ComputeMomentumMapping.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_COMPUTEMOMENTUMMAPPING_H_
#define _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_COMPUTEMOMENTUMMAPPING_H_
 
#include "coupling/interface/MDSolverInterface.h"
#include "coupling/interface/Molecule.h"
#include <iostream>
 
namespace coupling {
namespace cellmappings {
template <class LinkedCell, unsigned int dim> class ComputeMomentumMapping;
}
} // namespace coupling

template <class LinkedCell, unsigned int dim> class coupling::cellmappings::ComputeMomentumMapping {
public:
  ComputeMomentumMapping(coupling::interface::MDSolverInterface<LinkedCell, dim>* const mdSolverInterface)
      : _mdSolverInterface(mdSolverInterface), _momentum(0.0), _meanVelocity(0.0), _particleCounter(0) {}

  ~ComputeMomentumMapping() {}

  void beginCellIteration() {
    _momentum = tarch::la::Vector<dim, double>(0.0);
    _meanVelocity = tarch::la::Vector<dim, double>(0.0);
    _particleCounter = 0;
  }

  void endCellIteration() {
    if (_particleCounter != 0) {
      _meanVelocity = (1.0 / ((double)_particleCounter)) * _momentum;
      _momentum = _mdSolverInterface->getMoleculeMass() * _momentum;
    }
  }

  void handleCell(LinkedCell& cell) {
    coupling::interface::MoleculeIterator<LinkedCell, dim>* it = _mdSolverInterface->getMoleculeIterator(cell);
    it->begin();
    while (it->continueIteration()) {
      const coupling::interface::Molecule<dim>& wrapper(it->getConst());
      _momentum += wrapper.getVelocity();
      _particleCounter++;
 
      it->next();
    }
    delete it;
  }

  tarch::la::Vector<dim, double> getMomentum() const { return _momentum; }

  tarch::la::Vector<dim, double> getMeanVelocity() const { return _meanVelocity; }
 
private:
  coupling::interface::MDSolverInterface<LinkedCell, dim>* const _mdSolverInterface;
  tarch::la::Vector<dim, double> _momentum;
  tarch::la::Vector<dim, double> _meanVelocity;
  unsigned int _particleCounter;
};
#endif // _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_COMPUTEMOMENTUMMAPPING_H_