trkf::Geometric3DVertexFitter Class Reference

3D vertex fitter based on the geometric properties (start position, direction, covariance) of the tracks. More...

#include <Geometric3DVertexFitter.h>

Classes
struct	Config
struct	ParsCovsOnPlane
struct	TracksFromVertexSorter

Public Member Functions
	Geometric3DVertexFitter (const fhicl::Table< Config > &o, const fhicl::Table< TrackStatePropagator::Config > &p)
VertexWrapper	fitPFP (detinfo::DetectorPropertiesData const &detProp, size_t iPF, const art::ValidHandle< std::vector< recob::PFParticle >> &inputPFParticle, const std::unique_ptr< art::FindManyP< recob::Track >> &assocTracks) const
VertexWrapper	fitTracks (detinfo::DetectorPropertiesData const &detProp, const std::vector< art::Ptr< recob::Track >> &arttracks) const
VertexWrapper	fitTracks (detinfo::DetectorPropertiesData const &detProp, TrackRefVec &tracks) const
VertexWrapper	fitTracksWithVtx (detinfo::DetectorPropertiesData const &detProp, const std::vector< art::Ptr< recob::Track >> &tracks, const recob::tracking::Point_t &vtxPos) const
VertexWrapper	fitTracksWithVtx (detinfo::DetectorPropertiesData const &detProp, TrackRefVec &tracks, const recob::tracking::Point_t &vtxPos) const
VertexWrapper	closestPointAlongTrack (detinfo::DetectorPropertiesData const &detProp, const recob::Track &track, const recob::Track &other) const
VertexWrapper	fitTwoTracks (detinfo::DetectorPropertiesData const &detProp, const recob::Track &tk1, const recob::Track &tk2) const
void	addTrackToVertex (detinfo::DetectorPropertiesData const &detProp, VertexWrapper &vtx, const recob::Track &tk) const
std::vector < recob::VertexAssnMeta >	computeMeta (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx)
std::vector < recob::VertexAssnMeta >	computeMeta (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const std::vector< art::Ptr< recob::Track >> &arttracks)
std::vector < recob::VertexAssnMeta >	computeMeta (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const TrackRefVec &trks)
double	chi2 (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	ip (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	ipErr (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	sip (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	pDist (const VertexWrapper &vtx, const recob::Track &tk) const
VertexWrapper	unbiasedVertex (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	chi2Unbiased (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	ipUnbiased (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	ipErrUnbiased (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	sipUnbiased (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const
double	pDistUnbiased (detinfo::DetectorPropertiesData const &detProp, const VertexWrapper &vtx, const recob::Track &tk) const

Private Member Functions
double	chi2 (const ParsCovsOnPlane &pcp) const
double	ip (const ParsCovsOnPlane &pcp) const
double	ipErr (const ParsCovsOnPlane &pcp) const
double	sip (const ParsCovsOnPlane &pcp) const
ParsCovsOnPlane	getParsCovsOnPlane (detinfo::DetectorPropertiesData const &detProp, const trkf::VertexWrapper &vtx, const recob::Track &tk) const
std::pair< TrackState, double >	weightedAverageState (ParsCovsOnPlane &pcop) const
std::pair< TrackState, double >	weightedAverageState (SVector2 &par1, SVector2 &par2, SMatrixSym22 &cov1, SMatrixSym22 &cov2, recob::tracking::Plane &target) const

Private Attributes
std::unique_ptr < TrackStatePropagator >	prop
int	debugLevel
double	sipCut

Detailed Description

3D vertex fitter based on the geometric properties (start position, direction, covariance) of the tracks.

This algorithm fits vertices with following procedure. First, tracks are sorted based on their start positions and the number of hits. A vertex is created from the first two tracks: it is defined as the weighted average of the points of closest approaches of the two tracks. Then the other tracks are added, to the vertex: the updated vertex is defined as the weighted average of the n-1 track vertex position and the point of closest approach of the n-th track. Methods to obtain the (unbiased) propagation distance, impact parameter, impact parameter error, impact parameter significance, and chi2 of a track with respect to the vertex are provided.

Inputs are: a set of tracks; interface is provided allowing these to be passed directly of through a PFParticle hierarchy.

Outputs are: a VertexWrapper, containing the vertex and the reference to the tracks actually used in the fit; also methods to produce recob::VertexAssnMeta are provided.

For configuration options see Geometric3DVertexFitter::Config

Author

G. Cerati (FNAL, MicroBooNE)

Date

2017

Version

1.0

Definition at line 60 of file Geometric3DVertexFitter.h.

