#include <CaloGeometryHelper.h>

Inheritance diagram for CaloGeometryHelper:

Public Types
typedef math::XYZVector	XYZPoint
typedef math::XYZVector	XYZVector
Public Member Functions
bool	borderCrossing (const DetId &, const DetId &) const
void	buildCrystal (const DetId &id, Crystal &) const
	CaloGeometryHelper (const edm::ParameterSet &fastCalo)
	CaloGeometryHelper ()
DetId	getClosestCell (const XYZPoint &point, bool ecal, bool central) const
const std::vector< DetId > &	getNeighbours (const DetId &det) const
void	getWindow (const DetId &pivot, int s1, int s2, std::vector< DetId > &) const
void	initialize (double bField)
double	magneticField () const
bool	move (DetId &cell, const CaloDirection &dir, bool fast=true) const
bool	preshowerPresent () const
double	preshowerZPosition (int layer) const
	~CaloGeometryHelper ()
Private Member Functions
void	buildCrystalArray ()
void	buildNeighbourArray ()
bool	diagonalmove (DetId &cell, const CaloDirection &dir) const
bool	simplemove (DetId &cell, const CaloDirection &dir) const
Private Attributes
std::vector< BaseCrystal >	barrelCrystals_
std::vector< std::vector< DetId > >	barrelNeighbours_
double	bfield_
std::vector< BaseCrystal >	endcapCrystals_
std::vector< std::vector< DetId > >	endcapNeighbours_
bool	neighbourmapcalculated_
bool	preshowerPresent_
double	psLayer1Z_
double	psLayer2Z_

Detailed Description

Definition at line 17 of file CaloGeometryHelper.h.

Member Typedef Documentation

typedef math::XYZVector CaloGeometryHelper::XYZPoint

Definition at line 23 of file CaloGeometryHelper.h.

typedef math::XYZVector CaloGeometryHelper::XYZVector

Definition at line 22 of file CaloGeometryHelper.h.

Constructor & Destructor Documentation

CaloGeometryHelper::CaloGeometryHelper ( )

Definition at line 25 of file CaloGeometryHelper.cc.

References neighbourmapcalculated_, psLayer1Z_, and psLayer2Z_.

                                      :Calorimeter()
{
  neighbourmapcalculated_= false;
  psLayer1Z_ = 303;
  psLayer2Z_ = 307;
}

CaloGeometryHelper::CaloGeometryHelper ( const edm::ParameterSet & fastCalo )

Definition at line 32 of file CaloGeometryHelper.cc.

References psLayer1Z_, and psLayer2Z_.

                                                                     :Calorimeter(fastCalo)
{
  //  std::cout << " In the constructor with ParameterSet " << std::endl;
  psLayer1Z_ = 303;
  psLayer2Z_ = 307;
}

CaloGeometryHelper::~CaloGeometryHelper ( )

Definition at line 61 of file CaloGeometryHelper.cc.

{;
}

Member Function Documentation

bool CaloGeometryHelper::borderCrossing	(	const DetId &	c1,
		const DetId &	c2
	)		const

Definition at line 427 of file CaloGeometryHelper.cc.

References EcalBarrel, EcalEndcap, EBDetId::im(), EEDetId::isc(), EBDetId::ism(), and DetId::subdetId().

Referenced by EcalHitMaker::buildSegments(), and EcalHitMaker::configureGeometry().

{
  if(c1.subdetId()!=c2.subdetId()) return false;

  if(c1.subdetId()==EcalBarrel)
    {
      // there is a crack if the two cells don't belong to the same 
      // module
      EBDetId cc1(c1);
      EBDetId cc2(c2);
      return (cc1.im()!=cc2.im()||cc1.ism()!=cc2.ism() );
    }
  
if(c1.subdetId()==EcalEndcap)
    {
      // there is a crack if the two cells don't belong to the same 
      // module
      return (EEDetId(c1).isc()!=EEDetId(c2).isc());
    }
 return false;
}

void CaloGeometryHelper::buildCrystal	(	const DetId &	id,
		Crystal &	xtal
	)		const

Definition at line 172 of file CaloGeometryHelper.cc.

References barrelCrystals_, EcalBarrel, EcalEndcap, endcapCrystals_, ecalpyutils::hashedIndex(), and DetId::subdetId().

Referenced by EcalHitMaker::buildGeometry(), and EcalHitMaker::EcalHitMaker().

