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First cut on generalised HMC

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Backward compatibility OK
This commit is contained in:
Guido Cossu
2016-10-03 15:28:00 +01:00
parent 7ea4b959a4
commit e415260961
7 changed files with 376 additions and 345 deletions
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107
lib/qcd/hmc/integrators/Integrator.h
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@@ -49,60 +49,53 @@ namespace Grid {
namespace QCD {
struct IntegratorParameters {
int Nexp;
int MDsteps; // number of outer steps
RealD trajL; // trajectory length
RealD stepsize;
unsigned int
Nexp; // number of terms in the Taylor expansion of the exponential
unsigned int MDsteps; // number of outer steps
RealD trajL; // trajectory length
RealD stepsize; // trajectory stepsize
IntegratorParameters(int MDsteps_, RealD trajL_ = 1.0, int Nexp_ = 12)
IntegratorParameters(int MDsteps_, RealD trajL_ = 1.0,
unsigned int Nexp_ = 12)
: Nexp(Nexp_),
MDsteps(MDsteps_),
trajL(trajL_),
stepsize(trajL / MDsteps){
// empty body constructor
};
};
void print_parameters() {
std::cout << GridLogMessage << "[Integrator] Trajectory length : " << trajL << std::endl;
std::cout << GridLogMessage << "[Integrator] Number of MD steps : " << MDsteps << std::endl;
std::cout << GridLogMessage << "[Integrator] Step size : " << stepsize << std::endl;
std::cout << GridLogMessage << "[Integrator] Exponential approx.: " << Nexp << std::endl;
}
};
/*! @brief Class for Molecular Dynamics management */
template <class GaugeField, class SmearingPolicy, class RepresentationPolicy>
template <class FieldImplementation, class SmearingPolicy, class RepresentationPolicy>
class Integrator {
protected:
typedef IntegratorParameters ParameterType;
typedef typename FieldImplementation::Field MomentaField; //for readability
typedef typename FieldImplementation::Field Field;
IntegratorParameters Params;
const ActionSet<GaugeField, RepresentationPolicy> as;
const ActionSet<Field, 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;
MomentaField 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) {
void update_P(Field& U, int level, double ep) {
t_P[level] += ep;
update_P(P, U, level, ep);
@@ -129,12 +122,12 @@ class Integrator {
}
} update_P_hireps{};
void update_P(GaugeField& Mom, GaugeField& U, int level, double ep) {
void update_P(MomentaField& Mom, Field& 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);
Field force(U._grid);
Field& 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
@@ -152,7 +145,7 @@ class Integrator {
as[level].apply(update_P_hireps, Representations, Mom, U, ep);
}
void update_U(GaugeField& U, double ep) {
void update_U(Field& U, double ep) {
update_U(P, U, ep);
t_U += ep;
@@ -161,26 +154,21 @@ class Integrator {
<< "[" << fl << "] U "
<< " dt " << ep << " : t_U " << t_U << std::endl;
}
void update_U(GaugeField& Mom, GaugeField& U, double ep) {
// rewrite exponential to deal internally 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);
}
void update_U(MomentaField& Mom, Field& U, double ep) {
FieldImplementation::update_field(Mom, U, ep, Params.Nexp);
// Update the smeared fields, can be implemented as observer
Smearer.set_GaugeField(U);
Smearer.set_Field(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;
virtual void step(Field& U, int level, int first, int last) = 0;
public:
Integrator(GridBase* grid, IntegratorParameters Par,
ActionSet<GaugeField, RepresentationPolicy>& Aset,
ActionSet<Field, RepresentationPolicy>& Aset,
SmearingPolicy& Sm)
: Params(Par),
as(Aset),
@@ -195,6 +183,13 @@ class Integrator {
virtual ~Integrator() {}
virtual std::string integrator_name() = 0;
void print_parameters(){
std::cout << GridLogMessage << "[Integrator] Name : "<< integrator_name() << std::endl;
Params.print_parameters();
}
// to be used by the actionlevel class to iterate
// over the representations
struct _refresh {
@@ -210,14 +205,14 @@ class Integrator {
} refresh_hireps{};
// Initialization of momenta and actions
void refresh(GaugeField& U, GridParallelRNG& pRNG) {
void refresh(Field& U, GridParallelRNG& pRNG) {
std::cout << GridLogIntegrator << "Integrator refresh\n";
generate_momenta(P, pRNG);
FieldImplementation::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);
Smearer.set_Field(U);
// Set the (eventual) representations gauge fields
Representations.update(U);
@@ -228,7 +223,7 @@ class Integrator {
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 =
Field& Us =
Smearer.get_U(as[level].actions.at(actionID)->is_smeared);
as[level].actions.at(actionID)->refresh(Us, pRNG);
}
@@ -256,11 +251,12 @@ class Integrator {
} S_hireps{};
// Calculate action
RealD S(GaugeField& U) { // here also U not used
RealD S(Field& U) { // here also U not used
LatticeComplex Hloc(U._grid);
Hloc = zero;
// Momenta
// Momenta --- modify this (take the trace of field)
// momenta_action()
for (int mu = 0; mu < Nd; mu++) {
auto Pmu = PeekIndex<LorentzIndex>(P, mu);
Hloc -= trace(Pmu * Pmu);
@@ -276,7 +272,7 @@ class Integrator {
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 =
Field& 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 "
@@ -289,7 +285,7 @@ class Integrator {
return H;
}
void integrate(GaugeField& U) {
void integrate(Field& U) {
// reset the clocks
t_U = 0;
for (int level = 0; level < as.size(); ++level) {
@@ -312,7 +308,12 @@ class Integrator {
// and that we indeed got to the end of the trajectory
assert(fabs(t_U - Params.trajL) < 1.0e-6);
}
};
}
}
#endif // INTEGRATOR_INCLUDED