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mirror of https://github.com/paboyle/Grid.git synced 2024-11-09 23:45:36 +00:00

Refactored Wilson flow class; previously the class implemented both iterative and adaptive smearing, but only the iterative method was accessible through the Smearing base class. The implementation of Smearing also forced a clunky need to pass iterative smearing parameters through the constructor but adaptive smearing parameters through the function call. Now there is a WilsonFlowBase class that implements common functionality, and separate WilsonFlow (iterative) and WilsonFlowAdaptive (adaptive) classes, both of which implement Smearing virtual functions.

Modified the Wilson flow adaptive smearing step size update to implement the original Ramos definition of the distance, where previously it used the norm of a difference which scales with the volume and so would choose too coarse or too fine steps depending on the volume. This is based on Chulwoo's code.

Added a test comparing adaptive (with tuneable tolerance) to iterative Wilson flow smearing on a random gauge configuration.
This commit is contained in:
Christopher Kelly 2022-10-03 10:59:38 -04:00
parent 19da647e3c
commit 66d001ec9e
3 changed files with 336 additions and 134 deletions

View File

@ -31,15 +31,16 @@ directory
NAMESPACE_BEGIN(Grid);
struct TopologySmearingParameters : Serializable {
GRID_SERIALIZABLE_CLASS_MEMBERS(TopologySmearingParameters,
int, steps,
float, step_size,
int, meas_interval,
float, maxTau);
float, init_step_size,
float, maxTau,
float, tolerance);
TopologySmearingParameters(int s = 0, float ss = 0.0f, int mi = 0, float mT = 0.0f):
steps(s), step_size(ss), meas_interval(mi), maxTau(mT){}
TopologySmearingParameters(float ss = 0.0f, int mi = 0, float mT = 0.0f, float tol = 1e-4):
init_step_size(ss), meas_interval(mi), maxTau(mT), tolerance(tol){}
template < class ReaderClass >
TopologySmearingParameters(Reader<ReaderClass>& Reader){
@ -97,8 +98,8 @@ public:
if (Pars.do_smearing){
// using wilson flow by default here
WilsonFlow<PeriodicGimplR> WF(Pars.Smearing.steps, Pars.Smearing.step_size, Pars.Smearing.meas_interval);
WF.smear_adaptive(Usmear, U, Pars.Smearing.maxTau);
WilsonFlowAdaptive<PeriodicGimplR> WF(Pars.Smearing.init_step_size, Pars.Smearing.maxTau, Pars.Smearing.tolerance, Pars.Smearing.meas_interval);
WF.smear(Usmear, U);
Real T0 = WF.energyDensityPlaquette(Pars.Smearing.maxTau, Usmear);
std::cout << GridLogMessage << std::setprecision(std::numeric_limits<Real>::digits10 + 1)
<< "T0 : [ " << traj << " ] "<< T0 << std::endl;

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@ -33,27 +33,25 @@ directory
NAMESPACE_BEGIN(Grid);
template <class Gimpl>
class WilsonFlow: public Smear<Gimpl>{
class WilsonFlowBase: 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;
RealD epsilon; //for regular smearing this is the time step, for adaptive it is the initial time step
protected:
std::vector< std::pair<int, FunctionType> > functions; //The int maps to the measurement frequency
mutable WilsonGaugeAction<Gimpl> SG;
//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)
explicit WilsonFlowBase(unsigned int meas_interval =1):
SG(WilsonGaugeAction<Gimpl>(3.0)) {
// WilsonGaugeAction with beta 3.0
setDefaultMeasurements(meas_interval);
}
void resetActions(){ functions.clear(); }