{
  if(cell.subdetId()==EcalBarrel)
    {
      xtal=Crystal(cell,&barrelCrystals_[EBDetId(cell).hashedIndex()]);
      return;
    }
  if(cell.subdetId()==EcalEndcap)
    {
      xtal=Crystal(cell,&endcapCrystals_[EEDetId(cell).hashedIndex()]);
      return;
    }     
}

void CaloGeometryHelper::buildCrystalArray ( ) [private]

Definition at line 449 of file CaloGeometryHelper.cc.

References barrelCrystals_, DetId::Ecal, EcalBarrel, Calorimeter::EcalBarrelGeometry_, EcalEndcap, Calorimeter::EcalEndcapGeometry_, endcapCrystals_, relativeConstraints::geom, CaloCellGeometry::getCorners(), CaloSubdetectorGeometry::getGeometry(), CaloCellGeometry::getPosition(), CaloSubdetectorGeometry::getValidDetIds(), EEDetId::hashedIndex(), EBDetId::hashedIndex(), EBDetId::kSizeForDenseIndexing, EEDetId::kSizeForDenseIndexing, BaseCrystal::setCorners(), and findQualityFiles::size.

Referenced by initialize().

{
  const unsigned nbarrel = EBDetId::kSizeForDenseIndexing;
  // Barrel first. The hashed index runs from 0 to 61199
  barrelCrystals_.resize(nbarrel,BaseCrystal());

  //std::cout << " Building the array of crystals (barrel) " ;
  const std::vector<DetId>&  vec(EcalBarrelGeometry_->getValidDetIds(DetId::Ecal,EcalBarrel));
  unsigned size=vec.size();    
  const CaloCellGeometry * geom=0;
  for(unsigned ic=0; ic<size; ++ic) 
    {
      unsigned hashedindex=EBDetId(vec[ic]).hashedIndex();
      geom = EcalBarrelGeometry_->getGeometry(vec[ic]);
      BaseCrystal xtal(vec[ic]);
      xtal.setCorners(geom->getCorners(),geom->getPosition());
      barrelCrystals_[hashedindex]=xtal;
    }
  
  //  std::cout << " done " << size << std::endl;
  //  std::cout << " Building the array of crystals (endcap) " ;
  

  const std::vector<DetId>&  vece(EcalEndcapGeometry_->getValidDetIds(DetId::Ecal,EcalEndcap));
  size=vece.size();    
  // There are some holes in the hashedIndex for the EE. Hence the array is bigger than the number
  // of crystals
  const unsigned nendcap=EEDetId::kSizeForDenseIndexing;

  endcapCrystals_.resize(nendcap,BaseCrystal());
  for(unsigned ic=0; ic<size; ++ic) 
    {
      unsigned hashedindex=EEDetId(vece[ic]).hashedIndex();
      geom = EcalEndcapGeometry_->getGeometry(vece[ic]);
      BaseCrystal xtal(vece[ic]);
      xtal.setCorners(geom->getCorners(),geom->getPosition());
      endcapCrystals_[hashedindex]=xtal;
    }
  //  std::cout << " done " << size << std::endl;
}

void CaloGeometryHelper::buildNeighbourArray ( ) [private]

Definition at line 187 of file CaloGeometryHelper.cc.

References barrelNeighbours_, EAST, DetId::Ecal, EcalBarrel, Calorimeter::EcalBarrelGeometry_, Calorimeter::EcalBarrelTopology_, EcalEndcap, Calorimeter::EcalEndcapGeometry_, Calorimeter::EcalEndcapTopology_, endcapNeighbours_, CaloSubdetectorGeometry::getValidDetIds(), CaloSubdetectorTopology::getWindow(), EEDetId::hashedIndex(), EBDetId::hashedIndex(), recoMuon::in, EBDetId::kSizeForDenseIndexing, EEDetId::kSizeForDenseIndexing, LogDebug, move(), neighbourmapcalculated_, NORTH, NORTHEAST, NORTHWEST, findQualityFiles::size, SOUTH, SOUTHEAST, SOUTHWEST, ntuplemaker::status, and WEST.

Referenced by initialize().

