#include "MergeClusterAlg.h"

Public Member Functions
	MergeClusterAlg (fhicl::ParameterSet const &pset)

void	FindClusterEndPoints (art::PtrVector< recob::Hit > const &cluster, TVector2 const &centre, TVector2 const &direction, TVector2 &start, TVector2 &end) const

double	FindClusterOverlap (TVector2 const &direction, TVector2 const &centre, TVector2 const &start1, TVector2 const &end1, TVector2 const &start2, TVector2 const &end2) const

double	FindCrossingDistance (TVector2 const &direction1, TVector2 const &centre1, TVector2 const &direction2, TVector2 const &centre2) const

double	FindMinSeparation (art::PtrVector< recob::Hit > const &cluster1, art::PtrVector< recob::Hit > const &cluster2) const

double	FindProjectedWidth (TVector2 const &centre1, TVector2 const &start1, TVector2 const &end1, TVector2 const &centre2, TVector2 const &start2, TVector2 const &end2) const

double	GlobalWire (geo::WireID const &wireID) const

TVector2	HitCoordinates (art::Ptr< recob::Hit > const &hit) const

int	MergeClusters (std::vector< art::PtrVector< recob::Hit >> const &planeClusters, std::vector< art::PtrVector< recob::Hit >> &clusters) const

bool	PassCuts (double angle, double crossingDistance, double projectedWidth, double separation, double longLength) const

Private Attributes
unsigned int	fMinMergeClusterSize

double	fMaxMergeSeparation

double	fProjWidthThreshold

art::ServiceHandle< art::TFileService const >	tfs

geo::WireReadoutGeom const *	fWireReadoutGeom

std::map< int, int >	trueClusterMap

TTree *	fTree

double	fAngle

double	fEigenvalue

int	fCluster1Size

int	fCluster2Size

double	fLength1

double	fLength2

double	fSeparation

double	fCrossingDistance

double	fProjectedWidth

double	fOverlap

bool	fTrueMerge

Detailed Description

Definition at line 38 of file MergeClusterAlg.h.

Constructor & Destructor Documentation

cluster::MergeClusterAlg::MergeClusterAlg ( fhicl::ParameterSet const & pset )

Definition at line 19 of file MergeClusterAlg.cxx.

References fAngle, fCluster1Size, fCluster2Size, fCrossingDistance, fEigenvalue, fLength1, fLength2, fMaxMergeSeparation, fMinMergeClusterSize, fOverlap, fProjectedWidth, fProjWidthThreshold, fSeparation, fTree, fTrueMerge, Get, and tfs.

   : fWireReadoutGeom{&art::ServiceHandle<geo::WireReadout const>()->Get()}
 {
   fMinMergeClusterSize = pset.get<int>("MinMergeClusterSize");
   fMaxMergeSeparation = pset.get<double>("MaxMergeSeparation");
   fProjWidthThreshold = pset.get<double>("ProjWidthThreshold");
   fTree = tfs->make<TTree>("MatchingVariables", "MatchingVariables");
   fTree->Branch("Angle", &fAngle);
   fTree->Branch("Eigenvalue", &fEigenvalue);
   fTree->Branch("Cluster1Size", &fCluster1Size);
   fTree->Branch("Cluster2Size", &fCluster2Size);
   fTree->Branch("Length1", &fLength1);
   fTree->Branch("Length2", &fLength2);
   fTree->Branch("Separation", &fSeparation);
   fTree->Branch("CrossingDistance", &fCrossingDistance);
   fTree->Branch("ProjectedWidth", &fProjectedWidth);
   fTree->Branch("Overlap", &fOverlap);
   fTree->Branch("TrueMerge", &fTrueMerge);
 }

Member Function Documentation

void cluster::MergeClusterAlg::FindClusterEndPoints	(	art::PtrVector< recob::Hit > const &	cluster,
		TVector2 const &	centre,
		TVector2 const &	direction,
		TVector2 &	start,
		TVector2 &	end
	)		const

Find estimates of cluster start/end points

Definition at line 39 of file MergeClusterAlg.cxx.

References HitCoordinates().

Referenced by MergeClusters().