void addMeasurement(int meas_interval, FunctionType meas){ functions.push_back({meas_interval, meas}); }
@ -64,34 +62,11 @@ public:
//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),
SG(WilsonGaugeAction<Gimpl>(3.0)) {
// WilsonGaugeAction with beta 3.0
assert(epsilon > 0.0);
LogMessage();
setDefaultMeasurements(interval);
}
void LogMessage() {
std::cout << GridLogMessage
<< "[WilsonFlow] Nstep : " << Nstep << std::endl;
std::cout << GridLogMessage
<< "[WilsonFlow] epsilon : " << epsilon << std::endl;
std::cout << GridLogMessage
<< "[WilsonFlow] full trajectory : " << Nstep * epsilon << std::endl;
}
virtual void smear(GaugeField&, const GaugeField&) const;
virtual void derivative(GaugeField&, const GaugeField&, const GaugeField&) const {
void derivative(GaugeField&, const GaugeField&, const GaugeField&) const override{
assert(0);
// undefined for WilsonFlow
}
void smear_adaptive(GaugeField&, const GaugeField&, RealD maxTau) const;
//Compute t^2 <E(t)> for time t from the plaquette
static RealD energyDensityPlaquette(const RealD t, const GaugeField& U);
@ -115,82 +90,63 @@ public:
std::vector<RealD> flowMeasureEnergyDensityCloverleaf(const GaugeField& U, int measure_interval = 1);
};
//Basic iterative Wilson flow
template <class Gimpl>
class WilsonFlow: public WilsonFlowBase<Gimpl>{
private:
int Nstep; //number of steps
RealD epsilon; //step size
//Evolve the gauge field by 1 step of size eps and update tau
void evolve_step(typename Gimpl::GaugeField &U, RealD &tau) const;
public:
INHERIT_GIMPL_TYPES(Gimpl)
//Integrate the Wilson flow for Nstep steps of size epsilon
WilsonFlow(const RealD epsilon, const int Nstep, unsigned int meas_interval = 1): WilsonFlowBase<Gimpl>(meas_interval), Nstep(Nstep), epsilon(epsilon){}
void smear(GaugeField& out, const GaugeField& in) const override;
};
//Wilson flow with adaptive step size
template <class Gimpl>
class WilsonFlowAdaptive: public WilsonFlowBase<Gimpl>{
private:
RealD init_epsilon; //initial step size
RealD maxTau; //integrate to t=maxTau
RealD tolerance; //integration error tolerance
//Evolve the gauge field by 1 step and update tau and the current time step eps
//
//If the step size eps is too large that a significant integration error results,
//the gauge field (U) and tau will not be updated and the function will return 0; eps will be adjusted to a smaller
//value for the next iteration.
//
//For a successful integration step the function will return 1
int evolve_step_adaptive(typename Gimpl::GaugeField&U, RealD &tau, RealD &eps) const;
public:
INHERIT_GIMPL_TYPES(Gimpl)
WilsonFlowAdaptive(const RealD init_epsilon, const RealD maxTau, const RealD tolerance, unsigned int meas_interval = 1):
WilsonFlowBase<Gimpl>(meas_interval), init_epsilon(init_epsilon), maxTau(maxTau), tolerance(tolerance){}
void smear(GaugeField& out, const GaugeField& in) const override;
};
////////////////////////////////////////////////////////////////////////////////
// Implementations
////////////////////////////////////////////////////////////////////////////////
template <class Gimpl>
void WilsonFlow<Gimpl>::evolve_step(typename Gimpl::GaugeField &U, RealD &tau) const{
GaugeField Z(U.Grid());
GaugeField tmp(U.Grid());
SG.deriv(U, Z);
Z *= 0.25; // Z0 = 1/4 * F(U)
Gimpl::update_field(Z, U, -2.0*epsilon); // U = W1 = exp(ep*Z0)*W0
Z *= -17.0/8.0;
SG.deriv(U, tmp); Z += tmp; // -17/32*Z0 +Z1
