pma::PMAlgStitching Class Reference

#include <PMAlgStitching.h>

Classes
struct	Config

Public Member Functions
	PMAlgStitching (const pma::PMAlgStitching::Config &config)
void	StitchTracksCPA (const detinfo::DetectorClocksData &clockData, const detinfo::DetectorPropertiesData &detProp, pma::TrkCandidateColl &tracks)
void	StitchTracksAPA (const detinfo::DetectorClocksData &clockData, const detinfo::DetectorPropertiesData &detProp, pma::TrkCandidateColl &tracks)

Private Member Functions
void	StitchTracks (const detinfo::DetectorClocksData &clockData, const detinfo::DetectorPropertiesData &detProp, pma::TrkCandidateColl &tracks, bool isCPA)
double	GetOptimalStitchShift (TVector3 &pos1, TVector3 &pos2, TVector3 &dir1, TVector3 &dir2, double &shift) const
double	GetTrackPairDelta (TVector3 &pos1, TVector3 &pos2, TVector3 &dir1, TVector3 &dir2) const
void	GetTPCXOffsets ()
double	GetTPCOffset (unsigned int tpc, unsigned int cryo, bool isCPA)

Private Attributes
std::map< geo::TPCID, double >	fTPCXOffsetsAPA
std::map< geo::TPCID, double >	fTPCXOffsetsCPA
double	fStitchingThreshold
unsigned int	fNodesFromEnd

Detailed Description

Definition at line 27 of file PMAlgStitching.h.

Constructor & Destructor Documentation

pma::PMAlgStitching::PMAlgStitching

(

const pma::PMAlgStitching::Config &

config

)

Definition at line 20 of file PMAlgStitching.cxx.

{

  // Set parameters from the config.
  fStitchingThreshold = config.StitchingThreshold();
  fNodesFromEnd = config.NodesFromEnd();

  // Get CPA and APA positions.
  GetTPCXOffsets();
}

Member Function Documentation

double pma::PMAlgStitching::GetOptimalStitchShift ( TVector3 &  pos1, TVector3 &  pos2, TVector3 &  dir1, TVector3 &  dir2, double &  shift  ) const

private

Definition at line 311 of file PMAlgStitching.cxx.

{

  double stepSize = 0.1;
  double minShift = shift - (50. * stepSize);
  double maxShift = shift + (50. * stepSize);
  double bestShift = 99999;
  double bestScore = 99999;

  for (shift = minShift; shift <= maxShift; shift += stepSize) {
    TVector3 newPos1 = pos1;
    TVector3 newPos2 = pos2;
    newPos1.SetX(pos1.X() - shift);
    newPos2.SetX(pos2.X() + shift);
    double thisScore = GetTrackPairDelta(newPos1, newPos2, dir1, dir2);
    if (thisScore < bestScore) {
      bestShift = shift;
      bestScore = thisScore;
    }
  }

  shift = bestShift;
  return bestScore;
}

double pma::PMAlgStitching::GetTPCOffset ( unsigned int  tpc, unsigned int  cryo, bool  isCPA  )

private

Definition at line 411 of file PMAlgStitching.cxx.

{

  geo::TPCID thisTPCID(cryo, tpc);
  double offset = 0.0;
  if (isCPA) { offset = fTPCXOffsetsCPA[thisTPCID]; }
  else {
    offset = fTPCXOffsetsAPA[thisTPCID];
  }
  return offset;
}

void pma::PMAlgStitching::GetTPCXOffsets ( )

private

Definition at line 366 of file PMAlgStitching.cxx.

{

  // Grab hold of the geometry
  auto const* geom = lar::providerFrom<geo::Geometry>();

  // Loop over each TPC and store the require information
  for (geo::TPCID const& tID : geom->IterateTPCIDs()) {

    geo::TPCGeo const& aTPC = geom->TPC(tID);

    // Loop over the 3 possible readout planes to find the x position
    unsigned int plane = 0;
    bool hasPlane = false;
    for (; plane < 4; ++plane) {
      hasPlane = aTPC.HasPlane(plane);
      if (hasPlane) { break; }
    }

    if (!hasPlane) { continue; }

    // Get the x position of the readout plane
    double xAnode = aTPC.PlaneLocation(plane)[0];
    fTPCXOffsetsAPA.insert(std::make_pair(tID, xAnode));

    // For the cathode, we have to try a little harder. Firstly, find the
    // min and max x values for the TPC.
    double origin[3] = {0.};
    double center[3] = {0.};
    aTPC.LocalToWorld(origin, center);
    double tpcDim[3] = {aTPC.HalfWidth(), aTPC.HalfHeight(), 0.5 * aTPC.Length()};
    double xmin = center[0] - tpcDim[0];
    double xmax = center[0] + tpcDim[0];
    double xCathode = 0.;
    // Now check which is further from the APA and use that as the cathode value.
    if (fabs(xmin - xAnode) > fabs(xmax - xAnode)) { xCathode = xmin; }
    else {
      xCathode = xmax;
    }
    fTPCXOffsetsCPA.insert(std::make_pair(tID, xCathode));
  }
}

double pma::PMAlgStitching::GetTrackPairDelta ( TVector3 &  pos1, TVector3 &  pos2, TVector3 &  dir1, TVector3 &  dir2  ) const

private

Definition at line 342 of file PMAlgStitching.cxx.