{

  static const CaloDirection orderedDir[8]={SOUTHWEST,SOUTH,SOUTHEAST,WEST,EAST,NORTHWEST,NORTH,
                                            NORTHEAST};

  const unsigned nbarrel = EBDetId::kSizeForDenseIndexing;
  // Barrel first. The hashed index runs from 0 to 61199
  barrelNeighbours_.resize(nbarrel);
  
  //std::cout << " Building the array of neighbours (barrel) " ;

  const std::vector<DetId>&  vec(EcalBarrelGeometry_->getValidDetIds(DetId::Ecal,EcalBarrel));
  unsigned size=vec.size();    
  for(unsigned ic=0; ic<size; ++ic) 
    {
      // We get the 9 cells in a square. 
      std::vector<DetId> neighbours(EcalBarrelTopology_->getWindow(vec[ic],3,3));
      //      std::cout << " Cell " << EBDetId(vec[ic]) << std::endl;
      unsigned nneighbours=neighbours.size();

      unsigned hashedindex=EBDetId(vec[ic]).hashedIndex();
      if(hashedindex>=nbarrel)
        {
          LogDebug("CaloGeometryTools")  << " Array overflow " << std::endl;
        }


      // If there are 9 cells, it is easy, and this order is know:
//      6  7  8
//      3  4  5 
//      0  1  2   (0 = SOUTHWEST)

      if(nneighbours==9)
        {
          barrelNeighbours_[hashedindex].reserve(8);
          for(unsigned in=0;in<nneighbours;++in)
            {
              // remove the centre
              if(neighbours[in]!=vec[ic]) 
                {
                  barrelNeighbours_[hashedindex].push_back(neighbours[in]);
                  //          std::cout << " Neighbour " << in << " " << EBDetId(neighbours[in]) << std::endl;
                }
            }
        }
      else
        {
          DetId central(vec[ic]);
          barrelNeighbours_[hashedindex].resize(8,DetId(0));
          for(unsigned idir=0;idir<8;++idir)
            {
              DetId testid=central;
              bool status=move(testid,orderedDir[idir],false);
              if(status) barrelNeighbours_[hashedindex][idir]=testid;
            }

        }
    }

  // Moved to the endcap

  //  std::cout << " done " << size << std::endl;
  //  std::cout << " Building the array of neighbours (endcap) " ;


  const std::vector<DetId> & vece(EcalEndcapGeometry_->getValidDetIds(DetId::Ecal,EcalEndcap));
  size=vece.size();    
  // There are some holes in the hashedIndex for the EE. Hence the array is bigger than the number
  // of crystals
  const unsigned nendcap=EEDetId::kSizeForDenseIndexing;

  endcapNeighbours_.resize(nendcap);
  for(unsigned ic=0; ic<size; ++ic) 
    {
      // We get the 9 cells in a square. 
      std::vector<DetId> neighbours(EcalEndcapTopology_->getWindow(vece[ic],3,3));
      unsigned nneighbours=neighbours.size();
      // remove the centre
      unsigned hashedindex=EEDetId(vece[ic]).hashedIndex();
      
      if(hashedindex>=nendcap)
        {
          LogDebug("CaloGeometryTools")  << " Array overflow " << std::endl;
        }

      if(nneighbours==9)
        {
          endcapNeighbours_[hashedindex].reserve(8);
          for(unsigned in=0;in<nneighbours;++in)
            {     
              // remove the centre
              if(neighbours[in]!=vece[ic]) 
                {
                  endcapNeighbours_[hashedindex].push_back(neighbours[in]);
                }
            }
        }
      else
        {
          DetId central(vece[ic]);
          endcapNeighbours_[hashedindex].resize(8,DetId(0));
          for(unsigned idir=0;idir<8;++idir)
            {
              DetId testid=central;
              bool status=move(testid,orderedDir[idir],false);
              if(status) endcapNeighbours_[hashedindex][idir]=testid;
            }

        }
    }
  //  std::cout << " done " << size <<std::endl;
  neighbourmapcalculated_ = true;
}

bool CaloGeometryHelper::diagonalmove	(	DetId &	cell,
		const CaloDirection &	dir
	)		const `[private]`

Definition at line 363 of file CaloGeometryHelper.cc.

References EAST, NORTH, NORTHEAST, NORTHWEST, query::result, simplemove(), SOUTH, SOUTHEAST, SOUTHWEST, and WEST.

Referenced by move().