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
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
tau += epsilon;
}
template <class Gimpl>
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());
GaugeField Zprime(U.Grid());
GaugeField tmp(U.Grid()), Uprime(U.Grid());
Uprime = U;
SG.deriv(U, Z);
Zprime = -Z;
Z *= 0.25; // Z0 = 1/4 * F(U)
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*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*eps); // V(t+e) = exp(ep*Z)*W2
// Ramos
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
tau += eps;
//std::cout << GridLogMessage << "Adjusting integration step with distance: " << diff << std::endl;
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(const RealD t, const GaugeField& U){
RealD WilsonFlowBase<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(const RealD t, const GaugeField& U){
RealD WilsonFlowBase<Gimpl>::energyDensityCloverleaf(const RealD t, const GaugeField& U){
typedef typename Gimpl::GaugeLinkField GaugeMat;
typedef typename Gimpl::GaugeField GaugeLorentz;
@ -215,7 +171,7 @@ RealD WilsonFlow<Gimpl>::energyDensityCloverleaf(const RealD t, const GaugeField
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(GaugeField &V, const GaugeField& U, int measure_interval){
std::vector<RealD> WilsonFlowBase<Gimpl>::flowMeasureEnergyDensityPlaquette(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){
@ -227,13 +183,13 @@ std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(GaugeFie
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityPlaquette(const GaugeField& U, int measure_interval){
std::vector<RealD> WilsonFlowBase<Gimpl>::flowMeasureEnergyDensityPlaquette(const GaugeField& U, int measure_interval){
GaugeField 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> WilsonFlowBase<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){
@ -245,16 +201,52 @@ std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityCloverleaf(GaugeFi
}
template <class Gimpl>
std::vector<RealD> WilsonFlow<Gimpl>::flowMeasureEnergyDensityCloverleaf(const GaugeField& U, int measure_interval){
std::vector<RealD> WilsonFlowBase<Gimpl>::flowMeasureEnergyDensityCloverleaf(const GaugeField& U, int measure_interval){
GaugeField V(U);
return flowMeasureEnergyDensityCloverleaf(V,U, measure_interval);
}
template <class Gimpl>
void WilsonFlowBase<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;
});
}
//#define WF_TIMING
template <class Gimpl>
void WilsonFlow<Gimpl>::evolve_step(typename Gimpl::GaugeField &U, RealD &tau) const{
GaugeField Z(U.Grid());
GaugeField tmp(U.Grid());
this->SG.deriv(U, Z);
Z *= 0.25; // Z0 = 1/4 * F(U)
Gimpl::update_field(Z, U, -2.0*epsilon); // U = W1 = exp(ep*Z0)*W0
Z *= -17.0/8.0;
this->SG.deriv(U, tmp); Z += tmp; // -17/32*Z0 +Z1
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
Z *= -4.0/3.0;
this->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>::smear(GaugeField& out, const GaugeField& in) const{
std::cout << GridLogMessage
<< "[WilsonFlow] Nstep : " << Nstep << std::endl;
std::cout << GridLogMessage
<< "[WilsonFlow] epsilon : " << epsilon << std::endl;
std::cout << GridLogMessage
<< "[WilsonFlow] full trajectory : " << Nstep * epsilon << std::endl;
out = in;
RealD taus = 0.;
for (unsigned int step = 1; step <= Nstep; step++) { //step indicates the number of smearing steps applied at the time of measurement
