HMC ready but untested

lib/qcd/hmc/integrators/Integrator_base.h

@@ -9,6 +9,8 @@
 #ifndef INTEGRATOR_INCLUDED
 #define INTEGRATOR_INCLUDED
 
+#include <memory>
+
 class Observer;
 
 
@@ -22,59 +24,188 @@ namespace Grid{
     typedef std::vector<ActionLevel> ActionSet;
     typedef std::vector<Observer*> ObserverList;
     
-    
-    class Integrator2MN{
-      const double lambda = 0.1931833275037836;
-      void step (LatticeColourMatrix&, LatticeColourMatrix&, 
-		 int, std::vector<int>&);
-      
+    class LeapFrog;
+
+
+    struct IntegratorParameters{
+      int Nexp;
+      int MDsteps;  // number of outer steps
+      RealD trajL;  // trajectory length 
+      RealD stepsize;
+
+      IntegratorParameters(int Nexp_,
+			   int MDsteps_, 
+			   RealD trajL_):
+	Nexp(Nexp_),MDsteps(MDsteps_),trajL(trajL_),stepsize(trajL/MDsteps){};
     };
+
+
+    namespace MDutils{
+      void generate_momenta(LatticeLorentzColourMatrix&,GridParallelRNG&);
+      void generate_momenta_su3(LatticeLorentzColourMatrix&,GridParallelRNG&);
+    }
+
     
-    class IntegratorLeapFrog{
-      void step (LatticeColourMatrix&, LatticeColourMatrix&,
-		 int, std::vector<int>&);
-    };
     
 
 
     template< class IntegratorPolicy >
     class Integrator{
     private:
-      int Nexp;
-      int MDsteps;  // number of outer steps
-      RealD trajL;  // trajectory length 
-      RealD stepsize;
-
-      const std::vector<int> Nrel; // relative steps per level
+      IntegratorParameters Params;
       const ActionSet as;
-      ObserverList observers;
-      //      LatticeColourMatrix* const U;  // is shared among all actions - or use a singleton...
-      LatticeColourMatrix P;
+      const std::vector<int> Nrel; //relative step size per level
+      //ObserverList observers; // not yet
+      std::unique_ptr<LatticeLorentzColourMatrix> P;
       
       IntegratorPolicy TheIntegrator;// contains parameters too
-      void update_P(int lv,double ep);
-      void update_U(double ep);
+
+
+      void update_P(LatticeLorentzColourMatrix&U, int level,double ep){
+	for(int a=0; a<as[level].size(); ++a){
+	  LatticeLorentzColourMatrix force(U._grid);
+	  as[level].at(a)->deriv(U,force);
+	  *P -= force*ep;
+	}
+      }
+
+
+      void update_U(LatticeLorentzColourMatrix&U, double ep){
+	//rewrite exponential to deal with the lorentz index?
+	LatticeColourMatrix Umu(U._grid);
+	LatticeColourMatrix Pmu(U._grid);
+	for (int mu = 0; mu < Nd; mu++){
+	  Umu=peekLorentz(U, mu);
+	  Pmu=peekLorentz(*P, mu);
+	  Umu = expMat(Pmu, Complex(ep, 0.0))*Umu;
+	}
+
+      }
       
       void register_observers();
       void notify_observers();
-      void integrator_step(int level ,std::vector<Integer>& clock);
+      
+      friend void IntegratorPolicy::step (LatticeLorentzColourMatrix& U, 
+				     int level, std::vector<int>& clock,
+				     Integrator<LeapFrog>* Integ);
+    public:
+      Integrator(IntegratorParameters Par,
+		 ActionSet& Aset, std::vector<int> Nrel_):
+	Params(Par),as(Aset),Nrel(Nrel_){
+	assert(as.size() == Nrel.size());
+      };
+      
+      ~Integrator(){}
+
+
+      //Initialization of momenta and actions
+      void init(LatticeLorentzColourMatrix& U,
+		GridParallelRNG& pRNG){
+	std::cout<< "Integrator init\n";
+	if (!P)
+	  P = new LatticeLorentzColourMatrix(U._grid);
+	MDutils::generate_momenta(*P,pRNG);
+	
+	for(int level=0; level< as.size(); ++level){
+	  for(int actionID=0; actionID<as.at(level).size(); ++actionID){
+	    as[level].at(actionID)->init(U, pRNG);
+	  }
+	}
+      }
 
