ActsTrk::StripSpacePointFormationTool Class Reference

#include <StripSpacePointFormationTool.h>

Inheritance diagram for ActsTrk::StripSpacePointFormationTool:

Collaboration diagram for ActsTrk::StripSpacePointFormationTool:

Public Member Functions
AthAlgTool methods
	StripSpacePointFormationTool (const std::string &type, const std::string &name, const IInterface *parent)
virtual	~StripSpacePointFormationTool ()=default
virtual StatusCode	initialize () override

Private Attributes
Id helpers
const SCT_ID *	m_stripId {}
tool handles
ToolHandle< ISiLorentzAngleTool >	m_lorentzAngleTool
	Using Lorentz angle tool.
Configuration flags
Gaudi::Property< bool >	m_allClusters {this, "AllClusters", false, "Process all clusters without limits."}
Gaudi::Property< bool >	m_useTopSp {this, "useTopSp", false, "SP global position is for second strip module."}
Gaudi::Property< bool >	m_isITk {this, "isITk", true, "True if running in ITk"}
Cut parameters
The following are ranges within which clusters must lie to make a spacepoint. Opposite and eta neighbours clusters must lie within range of each other. Phi clusters must lie in region of each wafer separately.
Gaudi::Property< float >	m_overlapLimitOpposite {this, "OverlapLimitOpposite", 2.8, "Overlap limit for opposite-neighbour."}
Gaudi::Property< float >	m_overlapLimitPhi {this, "OverlapLimitPhi", 5.64, "Overlap limit for phi-neighbours."}
Gaudi::Property< float >	m_overlapLimitEtaMin {this, "OverlapLimitEtaMin", 1.68, "Low overlap limit for eta-neighbours."}
Gaudi::Property< float >	m_overlapLimitEtaMax {this, "OverlapLimitEtaMax", 3.0, "High overlap limit for eta-neighbours."}
Gaudi::Property< float >	m_stripLengthTolerance {this, "StripLengthTolerance", 0.01}
	The following are parameters to build the space points.
Gaudi::Property< float >	m_stripGapParameter {this, "StripGapParameter", 0.0015, "Recommend 0.001 - 0.0015 for ITK geometry"}
Gaudi::Property< bool >	m_useSCTLayerDep_OverlapCuts {this,"useSCTLayerDep_OverlapCuts", true}
Gaudi::Property< bool >	m_useBeamSpotConstraint {this, "useBeamSpotConstraint", true, "Reject space points which are not compatible with a particle originating from the beamspot"}
	For applying geometric cuts on SPs using beamspot constraint.

Production of space points
virtual StatusCode	produceSpacePoints (const EventContext &ctx, const xAOD::StripClusterContainer &clusterContainer, const InDet::SiElementPropertiesTable &properties, const InDetDD::SiDetectorElementCollection &elements, const Amg::Vector3D &beamSpotVertex, std::vector< StripSP > &spacePoints, std::vector< StripSP > &overlapSpacePoints, bool processOverlaps, const std::vector< IdentifierHash > &hashesToProcess, const ContainerAccessor< xAOD::StripCluster, IdentifierHash, 1 > &stripAccessor) const override
StatusCode	fillStripSpacePoints (const std::array< const InDetDD::SiDetectorElement *, nNeighbours > &neighbourElements, const std::array< std::vector< std::pair< const xAOD::StripCluster *, size_t > >, nNeighbours > &neighbourClusters, const std::array< double, 14 > &overlapExtents, const Amg::Vector3D &beamSpotVertex, std::vector< StripSP > &spacePoints, std::vector< StripSP > &overlapSpacePoints) const
StatusCode	makeStripSpacePoint (std::vector< StripSP > &, const StripInformationHelper &firstInfo, const StripInformationHelper &secondInfo, bool isEndcap, double limit, double slimit) const
void	updateRange (const InDetDD::SiDetectorElement *element1, const InDetDD::SiDetectorElement *element2, double &stripLengthGapTolerance, double &min, double &max) const
double	offset (const InDetDD::SiDetectorElement *element1, const InDetDD::SiDetectorElement *element2, double &stripLengthGapTolerance) const
void	correctPolarRange (const InDetDD::SiDetectorElement *element, double &min, double &max, size_t &minStrip, size_t &maxStrip) const
std::pair< Amg::Vector3D, Amg::Vector3D >	getStripEnds (const xAOD::StripCluster *cluster, const InDetDD::SiDetectorElement *element, size_t &stripIndex) const

Detailed Description

Definition at line 34 of file StripSpacePointFormationTool.h.

Constructor & Destructor Documentation

StripSpacePointFormationTool()

ActsTrk::StripSpacePointFormationTool::StripSpacePointFormationTool	(	const std::string &	type,
		const std::string &	name,
		const IInterface *	parent )

Definition at line 16 of file StripSpacePointFormationTool.cxx.

