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Reworked WilsonFlow:

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Both smear and smear_adaptive now maintain the Wilson flow time as a function variable rather than a class member variable. smear_adaptive does likewise for the current time step. This allows the evolve and smear functions to be const
	Fixed smear_adaptive setting initial time to epsilon rather than 0
	Added ability to assign generic measurement actions at user specified frequencies during the smearing and reimplemented current energy density / topq output in this framework
	Reimplemented the "flowMeasure" methods using the above framework
Fixed const correctness for WilsonLoops::TopologicalCharge
This commit is contained in:
Christopher Kelly 2022-01-24 12:06:05 -05:00
parent adeba8059a
commit 2c46c942cc
2 changed files with 104 additions and 96 deletions
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198
Grid/qcd/smearing/WilsonFlow.h
View File

@ -34,28 +34,44 @@ NAMESPACE_BEGIN(Grid);
template <class Gimpl>
class WilsonFlow: public Smear<Gimpl>{
public:
//Store generic measurements to take during smearing process using std::function
typedef std::function<void(int, RealD, const typename Gimpl::GaugeField &)> FunctionType; //int: step, RealD: flow time, GaugeField : the gauge field
private:
unsigned int Nstep;
unsigned int measure_interval;
mutable RealD epsilon, taus;
RealD epsilon; //for regular smearing this is the time step, for adaptive it is the initial time step
std::vector< std::pair<int, FunctionType> > functions; //The int maps to the measurement frequency
mutable WilsonGaugeAction<Gimpl> SG;
void evolve_step(typename Gimpl::GaugeField&) const;
void evolve_step_adaptive(typename Gimpl::GaugeField&, RealD);
RealD tau(unsigned int t)const {return epsilon*(t+1.0); }
//Evolve the gauge field by 1 step and update tau
void evolve_step(typename Gimpl::GaugeField &U, RealD &tau) const;
//Evolve the gauge field by 1 step and update tau and the current time step eps
void evolve_step_adaptive(typename Gimpl::GaugeField&U, RealD &tau, RealD &eps, RealD maxTau) const;
public:
INHERIT_GIMPL_TYPES(Gimpl)
void resetActions(){ functions.clear(); }
void addMeasurement(int meas_interval, FunctionType meas){ functions.push_back({meas_interval, meas}); }
//Set the class to perform the default measurements:
//the plaquette energy density every step
//the plaquette topological charge every 'topq_meas_interval' steps
//and output to stdout
void setDefaultMeasurements(int topq_meas_interval = 1);
explicit WilsonFlow(unsigned int Nstep, RealD epsilon, unsigned int interval = 1):
Nstep(Nstep),
epsilon(epsilon),
measure_interval(interval),
SG(WilsonGaugeAction<Gimpl>(3.0)) {
// WilsonGaugeAction with beta 3.0
assert(epsilon > 0.0);
LogMessage();
setDefaultMeasurements(interval);
}
void LogMessage() {
@ -74,29 +90,29 @@ public:
// undefined for WilsonFlow
}
void smear_adaptive(GaugeField&, const GaugeField&, RealD maxTau);
void smear_adaptive(GaugeField&, const GaugeField&, RealD maxTau) const;
//Compute t^2 <E(t)> for timestep 'step' from the plaquette
RealD energyDensityPlaquette(unsigned int step, const GaugeField& U) const;
//Compute t^2 <E(t)> for time t from the plaquette
static RealD energyDensityPlaquette(const RealD t, const GaugeField& U);
//Compute t^2 <E(t)> for time taus, set by smear_adaptive, from the plaquette
RealD energyDensityPlaquette(const GaugeField& U) const;
//Compute t^2 <E(t)> for time t from the 1x1 cloverleaf form