{

  double delta = -999.;

  // Calculate number of steps to reach the merge point in x.
  double steps1 = (pos2.X() - pos1.X()) / dir1.X();
  double steps2 = (pos1.X() - pos2.X()) / dir2.X();

  // Extrapolate each vector to the other's extrapolation point
  TVector3 trk1Merge = pos1 + steps1 * dir1;
  TVector3 trk2Merge = pos2 + steps2 * dir2;

  // Find the difference between each vector and the extrapolation
  delta = (trk1Merge - pos2).Mag() + (trk2Merge - pos1).Mag();

  return delta;
}

void pma::PMAlgStitching::StitchTracks ( const detinfo::DetectorClocksData &  clockData, const detinfo::DetectorPropertiesData &  detProp, pma::TrkCandidateColl &  tracks, bool  isCPA  )

private

Definition at line 55 of file PMAlgStitching.cxx.

{

  unsigned int minTrkLength = 2 * fNodesFromEnd + 3;
  // Special case for fNodesFromEnd = 0
  if (minTrkLength < 6) minTrkLength = 6;

  // Loop over the track collection
  unsigned int t = 0;
  while (t < tracks.size()) {

    pma::Track3D* t1 = tracks[t].Track();
    if (t1->Nodes().size() < minTrkLength) {
      ++t;
      continue;
    }

    // Look through the following tracks for one to stitch
    pma::Track3D* bestTrkMatch = 0x0;

    // Don't use the very end points of the tracks in case of scatter or distortion.
    TVector3 trk1Front = t1->Nodes()[(fNodesFromEnd)]->Point3D();
    TVector3 trk1Back = t1->Nodes()[t1->Nodes().size() - 1 - fNodesFromEnd]->Point3D();
    TVector3 trk1FrontDir = (trk1Front - t1->Nodes()[(fNodesFromEnd + 1)]->Point3D()).Unit();
    TVector3 trk1BackDir =
      (trk1Back - t1->Nodes()[t1->Nodes().size() - 1 - (fNodesFromEnd + 1)]->Point3D()).Unit();

    // For stitching, we need to consider both ends of the track.
    double offsetFront1 = GetTPCOffset(t1->FrontTPC(), t1->FrontCryo(), isCPA);
    double offsetBack1 = GetTPCOffset(t1->BackTPC(), t1->BackCryo(), isCPA);

    bool isBestFront1 = false;
    bool isBestFront2 = false;
    double xBestShift = 0;
    double frontShift1 = t1->Nodes()[0]->Point3D().X() - offsetFront1;
    double backShift1 = t1->Nodes()[t1->Nodes().size() - 1]->Point3D().X() - offsetBack1;

    double bestMatchScore = 99999;

    for (unsigned int u = t + 1; u < tracks.size(); ++u) {

      pma::Track3D* t2 = tracks[u].Track();
      if (t2->Nodes().size() < minTrkLength) continue;

      // Don't use the very end points of the tracks in case of scatter or distortion.
      TVector3 trk2Front = t2->Nodes()[(fNodesFromEnd)]->Point3D();
      TVector3 trk2Back = t2->Nodes()[t2->Nodes().size() - 1 - fNodesFromEnd]->Point3D();
      TVector3 trk2FrontDir = (trk2Front - t2->Nodes()[(fNodesFromEnd + 1)]->Point3D()).Unit();
      TVector3 trk2BackDir =
        (trk2Back - t2->Nodes()[t2->Nodes().size() - 1 - (fNodesFromEnd + 1)]->Point3D()).Unit();

      // For stitching, we need to consider both ends of the track.
      double offsetFront2 = GetTPCOffset(t2->FrontTPC(), t2->FrontCryo(), isCPA);
      double offsetBack2 = GetTPCOffset(t2->BackTPC(), t2->BackCryo(), isCPA);