    : base_class(type, name, parent)
    {}

~StripSpacePointFormationTool()

virtual ActsTrk::StripSpacePointFormationTool::~StripSpacePointFormationTool ( )

virtualdefault

Member Function Documentation

correctPolarRange()

void ActsTrk::StripSpacePointFormationTool::correctPolarRange ( const InDetDD::SiDetectorElement * element, double & min, double & max, size_t & minStrip, size_t & maxStrip ) const

private

Definition at line 572 of file StripSpacePointFormationTool.cxx.

    {
        // for Inner Detector SCT, gap = 0 in config. 
        if (element->isBarrel() or (not m_isITk))
            return;
 
        // design for endcap modules
        const InDetDD::StripStereoAnnulusDesign *design
            = dynamic_cast<const InDetDD::StripStereoAnnulusDesign *> (&element->design());
        if ( design==nullptr ) {
            ATH_MSG_FATAL( "Invalid strip annulus design for module with identifier/identifierHash " << element->identify() << "/" << element->identifyHash());
            return;
        }
 
        // converting min and max from cartesian reference frame to polar frame
        auto firstPosition = (design->localPositionOfCell(design->strip1Dim(0, 0))+
            design->localPositionOfCell(design->strip1Dim(design->diodesInRow(0)-1, 0)))*0.5;
 
        double radius = firstPosition.xEta();
 
        InDetDD::SiCellId minCellId = element->cellIdOfPosition(InDetDD::SiLocalPosition(radius, min, 0.));
        InDetDD::SiCellId maxCellId = element->cellIdOfPosition(InDetDD::SiLocalPosition(radius, max, 0.));
 
        if (not minCellId.isValid()) {
            minCellId = InDetDD::SiCellId(0);
        }
 
        if (not maxCellId.isValid()) {
            maxCellId = InDetDD::SiCellId(design->diodesInRow(0)-1);
        }
 
        minStrip = minCellId.strip();
        maxStrip = maxCellId.strip();
 
        // re-evaluate min and max in polar coordinate
        min = std::atan2(min, radius);
        max = std::atan2(max, radius);
    }

fillStripSpacePoints()

StatusCode ActsTrk::StripSpacePointFormationTool::fillStripSpacePoints ( const std::array< const InDetDD::SiDetectorElement *, nNeighbours > & neighbourElements, const std::array< std::vector< std::pair< const xAOD::StripCluster *, size_t > >, nNeighbours > & neighbourClusters, const std::array< double, 14 > & overlapExtents, const Amg::Vector3D & beamSpotVertex, std::vector< StripSP > & spacePoints, std::vector< StripSP > & overlapSpacePoints ) const

private

Definition at line 221 of file StripSpacePointFormationTool.cxx.

    {
 
        // This function is called once all the needed quantities are collected.
        // It is used to build space points checking the compatibility of clusters on pairs of detector elements.
        // Detector elements and cluster collections are elements and clusters, respectively.
        // [0] is the trigger element
        // [1] is the opposite element
        // [2]-[3] are the elements tested for eta overlaps
        // [4]-[5] are the elements tested for phi overlaps
        //
        // To build space points:
        // - For the opposite element and the ones tested for eta overlaps, you have to check
        //   if clusters are compatible with the local position of the trigger cluster
        //   requiring that the distance between the two clusters in phi is withing a specified range.
        //   - overlapExtents[0], overlapExtents[1] are filled for the opposite element
        //   - overlapExtents[2], overlapExtents[3], overlapExtents[4], overlapExtents[5] are filled for the eta overlapping elements
        // - For the elements tested for phi overlaps, you have to check
        //   if clusters are compatible with the local position of the trigger cluster.
        //   This needs that the trigger cluster is at the edge of the trigger module
        //   and that the other cluster is on the compatible edge of its module
        //   - overlapExtents[6], overlapExtents[7], overlapExtents[10], overlapExtents[11]
        //     overlapExtents[8], overlapExtents[9], overlapExtents[12], overlapExtents[13] are filled for the phi overlapping elements
 
        constexpr int otherSideIndex{1};
        constexpr int maxEtaIndex{3};
        std::array<int, nNeighbours-1> elementIndex{};
        int nElements = 0;
 
        // For the nNeighbours sides, fill elementIndex with the indices of the existing elements.
        // Same the number of elements in nElements to loop on the later on
        for(int n=1; n!=nNeighbours; ++n) {
            if(elements[n]) {
                elementIndex[nElements++] = n;
            }
        }
        // return if all detector elements are nullptr
        if(!nElements) return StatusCode::SUCCESS;
 
        // trigger element and clusters
        const InDetDD::SiDetectorElement* element = elements[0];
        bool isEndcap = element->isEndcap();
 
        std::vector<StripInformationHelper> stripInfos;
        stripInfos.reserve(clusters[0].size());
 