 {
 
   std::map<double, TVector2> hitProjection;
 
   // Project all hits onto line to determine end points
   for (auto& hit : cluster) {
     TVector2 pos = HitCoordinates(hit) - centre;
     hitProjection[direction * pos] = pos;
   }
 
   // Project end points onto line which passes through centre of cluster
   start = hitProjection.begin()->second.Proj(direction) + centre;
   end = hitProjection.rbegin()->second.Proj(direction) + centre;
 }

double cluster::MergeClusterAlg::FindClusterOverlap	(	TVector2 const &	direction,
		TVector2 const &	centre,
		TVector2 const &	start1,
		TVector2 const &	end1,
		TVector2 const &	start2,
		TVector2 const &	end2
	)		const

Calculates the overlap of the clusters on the line projected between them

Definition at line 60 of file MergeClusterAlg.cxx.

References tmp.

 {
 
   double clusterOverlap = 0;
 
   // Project onto the average direction through both clusters
   double s1 = (start1 - centre) * direction;
   double e1 = (end1 - centre) * direction;
   double s2 = (start2 - centre) * direction;
   double e2 = (end2 - centre) * direction;
 
   // Make sure end > start
   if (s1 > e1) {
     std::cout << "s1>e1: " << s1 << " and " << e1 << std::endl;
     double tmp = e1;
     e1 = s1;
     s1 = tmp;
   }
   if (s2 > e2) {
     std::cout << "s1>e1: " << s1 << " and " << e1 << std::endl;
     double tmp = e2;
     e2 = s2;
     s2 = tmp;
   }
 
   // Find the overlap of the clusters on the centre line
   if ((e1 > s2) && (e2 > s1)) clusterOverlap = std::min((e1 - s2), (e2 - s1));
 
   return clusterOverlap;
 }

double cluster::MergeClusterAlg::FindCrossingDistance	(	TVector2 const &	direction1,
		TVector2 const &	centre1,
		TVector2 const &	direction2,
		TVector2 const &	centre2
	)		const

Finds the distance between the crossing point of the lines and the closest line centre

Definition at line 97 of file MergeClusterAlg.cxx.

Referenced by MergeClusters().

 {
 
   // Find intersection point of two lines drawn through the centre of the clusters
   double dcross = (direction1.X() * direction2.Y()) - (direction1.Y() * direction2.X());
   TVector2 p = centre2 - centre1;
   double pcrossd = (p.X() * direction2.Y()) - (p.Y() * direction2.X());
   TVector2 crossing = centre1 + ((pcrossd / dcross) * direction1);
 
   // Get distance from this point to the clusters
   return std::min((centre1 - crossing).Mod(), (centre2 - crossing).Mod());
 }

double cluster::MergeClusterAlg::FindMinSeparation	(	art::PtrVector< recob::Hit > const &	cluster1,
		art::PtrVector< recob::Hit > const &	cluster2
	)		const

Calculates the minimum separation between two clusters

Definition at line 114 of file MergeClusterAlg.cxx.

References HitCoordinates().

Referenced by MergeClusters().

 {
 
   double minDistance = 99999.;
 
   // Loop over the two clusters to find the smallest distance
   for (auto const& hit1 : cluster1) {
     for (auto const& hit2 : cluster2) {
 
       TVector2 pos1 = HitCoordinates(hit1);
       TVector2 pos2 = HitCoordinates(hit2);
 
       double distance = (pos1 - pos2).Mod();
 
       if (distance < minDistance) minDistance = distance;
     }
   }
 
   return minDistance;
 }

double cluster::MergeClusterAlg::FindProjectedWidth	(	TVector2 const &	centre1,
		TVector2 const &	start1,
		TVector2 const &	end1,
		TVector2 const &	centre2,
		TVector2 const &	start2,
		TVector2 const &	end2
	)		const

Projects clusters parallel to the line which runs through their centres and finds the minimum containing width

Definition at line 137 of file MergeClusterAlg.cxx.

Referenced by MergeClusters().

 {
 
   // Get the line running through the centre of the two clusters
   TVector2 parallel = (centre2 - centre1).Unit();
   TVector2 perpendicular = parallel.Rotate(TMath::Pi() / 2);
 
   // Project the cluster vector onto this perpendicular line
   double s1 = (start1 - centre1) * perpendicular;
   double e1 = (end1 - centre1) * perpendicular;
   double s2 = (start2 - centre2) * perpendicular;
   double e2 = (end2 - centre2) * perpendicular;
 
   // Find the width in each direction
   double projectionStart = std::max(TMath::Abs(s1), TMath::Abs(s2));
   double projectionEnd = std::max(TMath::Abs(e1), TMath::Abs(e2));
 
   return projectionStart + projectionEnd; // FIXME (KJK): Really?  The width is the start + the end?
 }

double cluster::MergeClusterAlg::GlobalWire ( geo::WireID const & wireID ) const

Find the global wire position

Definition at line 163 of file MergeClusterAlg.cxx.