{
  bool result; 
  // One has to try both paths
  if(dir==NORTHEAST)
    {
      result = simplemove(cell,NORTH);
      if(result)
        return simplemove(cell,EAST);
      else
        {
          result = simplemove(cell,EAST);
          if(result)
            return simplemove(cell,NORTH);
          else
            return false; 
        }
    }
  else if(dir==NORTHWEST)
    {
      result = simplemove(cell,NORTH);
      if(result)
        return simplemove(cell,WEST);
      else
        {
          result = simplemove(cell,WEST);
          if(result)
            return simplemove(cell,NORTH);
          else
            return false; 
        }
    }
  else if(dir == SOUTHEAST)
    {
      result = simplemove(cell,SOUTH);
      if(result)
        return simplemove(cell,EAST);
      else
        {
          result = simplemove(cell,EAST);
          if(result)
            return simplemove(cell,SOUTH);
          else
            return false; 
        }
    }
  else if(dir == SOUTHWEST)
    {
      result = simplemove(cell,SOUTH);
      if(result)
        return simplemove(cell,WEST);
      else
        {
          result = simplemove(cell,SOUTH);
          if(result)
            return simplemove(cell,WEST);
          else
            return false; 
        }
    }
  cell = DetId(0);
  return false;
}

DetId CaloGeometryHelper::getClosestCell	(	const XYZPoint &	point,
		bool	ecal,
		bool	central
	)		const

in sync with BaseParticlePropagator

Definition at line 65 of file CaloGeometryHelper.cc.

References funct::cos(), HcalDetId::depth(), Calorimeter::EcalBarrelGeometry_, Calorimeter::EcalEndcapGeometry_, PV3DBase< T, PVType, FrameType >::eta(), Histos::fill(), first, CaloSubdetectorGeometry::getClosestCell(), EcalBarrelGeometry::getClosestCell(), EcalEndcapGeometry::getClosestCell(), CaloSubdetectorGeometry::getGeometry(), CaloCellGeometry::getPosition(), HcalEndcap, HcalForward, Calorimeter::HcalGeometry_, HcalDetId::ieta(), HcalDetId::ietaAbs(), Histos::instance(), HcalDetId::iphi(), DetId::null(), perp(), PV3DBase< T, PVType, FrameType >::phi(), query::result, edm::second(), mathSSE::sqrt(), and DetId::subdetId().

Referenced by HcalHitMaker::addHit(), EcalHitMaker::EcalHitMaker(), CalorimetryManager::EMShowerSimulation(), CalorimetryManager::HDShowerSimulation(), CalorimetryManager::MuonMipSimulation(), CalorimetryManager::reconstructECAL(), and CalorimetryManager::reconstructHCAL().

{
  DetId result;
  if(ecal)
    {
      if(central)
        {
          //      std::cout << "EcalBarrelGeometry_" << " " << EcalBarrelGeometry_ << std::endl;
          result = EcalBarrelGeometry_->getClosestCell(GlobalPoint(point.X(),point.Y(),point.Z()));
#ifdef DEBUGGCC
          if(result.null()) return result;
          GlobalPoint ip=GlobalPoint(point.X(),point.Y(),point.Z());
          GlobalPoint cc=EcalBarrelGeometry_->getGeometry(result)->getPosition();
          float deltaeta2 = ip.eta()-cc.eta();
          deltaeta2 *= deltaeta2;
          float deltaphi2 = acos(cos(ip.phi()-cc.phi()));
          deltaphi2 *= deltaphi2;
          Histos::instance()->fill("h100",point.eta(),sqrt(deltaeta2+deltaphi2));
#endif
        }
      else
        {
          result = EcalEndcapGeometry_->getClosestCell(GlobalPoint(point.X(),point.Y(),point.Z()));
#ifdef DEBUGGCC
          if(result.null()) 
            {
              return result;
            }
          GlobalPoint ip=GlobalPoint(point.X(),point.Y(),point.Z());
          GlobalPoint cc=EcalEndcapGeometry_->getGeometry(result)->getPosition();
          Histos::instance()->fill("h110",point.eta(),(ip-cc).perp());
#endif
        }
    }
  else
    {
      result=HcalGeometry_->getClosestCell(GlobalPoint(point.X(),point.Y(),point.Z()));
      HcalDetId myDetId(result);

