CachedTrajectory.cc

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// -*- C++ -*-
//
// Package:    TrackAssociator
// Class:      CachedTrajectory
//
//
//
 
#include "TrackingTools/TrackAssociator/interface/CachedTrajectory.h"
// #include "Utilities/Timing/interface/TimerStack.h"
#include "TrackPropagation/SteppingHelixPropagator/interface/SteppingHelixPropagator.h"
#include "DataFormats/GeometrySurface/interface/Plane.h"
#include "Geometry/DTGeometry/interface/DTChamber.h"
#include "Geometry/CSCGeometry/interface/CSCChamber.h"
#include <deque>
#include <algorithm>
 
std::vector<SteppingHelixStateInfo> propagateThoughFromIP(const SteppingHelixStateInfo& state,
                                                          const Propagator* prop,
                                                          const FiducialVolume& volume,
                                                          int nsteps,
                                                          float step,
                                                          float minR,
                                                          float minZ,
                                                          float maxR,
                                                          float maxZ) {
  CachedTrajectory neckLace;
  neckLace.setStateAtIP(state);
  neckLace.reset_trajectory();
  neckLace.setPropagator(prop);
  neckLace.setPropagationStep(0.1);
  neckLace.setMinDetectorRadius(minR);
  neckLace.setMinDetectorLength(minZ * 2.);
  neckLace.setMaxDetectorRadius(maxR);
  neckLace.setMaxDetectorLength(maxZ * 2.);
 
  // Propagate track
  bool isPropagationSuccessful = neckLace.propagateAll(state);
 
  if (!isPropagationSuccessful)
    return std::vector<SteppingHelixStateInfo>();
 
  std::vector<SteppingHelixStateInfo> complicatePoints;
  neckLace.getTrajectory(complicatePoints, volume, nsteps);
 
  return complicatePoints;
}
 
CachedTrajectory::CachedTrajectory() : propagator_(nullptr) {
  reset_trajectory();
  setMaxDetectorRadius();
  setMaxDetectorLength();
  setMinDetectorRadius();
  setMinDetectorLength();
  setPropagationStep();
}
 
void CachedTrajectory::propagateForward(SteppingHelixStateInfo& state, float distance) {
  // defined a normal plane wrt the particle trajectory direction
  // let's hope that I computed the rotation matrix correctly.
  GlobalVector vector(state.momentum().unit());
  float r21 = 0;
  float r22 = vector.z() / sqrt(1 - pow(vector.x(), 2));
  float r23 = -vector.y() / sqrt(1 - pow(vector.x(), 2));
  float r31 = vector.x();
  float r32 = vector.y();
  float r33 = vector.z();
  float r11 = r22 * r33 - r23 * r32;
  float r12 = r23 * r31;
  float r13 = -r22 * r31;
 
  Surface::RotationType rotation(r11, r12, r13, r21, r22, r23, r31, r32, r33);
  Plane::PlanePointer target = Plane::build(state.position() + vector * distance, rotation);
  propagate(state, *target);
}
 
void CachedTrajectory::propagate(SteppingHelixStateInfo& state, const Plane& plane) {
  if (const SteppingHelixPropagator* shp = dynamic_cast<const SteppingHelixPropagator*>(propagator_)) {
    try {
      shp->propagate(state, plane, state);
    } catch (cms::Exception& ex) {
      edm::LogWarning("TrackAssociator") << "Caught exception " << ex.category() << ": " << ex.explainSelf();
      edm::LogWarning("TrackAssociator") << "An exception is caught during the track propagation\n"
                                         << state.momentum().x() << ", " << state.momentum().y() << ", "
                                         << state.momentum().z();
      state = SteppingHelixStateInfo();
    }
  } else {
    FreeTrajectoryState fts;
    state.getFreeState(fts);
    TrajectoryStateOnSurface stateOnSurface = propagator_->propagate(fts, plane);
    state = SteppingHelixStateInfo(*(stateOnSurface.freeState()));
  }
}
 