Constructor & Destructor Documentation

trkf::Geometric3DVertexFitter::Geometric3DVertexFitter ( const fhicl::Table< Config > &  o, const fhicl::Table< TrackStatePropagator::Config > &  p  )

inline

Definition at line 102 of file Geometric3DVertexFitter.h.

      : debugLevel(o().debugLevel()), sipCut(o().sipCut())
    {
      prop = std::make_unique<TrackStatePropagator>(p);
    }

Member Function Documentation

void trkf::Geometric3DVertexFitter::addTrackToVertex	(	detinfo::DetectorPropertiesData const &	detProp,
		trkf::VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 429 of file Geometric3DVertexFitter.cxx.

{

  if (debugLevel > 0) {
    std::cout << "adding track with start=" << tk.Start() << " dir=" << tk.StartDirection()
              << " length=" << tk.Length() << " points=" << tk.CountValidPoints() << std::endl;
    std::cout << "covariance=\n" << tk.VertexCovarianceGlobal6D() << std::endl;
  }

  ParsCovsOnPlane pcp = getParsCovsOnPlane(detProp, vtx, tk);
  std::pair<TrackState, double> was = weightedAverageState(pcp);
  if (was.second <= (util::kBogusD - 1.)) { return; }

  const int ndof = 2; // Each measurement is 2D because it is defined on a plane
  vtx.addTrackAndUpdateVertex(
    was.first.position(), was.first.covariance6D().Sub<SMatrixSym33>(0, 0), was.second, ndof, tk);

  if (debugLevel > 0) {
    std::cout << "updvtxpos=" << vtx.position() << std::endl;
    std::cout << "updvtxcov=\n" << vtx.covariance() << std::endl;
    std::cout << "add chi2=" << was.second << std::endl;
  }
}

double trkf::Geometric3DVertexFitter::chi2	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 468 of file Geometric3DVertexFitter.cxx.

{
  return chi2(getParsCovsOnPlane(detProp, vtx, tk));
}

double trkf::Geometric3DVertexFitter::chi2 ( const ParsCovsOnPlane &  pcp ) const

private

Definition at line 456 of file Geometric3DVertexFitter.cxx.

{
  const SVector2 deltapar = pcp.par2 - pcp.par1;
  SMatrixSym22 covsum = (pcp.cov2 + pcp.cov1);

  bool invertok = covsum.Invert();
  if (!invertok) return -1.;

  return ROOT::Math::Similarity(deltapar, covsum);
}

double trkf::Geometric3DVertexFitter::chi2Unbiased	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 542 of file Geometric3DVertexFitter.cxx.

{
  auto ittoerase = vtx.findTrack(tk);
  if (ittoerase == vtx.tracksSize()) { return chi2(detProp, vtx, tk); }
  else {
    auto tks = vtx.tracksWithoutElement(ittoerase);
    return chi2(detProp, fitTracks(detProp, tks), tk);
  }
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::closestPointAlongTrack	(	detinfo::DetectorPropertiesData const &	detProp,
		const recob::Track &	track,
		const recob::Track &	other
	)		const

Definition at line 204 of file Geometric3DVertexFitter.cxx.

{
  // find the closest approach point along track
  const auto& start1 = track.Trajectory().Start();
  const auto& start2 = other.Trajectory().Start();

  const auto dir1 = track.Trajectory().StartDirection();
  const auto dir2 = other.Trajectory().StartDirection();

  if (debugLevel > 0) {
    std::cout << "track1 with start=" << start1 << " dir=" << dir1 << " length=" << track.Length()
              << " points=" << track.CountValidPoints() << std::endl;
    std::cout << "covariance=\n" << track.VertexCovarianceGlobal6D() << std::endl;
    std::cout << "track2 with start=" << start2 << " dir=" << dir2 << " length=" << other.Length()
              << " points=" << other.CountValidPoints() << std::endl;
    std::cout << "covariance=\n" << other.VertexCovarianceGlobal6D() << std::endl;
  }

  const auto dpos = start1 - start2;
  const auto dotd1d2 = dir1.Dot(dir2);
  const auto dotdpd1 = dpos.Dot(dir1);
  const auto dotdpd2 = dpos.Dot(dir2);
  const auto dist2 = (dotd1d2 * dotdpd1 - dotdpd2) / (dotd1d2 * dotd1d2 - 1);
  const auto dist1 = (dotd1d2 * dist2 - dotdpd1);

  if (debugLevel > 0) {
    std::cout << "track1 pca=" << start1 + dist1 * dir1 << " dist=" << dist1 << std::endl;
    std::cout << "track2 pca=" << start2 + dist2 * dir2 << " dist=" << dist2 << std::endl;
  }