        // loop on all clusters on the trigger detector element and save the related information
        for (auto& cluster_index : clusters[0]) {
            size_t stripIndex = -1;
            auto ends = getStripEnds(cluster_index.first, element, stripIndex);
            const auto& localPos = cluster_index.first->localPosition<1>();
            StripInformationHelper stripInfo(cluster_index.first->identifierHash(), ends.first, ends.second, beamSpotVertex, localPos(0, 0), cluster_index.second, stripIndex);
            stripInfos.push_back( std::move(stripInfo) );
        }
 
        double  limit  = 1. + m_stripLengthTolerance;
        double slimit  = 0.;
 
        if(not m_allClusters) {
            // Start processing the opposite side and the eta overlapping elements
            int n = 0;
            for(; n < nElements; ++n) {
                int currentIndex = elementIndex[n];
                if(currentIndex > maxEtaIndex) break;
 
                // get the detector element and the IdentifierHash
                const InDetDD::SiDetectorElement* currentElement  = elements[currentIndex];
 
                // retrieve the range
                double min = overlapExtents[currentIndex*2-2];
                double max = overlapExtents[currentIndex*2-1];
 
                size_t minStrip, maxStrip = 0;
 
                if (m_stripGapParameter != 0.) {
                    updateRange(element, currentElement, slimit, min, max);
                    correctPolarRange(element, min, max, minStrip, maxStrip);
                }
 
                StripInformationHelper currentStripInfo;
                for (auto& cluster_index : clusters[currentIndex]) {
                    bool processed = false;
                    const auto& currentLocalPos = cluster_index.first->localPosition<1>();
 
                    for(auto& stripInfo : stripInfos) {
                        double diff = currentLocalPos(0, 0)-stripInfo.locX();
                        // In negative endcap, local z is opposite of positive endcap
                        // need to invert the difference for proper comparison
                        if( m_stripId->barrel_ec(currentElement->identify())<0 ) diff = -diff;
 
                        if(diff < min || diff > max) continue;
 
                        if (not processed) {
                            processed = true;
                            size_t currentStripIndex = 0;
                            auto ends = getStripEnds(cluster_index.first, currentElement, currentStripIndex);
                            currentStripInfo.set(cluster_index.first->identifierHash(), ends.first, ends.second, beamSpotVertex, currentLocalPos(0, 0), cluster_index.second, currentStripIndex);
                        }
 
                        // depending on the index you are processing, you save the space point in the correct container
                        if (currentIndex==otherSideIndex) {
                          ATH_CHECK( makeStripSpacePoint(spacePoints, stripInfo, currentStripInfo, isEndcap, limit, slimit) );
                        } else {
                          ATH_CHECK( makeStripSpacePoint(overlapSpacePoints, stripInfo, currentStripInfo, isEndcap, limit, slimit) );
                        }
                    }
                }
            }
            // process the phi overlapping elements
            // if possible n starts from 4
            for(; n < nElements; ++n) {
                int currentIndex = elementIndex[n];
                const InDetDD::SiDetectorElement* currentElement = elements[currentIndex];
 
                double min = overlapExtents[4*currentIndex-10];
                double max = overlapExtents[4*currentIndex- 9];
 
                std::size_t minStrip = 0;
                std::size_t maxStrip = 0;
 
                if (m_stripGapParameter != 0.) {
                    updateRange(element, currentElement, slimit, min, max);
                    correctPolarRange(element, min, max, minStrip, maxStrip);
                }
 
                std::vector<StripInformationHelper*> stripPhiInfos;
                stripPhiInfos.reserve(stripInfos.size());
 
                for(auto& stripInfo : stripInfos) {
                    auto stripIndex = stripInfo.stripIndex();
                    auto localPosition = stripInfo.locX();
                    auto centralValue = localPosition;
                    auto minValue = min;
                    auto maxValue = max;
                    if (isEndcap and  m_isITk) { // for Inner Detector SCT, use the same cut as barrel
                        centralValue = stripIndex;
                        minValue = minStrip;
                        maxValue = maxStrip;
                    }
 
                    if (minValue <= centralValue and centralValue <= maxValue) {
                        stripPhiInfos.push_back(&stripInfo);
                    }
                }
                // continue if you have no cluster from the phi overlapping region of the trigger element
                if(stripPhiInfos.empty()) continue;
 
                min = overlapExtents[4*currentIndex-8];
                max = overlapExtents[4*currentIndex-7];
 
                if (m_stripGapParameter != 0.) {
                    updateRange(element, currentElement, slimit, min, max);
                    correctPolarRange(currentElement, min, max, minStrip, maxStrip);
                }
 
                for (auto& cluster_index : clusters[currentIndex]) {
                    const auto& currentLocalPos = cluster_index.first->localPosition<1>();
 
                    size_t currentStripIndex = 0;
                    auto ends = getStripEnds(cluster_index.first, currentElement, currentStripIndex);
                    StripInformationHelper currentStripInfo(cluster_index.first->identifierHash(), ends.first, ends.second, beamSpotVertex, currentLocalPos(0, 0), cluster_index.second, currentStripIndex);
                    auto centralValue = currentLocalPos(0, 0);
                    auto minValue = min;
                    auto maxValue = max;
                    if (isEndcap and m_isITk) { // for Inner Detector SCT, use the same cut as barrel
                        centralValue = currentStripIndex;
                        minValue = minStrip;
                        maxValue = maxStrip;
                    }
 