void CachedTrajectory::propagate(SteppingHelixStateInfo& state, const Cylinder& cylinder) {
  if (const SteppingHelixPropagator* shp = dynamic_cast<const SteppingHelixPropagator*>(propagator_)) {
    try {
      shp->propagate(state, cylinder, state);
    } catch (cms::Exception& ex) {
      edm::LogWarning("TrackAssociator") << "Caught exception " << ex.category() << ": " << ex.explainSelf();
      edm::LogWarning("TrackAssociator") << "An exception is caught during the track propagation\n"
                                         << state.momentum().x() << ", " << state.momentum().y() << ", "
                                         << state.momentum().z();
      state = SteppingHelixStateInfo();
    }
  } else {
    FreeTrajectoryState fts;
    state.getFreeState(fts);
    TrajectoryStateOnSurface stateOnSurface = propagator_->propagate(fts, cylinder);
    state = SteppingHelixStateInfo(*(stateOnSurface.freeState()));
  }
}
 
bool CachedTrajectory::propagateAll(const SteppingHelixStateInfo& initialState) {
  if (fullTrajectoryFilled_) {
    edm::LogWarning("TrackAssociator")
        << "Reseting all trajectories. Please call reset_trajectory() explicitely to avoid this message";
    reset_trajectory();
  }
 
  //   TimerStack timers(TimerStack::Disableable);
 
  reset_trajectory();
  if (propagator_ == nullptr)
    throw cms::Exception("FatalError") << "Track propagator is not defined\n";
  SteppingHelixStateInfo currentState(initialState);
  fullTrajectory_.push_back(currentState);
 
  while (currentState.position().perp() < maxRho_ && fabs(currentState.position().z()) < maxZ_) {
    LogTrace("TrackAssociator") << "[propagateAll] Propagate outward from (rho, r, z, phi) ("
                                << currentState.position().perp() << ", " << currentState.position().mag() << ", "
                                << currentState.position().z() << ", " << currentState.position().phi() << ")";
    propagateForward(currentState, step_);
    if (!currentState.isValid()) {
      LogTrace("TrackAssociator") << "Failed to propagate the track; moving on\n";
      break;
    }
    LogTrace("TrackAssociator") << "\treached (rho, r, z, phi) (" << currentState.position().perp() << ", "
                                << currentState.position().mag() << ", " << currentState.position().z() << ", "
                                << currentState.position().phi() << ")";
    fullTrajectory_.push_back(currentState);
  }
 
  SteppingHelixStateInfo currentState2(initialState);
  SteppingHelixStateInfo previousState;
  while (currentState2.position().perp() > minRho_ || fabs(currentState2.position().z()) > minZ_) {
    previousState = currentState2;
    propagateForward(currentState2, -step_);
    if (!currentState2.isValid()) {
      LogTrace("TrackAssociator") << "Failed to propagate the track; moving on\n";
      break;
    }
    if (previousState.position().perp() - currentState2.position().perp() < 0) {
      LogTrace("TrackAssociator")
          << "Error: TrackAssociator has propogated the particle past the point of closest approach to IP" << std::endl;
      break;
    }
    LogTrace("TrackAssociator") << "[propagateAll] Propagated inward from (rho, r, z, phi) ("
                                << previousState.position().perp() << ", " << previousState.position().mag() << ", "
                                << previousState.position().z() << "," << previousState.position().phi() << ") to ("
                                << currentState2.position().perp() << ", " << currentState2.position().mag() << ", "
                                << currentState2.position().z() << ", " << currentState2.position().phi() << ")";
    fullTrajectory_.push_front(currentState2);
  }
 
  // LogTrace("TrackAssociator") << "fullTrajectory_ has " << fullTrajectory_.size() << " states with (R, z):\n";
  // for(unsigned int i=0; i<fullTrajectory_.size(); i++) {
  //  LogTrace("TrackAssociator") << "state " << i << ": (" << fullTrajectory_[i].position().perp() << ", "
  //    << fullTrajectory_[i].position().z() << ")\n";
  // }
 
  LogTrace("TrackAssociator") << "Done with the track propagation in the detector. Number of steps: "
                              << fullTrajectory_.size();
  fullTrajectoryFilled_ = true;
  return !fullTrajectory_.empty();
}
 
