetHirep<GaugeField, RepresentationPolicy>& Aset,
SmearingPolicy& Sm)
: Params(Par),
as(Aset),
P(grid),
levels(Aset.size()),
Smearer(Sm),
Representations(grid) {
t_P.resize(levels, 0.0);
t_U = 0.0;
// initialization of smearer delegated outside of Integrator
};
virtual ~Integrator() {}
// to be used by the actionlevel class to iterate
// over the representations
struct _refresh {
template <class FieldType, class Repr>
void operator()(std::vector<Action<FieldType>*> repr_set, Repr& Rep,
GridParallelRNG& pRNG) {
for (int a = 0; a < repr_set.size(); ++a)
repr_set.at(a)->refresh(Rep.U, pRNG);
std::cout << GridLogDebug << "Hirep refreshing pseudofermions" << std::endl;
}
} refresh_hireps{};
// Initialization of momenta and actions
void refresh(GaugeField& U, GridParallelRNG& pRNG) {
std::cout << GridLogIntegrator << "Integrator refresh\n";
generate_momenta(P, pRNG);
// Update the smeared fields, can be implemented as observer
// necessary to keep the fields updated even after a reject
// of the Metropolis
Smearer.set_GaugeField(U);
// Set the (eventual) representations gauge fields
Representations.update(U);
// The Smearer is attached to a pointer of the gauge field
// automatically gets the correct field
// whether or not has been accepted in the previous sweep
for (int level = 0; level < as.size(); ++level) {
for (int actionID = 0; actionID < as[level].actions.size(); ++actionID) {
// get gauge field from the SmearingPolicy and
// based on the boolean is_smeared in actionID
GaugeField& Us =
Smearer.get_U(as[level].actions.at(actionID)->is_smeared);
as[level].actions.at(actionID)->refresh(Us, pRNG);
}
// Refresh the higher representation actions
as[level].apply(refresh_hireps, Representations, pRNG);
}
}
// to be used by the actionlevel class to iterate
// over the representations
struct _S {
template <class FieldType, class Repr>
void operator()(std::vector<Action<FieldType>*> repr_set, Repr& Rep,
int level, RealD& H) {
for (int a = 0; a < repr_set.size(); ++a) {
RealD Hterm = repr_set.at(a)->S(Rep.U);
std::cout << GridLogMessage << "S Level " << level << " term " << a
<< " H Hirep = " << Hterm << std::endl;
H += Hterm;
}
}
} S_hireps{};
// Calculate action
RealD S(GaugeField& U) { // here also U not used
LatticeComplex Hloc(U._grid);
Hloc = zero;
// Momenta
for (int mu = 0; mu < Nd; mu++) {
auto Pmu = PeekIndex<LorentzIndex>(P, mu);
Hloc -= trace(Pmu * Pmu);
}
Complex Hsum = sum(Hloc);
RealD H = Hsum.real();
RealD Hterm;
std::cout << GridLogMessage << "Momentum action H_p = " << H << "\n";
// Actions
for (int level = 0; level < as.size(); ++level) {
for (int actionID = 0; actionID < as[level].actions.size(); ++actionID) {
// get gauge field from the SmearingPolicy and
// based on the boolean is_smeared in actionID
GaugeField& Us =
Smearer.get_U(as[level].actions.at(actionID)->is_smeared);
Hterm = as[level].actions.at(actionID)->S(Us);
std::cout << GridLogMessage << "S Level " << level << " term "
<< actionID << " H = " << Hterm << std::endl;
H += Hterm;
}
as[level].apply(S_hireps, Representations, level, H);
}
return H;
}
void integrate(GaugeField& U) {
// reset the clocks
t_U = 0;
for (int level = 0; level < as.size(); ++level) {
t_P[level] = 0;
}
for (int step = 0; step < Params.MDsteps; ++step) { // MD step
int first_step = (step == 0);
int last_step = (step == Params.MDsteps - 1);
this->step(U, 0, first_step, last_step);
}
// Check the clocks all match on all levels
for (int level = 0; level < as.size(); ++level) {
assert(fabs(t_U - t_P[level]) < 1.0e-6); // must be the same
std::cout << GridLogIntegrator << " times[" << level
<< "]= " << t_P[level] << " " << t_U << std::endl;
}
// and that we indeed got to the end of the trajectory
assert(fabs(t_U - Params.trajL) < 1.0e-6);
}
};
}
}
#endif // INTEGRATOR_INCLUDED
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