                    if (centralValue < minValue or centralValue > maxValue)
                        continue;
 
                    for(auto& stripInfo : stripPhiInfos) {
                      ATH_CHECK( makeStripSpacePoint(overlapSpacePoints, *stripInfo, currentStripInfo, isEndcap, limit, slimit) );
                    }
                }
            }
            return StatusCode::SUCCESS;
        }
 
        for(int n=0; n!=nElements; ++n) {
          
            int currentIndex = elementIndex[n];
            const InDetDD::SiDetectorElement* currentElement = elements[currentIndex];
 
            if (m_stripGapParameter != 0.) {
                offset(element, currentElement, slimit);
            }
 
            for (auto& cluster_index : clusters[currentIndex]) {
                size_t currentStripIndex = 0;
                auto ends = getStripEnds(cluster_index.first, element, currentStripIndex);
                const auto& currentLocalPos = cluster_index.first->localPosition<1>();
                StripInformationHelper currentStripInfo(cluster_index.first->identifierHash(), ends.first, ends.second, beamSpotVertex, currentLocalPos(0, 0), cluster_index.second, currentStripIndex);
 
                for(auto& stripInfo : stripInfos) {
                    // depending on the index you are processing, you save the space point in the correct container
                    if (currentIndex==otherSideIndex) {
                      ATH_CHECK( makeStripSpacePoint(spacePoints, stripInfo, currentStripInfo, isEndcap, limit, slimit) );
                    } else {
                      ATH_CHECK( makeStripSpacePoint(overlapSpacePoints, stripInfo, currentStripInfo, isEndcap, limit, slimit) );
                    }
                }
            }
        }
        return StatusCode::SUCCESS;
    }

getStripEnds()

std::pair< Amg::Vector3D, Amg::Vector3D > ActsTrk::StripSpacePointFormationTool::getStripEnds ( const xAOD::StripCluster * cluster, const InDetDD::SiDetectorElement * element, size_t & stripIndex ) const

private

Definition at line 616 of file StripSpacePointFormationTool.cxx.

    {
        const Eigen::Matrix<float,1,1>& localPos = cluster->localPosition<1>();
 
        if (element->isEndcap() and m_isITk) {
            // design for endcap modules
            const InDetDD::StripStereoAnnulusDesign *design
                = dynamic_cast<const InDetDD::StripStereoAnnulusDesign *> (&element->design());
            if ( design==nullptr ) {
                ATH_MSG_FATAL( "Invalid strip annulus design for module with identifier/identifierHash " << element->identify() << "/" << element->identifyHash());
                return std::pair<Amg::Vector3D, Amg::Vector3D >();
            }
 
            // calculate phi pitch for evaluating the strip index
            double phiPitchPhi = design->phiWidth()/design->diodesInRow(0);
            stripIndex = -std::floor(localPos(0, 0) / phiPitchPhi) + design->diodesInRow(0) *0.5 - 0.5;
 
            std::pair<Amg::Vector3D, Amg::Vector3D > ends = {
                element->globalPosition(design->stripPosAtR(stripIndex, 0, design->minR())),
                element->globalPosition(design->stripPosAtR(stripIndex, 0, design->maxR()))
            };
            return ends;
 
        }
 
        InDetDD::SiLocalPosition localPosition(0., localPos(0, 0), 0.);
        std::pair<Amg::Vector3D, Amg::Vector3D > ends(element->endsOfStrip(localPosition));
 
        return ends;
    }

initialize()

StatusCode ActsTrk::StripSpacePointFormationTool::initialize ( )

overridevirtual

Definition at line 22 of file StripSpacePointFormationTool.cxx.

                                                        {
 
        ATH_CHECK(detStore()->retrieve(m_stripId,"SCT_ID"));
 
        ATH_CHECK(m_lorentzAngleTool.retrieve());
 
        if(m_useSCTLayerDep_OverlapCuts)
          ATH_MSG_INFO("Use SCT SP overlap cuts based on layer number parity");
        
        return StatusCode::SUCCESS;
    }

makeStripSpacePoint()

StatusCode ActsTrk::StripSpacePointFormationTool::makeStripSpacePoint ( std::vector< StripSP > & collection, const StripInformationHelper & firstInfo, const StripInformationHelper & secondInfo, bool isEndcap, double limit, double slimit ) const

private

Definition at line 436 of file StripSpacePointFormationTool.cxx.