TrajectoryStateOnSurface CachedTrajectory::propagate(const Plane* plane) {
  // TimerStack timers(TimerStack::Disableable);
  // timers.benchmark("CachedTrajectory::propagate::benchmark");
  // timers.push("CachedTrajectory::propagate",TimerStack::FastMonitoring);
  // timers.push("CachedTrajectory::propagate::findClosestPoint",TimerStack::FastMonitoring);
 
  // Assume that all points along the trajectory are equally spread out.
  // For simplication assume that the trajectory is just a straight
  // line and find a point closest to the target plane. Propagate to
  // the plane from the point.
 
  const float matchingDistance = 1;
  // find the closest point to the plane
  int leftIndex = 0;
  int rightIndex = fullTrajectory_.size() - 1;
  int closestPointOnLeft = 0;
 
  // check whether the trajectory crossed the plane (signs should be different)
  if (sign(distance(plane, leftIndex)) * sign(distance(plane, rightIndex)) != -1) {
    LogTrace("TrackAssociator") << "Track didn't cross the plane:\n\tleft distance: " << distance(plane, leftIndex)
                                << "\n\tright distance: " << distance(plane, rightIndex);
    return TrajectoryStateOnSurface();
  }
 
  while (leftIndex + 1 < rightIndex) {
    closestPointOnLeft = int((leftIndex + rightIndex) / 2);
    float dist = distance(plane, closestPointOnLeft);
    // LogTrace("TrackAssociator") << "Closest point on left: " << closestPointOnLeft << "\n"
    //    << "Distance to the plane: " << dist;
    if (fabs(dist) < matchingDistance) {
      // found close match, verify that we are on the left side
      if (closestPointOnLeft > 0 && sign(distance(plane, closestPointOnLeft - 1)) * dist == -1)
        closestPointOnLeft--;
      break;
    }
 
    // check where is the plane
    if (sign(distance(plane, leftIndex) * dist) == -1)
      rightIndex = closestPointOnLeft;
    else
      leftIndex = closestPointOnLeft;
 
    // LogTrace("TrackAssociator") << "Distance on left: " << distance(plane, leftIndex) << "\n"
    //  << "Distance to closest point: " <<  distance(plane, closestPointOnLeft) << "\n"
    //  << "Left index: " << leftIndex << "\n"
    //  << "Right index: " << rightIndex;
  }
  LogTrace("TrackAssociator") << "closestPointOnLeft: " << closestPointOnLeft << "\n\ttrajectory point (z,R,eta,phi): "
                              << fullTrajectory_[closestPointOnLeft].position().z() << ", "
                              << fullTrajectory_[closestPointOnLeft].position().perp() << " , "
                              << fullTrajectory_[closestPointOnLeft].position().eta() << " , "
                              << fullTrajectory_[closestPointOnLeft].position().phi()
                              << "\n\tplane center (z,R,eta,phi): " << plane->position().z() << ", "
                              << plane->position().perp() << " , " << plane->position().eta() << " , "
                              << plane->position().phi();
 
  // propagate to the plane
  // timers.pop_and_push("CachedTrajectory::propagate::localPropagation",TimerStack::FastMonitoring);
  if (const SteppingHelixPropagator* shp = dynamic_cast<const SteppingHelixPropagator*>(propagator_)) {
    SteppingHelixStateInfo state;
    try {
      shp->propagate(fullTrajectory_[closestPointOnLeft], *plane, state);
    } catch (cms::Exception& ex) {
      edm::LogWarning("TrackAssociator") << "Caught exception " << ex.category() << ": " << ex.explainSelf();
      edm::LogWarning("TrackAssociator") << "An exception is caught during the track propagation\n"
                                         << state.momentum().x() << ", " << state.momentum().y() << ", "
                                         << state.momentum().z();
      return TrajectoryStateOnSurface();
    }
    return state.getStateOnSurface(*plane);
  } else {
    FreeTrajectoryState fts;
    fullTrajectory_[closestPointOnLeft].getFreeState(fts);
    return propagator_->propagate(fts, *plane);
  }
}
 