  //by construction both point of closest approach on the two lines lie on this plane
  recob::tracking::Plane target(start1 + dist1 * dir1, dir1);

  recob::tracking::Plane plane1(start1, dir1);
  trkf::TrackState state1(track.VertexParametersLocal5D(),
                          track.VertexCovarianceLocal5D(),
                          plane1,
                          true,
                          track.ParticleId());
  bool propok1 = true;
  state1 = prop->propagateToPlane(
    propok1, detProp, state1, target, true, true, trkf::TrackStatePropagator::UNKNOWN);
  if (!propok1) {
    std::cout << "failed propagation, return track1 start pos=" << track.Start() << std::endl;
    VertexWrapper vtx;
    vtx.addTrackAndUpdateVertex(
      track.Start(), track.VertexCovarianceGlobal6D().Sub<SMatrixSym33>(0, 0), 0, 0, track);
    return vtx;
  }
  else {
    VertexWrapper vtx;
    vtx.addTrackAndUpdateVertex(
      state1.position(), state1.covariance6D().Sub<SMatrixSym33>(0, 0), 0, 0, track);
    return vtx;
  }
}

std::vector< recob::VertexAssnMeta > trkf::Geometric3DVertexFitter::computeMeta	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx
	)

Definition at line 607 of file Geometric3DVertexFitter.cxx.

{
  return computeMeta(detProp, vtx, vtx.tracks());
}

std::vector< recob::VertexAssnMeta > trkf::Geometric3DVertexFitter::computeMeta	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const std::vector< art::Ptr< recob::Track >> &	arttracks
	)

Definition at line 614 of file Geometric3DVertexFitter.cxx.

{
  TrackRefVec tracks;
  for (auto t : arttracks)
    tracks.push_back(*t);
  return computeMeta(detProp, vtx, tracks);
}

std::vector< recob::VertexAssnMeta > trkf::Geometric3DVertexFitter::computeMeta	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const TrackRefVec &	trks
	)

Definition at line 625 of file Geometric3DVertexFitter.cxx.

{
  std::vector<recob::VertexAssnMeta> result;
  for (auto tk : trks) {
    float d = util::kBogusF;
    float i = util::kBogusF;
    float e = util::kBogusF;
    float c = util::kBogusF;
    auto ittoerase = vtx.findTrack(tk);
    if (debugLevel > 1)
      std::cout << "computeMeta for vertex with ntracks=" << vtx.tracksSize() << std::endl;
    auto ubvtx = unbiasedVertex(detProp, vtx, tk.get());
    if (debugLevel > 1)
      std::cout << "got unbiased vertex with ntracks=" << ubvtx.tracksSize()
                << " isValid=" << ubvtx.isValid() << std::endl;
    if (ubvtx.isValid()) {
      d = pDist(ubvtx, tk.get());
      auto pcop = getParsCovsOnPlane(detProp, ubvtx, tk.get());
      i = ip(pcop);
      e = ipErr(pcop);
      c = chi2(pcop);
      if (debugLevel > 1)
        std::cout << "unbiasedVertex d=" << d << " i=" << i << " e=" << e << " c=" << c
                  << std::endl;
    }
    else if (vtx.tracksSize() == 2 && ittoerase != vtx.tracksSize()) {
      auto tks = vtx.tracksWithoutElement(ittoerase);
      auto fakevtx = closestPointAlongTrack(detProp, tks[0], tk);
      d = pDist(fakevtx, tk.get());
      // these will be identical for the two tracks (modulo numerical instabilities in the matrix inversion for the chi2)
      auto pcop = getParsCovsOnPlane(detProp, fakevtx, tk.get());
      i = ip(pcop);
      e = ipErr(pcop);
      c = chi2(pcop);
      if (debugLevel > 1)
        std::cout << "closestPointAlongTrack d=" << d << " i=" << i << " e=" << e << " c=" << c
                  << std::endl;
    }
    if (ittoerase == vtx.tracksSize()) {
      result.push_back(recob::VertexAssnMeta(d, i, e, c, recob::VertexAssnMeta::NotUsedInFit));
    }
    else {
      result.push_back(recob::VertexAssnMeta(d, i, e, c, recob::VertexAssnMeta::IncludedInFit));
    }
  }
  return result;
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::fitPFP	(	detinfo::DetectorPropertiesData const &	detProp,
		size_t	iPF,
		const art::ValidHandle< std::vector< recob::PFParticle >> &	inputPFParticle,
		const std::unique_ptr< art::FindManyP< recob::Track >> &	assocTracks
	)		const

Definition at line 4 of file Geometric3DVertexFitter.cxx.