    {
        double a  =-firstInfo.trajDirection().dot(secondInfo.normal());
        double b  = firstInfo.stripDirection().dot(secondInfo.normal());
        double l0 = firstInfo.oneOverStrip()*slimit+limit ;
 
        if(std::abs(a) > (std::abs(b)*l0)) {
          ATH_MSG_DEBUG("SP fails geometric cuts (first)");
          if(m_useBeamSpotConstraint) {
            return StatusCode::SUCCESS;
          }
        }
 
        double c  =-secondInfo.trajDirection().dot(firstInfo.normal());
        double d  = secondInfo.stripDirection().dot(firstInfo.normal());
        double l1 = secondInfo.oneOverStrip()*slimit+limit ;
 
        if(std::abs(c) > (std::abs(d)*l1)) {
          ATH_MSG_DEBUG("SP fails geometric cuts (second)");
          if(m_useBeamSpotConstraint) {
            return StatusCode::SUCCESS;
          }
        }
 
        double m = a/b;
 
        if(slimit!=0.) {
            double n = c/d;
            if (m >  limit || n >  limit) {
                double cs  = firstInfo.stripDirection().dot(secondInfo.stripDirection())*(firstInfo.oneOverStrip()*firstInfo.oneOverStrip());
                double dm  = (m-1);
                double dmn = (n-1.)*cs;
                if(dmn > dm) dm = dmn;
                m-=dm; n-=(dm/cs);
                if(std::abs(m) > limit || std::abs(n) > limit) {
                  ATH_MSG_DEBUG("SP falls outside of limit");
                  if(m_useBeamSpotConstraint) {
                    return StatusCode::SUCCESS;
                  }
                }
            } else if (m < -limit || n < -limit) {
                double cs  = firstInfo.stripDirection().dot(secondInfo.stripDirection())*(firstInfo.oneOverStrip()*firstInfo.oneOverStrip());
                double dm  = -(1.+m);
                double dmn = -(1.+n)*cs;
                if(dmn > dm) dm = dmn;
                m+=dm; n+=(dm/cs);
                if(std::abs(m) > limit || std::abs(n) > limit) {
                  ATH_MSG_DEBUG("SP falls outside of limit");
                  if(m_useBeamSpotConstraint) {
                    return StatusCode::SUCCESS;
                  }
                }
            }
        }
 
        Eigen::Matrix<double, 3, 1> globalPosition(m_useTopSp ? secondInfo.position(m) : firstInfo.position(m));
 
        // evaluation of the local covariance
        // Lines taken from SCT_SpacePoint::setupLocalCovarianceSCT()
        constexpr float deltaY = 0.0004; // roughly pitch of SCT (80 mu) / sqrt(12)
        constexpr float covTerm = 1600.*deltaY;
 
        Eigen::Matrix<float, 2, 1> variance(0.1f, 8.f*covTerm);
        // Swap r/z covariance terms for endcap clusters
        if ( isEndcap )
            std::swap( variance(0, 0), variance(1, 0) );
 
        // evaluation of measurement details
        double topHalfStripLength = 0.5*firstInfo.stripDirection().norm();
        Eigen::Matrix<double, 3, 1> topStripDirection = -firstInfo.stripDirection()/(2.*topHalfStripLength);
        Eigen::Matrix<double, 3, 1> topStripCenter = 0.5*firstInfo.trajDirection();
 
        double bottomHalfStripLength = 0.5*secondInfo.stripDirection().norm();
        Eigen::Matrix<double, 3, 1> bottomStripDirection = -secondInfo.stripDirection()/(2.*bottomHalfStripLength);
 
        Eigen::Matrix<double, 3, 1> stripCenterDistance = firstInfo.stripCenter() - secondInfo.stripCenter();
 
 
 
        StripSP toAdd;
        toAdd.idHashes = {firstInfo.idHash(), secondInfo.idHash()};
        toAdd.globPos = globalPosition.cast<float>();
        toAdd.cov_r = variance(0,0);
        toAdd.cov_z = variance(1,0);
        toAdd.measurementIndexes = std::array<std::size_t,2> ({firstInfo.clusterIndex(), secondInfo.clusterIndex()});
        toAdd.topHalfStripLength = static_cast<float>(topHalfStripLength);
        toAdd.bottomHalfStripLength = static_cast<float>(bottomHalfStripLength);
        toAdd.topStripDirection = topStripDirection.cast<float>();
        toAdd.bottomStripDirection = bottomStripDirection.cast<float>();
        toAdd.stripCenterDistance = stripCenterDistance.cast<float>();
        toAdd.topStripCenter = topStripCenter.cast<float>();
 
        collection.push_back(std::move(toAdd));
 
        return StatusCode::SUCCESS;
    }

offset()

double ActsTrk::StripSpacePointFormationTool::offset ( const InDetDD::SiDetectorElement * element1, const InDetDD::SiDetectorElement * element2, double & stripLengthGapTolerance ) const

private

Definition at line 539 of file StripSpacePointFormationTool.cxx.