References geo::CryostatID::Cryostat, fWireReadoutGeom, geo::WireGeo::GetCenter(), geo::kInduction, geo::WireReadoutGeom::Nwires(), geo::WireReadoutGeom::Plane(), geo::PlaneID::Plane, geo::WireReadoutGeom::SignalType(), geo::TPCID::TPC, geo::WireReadoutGeom::Wire(), geo::WireID::Wire, and geo::PlaneGeo::WireCoordinate().

Referenced by HitCoordinates().

 {
 
   auto const wireCenter = fWireReadoutGeom->Wire(wireID).GetCenter();
   geo::PlaneID const planeID{wireID.Cryostat, wireID.TPC % 2, wireID.Plane};
 
   if (fWireReadoutGeom->SignalType(wireID) == geo::kInduction) {
     return fWireReadoutGeom->Plane(planeID).WireCoordinate(wireCenter);
   }
   return wireID.Wire + ((wireID.TPC / 2) * fWireReadoutGeom->Nwires(planeID));
 }

TVector2 cluster::MergeClusterAlg::HitCoordinates ( art::Ptr< recob::Hit > const & hit ) const

Return the coordinates of this hit in global wire/tick space

Definition at line 176 of file MergeClusterAlg.cxx.

References GlobalWire(), recob::Hit::PeakTime(), and recob::Hit::WireID().

Referenced by FindClusterEndPoints(), FindMinSeparation(), and MergeClusters().

 {
   return TVector2(GlobalWire(hit->WireID()), hit->PeakTime());
 }

int cluster::MergeClusterAlg::MergeClusters	(	std::vector< art::PtrVector< recob::Hit >> const &	planeClusters,
		std::vector< art::PtrVector< recob::Hit >> &	clusters
	)		const

Merges clusters which lie along a straight line

Definition at line 182 of file MergeClusterAlg.cxx.

References art::PtrVector< T >::at(), FindClusterEndPoints(), FindCrossingDistance(), FindMinSeparation(), FindProjectedWidth(), fMaxMergeSeparation, fMinMergeClusterSize, HitCoordinates(), hits(), PassCuts(), and art::PtrVector< T >::size().

Referenced by cluster::BlurredClustering::produce().

 {
 
   std::vector<unsigned int> mergedClusters;
 
   std::vector<art::PtrVector<recob::Hit>> oldClusters = planeClusters;
 
   // Sort the clusters by size
   std::sort(oldClusters.begin(),
             oldClusters.end(),
             [](const art::PtrVector<recob::Hit>& a, const art::PtrVector<recob::Hit>& b) {
               return a.size() > b.size();
             });
 
   // Find the numbers of clusters above size threshold
   unsigned int nclusters = 0;
   for (auto& cluster : oldClusters)
     if (cluster.size() >= fMinMergeClusterSize) ++nclusters;
 
   // Until all clusters are merged, create new clusters
   bool mergedAllClusters = false;
   while (!mergedAllClusters) {
 
     // New cluster
     art::PtrVector<recob::Hit> cluster;
 
     // Put the largest unmerged cluster in this new cluster
     for (unsigned int initCluster = 0; initCluster < oldClusters.size(); ++initCluster) {
       if (oldClusters.at(initCluster).size() < fMinMergeClusterSize or
           std::find(mergedClusters.begin(), mergedClusters.end(), initCluster) !=
             mergedClusters.end())
         continue;
       cluster = oldClusters.at(initCluster);
       mergedClusters.push_back(initCluster);
       break;
     }
 
     // Merge all aligned clusters to this
     bool mergedAllToThisCluster = false;
     while (!mergedAllToThisCluster) {
 
       // Look at all clusters and merge
       int nadded = 0;
       for (unsigned int trialCluster = 0; trialCluster < oldClusters.size(); ++trialCluster) {
 
         if (oldClusters.at(trialCluster).size() < fMinMergeClusterSize or
             std::find(mergedClusters.begin(), mergedClusters.end(), trialCluster) !=
               mergedClusters.end())
           continue;
 