{
  using namespace std;
  art::Ptr<recob::PFParticle> pfp(inputPFParticle, iPF);
  if (debugLevel > 1)
    std::cout << "pfp#" << iPF << " PdgCode=" << pfp->PdgCode() << " IsPrimary=" << pfp->IsPrimary()
              << " NumDaughters=" << pfp->NumDaughters() << std::endl;
  if (pfp->IsPrimary() == false || pfp->NumDaughters() < 2) return VertexWrapper();

  TrackRefVec tracks;

  auto& pfd = pfp->Daughters();
  for (auto ipfd : pfd) {
    vector<art::Ptr<recob::Track>> pftracks = assocTracks->at(ipfd);
    for (auto t : pftracks) {
      tracks.push_back(*t);
    }
  }

  if (size(tracks) < 2) { return VertexWrapper{}; }

  return fitTracks(detProp, tracks);
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::fitTracks	(	detinfo::DetectorPropertiesData const &	detProp,
		const std::vector< art::Ptr< recob::Track >> &	arttracks
	)		const

Definition at line 33 of file Geometric3DVertexFitter.cxx.

{
  TrackRefVec tracks;
  for (auto t : arttracks) {
    tracks.push_back(*t);
  }
  return fitTracks(detProp, tracks);
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::fitTracks	(	detinfo::DetectorPropertiesData const &	detProp,
		TrackRefVec &	tracks
	)		const

Definition at line 44 of file Geometric3DVertexFitter.cxx.

{
  if (debugLevel > 0) std::cout << "fitting vertex with ntracks=" << tracks.size() << std::endl;
  if (tracks.size() < 2) return VertexWrapper();

  // sort tracks by number of hits
  std::sort(
    tracks.begin(),
    tracks.end(),
    [](std::reference_wrapper<const recob::Track> a, std::reference_wrapper<const recob::Track> b) {
      return a.get().CountValidPoints() > b.get().CountValidPoints();
    });

  //find pair with closest start positions and put them upfront
  unsigned int tk0 = tracks.size();
  unsigned int tk1 = tracks.size();
  float mind = FLT_MAX;
  for (unsigned int i = 0; i < tracks.size() - 1; i++) {
    for (unsigned int j = i + 1; j < tracks.size(); j++) {
      float d =
        (tracks[i].get().Trajectory().Start() - tracks[j].get().Trajectory().Start()).Mag2();
      if (debugLevel > 1)
        std::cout << "test i=" << i << " start=" << tracks[i].get().Trajectory().Start()
                  << " j=" << j << " start=" << tracks[j].get().Trajectory().Start() << " d=" << d
                  << " mind=" << mind << " tk0=" << tk0 << " tk1=" << tk1 << std::endl;
      if (d < mind) {
        mind = d;
        tk0 = i;
        tk1 = j;
      }
    }
  }
  if (tk0 > 1 || tk1 > 1) {
    if (tk0 > 1 && tk1 > 1) {
      std::swap(tracks[0], tracks[tk0]);
      std::swap(tracks[1], tracks[tk1]);
    }
    if (tk0 == 0) std::swap(tracks[1], tracks[tk1]);
    if (tk0 == 1) std::swap(tracks[0], tracks[tk1]);
    if (tk1 == 0) std::swap(tracks[1], tracks[tk0]);
    if (tk1 == 1) std::swap(tracks[0], tracks[tk0]);
  }

  // find vertex between the first two tracks
  VertexWrapper vtx = fitTwoTracks(detProp, tracks[0], tracks[1]);
  if (vtx.isValid() == false || vtx.tracksSize() < 2) return vtx;

  // then add other tracks and update vertex measurement
  for (auto tk = tracks.begin() + 2; tk < tracks.end(); ++tk) {
    auto sipv = sip(detProp, vtx, *tk);
    if (debugLevel > 1) std::cout << "sip=" << sipv << std::endl;
    if (sipv > sipCut) continue;
    addTrackToVertex(detProp, vtx, *tk);
  }
  return vtx;
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::fitTracksWithVtx	(	detinfo::DetectorPropertiesData const &	detProp,
		const std::vector< art::Ptr< recob::Track >> &	tracks,
		const recob::tracking::Point_t &	vtxPos
	)		const

Definition at line 103 of file Geometric3DVertexFitter.cxx.