    {
        const Amg::Transform3D& T1 = element1->transform();
        const Amg::Transform3D& T2 = element2->transform();
        Amg::Vector3D           C  = element1->center() ;
        bool isAnnulus = (element1->design().shape() == InDetDD::Annulus);
 
        double x12 = T1(0,0)*T2(0,0)+T1(1,0)*T2(1,0)+T1(2,0)*T2(2,0);
        double r   = isAnnulus ? std::sqrt(C[0]*C[0]+C[1]*C[1]) : std::sqrt(T1(0,3)*T1(0,3)+T1(1,3)*T1(1,3));
        double s   = (T1(0,3)-T2(0,3))*T1(0,2)+(T1(1,3)-T2(1,3))*T1(1,2)+(T1(2,3)-T2(2,3))*T1(2,2);
 
        double dm  = (m_stripGapParameter*r)*std::abs(s*x12);
        double d   = isAnnulus ? dm/.04 : dm/std::sqrt((1.-x12)*(1.+x12));
 
        if (std::abs(T1(2,2)) > 0.7) d*=(r/std::abs(T1(2,3)));
 
        stripLengthGapTolerance = d;
 
        return dm;
    }

produceSpacePoints()

StatusCode ActsTrk::StripSpacePointFormationTool::produceSpacePoints ( const EventContext & ctx, const xAOD::StripClusterContainer & clusterContainer, const InDet::SiElementPropertiesTable & properties, const InDetDD::SiDetectorElementCollection & elements, const Amg::Vector3D & beamSpotVertex, std::vector< StripSP > & spacePoints, std::vector< StripSP > & overlapSpacePoints, bool processOverlaps, const std::vector< IdentifierHash > & hashesToProcess, const ContainerAccessor< xAOD::StripCluster, IdentifierHash, 1 > & stripAccessor ) const

overridevirtual

Production of StripSP from strip clusters Strip space points involves a more complex logic since they are made combining clusters from pairs of overlapping detectors.

For each trigger element, first evaluate and collect the quantities you need to build the space points. The detector element array has capacity 6: [0] is the trigger element [1] is the opposite element [2]-[3] are the elements tested for eta overlaps [4]-[5] are the elements tested for phi overlaps For each element you save the corresponding cluster collections and the space point compatibility range as described below.

For the opposite element and the ones tested for eta overlaps, you have to check if clusters are compatible with the local position of the trigger cluster requiring that the distance between the two clusters in phi is withing a specified range.

• For the clusters on the opposite element: [-m_overlapLimitOpposite, m_overlapLimitOpposite]
• For the eta overlapping clusters : you use m_overlapLimitEtaMin and m_overlapLimitEtaMax in different combination depending if you are checking a stereo module or not

For each element, the extremes of these ranges are saved in the overlapExtents array which is used later on

• overlapExtents[0], overlapExtents[1] are filled for the opposite element
• overlapExtents[2], overlapExtents[3], overlapExtents[4], overlapExtents[5] are filled for the eta overlapping elements

For the elements tested for phi overlaps, you have to check if clusters are compatible with the local position of the trigger cluster. This needs that the trigger cluster is at the edge of the trigger module: e.g. -hwidth < locX_trigger < -hwidth+m_overlapLimitPhi (or hwidth-m_overlapLimitPhi < locX_trigger < hwidth) and that the other cluster is on the compatible edge of its module: e.g. hwidth-m_overlapLimitPhi < locX_other < hwidth (or -hwidth < locX_other < -hwidth+m_overlapLimitPhi)

For each element, the extremes of these ranges are saved in the overlapExtents array which is used later on

• overlapExtents[6], overlapExtents[7], overlapExtents[10], overlapExtents[11] overlapExtents[8], overlapExtents[9], overlapExtents[12], overlapExtents[13] are filled for the phi overlapping elements

Access to the cluster from a given detector element is possible via the ContainerAccessor.

Definition at line 34 of file StripSpacePointFormationTool.cxx.

    {


 
        const auto hashesProc = (hashesToProcess.size() > 0 ? hashesToProcess : stripAccessor.allIdentifiers());
 
        //factor out floating point conversions
        double overlapLimitOpposite = m_overlapLimitOpposite;
        double overlapLimitPhi      = m_overlapLimitPhi;
        double overlapLimitEtaMin   = m_overlapLimitEtaMin;
        double overlapLimitEtaMax   = m_overlapLimitEtaMax;
 
        for (auto& idHash : hashesProc) {
            const InDetDD::SiDetectorElement* thisElement = elements.getDetectorElement(idHash);
            if ( not thisElement->isStereo() ) {
                // Retrieve the neighbours of the detector element
                const std::vector<IdentifierHash>* others(properties.neighbours(idHash));
                if (others==nullptr || others->empty() )
                    continue;
 
                // This flag is use to trigger if the search should be performed.
                // In case there are no clusters on the neighbours of the selected
                // detector element, the flag stays false.
                bool search=false;
                size_t neighbour = 0;
                while (not search and neighbour<others->size() ) {
                    search = stripAccessor.isIdentifierPresent(others->at(neighbour));
                    neighbour++;
                }
                if (not search)
                    continue;
 
