fts/montecarlo/BdMove.h

#ifndef RP_BD_MOVE_H
#define RP_BD_MOVE_H
 
/*
* PSCF - Polymer Self-Consistent Field
*
* Copyright 2015 - 2025, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
#include <util/containers/DArray.h>    // member
#include <iostream>
 
namespace Pscf {
namespace Rp {
 
   using namespace Util;

   template <int D, class T>
   class BdMove : public T::McMove
   {
 
   public:
 
      // Protected constructor and destrutor (see below)

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

      bool move() override;

      bool needsDc() override
      {  return true; }
 
   protected:

      BdMove(typename T::McSimulator& simulator);

      ~BdMove() = default;

      void bdSetup();

      bool bdStep();
 
      using McMoveT = typename T::McMove;
 
      // Inherited protected member functions
      using McMoveT::system;
      using McMoveT::simulator;
      using McMoveT::random;
      using McMoveT::vecRandom;
 
   private:
 
      using RFieldT = typename T::RField;
 
      // Private data members
 
      // New field values
      DArray< RFieldT > w_;
 
      // Random displacements (A)
      DArray< RFieldT > etaA_;
 
      // Random displacements (B)
      DArray< RFieldT > etaB_;
 
      // Change in one field component
      RFieldT dwc_;
 
      // Pointer to new random displacements
      DArray< RFieldT >* etaNewPtr_;
 
      // Pointer to old random displacements
      DArray< RFieldT >* etaOldPtr_;
 
      // Prefactor of -dc_ in deterministic drift term
      double mobility_;
 
      // Number of BD steps per MC move.
      double nStep_;
 
      // Private member functions
 
      RFieldT& etaNew(int i)
      {  return (*etaNewPtr_)[i]; }
 
      RFieldT& etaOld(int i)
      {  return (*etaOldPtr_)[i]; }

      void generateEtaNew();

      void exchangeOldNew();
 
   };
 
}
}
#endif