      // If the points to match are in the same TPC, then don't bother.
      // Remember we have 4 points to consider here.
      bool giveUp = false;
      geo::TPCID tpc1(0, 0);
      geo::TPCID tpc2(0, 0);
      // Front-to-front
      tpc1 = geo::TPCID(t1->FrontCryo(), t1->FrontTPC());
      tpc2 = geo::TPCID(t2->FrontCryo(), t2->FrontTPC());
      if (tpc1 == tpc2) giveUp = true;
      // Front-to-back
      tpc2 = geo::TPCID(t2->BackCryo(), t2->BackTPC());
      if (tpc1 == tpc2) giveUp = true;
      // Back-to-front
      tpc1 = geo::TPCID(t1->BackCryo(), t1->BackTPC());
      tpc2 = geo::TPCID(t2->FrontCryo(), t2->FrontTPC());
      if (tpc1 == tpc2) giveUp = true;
      // Back-to-back
      tpc2 = geo::TPCID(t2->BackCryo(), t2->BackTPC());
      if (tpc1 == tpc2) giveUp = true;

      // If the tracks have one end in the same TPC, give up.
      if (giveUp) continue;

      // Also check that these tpcs do meet at the stitching surface (not a problem for protoDUNE).
      double surfaceGap = 10.0;
      bool carryOn[4] = {true, true, true, true};
      if (fabs(offsetFront1 - offsetFront2) > surfaceGap) carryOn[0] = false;
      if (fabs(offsetFront1 - offsetBack2) > surfaceGap) carryOn[1] = false;
      if (fabs(offsetBack1 - offsetFront2) > surfaceGap) carryOn[2] = false;
      if (fabs(offsetBack1 - offsetBack2) > surfaceGap) carryOn[3] = false;

      // Loop over the four options
      for (int i = 0; i < 4; ++i) {

        if (!carryOn[i]) continue;

        TVector3 t1Pos;
        TVector3 t2Pos;
        TVector3 t1Dir;
        TVector3 t2Dir;
        double xShift1;
        if (i < 2) {
          t1Pos = trk1Front;
          t1Dir = trk1FrontDir;
          xShift1 = frontShift1;
        }
        else {
          t1Pos = trk1Back;
          t1Dir = trk1BackDir;
          xShift1 = backShift1;
        }
        if (i % 2 == 0) {
          t2Pos = trk2Front;
          t2Dir = trk2FrontDir;
        }
        else {
          t2Pos = trk2Back;
          t2Dir = trk2BackDir;
        }

        // Make sure the x directions point towards eachother (could be an issue for matching a short track)
        if (t1Dir.X() * t2Dir.X() > 0) { continue; }
        //        t1Pos.SetX(t1Pos.X() - xShift1);
        //        t2Pos.SetX(t2Pos.X() + xShift1);

        double score = 0;
        //        score = GetTrackPairDelta(t1Pos,t2Pos,t1Dir,t2Dir);
        score = GetOptimalStitchShift(t1Pos, t2Pos, t1Dir, t2Dir, xShift1);

        if (score < fStitchingThreshold && score < bestMatchScore) {

          bestTrkMatch = t2;
          xBestShift = xShift1;
          bestMatchScore = score;
          if (i < 2) { isBestFront1 = true; }
          else {
            isBestFront1 = false;
          }
          if (i % 2 == 0) { isBestFront2 = true; }
          else {
            isBestFront2 = false;
          }
          mf::LogInfo("pma::PMAlgStitcher")
            << "Tracks " << t << " and " << u << " matching score = " << score << std::endl
            << " - " << t1Pos.X() << ", " << t1Pos.Y() << ", " << t1Pos.Z() << " :: " << t1Dir.X()
            << ", " << t1Dir.Y() << ", " << t1Dir.Z() << std::endl
            << " - " << t2Pos.X() << ", " << t2Pos.Y() << ", " << t2Pos.Z() << " :: " << t2Dir.X()
            << ", " << t2Dir.Y() << ", " << t2Dir.Z() << std::endl
            << " - " << t1->FrontCryo() << ", " << t1->FrontTPC() << " :: " << t1->BackCryo()
            << ", " << t1->BackTPC() << std::endl
            << " - " << t2->FrontCryo() << ", " << t2->FrontTPC() << " :: " << t2->BackCryo()
            << ", " << t2->BackTPC() << std::endl
            << " - " << isBestFront1 << " :: " << isBestFront2 << std::endl;
        } // End successful match if
      }   // Loop over matching options
    }     // Loop over track 2

    // If we found a match, do something about it.
    if (bestTrkMatch != 0x0) {

      bool flip1 = false;
      bool flip2 = false;
      bool reverse = false;