                // prepare clusters, indices and modules for space point formation
                std::array<std::vector<std::pair<const xAOD::StripCluster*, size_t>>, nNeighbours> neighbourClusters{};
                std::array<const InDetDD::SiDetectorElement*, nNeighbours> neighbourElements{};
 
                auto groupStart = clusterContainer.begin();
                // Get the detector element and range for the idHash
                neighbourElements[0] = thisElement;
                for (auto& this_range : stripAccessor.rangesForIdentifierDirect(idHash)) {
                    for (auto start=this_range.first; start!=this_range.second; start++) {
                        size_t position = std::distance(groupStart, start);
                        neighbourClusters[0].push_back(std::make_pair(*start, position));
                    }
                }
 
                Identifier thisId = thisElement->identify();
 
                // define overlap extends before building space points
                std::array<double, 14> overlapExtents{};
                //   Default case: you test the opposite element and the overlapping in phi (total 3 elements)
                int Nmax = 4;
 
                // In the barrel, test the eta overlaps as well (total 5 elements)
                if (m_stripId->is_barrel(thisId))
                    Nmax = 6;
 
                // You can remove all the overlaps if requested.
                // Here you test only the opposite element
                if(not processOverlaps) Nmax = 2;
                //factor double conversion outside of loop
                double hwidth(static_cast<double>(properties.halfWidth(idHash)));
                int n = 0;
 
 
                // The order of the elements in others is such that you first get the opposite element,
                // the overlapping in phi and then the overlapping in eta
                // For this reason you need to re-order the indices, since the SiSpacePointMakerTool will process
                // first the eta overlaps and then the phi ones
                const std::array<size_t, nNeighbours> neigbourIndices{ThisOne, Opposite, EtaMinus, EtaPlus, PhiMinus, PhiPlus};
 
                for (const auto& otherHash : *others) {
 
                    if(++n==Nmax) break;
 
                    if(not stripAccessor.isIdentifierPresent(otherHash))
                        continue;
 
                    const InDetDD::SiDetectorElement* otherElement = elements.getDetectorElement(otherHash);
 
                    neighbourElements[neigbourIndices[n]] = otherElement;
                    for (auto& this_range : stripAccessor.rangesForIdentifierDirect(otherHash)) {
                        for (auto start=this_range.first; start!=this_range.second; start++) {
                            size_t position = std::distance(groupStart, start);
                            neighbourClusters[neigbourIndices[n]].push_back(std::make_pair(*start, position));
                        }
                    }
 
                    switch (n) {
                        case Opposite: {
                            overlapExtents[ 0] = -overlapLimitOpposite;
                            overlapExtents[ 1] =  overlapLimitOpposite;
                            break;
                        }
                        case PhiMinus: {
                            overlapExtents[ 6] =-hwidth;
                            overlapExtents[ 7] =-hwidth+overlapLimitPhi;
                            overlapExtents[ 8] = hwidth-overlapLimitPhi;
                            overlapExtents[ 9] = hwidth;
                            break;
                        }
                        case PhiPlus: {
                            overlapExtents[10] = hwidth-overlapLimitPhi;
                            overlapExtents[11] = hwidth;
                            overlapExtents[12] =-hwidth;
                            overlapExtents[13] =-hwidth+overlapLimitPhi;
                            break;
                        }
                        case EtaMinus: {
                          overlapExtents[ 2] = overlapLimitEtaMin;
                          overlapExtents[ 3] = overlapLimitEtaMax;
                          if (m_useSCTLayerDep_OverlapCuts && (m_stripId->layer_disk(thisId) & 1) != 0) {
                            overlapExtents[ 2] =-overlapLimitEtaMax;
                            overlapExtents[ 3] =-overlapLimitEtaMin;
                          }
                          break;
                        }
                        default: {
                          overlapExtents[ 4] = overlapLimitEtaMin;
                          overlapExtents[ 5] = overlapLimitEtaMax;
                          if (m_useSCTLayerDep_OverlapCuts && (m_stripId->layer_disk(thisId) & 1) == 0) {
                            overlapExtents[ 4] = -overlapLimitEtaMax;
                            overlapExtents[ 5] = -overlapLimitEtaMin;
                          }
                          break;
                        }
                    }
                }
 
                // producing and filling space points
                ATH_CHECK( fillStripSpacePoints(neighbourElements, neighbourClusters, overlapExtents, beamSpotVertex,
                                                spacePoints, overlapSpacePoints) );
            }
        }
        return StatusCode::SUCCESS;
    }

updateRange()

void ActsTrk::StripSpacePointFormationTool::updateRange ( const InDetDD::SiDetectorElement * element1, const InDetDD::SiDetectorElement * element2, double & stripLengthGapTolerance, double & min, double & max ) const

private

Definition at line 562 of file StripSpacePointFormationTool.cxx.