std::pair<float, float> CachedTrajectory::trajectoryDelta(TrajectorType trajectoryType) {
  // MEaning of trajectory change depends on its usage. In most cases we measure
  // change in a trajectory as difference between final track position and initial
  // direction. In some cases such as change of trajectory in the muon detector we
  // might want to compare theta-phi of two points or even find local maximum and
  // mimimum. In general it's not essential what defenition of the trajectory change
  // is used since we use these numbers only as a rough estimate on how much wider
  // we should make the preselection region.
  std::pair<float, float> result(0, 0);
  if (!stateAtIP_.isValid()) {
    edm::LogWarning("TrackAssociator") << "State at IP is not known set. Cannot estimate trajectory change. "
                                       << "Trajectory change is not taken into account in matching";
    return result;
  }
  switch (trajectoryType) {
    case IpToEcal:
      if (ecalTrajectory_.empty())
        edm::LogWarning("TrackAssociator") << "ECAL trajector is empty. Cannot estimate trajectory change. "
                                           << "Trajectory change is not taken into account in matching";
      else
        return delta(stateAtIP_.momentum().theta(),
                     ecalTrajectory_.front().position().theta(),
                     stateAtIP_.momentum().phi(),
                     ecalTrajectory_.front().position().phi());
      break;
    case IpToHcal:
      if (hcalTrajectory_.empty())
        edm::LogWarning("TrackAssociator") << "HCAL trajector is empty. Cannot estimate trajectory change. "
                                           << "Trajectory change is not taken into account in matching";
      else
        return delta(stateAtIP_.momentum().theta(),
                     hcalTrajectory_.front().position().theta(),
                     stateAtIP_.momentum().phi(),
                     hcalTrajectory_.front().position().phi());
      break;
    case IpToHO:
      if (hoTrajectory_.empty())
        edm::LogWarning("TrackAssociator") << "HO trajector is empty. Cannot estimate trajectory change. "
                                           << "Trajectory change is not taken into account in matching";
      else
        return delta(stateAtIP_.momentum().theta(),
                     hoTrajectory_.front().position().theta(),
                     stateAtIP_.momentum().phi(),
                     hoTrajectory_.front().position().phi());
      break;
    case FullTrajectory:
      if (fullTrajectory_.empty())
        edm::LogWarning("TrackAssociator") << "Full trajector is empty. Cannot estimate trajectory change. "
                                           << "Trajectory change is not taken into account in matching";
      else
        return delta(stateAtIP_.momentum().theta(),
                     fullTrajectory_.back().position().theta(),
                     stateAtIP_.momentum().phi(),
                     fullTrajectory_.back().position().phi());
      break;
    default:
      edm::LogWarning("TrackAssociator")
          << "Unkown or not supported trajector type. Cannot estimate trajectory change. "
          << "Trajectory change is not taken into account in matching";
  }
  return result;
}
 
std::pair<float, float> CachedTrajectory::delta(const double& theta1,
                                                const double& theta2,
                                                const double& phi1,
                                                const double& phi2) {
  std::pair<float, float> result(theta2 - theta1, phi2 - phi1);
  // this won't work for loopers, since deltaPhi cannot be larger than Pi.
  if (fabs(result.second) > 2 * M_PI - fabs(result.second)) {
    if (result.second > 0)
      result.second -= 2 * M_PI;
    else
      result.second += 2 * M_PI;
  }
  return result;
}
 
void CachedTrajectory::getTrajectory(std::vector<SteppingHelixStateInfo>& trajectory,
                                     const FiducialVolume& volume,
                                     int steps) {
  if (!fullTrajectoryFilled_)
    throw cms::Exception("FatalError") << "trajectory is not defined yet. Please use propagateAll first.";
  if (fullTrajectory_.empty()) {
    LogTrace("TrackAssociator") << "Trajectory is empty. Move on";
    return;
  }
  if (!volume.isValid()) {
    LogTrace("TrackAssociator") << "no trajectory is expected to be found since the fiducial volume is not valid";
    return;
  }
  double step = std::max(volume.maxR() - volume.minR(), volume.maxZ() - volume.minZ()) / steps;
 
  int closestPointOnLeft = -1;
 