@ -266,37 +258,93 @@ void WilsonFlow<Gimpl>::smear(GaugeField& out, const GaugeField& in) const{
std::cout << "Time to evolve " << diff.count() << " s\n";
#endif
//Perform measurements
for(auto const &meas : functions)
for(auto const &meas : this->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) const{
out = in;
RealD taus = 0.;
RealD eps = epsilon;
unsigned int step = 0;
do{
step++;
//std::cout << GridLogMessage << "Evolution time :"<< taus << 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);
int WilsonFlowAdaptive<Gimpl>::evolve_step_adaptive(typename Gimpl::GaugeField &U, RealD &tau, RealD &eps) const{
if (maxTau - tau < eps){
eps = maxTau-tau;
}
//std::cout << GridLogMessage << "Integration epsilon : " << epsilon << std::endl;
GaugeField Z(U.Grid());
GaugeField Zprime(U.Grid());
GaugeField tmp(U.Grid()), Uprime(U.Grid()), Usave(U.Grid());
Uprime = U;
Usave = U;
this->SG.deriv(U, Z);
Zprime = -Z;
Z *= 0.25; // Z0 = 1/4 * F(U)
Gimpl::update_field(Z, U, -2.0*eps); // U = W1 = exp(ep*Z0)*W0
Z *= -17.0/8.0;
this->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*eps); // U_= W2 = exp(ep*Z)*W1
Z *= -4.0/3.0;
this->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*eps); // V(t+e) = exp(ep*Z)*W2
// Ramos arXiv:1301.4388
Gimpl::update_field(Zprime, Uprime, -2.0*eps); // V'(t+e) = exp(ep*Z')*W0
// Compute distance using Ramos' definition
GaugeField diffU = U - Uprime;
RealD max_dist = 0;
for(int mu=0;mu<Nd;mu++){
typename Gimpl::GaugeLinkField diffU_mu = PeekIndex<LorentzIndex>(diffU, mu);
RealD dist_mu = sqrt( maxLocalNorm2(diffU_mu) ) /Nc/Nc; //maximize over sites
max_dist = std::max(max_dist, dist_mu); //maximize over mu
}
int ret;
if(max_dist < tolerance) {
tau += eps;
ret = 1;
} else {
U = Usave;
ret = 0;
}
eps = eps*0.95*std::pow(tolerance/max_dist,1./3.);
std::cout << GridLogMessage << "Adaptive smearing : Distance: "<< max_dist <<" Step successful: " << ret << " New epsilon: " << eps << std::endl;
return ret;
}
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;
});
void WilsonFlowAdaptive<Gimpl>::smear(GaugeField& out, const GaugeField& in) const{
std::cout << GridLogMessage
<< "[WilsonFlow] initial epsilon : " << init_epsilon << std::endl;
std::cout << GridLogMessage
<< "[WilsonFlow] full trajectory : " << maxTau << std::endl;
std::cout << GridLogMessage
<< "[WilsonFlow] tolerance : " << tolerance << std::endl;
out = in;
RealD taus = 0.;
RealD eps = init_epsilon;
unsigned int step = 0;
do{
int step_success = evolve_step_adaptive(out, taus, eps);
step += step_success; //step will not be incremented if the integration step fails
//Perform measurements
if(step_success)
for(auto const &meas : this->functions)
if( step % meas.first == 0 ) meas.second(step,taus,out);
} while (taus < maxTau);
}
NAMESPACE_END(Grid);

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@ -0,0 +1,153 @@
/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./tests/hmc/Test_WilsonFlow_adaptive.cc
Copyright (C) 2017
Author: Christopher Kelly <ckelly@bnl.gov>
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 Grid;
//Linearly interpolate between two nearest times
RealD interpolate(const RealD t_int, const std::vector<std::pair<RealD,RealD> > &data){
RealD tdiff1=1e32; int t1_idx=-1;
RealD tdiff2=1e32; int t2_idx=-1;
for(int i=0;i<data.size();i++){