    {
        double dm = offset(element1, element2, stripLengthGapTolerance);
        min -= dm;
        max += dm;
    }

Member Data Documentation

m_allClusters

Gaudi::Property< bool > ActsTrk::StripSpacePointFormationTool::m_allClusters {this, "AllClusters", false, "Process all clusters without limits."}

private

Definition at line 109 of file StripSpacePointFormationTool.h.

{this, "AllClusters", false, "Process all clusters without limits."};

m_isITk

Gaudi::Property<bool> ActsTrk::StripSpacePointFormationTool::m_isITk {this, "isITk", true, "True if running in ITk"}

private

Definition at line 111 of file StripSpacePointFormationTool.h.

{this, "isITk", true, "True if running in ITk"};

m_lorentzAngleTool

ToolHandle<ISiLorentzAngleTool> ActsTrk::StripSpacePointFormationTool::m_lorentzAngleTool

private

Initial value:

{this, "LorentzAngleTool", "",
      "Tool to retreive Lorentz angle of SCT"}

Using Lorentz angle tool.

Definition at line 103 of file StripSpacePointFormationTool.h.

                                                          {this, "LorentzAngleTool", "",
      "Tool to retreive Lorentz angle of SCT"};

m_overlapLimitEtaMax

Gaudi::Property< float > ActsTrk::StripSpacePointFormationTool::m_overlapLimitEtaMax {this, "OverlapLimitEtaMax", 3.0, "High overlap limit for eta-neighbours."}

private

Definition at line 123 of file StripSpacePointFormationTool.h.

{this, "OverlapLimitEtaMax", 3.0, "High overlap limit for eta-neighbours."};

m_overlapLimitEtaMin

Gaudi::Property< float > ActsTrk::StripSpacePointFormationTool::m_overlapLimitEtaMin {this, "OverlapLimitEtaMin", 1.68, "Low overlap limit for eta-neighbours."}

private

Definition at line 122 of file StripSpacePointFormationTool.h.

{this, "OverlapLimitEtaMin", 1.68, "Low overlap limit for eta-neighbours."};

m_overlapLimitOpposite

Gaudi::Property< float > ActsTrk::StripSpacePointFormationTool::m_overlapLimitOpposite {this, "OverlapLimitOpposite", 2.8, "Overlap limit for opposite-neighbour."}

private

Definition at line 120 of file StripSpacePointFormationTool.h.

{this, "OverlapLimitOpposite", 2.8, "Overlap limit for opposite-neighbour."};

m_overlapLimitPhi

Gaudi::Property< float > ActsTrk::StripSpacePointFormationTool::m_overlapLimitPhi {this, "OverlapLimitPhi", 5.64, "Overlap limit for phi-neighbours."}

private

Definition at line 121 of file StripSpacePointFormationTool.h.

{this, "OverlapLimitPhi", 5.64, "Overlap limit for phi-neighbours."};

m_stripGapParameter

Gaudi::Property< float > ActsTrk::StripSpacePointFormationTool::m_stripGapParameter {this, "StripGapParameter", 0.0015, "Recommend 0.001 - 0.0015 for ITK geometry"}

private

Definition at line 126 of file StripSpacePointFormationTool.h.

{this, "StripGapParameter", 0.0015, "Recommend 0.001 - 0.0015 for ITK geometry"};

m_stripId

const SCT_ID* ActsTrk::StripSpacePointFormationTool::m_stripId {}

private

Definition at line 97 of file StripSpacePointFormationTool.h.

{};

m_stripLengthTolerance

Gaudi::Property< float > ActsTrk::StripSpacePointFormationTool::m_stripLengthTolerance {this, "StripLengthTolerance", 0.01}

private

The following are parameters to build the space points.

Definition at line 125 of file StripSpacePointFormationTool.h.

{this, "StripLengthTolerance", 0.01};

m_useBeamSpotConstraint

Gaudi::Property< bool > ActsTrk::StripSpacePointFormationTool::m_useBeamSpotConstraint {this, "useBeamSpotConstraint", true, "Reject space points which are not compatible with a particle originating from the beamspot"}

private

For applying geometric cuts on SPs using beamspot constraint.

Definition at line 129 of file StripSpacePointFormationTool.h.

{this, "useBeamSpotConstraint", true, "Reject space points which are not compatible with a particle originating from the beamspot"};

m_useSCTLayerDep_OverlapCuts

Gaudi::Property< bool > ActsTrk::StripSpacePointFormationTool::m_useSCTLayerDep_OverlapCuts {this,"useSCTLayerDep_OverlapCuts", true}

private

Definition at line 127 of file StripSpacePointFormationTool.h.

{this,"useSCTLayerDep_OverlapCuts", true};

m_useTopSp

Gaudi::Property< bool > ActsTrk::StripSpacePointFormationTool::m_useTopSp {this, "useTopSp", false, "SP global position is for second strip module."}

private

Definition at line 110 of file StripSpacePointFormationTool.h.

{this, "useTopSp", false, "SP global position is for second strip module."};

---

The documentation for this class was generated from the following files:

• StripSpacePointFormationTool.h
• StripSpacePointFormationTool.cxx