//t is the Wilson flow time
static RealD energyDensityCloverleaf(const RealD t, const GaugeField& U);
//Evolve the gauge field by Nstep steps of epsilon and return the energy density computed every interval steps
//The smeared field is output as V
std::vector<RealD> flowMeasureEnergyDensityPlaquette(GaugeField &V, const GaugeField& U) const;
std::vector<RealD> flowMeasureEnergyDensityPlaquette(GaugeField &V, const GaugeField& U, int measure_interval = 1);
std::vector<RealD> flowMeasureEnergyDensityPlaquette(const GaugeField& U) const;
//Version that does not return the smeared field
std::vector<RealD> flowMeasureEnergyDensityPlaquette(const GaugeField& U, int measure_interval = 1);
//Compute t^2 <E(t)> for time from the 1x1 cloverleaf form
//t is the Wilson flow time
RealD energyDensityCloverleaf(RealD t, const GaugeField& U) const;
//Evolve the gauge field by Nstep steps of epsilon and return the Cloverleaf energy density computed every interval steps
//The smeared field is output as V
std::vector<RealD> flowMeasureEnergyDensityCloverleaf(GaugeField &V, const GaugeField& U) const;
std::vector<RealD> flowMeasureEnergyDensityCloverleaf(GaugeField &V, const GaugeField& U, int measure_interval = 1);
std::vector<RealD> flowMeasureEnergyDensityCloverleaf(const GaugeField& U) const;
//Version that does not return the smeared field
std::vector<RealD> flowMeasureEnergyDensityCloverleaf(const GaugeField& U, int measure_interval = 1);
};
@ -104,7 +120,7 @@ public:
// Implementations
////////////////////////////////////////////////////////////////////////////////
template <class Gimpl>
void WilsonFlow<Gimpl>::evolve_step(typename Gimpl::GaugeField &U) const{
void WilsonFlow<Gimpl>::evolve_step(typename Gimpl::GaugeField &U, RealD &tau) const{
GaugeField Z(U.Grid());
GaugeField tmp(U.Grid());
SG.deriv(U, Z);
@ -120,12 +136,13 @@ void WilsonFlow<Gimpl>::evolve_step(typename Gimpl::GaugeField &U) const{
SG.deriv(U, tmp); Z += tmp; // 4/3*(17/36*Z0 -8/9*Z1) +Z2
Z *= 3.0/4.0; // Z = 17/36*Z0 -8/9*Z1 +3/4*Z2
Gimpl::update_field(Z, U, -2.0*epsilon); // V(t+e) = exp(ep*Z)*W2
tau += epsilon;
}
template <class Gimpl>
void WilsonFlow<Gimpl>::evolve_step_adaptive(typename Gimpl::GaugeField &U, RealD maxTau) {
if (maxTau - taus < epsilon){
epsilon = maxTau-taus;
void WilsonFlow<Gimpl>::evolve_step_adaptive(typename Gimpl::GaugeField &U, RealD &tau, RealD &eps, RealD maxTau) const{
if (maxTau - tau < eps){
eps = maxTau-tau;
}
//std::cout << GridLogMessage << "Integration epsilon : " << epsilon << std::endl;
GaugeField Z(U.Grid());
@ -135,70 +152,45 @@ void WilsonFlow<Gimpl>::evolve_step_adaptive(typename Gimpl::GaugeField &U, Real
SG.deriv(U, Z);
Zprime = -Z;
Z *= 0.25; // Z0 = 1/4 * F(U)
Gimpl::update_field(Z, U, -2.0*epsilon); // U = W1 = exp(ep*Z0)*W0
Gimpl::update_field(Z, U, -2.0*eps); // U = W1 = exp(ep*Z0)*W0
Z *= -17.0/8.0;
SG.deriv(U, tmp); Z += tmp; // -17/32*Z0 +Z1
Zprime += 2.0*tmp;
Z *= 8.0/9.0; // Z = -17/36*Z0 +8/9*Z1
Gimpl::update_field(Z, U, -2.0*epsilon); // U_= W2 = exp(ep*Z)*W1
Gimpl::update_field(Z, U, -2.0*eps); // U_= W2 = exp(ep*Z)*W1
Z *= -4.0/3.0;
SG.deriv(U, tmp); Z += tmp; // 4/3*(17/36*Z0 -8/9*Z1) +Z2
Z *= 3.0/4.0; // Z = 17/36*Z0 -8/9*Z1 +3/4*Z2
Gimpl::update_field(Z, U, -2.0*epsilon); // V(t+e) = exp(ep*Z)*W2
Gimpl::update_field(Z, U, -2.0*eps); // V(t+e) = exp(ep*Z)*W2
// Ramos
Gimpl::update_field(Zprime, Uprime, -2.0*epsilon); // V'(t+e) = exp(ep*Z')*W0
Gimpl::update_field(Zprime, Uprime, -2.0*eps); // V'(t+e) = exp(ep*Z')*W0