      // special patch for HF
      if ( myDetId.subdetId() == HcalForward ) {
        int mylayer;
        if ( fabs(point.Z()) > 1132. ) {
          mylayer = 2;
        } else {
          mylayer = 1;
        }
        HcalDetId myDetId2((HcalSubdetector)myDetId.subdetId(),myDetId.ieta(),myDetId.iphi(),mylayer);
        result = myDetId2;
        return result;
      }


      if(result.subdetId()!=HcalEndcap) return result;
      // Special patch to correct the HCAL geometry
      if(myDetId.depth()==3) return result;

      int ieta=myDetId.ietaAbs();
      float azmin=400.458;         

      if(ieta<=17) 
        return result;
      else if(ieta>=18 && ieta<=26) 
        azmin += 35.0;    // don't consider ieta=18 nose separately
      else if(ieta>=27)
        azmin += 21.0;

      HcalDetId first(HcalEndcap,myDetId.ieta(),myDetId.iphi(),1);
      bool layer2=(fabs(point.Z())>azmin);
      if(!layer2)
        {
          return first;
        }
      else
        {
          HcalDetId second(HcalEndcap,myDetId.ieta(),myDetId.iphi(),2);
          if(second!=HcalDetId()) result=second;
        }
#ifdef DEBUGGCC
      if(result.null()) 
        {
          return result;
        }
      GlobalPoint ip=GlobalPoint(point.x(),point.y(),point.z());
      GlobalPoint cc=HcalGeometry_->getGeometry(result)->getPosition();
      float deltaeta2 = ip.eta()-cc.eta();
      deltaeta2 *= deltaeta2;
      float deltaphi2 = acos(cos(ip.phi()-cc.phi()));
      deltaphi2 *= deltaphi2;

      Histos::instance()->fill("h120",point.eta(),sqrt(deltaeta2+deltaphi2));
#endif
      
    }
  return result;
}

const std::vector< DetId > & CaloGeometryHelper::getNeighbours ( const DetId & det ) const

Definition at line 302 of file CaloGeometryHelper.cc.

References barrelNeighbours_, EcalBarrel, endcapNeighbours_, EEDetId::hashedIndex(), EBDetId::hashedIndex(), and DetId::subdetId().

Referenced by CrystalWindowMap::CrystalWindowMap().

{
  return (detid.subdetId()==EcalBarrel)?barrelNeighbours_[EBDetId(detid).hashedIndex()]:
    endcapNeighbours_[EEDetId(detid).hashedIndex()];
}

void CaloGeometryHelper::getWindow	(	const DetId &	pivot,
		int	s1,
		int	s2,
		std::vector< DetId > &	vec
	)		const

Definition at line 162 of file CaloGeometryHelper.cc.

References Calorimeter::getEcalGeometry(), Calorimeter::getEcalTopology(), python::multivaluedict::sort(), and DetId::subdetId().

Referenced by EcalHitMaker::EcalHitMaker().

{
  // currently the getWindow method is the same for EcalBarrelTopology and EndcapTopology
  // (implemented in CaloSubDetectorTopology)
  // optimized versions are foreseen 
  vec=getEcalTopology(pivot.subdetId())->getWindow(pivot,s1,s2);
  DistanceToCell distance(getEcalGeometry(pivot.subdetId()),pivot);
  sort(vec.begin(),vec.end(),distance);
}

void CaloGeometryHelper::initialize ( double bField )

Definition at line 39 of file CaloGeometryHelper.cc.

References ecalTB2006H4_GenSimDigiReco_cfg::bField, bfield_, buildCrystalArray(), buildNeighbourArray(), Calorimeter::getEcalPreshowerGeometry(), CaloSubdetectorGeometry::getGeometry(), CaloCellGeometry::getPosition(), LogDebug, preshowerPresent_, psLayer1Z_, psLayer2Z_, and PV3DBase< T, PVType, FrameType >::z().

Referenced by FamosManager::setupGeometryAndField().

{
  buildCrystalArray();
  buildNeighbourArray();
  bfield_ = bField;
  preshowerPresent_=(getEcalPreshowerGeometry()!=0);
    
  if(preshowerPresent_)
    {
      ESDetId cps1(getEcalPreshowerGeometry()->getClosestCellInPlane(GlobalPoint(80.,80.,303.),1));
      psLayer1Z_ = getEcalPreshowerGeometry()->getGeometry(cps1)->getPosition().z();
      ESDetId cps2(getEcalPreshowerGeometry()->getClosestCellInPlane(GlobalPoint(80.,80.,307.),2));
      psLayer2Z_ = getEcalPreshowerGeometry()->getGeometry(cps2)->getPosition().z();
      LogDebug("CaloGeometryTools")  << " Preshower layer positions " << psLayer1Z_ << " " << psLayer2Z_ << std::endl;
    }
  else
    LogDebug("CaloGeometryTools")  << " No preshower present" << std::endl;

  //  std::cout << " Preshower layer positions " << psLayer1Z_ << " " << psLayer2Z_ << std::endl;

}

double CaloGeometryHelper::magneticField ( ) const [inline]

Definition at line 50 of file CaloGeometryHelper.h.

