AveragingTransferStrategy.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_TRANSFERSTRATEGIES_AVERAGINGTRANSFERSTRATEGY_H_
#define _MOLECULARDYNAMICS_COUPLING_TRANSFERSTRATEGIES_AVERAGINGTRANSFERSTRATEGY_H_
 
#include "coupling/cell-mappings/ComputeMassMapping.h"
#include "coupling/cell-mappings/ComputeMomentumMapping.h"
#include "coupling/indexing/IndexingService.h"
#include "coupling/transferstrategies/TransferStrategy.h"
#include <list>
#include <map>
 
namespace coupling {
namespace transferstrategies {
template <class LinkedCell, unsigned int dim> class AveragingTransferStrategy;
}
} // namespace coupling

template <class LinkedCell, unsigned int dim>
class coupling::transferstrategies::AveragingTransferStrategy : public coupling::transferstrategies::TransferStrategy<LinkedCell, dim> {
public:
  AveragingTransferStrategy(coupling::interface::MDSolverInterface<LinkedCell, dim>* const mdSolverInterface)
      : coupling::transferstrategies::TransferStrategy<LinkedCell, dim>(mdSolverInterface), _massMapping(mdSolverInterface),
        _momentumMapping(mdSolverInterface), _sampleCounter(0), _rank(IDXS.getRank()) {}

  virtual ~AveragingTransferStrategy() {}

  void beginProcessInnerCouplingCellsBeforeReceivingMacroscopicSolverData() override {
    // reset sample counter for each coupling cycle
    _sampleCounter = 0;
  }

  void processInnerCouplingCellBeforeReceivingMacroscopicSolverData(coupling::datastructures::CouplingCellWithLinkedCells<LinkedCell, dim>& cell,
                                                                    I02 index) override {
    // reset buffers for sampling mass and momentum in each inner coupling
    // cell
    cell.setMacroscopicMass(0.0);
    cell.setMacroscopicMomentum(tarch::la::Vector<dim, double>(0.0));
  }

  void beginProcessInnerCouplingCellsAfterMDTimestep() override {
    // output information of last sampling...
    if (_rank == 0) {
      std::cout << "Global quantities of sampling no. " << _sampleCounter << " on rank 0: mass=" << _avgMass << ", momentum=" << _avgMomentum << std::endl;
    }
    // reset avg. mass and momentum...
    _avgMass = 0.0;
    _avgMomentum = tarch::la::Vector<dim, double>(0.0);
    // and increment sample counter
    _sampleCounter++;
  }

  void processInnerCouplingCellAfterMDTimestep(coupling::datastructures::CouplingCellWithLinkedCells<LinkedCell, dim>& cell, I02 index) override {
    // compute total mass/momentum from previous samples
    const double oldMass = (_sampleCounter - 1) * cell.getMacroscopicMass();
    const tarch::la::Vector<dim, double> oldMomentum = ((double)(_sampleCounter - 1)) * cell.getMacroscopicMomentum();
 
    // compute new averaged mass and momentum
    cell.iterateConstCells(_massMapping);
    cell.iterateConstCells(_momentumMapping);
    const double mass = (1.0 / _sampleCounter) * (oldMass + _massMapping.getMass());
    const tarch::la::Vector<dim, double> momentum = (1.0 / _sampleCounter) * (oldMomentum + _momentumMapping.getMomentum());
    _avgMass += mass;
    _avgMomentum = _avgMomentum + momentum;
    // set mass and momentum in buffers
    cell.setMacroscopicMass(mass);
    cell.setMacroscopicMomentum(momentum);
  }
 
private:
  coupling::cellmappings::ComputeMassMapping<LinkedCell, dim> _massMapping;
  coupling::cellmappings::ComputeMomentumMapping<LinkedCell, dim> _momentumMapping;
  unsigned int _sampleCounter;
  const unsigned int _rank;
  tarch::la::Vector<dim, double> _avgMomentum;
  double _avgMass;
};
#endif // _MOLECULARDYNAMICS_COUPLING_TRANSFERSTRATEGIES_AVERAGINGTRANSFERSTRATEGY_H_