         // Calculate the PCA for each
         TPrincipal *pca1 = new TPrincipal(2, ""), *pca2 = new TPrincipal(2, "");
         double hits[2];
         TVector2 pos;
 
         // Cluster centre
         TVector2 chargePoint1 = TVector2(0, 0), chargePoint2 = TVector2(0, 0);
         double totalCharge1 = 0, totalCharge2 = 0;
 
         for (auto& hit1 : cluster) {
           pos = HitCoordinates(hit1);
           hits[0] = pos.X();
           hits[1] = pos.Y();
           pca1->AddRow(hits);
           chargePoint1 += hit1->Integral() * pos;
           totalCharge1 += hit1->Integral();
         }
         for (auto& hit2 : oldClusters.at(trialCluster)) {
           pos = HitCoordinates(hit2);
           hits[0] = pos.X();
           hits[1] = pos.Y();
           pca2->AddRow(hits);
           chargePoint2 += hit2->Integral() * pos;
           totalCharge2 += hit2->Integral();
         }
 
         pca1->MakePrincipals();
         pca2->MakePrincipals();
 
         // Properties of these clusters
         TVector2 direction1 =
           TVector2((*pca1->GetEigenVectors())[0][0], (*pca1->GetEigenVectors())[1][0]).Unit();
         TVector2 direction2 =
           TVector2((*pca2->GetEigenVectors())[0][0], (*pca2->GetEigenVectors())[1][0]).Unit();
         TVector2 direction = ((direction1 + direction2) / 2).Unit();
         TVector2 centre1 = chargePoint1 / totalCharge1;
         TVector2 centre2 = chargePoint2 / totalCharge2;
         TVector2 centre = (centre1 + centre2) / 2;
         TVector2 start1, end1;
         TVector2 start2, end2;
         FindClusterEndPoints(cluster, centre1, direction1, start1, end1);
         FindClusterEndPoints(oldClusters.at(trialCluster), centre2, direction2, start2, end2);
         double length1 = (end1 - start1).Mod();
         double length2 = (end2 - start2).Mod();
 
         // Properties of the pair of clusters
         double crossingDistance = FindCrossingDistance(direction1, centre1, direction2, centre2);
         double projectedWidth = FindProjectedWidth(centre1, start1, end1, centre2, start2, end2);
         double angle = direction1.DeltaPhi(direction2);
         if (angle > 1.57) angle = 3.14159 - angle;
         double separation = FindMinSeparation(cluster, oldClusters.at(trialCluster));
 
         if (separation > fMaxMergeSeparation) continue;
         if (PassCuts(
               angle, crossingDistance, projectedWidth, separation, TMath::Max(length1, length2))) {
 
           for (auto& hit : oldClusters.at(trialCluster))
             cluster.push_back(hit);
 
           mergedClusters.push_back(trialCluster);
           ++nadded;
         }
 
         delete pca1;
         delete pca2;
 
       } // loop over clusters to add
 
       if (nadded == 0) mergedAllToThisCluster = true;
 
     } // while loop
 
     clusters.push_back(cluster);
     if (mergedClusters.size() == nclusters) mergedAllClusters = true;
   }
 
   return clusters.size();
 }

bool cluster::MergeClusterAlg::PassCuts	(	double	angle,
		double	crossingDistance,
		double	projectedWidth,
		double	separation,
		double	longLength
	)		const

Boolean function which decides whether or not two clusters should be merged, depending on their properties

Definition at line 314 of file MergeClusterAlg.cxx.

References fProjWidthThreshold.

Referenced by MergeClusters().

 {
 
   bool passCrossingDistanceAngle = false;
   if (crossingDistance < (-2 + (5 / (1 * TMath::Abs(angle)) - 0))) passCrossingDistanceAngle = true;
 
   bool passSeparationAngle = false;
   if (separation < (200 * TMath::Abs(angle) + 40)) passSeparationAngle = true;
 
   bool passProjectedWidth = false;
   if (((double)projectedWidth / (double)longLength) < fProjWidthThreshold)
     passProjectedWidth = true;
 
   return passCrossingDistanceAngle and passSeparationAngle and passProjectedWidth;
 }