       
-    public:
-      Integrator(int Nexp_, int MDsteps_, RealD trajL_,
-		 ActionSet& Aset, ObserverList obs):as(Aset), observers(obs){};
-      ~Integrator(){}
-      void init(LatticeLorentzColourMatrix&,
-		GridParallelRNG&);
-      double S();
-      void integrate(int level);
-      LatticeColourMatrix get_U();
+
+      RealD S(LatticeLorentzColourMatrix& U){
+	// Momenta
+	LatticeComplex Hloc = - trace((*P)*adj(*P));
+	Complex Hsum = sum(Hloc);
+	
+	RealD H = Hsum.real();
+
+	// Actions
+	for(int level=0; level<as.size(); ++level)
+	  for(int actionID=0; actionID<as.at(level).size(); ++actionID)
+	    H += as[level].at(actionID)->S(U);
+	
+	return H;
+      }
+      
+      
+
+      void integrate(LatticeLorentzColourMatrix& U, int level){
+	std::vector<int> clock;
+	clock.resize(as.size(),0);
+	for(int step=0; step< Params.MDsteps; ++step)   // MD step
+	  TheIntegrator.step(U,0,clock, *(this));
+      }
     };
     
-    namespace MDutils{
-      void generate_momenta(LatticeLorentzColourMatrix&,GridParallelRNG&);
-      void generate_momenta_su3(LatticeLorentzColourMatrix&,GridParallelRNG&);
-    }
+
+    class MinimumNorm2{
+      const double lambda = 0.1931833275037836;
+    public:
+      void step (LatticeLorentzColourMatrix& U, int level, std::vector<int>& clock);
+      
+    };
+    
+    class LeapFrog{
+    public:
+      void step (LatticeLorentzColourMatrix& U, 
+		 int level, std::vector<int>& clock,
+		 Integrator<LeapFrog>* Integ){
+	// cl  : current level
+	// fl  : final level
+	// eps : current step size
+	
+	int fl = Integ->as.size() -1;
+	double eps = Integ->Params.stepsize;
+	
+	// Get current level step size
+	for(int l=0; l<=level; ++l) eps/= Integ->Nrel[l];
+	
+	int fin = 1;
+	for(int l=0; l<=level; ++l) fin*= Integ->Nrel[l];
+	fin = 2*Integ->Params.MDsteps*fin - 1;
+	
+	for(int e=0; e<Integ->Nrel[level]; ++e){
+	  
+	  if(clock[level] == 0){    // initial half step
+	    Integ->update_P(U, level,eps/2);
+	    ++clock[level];
+	    for(int l=0; l<level;++l) std::cout<<"   ";
+	    std::cout<<"P "<< 0.5*clock[level] <<std::endl;
+	  }
+	  if(level == fl){          // lowest level
+	    Integ->update_U(U, eps);
+	    for(int l=0; l<level;++l) std::cout<<"   ";
+	    std::cout<<"U "<< 0.5*(clock[level]+1) <<std::endl;
+	  }else{                 // recursive function call
+	    step(U, level+1,clock, Integ);
+	  }
+	  if(clock[level] == fin){  // final half step
+	    Integ->update_P(U, level,eps/2);
+	    
+	    ++clock[level];
+	    for(int l=0; l<level;++l) std::cout<<"   ";
+	    std::cout<<"P "<< 0.5*clock[level] <<std::endl;
+	  }else{                  // bulk step
+	    Integ->update_P(U, level,eps);
+	    
+	    clock[level]+=2;
+	    for(int l=0; l<level;++l) std::cout<<"   ";
+	    std::cout<<"P "<< 0.5*clock[level] <<std::endl;
+	  }
+	}
+
+
+
+
+      }
+    };
+
+
+
+
     
   }
 }