  // check whether the trajectory crossed the region
  if (!((fullTrajectory_.front().position().perp() < volume.maxR() &&
         fabs(fullTrajectory_.front().position().z()) < volume.maxZ()) &&
        (fullTrajectory_.back().position().perp() > volume.minR() ||
         fabs(fullTrajectory_.back().position().z()) > volume.minZ()))) {
    LogTrace("TrackAssociator") << "Track didn't cross the region (R1,R2,L1,L2): " << volume.minR() << ", "
                                << volume.maxR() << ", " << volume.minZ() << ", " << volume.maxZ();
    return;
  }
 
  // get distance along momentum to the surface.
 
  // the following code can be made faster, but it'll hardly be a significant improvement
  // simplifications:
  //   1) direct loop over stored trajectory points instead of some sort
  //      of fast root search (Newton method)
  //   2) propagate from the closest point outside the region with the
  //      requested step ignoring stored trajectory points.
  double dZ(-1.);
  double dR(-1.);
  int firstPointInside(-1);
  for (unsigned int i = 0; i < fullTrajectory_.size(); i++) {
    // LogTrace("TrackAssociator") << "Trajectory info (i,perp,r1,r2,z,z1,z2): " << i << ", " << fullTrajectory_[i].position().perp() <<
    //  ", " << volume.minR() << ", " << volume.maxR() << ", " << fullTrajectory_[i].position().z() << ", " << volume.minZ() << ", " <<
    //  volume.maxZ() << ", " << closestPointOnLeft;
    dR = fullTrajectory_[i].position().perp() - volume.minR();
    dZ = fabs(fullTrajectory_[i].position().z()) - volume.minZ();
    if (dR > 0 || dZ > 0) {
      if (i > 0) {
        firstPointInside = i;
        closestPointOnLeft = i - 1;
      } else {
        firstPointInside = 0;
        closestPointOnLeft = 0;
      }
      break;
    }
  }
  if (closestPointOnLeft == -1)
    throw cms::Exception("FatalError") << "This shouls never happen - internal logic error";
 
  SteppingHelixStateInfo currentState(fullTrajectory_[closestPointOnLeft]);
  if (currentState.position().x() * currentState.momentum().x() +
          currentState.position().y() * currentState.momentum().y() +
          currentState.position().z() * currentState.momentum().z() <
      0)
    step = -step;
 
  // propagate to the inner surface of the active volume
 
  if (firstPointInside != closestPointOnLeft) {
    if (dR > 0) {
      Cylinder::CylinderPointer barrel =
          Cylinder::build(volume.minR(), Cylinder::PositionType(0, 0, 0), Cylinder::RotationType());
      propagate(currentState, *barrel);
    } else {
      Plane::PlanePointer endcap =
          Plane::build(Plane::PositionType(0, 0, currentState.position().z() > 0 ? volume.minZ() : -volume.minZ()),
                       Plane::RotationType());
      propagate(currentState, *endcap);
    }
    if (currentState.isValid())
      trajectory.push_back(currentState);
  } else
    LogTrace("TrackAssociator") << "Weird message\n";
 
  while (currentState.isValid() && currentState.position().perp() < volume.maxR() &&
         fabs(currentState.position().z()) < volume.maxZ()) {
    propagateForward(currentState, step);
    if (!currentState.isValid()) {
      LogTrace("TrackAssociator") << "Failed to propagate the track; moving on\n";
      break;
    }
    // LogTrace("TrackAssociator") << "New state (perp, z): " << currentState.position().perp() << ", " << currentState.position().z();
    //if ( ( currentState.position().perp() < volume.maxR() && fabs(currentState.position().z()) < volume.maxZ() ) &&
    //     ( currentState.position().perp()-volume.minR() > 0  || fabs(currentState.position().z()) - volume.minZ() >0 ) )
    trajectory.push_back(currentState);
  }
}
 