// Compute distance as norm^2 of the difference
GaugeField diffU = U - Uprime;
RealD diff = norm2(diffU);
// adjust integration step
taus += epsilon;
tau += eps;
//std::cout << GridLogMessage << "Adjusting integration step with distance: " << diff << std::endl;
epsilon = epsilon*0.95*std::pow(1e-4/diff,1./3.);
eps = eps*0.95*std::pow(1e-4/diff,1./3.);
//std::cout << GridLogMessage << "New epsilon : " << epsilon << std::endl;
}
template <class Gimpl>
RealD WilsonFlow<Gimpl>::energyDensityPlaquette(unsigned int step, const GaugeField& U) const {
RealD td = tau(step);
return 2.0 * td * td * SG.S(U)/U.Grid()->gSites();
}
template <class Gimpl>
RealD WilsonFlow<Gimpl>::energyDensityPlaquette(const GaugeField& U) const {
return 2.0 * taus * taus * SG.S(U)/U.Grid()->gSites();
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(GaugeField &V, const GaugeField& U) const{
std::vector<RealD> out;
V = U;
for (unsigned int step = 0; step < Nstep; step++) { //bn tau = epsilon*(step+1) so tau after performing step=0 is epsilon
std::cout << GridLogMessage << "[WilsonFlow] Evolving step " << step << std::endl;
evolve_step(V);
if( step % measure_interval == 0){
std::cout << GridLogMessage << "[WilsonFlow] Computing energy density for step " << step << std::endl;
out.push_back( energyDensityPlaquette(step,V) );
}
}
return out;
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(const GaugeField& U) const{
GaugeField V(U);
return flowMeasureEnergyDensityPlaquette(V,U);
RealD WilsonFlow<Gimpl>::energyDensityPlaquette(const RealD t, const GaugeField& U){
static WilsonGaugeAction<Gimpl> SG(3.0);
return 2.0 * t * t * SG.S(U)/U.Grid()->gSites();
}
//Compute t^2 <E(t)> for time from the 1x1 cloverleaf form
template <class Gimpl>
RealD WilsonFlow<Gimpl>::energyDensityCloverleaf(RealD t, const GaugeField& U) const{
RealD WilsonFlow<Gimpl>::energyDensityCloverleaf(const RealD t, const GaugeField& U){
typedef typename Gimpl::GaugeLinkField GaugeMat;
typedef typename Gimpl::GaugeField GaugeLorentz;
@ -221,74 +213,90 @@ RealD WilsonFlow<Gimpl>::energyDensityCloverleaf(RealD t, const GaugeField& U) c
return -real(out); //minus sign necessary for +ve energy
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityCloverleaf(GaugeField &V, const GaugeField& U) const{
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(GaugeField &V, const GaugeField& U, int measure_interval){
std::vector<RealD> out;
V = U;
for (unsigned int step = 0; step < Nstep; step++) { //bn tau = epsilon*(step+1) so tau after performing step=0 is epsilon
std::cout << GridLogMessage << "[WilsonFlow] Evolving step " << step << std::endl;
evolve_step(V);
if( step % measure_interval == 0){
std::cout << GridLogMessage << "[WilsonFlow] Computing Cloverleaf energy density for step " << step << std::endl;
out.push_back( energyDensityCloverleaf(tau(step),V) );
}
}
resetActions();
addMeasurement(measure_interval, [&out](int step, RealD t, const typename Gimpl::GaugeField &U){
std::cout << GridLogMessage << "[WilsonFlow] Computing plaquette energy density for step " << step << std::endl;
out.push_back( energyDensityPlaquette(t,U) );
});
smear(V,U);
return out;
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityCloverleaf(const GaugeField& U) const{
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(const GaugeField& U, int measure_interval){
GaugeField V(U);
return flowMeasureEnergyDensityCloverleaf(V,U);
return flowMeasureEnergyDensityPlaquette(V,U, measure_interval);
