BennettsMethod.h

#ifdef MCMD_PERTURB
#ifdef UTIL_MPI
#ifndef MCMD_BENNETTS_METHOD_H
#define MCMD_BENNETTS_METHOD_H

/*
* Simpatico - Simulation Package for Polymeric and Molecular Liquids
*
* Copyright 2010, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/

#include <mcMd/analyzers/SystemAnalyzer.h>  // base class template
#include <mcMd/simulation/System.h>             // base template parameter
#include <util/accumulators/Average.h>          // member
#ifdef UTIL_MPI
#include <util/containers/DArray.h>
#include <util/mpi/MpiSendRecv.h>
#include <util/mpi/MpiLogger.h>
#endif
#include <mcMd/simulation/Simulation.h>
#include <util/space/Vector.h>          // Util namespace
#include <util/global.h>
#include <util/param/ParamComposite.h>

#include <fstream>
#include <cstdio> 

namespace McMd
{

   using namespace Util;

   class BennettsMethod : public SystemAnalyzer<System>
   {
   
   public:

      BennettsMethod(System& system);

      virtual void readParameters(std::istream& in);

      virtual void loadParameters(Serializable::IArchive& ar);

      virtual void save(Serializable::OArchive& ar);

      template <class Archive>
      void serialize(Archive& ar, const unsigned int version);

      virtual void setup();

      /* 
      * Evaluate Fermi functions and add to accumulators.
      *       
      * \param iStep step counter
      */
      virtual void sample(long iStep);
   
      virtual void output();
   
   protected:
  
      double shift_;
      
      double lowerShift_;

      #ifdef UTIL_MPI
      // Values of shift constants for all replicas.
      DArray<double> shifts_;
      #endif
     
   private:

      static const int TagDerivative[2];
      
      static const int TagFermi[2];
      
      MPI::Intracomm* communicatorPtr_;
      
      int  myId_;

      int  nProcs_;
      
      int  lowerId_;
      
      int  upperId_;
      
      int nParameter_;
      
      DArray<double> myParam_;

      DArray<double> lowerParam_;

      DArray<double> upperParam_;

      int nSamplePerBlock_;

      Average  myAccumulator_;
      
      Average  upperAccumulator_;

      double myArg_;
      
      double lowerArg_;
      
      double myFermi_;
      
      double lowerFermi_;
      
      double upperFermi_;

      std::ofstream outputFile_;
      
      long interval_;
 
      bool  isInitialized_;
      
      virtual void analyze();
   };

   /*
   * Serialize to/from an archive. 
   */
   template <class Archive>
   void BennettsMethod::serialize(Archive& ar, const unsigned int version)
   {
      Analyzer::serialize(ar, version);
      ar & nSamplePerBlock_;
      #ifdef UTIL_MPI
      if (hasIoCommunicator()) {
         ar & shifts_;
      } else {
         ar & shift_;
      }
      #else
      ar & shift_;
      #endif
      ar & myAccumulator_; 
      ar & upperAccumulator_; 

      // Set in constructor
      //ar & myId_;
      //ar & nProcs_;
      //ar & lowerId_;
      //ar & upperId_;
      //ar & nParameter_;
      // ar & myParam_;
      
      ar & lowerParam_;
      ar & upperParam_;
      ar & myArg_;
      ar & lowerArg_;
      ar & myFermi_;
      ar & lowerFermi_;
      ar & upperFermi_;
   }


}
#endif   // ifndef BENNETTS_METHOD_H
#endif   // ifdef  UTIL_MPI
#endif   // ifdef  UTIL_PERTURB