void CachedTrajectory::reset_trajectory() {
  fullTrajectory_.clear();
  ecalTrajectory_.clear();
  hcalTrajectory_.clear();
  hoTrajectory_.clear();
  preshowerTrajectory_.clear();
  wideEcalTrajectory_.clear();
  wideHcalTrajectory_.clear();
  wideHOTrajectory_.clear();
  fullTrajectoryFilled_ = false;
}
 
void CachedTrajectory::findEcalTrajectory(const FiducialVolume& volume) {
  LogTrace("TrackAssociator") << "getting trajectory in ECAL";
  getTrajectory(ecalTrajectory_, volume, 4);
  LogTrace("TrackAssociator") << "# of points in ECAL trajectory:" << ecalTrajectory_.size();
}
 
void CachedTrajectory::findPreshowerTrajectory(const FiducialVolume& volume) {
  LogTrace("TrackAssociator") << "getting trajectory in Preshower";
  getTrajectory(preshowerTrajectory_, volume, 2);
  LogTrace("TrackAssociator") << "# of points in Preshower trajectory:" << preshowerTrajectory_.size();
}
 
const std::vector<SteppingHelixStateInfo>& CachedTrajectory::getEcalTrajectory() const { return ecalTrajectory_; }
 
const std::vector<SteppingHelixStateInfo>& CachedTrajectory::getPreshowerTrajectory() const {
  return preshowerTrajectory_;
}
 
void CachedTrajectory::findHcalTrajectory(const FiducialVolume& volume) {
  LogTrace("TrackAssociator") << "getting trajectory in HCAL";
  getTrajectory(hcalTrajectory_, volume, 4);  // more steps to account for different depth
  LogTrace("TrackAssociator") << "# of points in HCAL trajectory:" << hcalTrajectory_.size();
}
 
const std::vector<SteppingHelixStateInfo>& CachedTrajectory::getHcalTrajectory() const { return hcalTrajectory_; }
 
void CachedTrajectory::findHOTrajectory(const FiducialVolume& volume) {
  LogTrace("TrackAssociator") << "getting trajectory in HO";
  getTrajectory(hoTrajectory_, volume, 2);
  LogTrace("TrackAssociator") << "# of points in HO trajectory:" << hoTrajectory_.size();
}
 
const std::vector<SteppingHelixStateInfo>& CachedTrajectory::getHOTrajectory() const { return hoTrajectory_; }
 
std::vector<GlobalPoint>* CachedTrajectory::getWideTrajectory(const std::vector<SteppingHelixStateInfo>& states,
                                                              WideTrajectoryType wideTrajectoryType) {
  std::vector<GlobalPoint>* wideTrajectory = nullptr;
  switch (wideTrajectoryType) {
    case Ecal:
      LogTrace("TrackAssociator") << "Filling ellipses in Ecal trajectory";
      wideTrajectory = &wideEcalTrajectory_;
      break;
    case Hcal:
      LogTrace("TrackAssociator") << "Filling ellipses in Hcal trajectory";
      wideTrajectory = &wideHcalTrajectory_;
      break;
    case HO:
      LogTrace("TrackAssociator") << "Filling ellipses in HO trajectory";
      wideTrajectory = &wideHOTrajectory_;
      break;
  }
  if (!wideTrajectory)
    return nullptr;
 
  for (std::vector<SteppingHelixStateInfo>::const_iterator state = states.begin(); state != states.end(); state++) {
    // defined a normal plane wrt the particle trajectory direction
    // let's hope that I computed the rotation matrix correctly.
    GlobalVector vector(state->momentum().unit());
    float r21 = 0;
    float r22 = vector.z() / sqrt(1 - pow(vector.x(), 2));
    float r23 = -vector.y() / sqrt(1 - pow(vector.x(), 2));
    float r31 = vector.x();
    float r32 = vector.y();
    float r33 = vector.z();
    float r11 = r22 * r33 - r23 * r32;
    float r12 = r23 * r31;
    float r13 = -r22 * r31;
 
    Plane::RotationType rotation(r11, r12, r13, r21, r22, r23, r31, r32, r33);
    Plane* target = new Plane(state->position(), rotation);
 