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityCloverleaf(GaugeField &V, const GaugeField& U, int measure_interval){
std::vector<RealD> out;
resetActions();
addMeasurement(measure_interval, [&out](int step, RealD t, const typename Gimpl::GaugeField &U){
std::cout << GridLogMessage << "[WilsonFlow] Computing Cloverleaf energy density for step " << step << std::endl;
out.push_back( energyDensityCloverleaf(t,U) );
});
smear(V,U);
return out;
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityCloverleaf(const GaugeField& U, int measure_interval){
GaugeField V(U);
return flowMeasureEnergyDensityCloverleaf(V,U, measure_interval);
}
//#define WF_TIMING
template <class Gimpl>
void WilsonFlow<Gimpl>::smear(GaugeField& out, const GaugeField& in) const {
void WilsonFlow<Gimpl>::smear(GaugeField& out, const GaugeField& in) const{
out = in;
for (unsigned int step = 1; step <= Nstep; step++) {
RealD taus = 0.;
for (unsigned int step = 1; step <= Nstep; step++) { //step indicates the number of smearing steps applied at the time of measurement
auto start = std::chrono::high_resolution_clock::now();
evolve_step(out);
evolve_step(out, taus);
auto end = std::chrono::high_resolution_clock::now();
std::chrono::duration<double> diff = end - start;
#ifdef WF_TIMING
std::cout << "Time to evolve " << diff.count() << " s\n";
#endif
std::cout << GridLogMessage << "[WilsonFlow] Energy density (plaq) : "
<< step << " " << tau(step) << " "
<< energyDensityPlaquette(step,out) << std::endl;
if( step % measure_interval == 0){
std::cout << GridLogMessage << "[WilsonFlow] Top. charge : "
<< step << " "
<< WilsonLoops<Gimpl>::TopologicalCharge(out) << std::endl;
}
//Perform measurements
for(auto const &meas : functions)
if( step % meas.first == 0 ) meas.second(step,taus,out);
}
}
template <class Gimpl>
void WilsonFlow<Gimpl>::smear_adaptive(GaugeField& out, const GaugeField& in, RealD maxTau){
void WilsonFlow<Gimpl>::smear_adaptive(GaugeField& out, const GaugeField& in, RealD maxTau) const{
out = in;
taus = epsilon;
RealD taus = 0.;
RealD eps = epsilon;
unsigned int step = 0;
do{
step++;
//std::cout << GridLogMessage << "Evolution time :"<< taus << std::endl;
evolve_step_adaptive(out, maxTau);
std::cout << GridLogMessage << "[WilsonFlow] Energy density (plaq) : "
<< step << " " << taus << " "
<< energyDensityPlaquette(out) << std::endl;
if( step % measure_interval == 0){
std::cout << GridLogMessage << "[WilsonFlow] Top. charge : "
<< step << " "
<< WilsonLoops<Gimpl>::TopologicalCharge(out) << std::endl;
}
evolve_step_adaptive(out, taus, eps, maxTau);
//Perform measurements
for(auto const &meas : functions)
if( step % meas.first == 0 ) meas.second(step,taus,out);
} while (taus < maxTau);
}
template <class Gimpl>
void WilsonFlow<Gimpl>::setDefaultMeasurements(int topq_meas_interval){
addMeasurement(1, [](int step, RealD t, const typename Gimpl::GaugeField &U){
std::cout << GridLogMessage << "[WilsonFlow] Energy density (plaq) : " << step << " " << t << " " << energyDensityPlaquette(t,U) << std::endl;
});
addMeasurement(topq_meas_interval, [](int step, RealD t, const typename Gimpl::GaugeField &U){
std::cout << GridLogMessage << "[WilsonFlow] Top. charge : " << step << " " << WilsonLoops<Gimpl>::TopologicalCharge(U) << std::endl;
});
}
NAMESPACE_END(Grid);

2
Grid/qcd/utils/WilsonLoops.h
View File

@ -367,7 +367,7 @@ public:
FS = 0.125*(FS - adj(FS));
}
static Real TopologicalCharge(GaugeLorentz &U){
static Real TopologicalCharge(const GaugeLorentz &U){
// 4d topological charge
assert(Nd==4);
// Bx = -iF(y,z), By = -iF(z,y), Bz = -iF(x,y)