{
  TrackRefVec tracks;
  for (auto t : arttracks) {
    tracks.push_back(*t);
  }
  return fitTracksWithVtx(detProp, tracks, vtxPos);
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::fitTracksWithVtx	(	detinfo::DetectorPropertiesData const &	detProp,
		TrackRefVec &	tracks,
		const recob::tracking::Point_t &	vtxPos
	)		const

Definition at line 116 of file Geometric3DVertexFitter.cxx.

{
  if (debugLevel > 0) std::cout << "fitting vertex with ntracks=" << tracks.size() << std::endl;
  if (tracks.size() < 2) return VertexWrapper();
  // sort tracks by proximity to input vertex
  std::sort(tracks.begin(), tracks.end(), TracksFromVertexSorter(vtxPos));

  // find vertex between the first two tracks
  VertexWrapper vtx = fitTwoTracks(detProp, tracks[0], tracks[1]);
  if (vtx.isValid() == false || vtx.tracks().size() < 2) return vtx;

  // then add other tracks and update vertex measurement
  for (auto tk = tracks.begin() + 2; tk < tracks.end(); ++tk) {
    auto sipv = sip(detProp, vtx, *tk);
    if (debugLevel > 1) std::cout << "sip=" << sipv << std::endl;
    if (sipv > sipCut) continue;
    addTrackToVertex(detProp, vtx, *tk);
  }
  return vtx;
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::fitTwoTracks	(	detinfo::DetectorPropertiesData const &	detProp,
		const recob::Track &	tk1,
		const recob::Track &	tk2
	)		const

Definition at line 265 of file Geometric3DVertexFitter.cxx.

{
  // find the closest approach points
  auto start1 = tk1.Trajectory().Start();
  auto start2 = tk2.Trajectory().Start();

  auto dir1 = tk1.Trajectory().StartDirection();
  auto dir2 = tk2.Trajectory().StartDirection();

  if (debugLevel > 0) {
    std::cout << "track1 with start=" << start1 << " dir=" << dir1 << " length=" << tk1.Length()
              << " points=" << tk1.CountValidPoints() << std::endl;
    std::cout << "covariance=\n" << tk1.VertexCovarianceGlobal6D() << std::endl;
    std::cout << "track2 with start=" << start2 << " dir=" << dir2 << " length=" << tk2.Length()
              << " points=" << tk2.CountValidPoints() << std::endl;
    std::cout << "covariance=\n" << tk2.VertexCovarianceGlobal6D() << std::endl;
  }

  auto dpos = start1 - start2;
  auto dotd1d2 = dir1.Dot(dir2);

  auto dotdpd1 = dpos.Dot(dir1);
  auto dotdpd2 = dpos.Dot(dir2);

  auto dist2 = (dotd1d2 * dotdpd1 - dotdpd2) / (dotd1d2 * dotd1d2 - 1);
  auto dist1 = (dotd1d2 * dist2 - dotdpd1);

  //by construction both point of closest approach on the two lines lie on this plane
  recob::tracking::Plane target(start1 + dist1 * dir1, dir1);

  recob::tracking::Plane plane1(start1, dir1);
  trkf::TrackState state1(
    tk1.VertexParametersLocal5D(), tk1.VertexCovarianceLocal5D(), plane1, true, tk1.ParticleId());
  bool propok1 = true;
  state1 = prop->propagateToPlane(
    propok1, detProp, state1, target, true, true, trkf::TrackStatePropagator::UNKNOWN);
  if (!propok1) {
    std::cout << "failed propagation, return track1 start pos=" << tk1.Start() << std::endl;
    VertexWrapper vtx;
    vtx.addTrackAndUpdateVertex(
      tk1.Start(), tk1.VertexCovarianceGlobal6D().Sub<SMatrixSym33>(0, 0), 0, 0, tk1);
    return vtx;
  }

  recob::tracking::Plane plane2(start2, dir2);
  trkf::TrackState state2(
    tk2.VertexParametersLocal5D(), tk2.VertexCovarianceLocal5D(), plane2, true, tk2.ParticleId());
  bool propok2 = true;
  state2 = prop->propagateToPlane(
    propok2, detProp, state2, target, true, true, trkf::TrackStatePropagator::UNKNOWN);
  if (!propok2) {
    std::cout << "failed propagation, return track1 start pos=" << tk1.Start() << std::endl;
    VertexWrapper vtx;
    vtx.addTrackAndUpdateVertex(
      tk1.Start(), tk1.VertexCovarianceGlobal6D().Sub<SMatrixSym33>(0, 0), 0, 0, tk1);
    return vtx;
  }

  if (debugLevel > 0) {
    std::cout << "track1 pca=" << start1 + dist1 * dir1 << " dist=" << dist1 << std::endl;
    std::cout << "track2 pca=" << start2 + dist2 * dir2 << " dist=" << dist2 << std::endl;
  }