      // Front-to-front match
      if (isBestFront1 && isBestFront2) { flip1 = true; }
      // Front-to-back match
      else if (isBestFront1 && !isBestFront2) {
        reverse = true;
      }
      // Back-to-back match
      else if (!isBestFront1 && !isBestFront2) {
        flip2 = true;
      }
      // Back-to-front match (do nothing)

      int tid1 = tracks.getCandidateTreeId(t1);
      int tid2 = tracks.getCandidateTreeId(bestTrkMatch);

      bool canMerge = true;
      if ((tid1 < 0) || (tid2 < 0)) {
        throw cet::exception("pma::PMAlgStitching")
          << "Track not found in the collection." << std::endl;
      }
      if (flip1) {

        std::vector<pma::Track3D*> newTracks;
        if (t1->Flip(detProp, newTracks)) {
          mf::LogInfo("pma::PMAlgStitching") << "Track 1 flipped.";
        }
        else {
          mf::LogInfo("pma::PMAlgStitching") << "Unable to flip Track 1.";
          canMerge = false;
        }
        for (const auto ts : newTracks) { // there may be a new track even if
                                          // entire flip was not possible
          tracks.tracks().emplace_back(ts, -1, tid1);
        }
      }
      if (flip2) {

        std::vector<pma::Track3D*> newTracks;
        if (bestTrkMatch->Flip(detProp, newTracks)) {
          mf::LogInfo("pma::PMAlgStitching") << "Track 2 flipped.";
        }
        else {
          mf::LogInfo("pma::PMAlgStitching") << "Unable to flip Track 1.";
          canMerge = false;
        }
        for (const auto ts : newTracks) { // there may be a new track even if
                                          // entire flip was not possible
          tracks.tracks().emplace_back(ts, -1, tid2);
        }
      }

      t1->GetRoot()->ApplyDriftShiftInTree(clockData, detProp, -xBestShift);
      bestTrkMatch->GetRoot()->ApplyDriftShiftInTree(clockData, detProp, +xBestShift);

      if (canMerge) {
        mf::LogInfo("pma::PMAlgStitching") << "Merging tracks...";
        int idx1 = tracks.getCandidateIndex(t1);
        int idx2 = tracks.getCandidateIndex(bestTrkMatch);
        if (reverse) // merge current track to another track, do not increase
                     // the outer loop index t (next after current track jumps
                     // in at t)
        {
          if (tracks.setTreeOriginAtFront(detProp, t1)) {
            tracks.merge((size_t)idx2, (size_t)idx1);
          }
          else {
            mf::LogWarning("pma::PMAlgStitching") << "   could not merge.";
            ++t;
          }
        }
        else // merge to the current track, do not increase the outer loop index t (maybe something else will match to the extended track)
        {
          if (tracks.setTreeOriginAtFront(detProp, bestTrkMatch)) {
            tracks.merge((size_t)idx1, (size_t)idx2);
          }
          else {
            mf::LogWarning("pma::PMAlgStitching") << "   could not merge.";
            ++t;
          }
        }
        mf::LogInfo("pma::PMAlgStitching") << "...done";
      }
      else {
        ++t;
      } // track matched, but not merged, go to the next track in the outer loop
    }
    else {
      ++t;
    } // no track matched, go to the next track in the outer loop
  }
}

void pma::PMAlgStitching::StitchTracksAPA	(	const detinfo::DetectorClocksData &	clockData,
		const detinfo::DetectorPropertiesData &	detProp,
		pma::TrkCandidateColl &	tracks
	)

Definition at line 43 of file PMAlgStitching.cxx.

{
  mf::LogInfo("pma::PMAlgStitching") << "Passed " << tracks.size() << " tracks for APA stitching.";
  StitchTracks(clockData, detProp, tracks, false);
}

void pma::PMAlgStitching::StitchTracksCPA	(	const detinfo::DetectorClocksData &	clockData,
		const detinfo::DetectorPropertiesData &	detProp,
		pma::TrkCandidateColl &	tracks
	)

Definition at line 33 of file PMAlgStitching.cxx.

{
  mf::LogInfo("pma::PMAlgStitching") << "Passed " << tracks.size() << " tracks for CPA stitching.";
  StitchTracks(clockData, detProp, tracks, true);
}

Member Data Documentation

unsigned int pma::PMAlgStitching::fNodesFromEnd

private

Definition at line 79 of file PMAlgStitching.h.

double pma::PMAlgStitching::fStitchingThreshold

private

Definition at line 77 of file PMAlgStitching.h.

std::map<geo::TPCID, double> pma::PMAlgStitching::fTPCXOffsetsAPA

private

Definition at line 73 of file PMAlgStitching.h.

std::map<geo::TPCID, double> pma::PMAlgStitching::fTPCXOffsetsCPA

private

Definition at line 74 of file PMAlgStitching.h.

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

• larreco/larreco/RecoAlg/PMAlgStitching.h
• larreco/larreco/RecoAlg/PMAlgStitching.cxx