RealD diff = fabs(data[i].first-t_int);
//std::cout << "targ " << t_int << " cur " << data[i].first << " diff " << diff << " best diff1 " << tdiff1 << " diff2 " << tdiff2 << std::endl;
if(diff < tdiff1){
if(tdiff1 < tdiff2){ //swap out tdiff2
tdiff2 = tdiff1; t2_idx = t1_idx;
}
tdiff1 = diff; t1_idx = i;
}
else if(diff < tdiff2){ tdiff2 = diff; t2_idx = i; }
}
assert(t1_idx != -1 && t2_idx != -1);
RealD t2 = data[t2_idx].first, v2 = data[t2_idx].second;
RealD t1 = data[t1_idx].first, v1 = data[t1_idx].second;
//v = a + bt
//v2-v1 = b(t2-t1)
RealD b = (v2-v1)/(t2-t1);
RealD a = v1 - b*t1;
RealD vout = a + b*t_int;
//std::cout << "Interpolate to " << t_int << " two closest points " << t1 << " " << t2
//<< " with values " << v1 << " "<< v2 << " : got " << vout << std::endl;
return vout;
}
int main(int argc, char **argv) {
Grid_init(&argc, &argv);
GridLogLayout();
auto latt_size = GridDefaultLatt();
auto simd_layout = GridDefaultSimd(Nd, vComplex::Nsimd());
auto mpi_layout = GridDefaultMpi();
GridCartesian Grid(latt_size, simd_layout, mpi_layout);
GridRedBlackCartesian RBGrid(&Grid);
std::vector<int> seeds({1, 2, 3, 4, 5});
GridSerialRNG sRNG;
GridParallelRNG pRNG(&Grid);
pRNG.SeedFixedIntegers(seeds);
LatticeGaugeField U(&Grid);
SU<Nc>::HotConfiguration(pRNG, U);
int Nstep = 300;
RealD epsilon = 0.01;
RealD maxTau = Nstep*epsilon;
RealD tolerance = 1e-4;
for(int i=1;i<argc;i++){
std::string sarg(argv[i]);
if(sarg == "--tolerance"){
std::stringstream ss; ss << argv[i+1]; ss >> tolerance;
}
}
std::cout << "Adaptive smear tolerance " << tolerance << std::endl;
//Setup iterative Wilson flow
WilsonFlow<PeriodicGimplD> wflow(epsilon,Nstep);
wflow.resetActions();
std::vector<std::pair<RealD, RealD> > meas_orig;
wflow.addMeasurement(1, [&wflow,&meas_orig](int step, RealD t, const LatticeGaugeField &U){
std::cout << GridLogMessage << "[WilsonFlow] Computing Cloverleaf energy density for step " << step << std::endl;
meas_orig.push_back( {t, wflow.energyDensityCloverleaf(t,U)} );
});
//Setup adaptive Wilson flow
WilsonFlowAdaptive<PeriodicGimplD> wflow_ad(epsilon,maxTau,tolerance);
wflow_ad.resetActions();
std::vector<std::pair<RealD, RealD> > meas_adaptive;
wflow_ad.addMeasurement(1, [&wflow_ad,&meas_adaptive](int step, RealD t, const LatticeGaugeField &U){
std::cout << GridLogMessage << "[WilsonFlow] Computing Cloverleaf energy density for step " << step << std::endl;
meas_adaptive.push_back( {t, wflow_ad.energyDensityCloverleaf(t,U)} );
});
//Run
LatticeGaugeFieldD Vtmp(U.Grid());
wflow.smear(Vtmp, U); //basic smear
Vtmp = Zero();
wflow_ad.smear(Vtmp, U);
//Output values for plotting
{
std::ofstream out("wflow_t2E_orig.dat");
out.precision(16);
for(auto const &e: meas_orig){
out << e.first << " " << e.second << std::endl;
}
}
{
std::ofstream out("wflow_t2E_adaptive.dat");
out.precision(16);
for(auto const &e: meas_adaptive){
out << e.first << " " << e.second << std::endl;
}
}
//Compare at times available with adaptive smearing
for(int i=0;i<meas_adaptive.size();i++){
RealD t = meas_adaptive[i].first;
RealD v_adaptive = meas_adaptive[i].second;
RealD v_orig = interpolate(t, meas_orig); //should be very precise due to fine timestep
std::cout << t << " orig: " << v_orig << " adaptive: " << v_adaptive << " reldiff: " << (v_adaptive-v_orig)/v_orig << std::endl;
}
std::cout << GridLogMessage << "Done" << std::endl;
Grid_finalize();
}