  //here we neglect that to find dist1 and dist2 one track depends on the other...
  SMatrixSym22 cov1 = state1.covariance().Sub<SMatrixSym22>(0, 0);
  SMatrixSym22 cov2 = state2.covariance().Sub<SMatrixSym22>(0, 0);

  if (debugLevel > 1) {
    std::cout << "target pos=" << target.position() << " dir=" << target.direction() << std::endl;
    //test if orthogonal
    auto dcp = state1.position() - state2.position();
    std::cout << "dot dcp-dir1=" << dcp.Dot(tk1.Trajectory().StartDirection()) << std::endl;
    std::cout << "dot dcp-dir2=" << dcp.Dot(tk2.Trajectory().StartDirection()) << std::endl;

    std::cout << "cov1=" << cov1 << std::endl;
    std::cout << "cov2=" << cov2 << std::endl;
  }

  SVector2 par1(state1.parameters()[0], state1.parameters()[1]);
  SVector2 par2(state2.parameters()[0], state2.parameters()[1]);

  std::pair<TrackState, double> was = weightedAverageState(par1, par2, cov1, cov2, target);
  if (was.second <= (util::kBogusD - 1)) {
    std::cout << "failed inversion, return track1 start pos=" << tk1.Start() << std::endl;
    VertexWrapper vtx;
    vtx.addTrackAndUpdateVertex(
      tk1.Start(), tk1.VertexCovarianceGlobal6D().Sub<SMatrixSym33>(0, 0), 0, 0, tk1);
    return vtx;
  }

  const int ndof = 1; //1=2*2-3; each measurement is 2D because it is defined on a plane
  trkf::VertexWrapper vtx(
    was.first.position(), was.first.covariance6D().Sub<SMatrixSym33>(0, 0), was.second, ndof);
  vtx.addTrack(tk1);
  vtx.addTrack(tk2);

  if (debugLevel > 0) {
    std::cout << "vtxpos=" << vtx.position() << std::endl;
    std::cout << "vtxcov=\n" << vtx.covariance() << std::endl;
    std::cout << "chi2=" << was.second << std::endl;
  }

  return vtx;
}

trkf::Geometric3DVertexFitter::ParsCovsOnPlane trkf::Geometric3DVertexFitter::getParsCovsOnPlane ( detinfo::DetectorPropertiesData const &  detProp, const trkf::VertexWrapper &  vtx, const recob::Track &  tk  ) const

private

Definition at line 373 of file Geometric3DVertexFitter.cxx.

{
  auto start = tk.Trajectory().Start();
  auto dir = tk.Trajectory().StartDirection();

  auto vtxpos = vtx.position();
  auto vtxcov = vtx.covariance();

  auto dist = dir.Dot(vtxpos - start);

  //by construction vtxpos also lies on this plane
  recob::tracking::Plane target(start + dist * dir, dir);

  recob::tracking::Plane plane(start, dir);
  trkf::TrackState state(
    tk.VertexParametersLocal5D(), tk.VertexCovarianceLocal5D(), plane, true, tk.ParticleId());
  bool propok = true;
  state = prop->propagateToPlane(
    propok, detProp, state, target, true, true, trkf::TrackStatePropagator::UNKNOWN);

  if (debugLevel > 0) {
    std::cout << "input vtx=" << vtxpos << std::endl;
    std::cout << "input cov=\n" << vtxcov << std::endl;
    std::cout << "track pca=" << start + dist * dir << " dist=" << dist << std::endl;
    std::cout << "target pos=" << target.position() << " dir=" << target.direction() << std::endl;
  }

  //rotate the vertex position and covariance to the target plane
  SVector6 vtxpar6(vtxpos.X(), vtxpos.Y(), vtxpos.Z(), 0, 0, 0);
  SMatrixSym66 vtxcov66;
  vtxcov66.Place_at(vtxcov, 0, 0);

  auto vtxpar5 = target.Global6DToLocal5DParameters(vtxpar6);
  SVector2 par1(vtxpar5[0], vtxpar5[1]);
  SVector2 par2(state.parameters()[0], state.parameters()[1]);