References bfield_.

Referenced by EcalHitMaker::configureGeometry().

{return bfield_;}

bool CaloGeometryHelper::move	(	DetId &	cell,
		const CaloDirection &	dir,
		bool	fast = `true`
	)		const

Definition at line 308 of file CaloGeometryHelper.cc.

References barrelNeighbours_, diagonalmove(), dir, EAST, EcalBarrel, endcapNeighbours_, EEDetId::hashedIndex(), EBDetId::hashedIndex(), neighbourmapcalculated_, NONE, NORTH, NORTHEAST, NORTHWEST, DetId::null(), query::result, simplemove(), SOUTH, SOUTHEAST, SOUTHWEST, ntuplemaker::status, DetId::subdetId(), and WEST.

Referenced by buildNeighbourArray(), and EcalHitMaker::configureGeometry().

{  
  DetId originalcell = cell; 
  if(dir==NONE || cell==DetId(0)) return false;

  // Conversion CaloDirection and index in the table
  // CaloDirection :NONE,SOUTH,SOUTHEAST,SOUTHWEST,EAST,WEST, NORTHEAST,NORTHWEST,NORTH
  // Table : SOUTHWEST,SOUTH,SOUTHEAST,WEST,EAST,NORTHWEST,NORTH, NORTHEAST
  static const int calodirections[9]={-1,1,2,0,4,3,7,5,6};
    
  if(fast&&neighbourmapcalculated_)
    {
      DetId result = (originalcell.subdetId()==EcalBarrel) ? 
        barrelNeighbours_[EBDetId(originalcell).hashedIndex()][calodirections[dir]]:
        endcapNeighbours_[EEDetId(originalcell).hashedIndex()][calodirections[dir]];
      bool status =  !result.null();
      cell = result;
      return status; 
    }
  
  if(dir==NORTH || dir ==SOUTH || dir==EAST || dir==WEST)
    {
      return simplemove(cell,dir);
    }
  else
    {
      if(dir == NORTHEAST || dir==NORTHWEST || dir==SOUTHEAST || dir==SOUTHWEST)
        return diagonalmove(cell,dir);
    }
  
  cell = DetId(0);
  return false;
}

bool CaloGeometryHelper::preshowerPresent ( ) const [inline]

Definition at line 57 of file CaloGeometryHelper.h.

References preshowerPresent_.

Referenced by CalorimetryManager::reconstruct().

{return preshowerPresent_;};

double CaloGeometryHelper::preshowerZPosition ( int layer ) const [inline]

Definition at line 37 of file CaloGeometryHelper.h.

References psLayer1Z_, and psLayer2Z_.

Referenced by PreshowerHitMaker::addHit(), and PreshowerHitMaker::PreshowerHitMaker().

  {
    return (layer==1) ? psLayer1Z_: psLayer2Z_ ; 
  }

bool CaloGeometryHelper::simplemove	(	DetId &	cell,
		const CaloDirection &	dir
	)		const `[private]`

Definition at line 343 of file CaloGeometryHelper.cc.

References EcalBarrel, Calorimeter::EcalBarrelTopology_, EcalEndcap, Calorimeter::EcalEndcapTopology_, CaloSubdetectorTopology::getNeighbours(), and DetId::subdetId().

Referenced by diagonalmove(), and move().

{
  std::vector<DetId> neighbours;
  if(cell.subdetId()==EcalBarrel)
    neighbours = EcalBarrelTopology_->getNeighbours(cell,dir);
  else if(cell.subdetId()==EcalEndcap)
    neighbours= EcalEndcapTopology_->getNeighbours(cell,dir);
  
  if(neighbours.size()>0 && !neighbours[0].null())
    {
      cell = neighbours[0];
      return true;
    }
  else 
    {
      cell = DetId(0);
      return false;
    }
}