    TrajectoryStateOnSurface tsos = state->getStateOnSurface(*target);
 
    if (!tsos.isValid()) {
      LogTrace("TrackAssociator") << "[getWideTrajectory] TSOS not valid";
      continue;
    }
    if (!tsos.hasError()) {
      LogTrace("TrackAssociator") << "[getWideTrajectory] TSOS does not have Errors";
      continue;
    }
    LocalError localErr = tsos.localError().positionError();
    localErr.scale(2);  // get the 2 sigma ellipse
    float xx = localErr.xx();
    float xy = localErr.xy();
    float yy = localErr.yy();
 
    float denom = yy - xx;
    float phi = 0.;
    if (xy == 0 && denom == 0)
      phi = M_PI_4;
    else
      phi = 0.5 * atan2(2. * xy, denom);  // angle of MAJOR axis
    // Unrotate the error ellipse to get the semimajor and minor axes. Then place points on
    // the endpoints of semiminor an seminajor axes on original(rotated) error ellipse.
    LocalError rotErr = localErr.rotate(-phi);  // xy covariance of rotErr should be zero
    float semi1 = sqrt(rotErr.xx());
    float semi2 = sqrt(rotErr.yy());
 
    // Just use one point if the ellipse is small
    // if(semi1 < 0.1 && semi2 < 0.1) {
    //   LogTrace("TrackAssociator") << "[getWideTrajectory] Error ellipse is small, using one trajectory point";
    //   wideTrajectory->push_back(state->position());
    //   continue;
    // }
 
    Local2DPoint bounds[4];
    bounds[0] = Local2DPoint(semi1 * cos(phi), semi1 * sin(phi));
    bounds[1] = Local2DPoint(semi1 * cos(phi + M_PI), semi1 * sin(phi + M_PI));
    phi += M_PI_2;  // add pi/2 for the semi2 axis
    bounds[2] = Local2DPoint(semi2 * cos(phi), semi2 * sin(phi));
    bounds[3] = Local2DPoint(semi2 * cos(phi + M_PI), semi2 * sin(phi + M_PI));
 
    // LogTrace("TrackAssociator") << "Axes " << semi1 <<","<< semi2 <<"   phi "<< phi;
    // LogTrace("TrackAssociator") << "Local error ellipse: " << bounds[0] << bounds[1] << bounds[2] << bounds[3];
 
    wideTrajectory->push_back(state->position());
    for (int index = 0; index < 4; ++index)
      wideTrajectory->push_back(target->toGlobal(bounds[index]));
 
    //LogTrace("TrackAssociator") <<"Global error ellipse: (" << target->toGlobal(bounds[0]) <<","<< target->toGlobal(bounds[1])
    //         <<","<< target->toGlobal(bounds[2]) <<","<< target->toGlobal(bounds[3]) <<","<<state->position() <<")";
  }
 
  return wideTrajectory;
}
 
SteppingHelixStateInfo CachedTrajectory::getStateAtEcal() {
  if (ecalTrajectory_.empty())
    return SteppingHelixStateInfo();
  else
    return ecalTrajectory_.front();
}
 
SteppingHelixStateInfo CachedTrajectory::getStateAtPreshower() {
  if (preshowerTrajectory_.empty())
    return SteppingHelixStateInfo();
  else
    return preshowerTrajectory_.front();
}
 
SteppingHelixStateInfo CachedTrajectory::getStateAtHcal() {
  if (hcalTrajectory_.empty())
    return SteppingHelixStateInfo();
  else
    return hcalTrajectory_.front();
}
 
SteppingHelixStateInfo CachedTrajectory::getStateAtHO() {
  if (hoTrajectory_.empty())
    return SteppingHelixStateInfo();
  else
    return hoTrajectory_.front();
}
 
SteppingHelixStateInfo CachedTrajectory::getInnerState() {
  if (fullTrajectory_.empty())
    return SteppingHelixStateInfo();
  else
    return fullTrajectory_.front();
}
 
SteppingHelixStateInfo CachedTrajectory::getOuterState() {
  if (fullTrajectory_.empty())
    return SteppingHelixStateInfo();
  else
    return fullTrajectory_.back();
}