  //here we neglect that to find dist, the vertex is used...
  SMatrixSym22 cov1 =
    target.Global6DToLocal5DCovariance(vtxcov66, false, Vector_t()).Sub<SMatrixSym22>(0, 0);
  SMatrixSym22 cov2 = state.covariance().Sub<SMatrixSym22>(0, 0);

  if (debugLevel > 1) {
    std::cout << "vtxpar5=" << vtxpar5 << std::endl;
    std::cout << "state.parameters()=" << state.parameters() << std::endl;
    std::cout << "vtx covariance=\n" << vtxcov66 << std::endl;
    std::cout << "trk covariance=\n" << state.covariance6D() << std::endl;
    std::cout << "cov1=\n" << cov1 << std::endl;
    std::cout << "cov2=\n" << cov2 << std::endl;
  }

  return ParsCovsOnPlane(par1, par2, cov1, cov2, target);
}

double trkf::Geometric3DVertexFitter::ip	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 483 of file Geometric3DVertexFitter.cxx.

{
  return ip(getParsCovsOnPlane(detProp, vtx, tk));
}

double trkf::Geometric3DVertexFitter::ip ( const ParsCovsOnPlane &  pcp ) const

private

Definition at line 476 of file Geometric3DVertexFitter.cxx.

{
  const SVector2 deltapar = pcp.par2 - pcp.par1;
  return std::sqrt(deltapar[0] * deltapar[0] + deltapar[1] * deltapar[1]);
}

double trkf::Geometric3DVertexFitter::ipErr	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 501 of file Geometric3DVertexFitter.cxx.

{
  return ipErr(getParsCovsOnPlane(detProp, vtx, tk));
}

double trkf::Geometric3DVertexFitter::ipErr ( const ParsCovsOnPlane &  pcp ) const

private

Definition at line 491 of file Geometric3DVertexFitter.cxx.

{
  SVector2 deltapar = pcp.par2 - pcp.par1;
  deltapar /= std::sqrt(deltapar[0] * deltapar[0] + deltapar[1] * deltapar[1]);
  SMatrixSym22 covsum = (pcp.cov2 + pcp.cov1);
  return std::sqrt(ROOT::Math::Similarity(deltapar, covsum));
}

double trkf::Geometric3DVertexFitter::ipErrUnbiased	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 568 of file Geometric3DVertexFitter.cxx.

{
  auto ittoerase = vtx.findTrack(tk);
  if (ittoerase == vtx.tracksSize()) { return ipErr(detProp, vtx, tk); }
  else {
    auto tks = vtx.tracksWithoutElement(ittoerase);
    return ipErr(detProp, fitTracks(detProp, tks), tk);
  }
}

double trkf::Geometric3DVertexFitter::ipUnbiased	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 555 of file Geometric3DVertexFitter.cxx.

{
  auto ittoerase = vtx.findTrack(tk);
  if (ittoerase == vtx.tracksSize()) { return ip(detProp, vtx, tk); }
  else {
    auto tks = vtx.tracksWithoutElement(ittoerase);
    return ip(detProp, fitTracks(detProp, tks), tk);
  }
}

double trkf::Geometric3DVertexFitter::pDist	(	const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 523 of file Geometric3DVertexFitter.cxx.

{
  return tk.Trajectory().StartDirection().Dot(vtx.position() - tk.Trajectory().Start());
}

double trkf::Geometric3DVertexFitter::pDistUnbiased	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 594 of file Geometric3DVertexFitter.cxx.

{
  auto ittoerase = vtx.findTrack(tk);
  if (ittoerase == vtx.tracksSize()) { return pDist(vtx, tk); }
  else {
    auto tks = vtx.tracksWithoutElement(ittoerase);
    return pDist(fitTracks(detProp, tks), tk);
  }
}

double trkf::Geometric3DVertexFitter::sip	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 515 of file Geometric3DVertexFitter.cxx.

{
  return sip(getParsCovsOnPlane(detProp, vtx, tk));
}

double trkf::Geometric3DVertexFitter::sip ( const ParsCovsOnPlane &  pcp ) const

private

Definition at line 509 of file Geometric3DVertexFitter.cxx.

{
  return ip(pcp) / ipErr(pcp);
}

double trkf::Geometric3DVertexFitter::sipUnbiased	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 581 of file Geometric3DVertexFitter.cxx.

