SetTemperatureMapping.h

// Copyright (C) 2015 Technische Universitaet Muenchen
// This file is part of the Mamico project. For conditions of distribution
// and use, please see the copyright notice in Mamico's main folder, or at
// www5.in.tum.de/mamico
#ifndef _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_SETTEMPERATUREMAPPING_H_
#define _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_SETTEMPERATUREMAPPING_H_
 
#include "coupling/interface/MDSolverInterface.h"
#include "coupling/interface/Molecule.h"
#include <cmath>
#include <iostream>
 
namespace coupling {
namespace cellmappings {
template <class LinkedCell, unsigned int dim> class SetTemperatureMapping;
}
} // namespace coupling

template <class LinkedCell, unsigned int dim> class coupling::cellmappings::SetTemperatureMapping {
public:
  SetTemperatureMapping(const double& oldTemperature, const double& newTemperature, const tarch::la::Vector<dim, double>& meanVelocity,
                        coupling::interface::MDSolverInterface<LinkedCell, dim>* const mdSolverInterface)
      : _mdSolverInterface(mdSolverInterface), _factor(getScalingFactor(oldTemperature, newTemperature)), _meanVelocity(meanVelocity) {}

  ~SetTemperatureMapping() {}

  void beginCellIteration() {}

  void endCellIteration() {}

  void handleCell(LinkedCell& cell) {
    coupling::interface::MoleculeIterator<LinkedCell, dim>* it = _mdSolverInterface->getMoleculeIterator(cell);
    it->begin();
    while (it->continueIteration()) {
      coupling::interface::Molecule<dim>& wrapper(it->get());
      tarch::la::Vector<dim, double> velocity = wrapper.getVelocity();
      // scale velocity
      velocity = _meanVelocity + _factor * (velocity - _meanVelocity);
      wrapper.setVelocity(velocity);
      it->next();
    }
    delete it;
  }
 
private:
  double getScalingFactor(const double& oldTemperature, const double& newTemperature) const {
 
    if (oldTemperature != 0.0) {
      return sqrt(newTemperature / oldTemperature);
    } else {
      return 1.0;
    }
  }
 
  coupling::interface::MDSolverInterface<LinkedCell, dim>* const _mdSolverInterface;
  const double _factor;
  const tarch::la::Vector<dim, double> _meanVelocity;
};
#endif // _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_SETTEMPERATUREMAPPING_H_