{
  auto ittoerase = vtx.findTrack(tk);
  if (ittoerase == vtx.tracksSize()) { return sip(detProp, vtx, tk); }
  else {
    auto tks = vtx.tracksWithoutElement(ittoerase);
    return sip(detProp, fitTracks(detProp, tks), tk);
  }
}

trkf::VertexWrapper trkf::Geometric3DVertexFitter::unbiasedVertex	(	detinfo::DetectorPropertiesData const &	detProp,
		const VertexWrapper &	vtx,
		const recob::Track &	tk
	)		const

Definition at line 529 of file Geometric3DVertexFitter.cxx.

{
  auto ittoerase = vtx.findTrack(tk);
  if (ittoerase == vtx.tracksSize()) { return vtx; }
  else {
    auto tks = vtx.tracksWithoutElement(ittoerase);
    return fitTracks(detProp, tks);
  }
}

std::pair<TrackState, double> trkf::Geometric3DVertexFitter::weightedAverageState ( ParsCovsOnPlane &  pcop ) const

inlineprivate

Definition at line 190 of file Geometric3DVertexFitter.h.

    {
      return weightedAverageState(pcop.par1, pcop.par2, pcop.cov1, pcop.cov2, pcop.plane);
    };

std::pair< trkf::TrackState, double > trkf::Geometric3DVertexFitter::weightedAverageState ( SVector2 &  par1, SVector2 &  par2, SMatrixSym22 &  cov1, SMatrixSym22 &  cov2, recob::tracking::Plane &  target  ) const

private

Definition at line 140 of file Geometric3DVertexFitter.cxx.

{
  SVector2 deltapar = par2 - par1;
  SMatrixSym22 covsum = (cov2 + cov1);

  if (debugLevel > 1) {
    std::cout << "par1=" << par1 << std::endl;
    std::cout << "par2=" << par2 << std::endl;
    std::cout << "deltapar=" << deltapar << std::endl;

    std::cout << "cov1=\n" << cov1 << std::endl;
    std::cout << "cov2=\n" << cov2 << std::endl;
    std::cout << "covsum=\n" << covsum << std::endl;
  }

  if (debugLevel > 1) {
    double det1;
    bool d1ok = cov1.Det2(det1);
    std::cout << "cov1 det=" << det1 << " ok=" << d1ok << std::endl;
    double det2;
    bool d2ok = cov2.Det2(det2);
    std::cout << "cov2 det=" << det2 << " ok=" << d2ok << std::endl;
    double detsum;
    bool dsok = covsum.Det2(detsum);
    std::cout << "covsum det=" << detsum << " ok=" << dsok << std::endl;
  }

  bool invertok = covsum.Invert();
  if (!invertok) {
    SVector5 vtxpar5(0, 0, 0, 0, 0);
    SMatrixSym55 vtxcov55;
    TrackState vtxstate(vtxpar5, vtxcov55, target, true, 0);
    return std::make_pair(vtxstate, util::kBogusD);
  }
  auto k = cov1 * covsum;

  if (debugLevel > 1) {
    std::cout << "inverted covsum=\n" << covsum << std::endl;
    std::cout << "k=\n" << k << std::endl;
  }

  SVector2 vtxpar2 = par1 + k * deltapar;
  SMatrixSym22 vtxcov22 = cov1 - ROOT::Math::SimilarityT(cov1, covsum);

  if (debugLevel > 1) {
    std::cout << "vtxpar2=" << vtxpar2 << std::endl;
    std::cout << "vtxcov22=\n" << vtxcov22 << std::endl;
  }

  auto chi2 = ROOT::Math::Similarity(deltapar, covsum);

  SVector5 vtxpar5(vtxpar2[0], vtxpar2[1], 0, 0, 0);
  SMatrixSym55 vtxcov55;
  vtxcov55.Place_at(vtxcov22, 0, 0);
  TrackState vtxstate(vtxpar5, vtxcov55, target, true, 0);

  return std::make_pair(vtxstate, chi2);
}

Member Data Documentation

int trkf::Geometric3DVertexFitter::debugLevel

private

Definition at line 179 of file Geometric3DVertexFitter.h.

std::unique_ptr<TrackStatePropagator> trkf::Geometric3DVertexFitter::prop

private

Definition at line 178 of file Geometric3DVertexFitter.h.

double trkf::Geometric3DVertexFitter::sipCut

private

Definition at line 180 of file Geometric3DVertexFitter.h.

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

• Geometric3DVertexFitter.h
• Geometric3DVertexFitter.cxx