algorithms/tracking/IterativeVertexFinder.cc

0001 // Created by Joe Osborn
0002 // Subject to the terms in the LICENSE file found in the top-level directory.
0003 //
0004
0005 #include "IterativeVertexFinder.h"
0006
0007 #include <Acts/Definitions/Units.hpp>
0008 #include <Acts/MagneticField/MagneticFieldProvider.hpp>
0009 #include <Acts/Propagator/EigenStepper.hpp>
0010 #include <Acts/Propagator/Propagator.hpp>
0011 #include <Acts/Propagator/VoidNavigator.hpp>
0012 #include <Acts/Utilities/Logger.hpp>
0013 #include <Acts/Utilities/Result.hpp>
0014 #include <Acts/Utilities/detail/ContextType.hpp>
0015 #include <Acts/Vertexing/FullBilloirVertexFitter.hpp>
0016 #include <Acts/Vertexing/HelicalTrackLinearizer.hpp>
0017 #include <Acts/Vertexing/IVertexFinder.hpp>
0018 #include <Acts/Vertexing/ImpactPointEstimator.hpp>
0019 #include <Acts/Vertexing/IterativeVertexFinder.hpp>
0020 #include <Acts/Vertexing/LinearizedTrack.hpp>
0021 #include <Acts/Vertexing/TrackAtVertex.hpp>
0022 #include <Acts/Vertexing/Vertex.hpp>
0023 #include <Acts/Vertexing/VertexingOptions.hpp>
0024 #include <Acts/Vertexing/ZScanVertexFinder.hpp>
0025 #include <ActsExamples/EventData/Track.hpp>
0026 #include <ActsExamples/EventData/Trajectories.hpp>
0027 #include <edm4eic/Cov4f.h>
0028 #include <edm4eic/ReconstructedParticleCollection.h>
0029 #include <edm4eic/Track.h>
0030 #include <edm4eic/TrackParameters.h>
0031 #include <edm4eic/Trajectory.h>
0032 #include <edm4eic/unit_system.h>
0033 #include <edm4hep/Vector2f.h>
0034 #include <edm4hep/Vector4f.h>
0035 #include <fmt/core.h>
0036 #include <fmt/format.h>
0037 #include <podio/RelationRange.h>
0038 #include <Eigen/Core>
0039 #include <cmath>
0040 #include <string>
0041 #include <utility>
0042
0043 #include "extensions/spdlog/SpdlogToActs.h"
0044
0045 void eicrecon::IterativeVertexFinder::init(std::shared_ptr<const ActsGeometryProvider> geo_svc,
0046                                            std::shared_ptr<spdlog::logger> log) {
0047
0048   m_log = log;
0049
0050   m_geoSvc = geo_svc;
0051
0052   m_BField =
0053       std::dynamic_pointer_cast<const eicrecon::BField::DD4hepBField>(m_geoSvc->getFieldProvider());
0054   m_fieldctx = eicrecon::BField::BFieldVariant(m_BField);
0055 }
0056
0057 std::unique_ptr<edm4eic::VertexCollection> eicrecon::IterativeVertexFinder::produce(
0058     std::vector<const ActsExamples::Trajectories*> trajectories,
0059     const edm4eic::ReconstructedParticleCollection* reconParticles) {
0060
0061   auto outputVertices = std::make_unique<edm4eic::VertexCollection>();
0062
0063   using Propagator           = Acts::Propagator<Acts::EigenStepper<>>;
0064   using Linearizer           = Acts::HelicalTrackLinearizer;
0065   using VertexFitter         = Acts::FullBilloirVertexFitter;
0066   using ImpactPointEstimator = Acts::ImpactPointEstimator;
0067   using VertexSeeder         = Acts::ZScanVertexFinder;
0068   using VertexFinder         = Acts::IterativeVertexFinder;
0069   using VertexFinderOptions  = Acts::VertexingOptions;
0070
0071   ACTS_LOCAL_LOGGER(eicrecon::getSpdlogLogger("IVF", m_log));
0072
0073   Acts::EigenStepper<> stepper(m_BField);
0074
0075   // Set up propagator with void navigator
0076   auto propagator = std::make_shared<Propagator>(stepper, Acts::VoidNavigator{},
0077                                                  logger().cloneWithSuffix("Prop"));
0078
0079   // Setup the track linearizer
0080   Linearizer::Config linearizerCfg;
0081   linearizerCfg.bField     = m_BField;
0082   linearizerCfg.propagator = propagator;
0083   Linearizer linearizer(linearizerCfg, logger().cloneWithSuffix("HelLin"));
0084
0085   // Setup the vertex fitter
0086   VertexFitter::Config vertexFitterCfg;
0087   vertexFitterCfg.extractParameters.connect<&Acts::InputTrack::extractParameters>();
0088   vertexFitterCfg.trackLinearizer.connect<&Linearizer::linearizeTrack>(&linearizer);
0089   VertexFitter vertexFitter(vertexFitterCfg);
0090
0091   // Setup the seed finder
0092   ImpactPointEstimator::Config ipEstCfg(m_BField, propagator);
0093   ImpactPointEstimator ipEst(ipEstCfg);
0094   VertexSeeder::Config seederCfg(ipEst);
0095   seederCfg.extractParameters.connect<&Acts::InputTrack::extractParameters>();
0096   auto seeder = std::make_shared<VertexSeeder>(seederCfg);
0097
0098   // Set up the actual vertex finder
0099   VertexFinder::Config finderCfg(std::move(vertexFitter), std::move(seeder), std::move(ipEst));
0100   finderCfg.maxVertices                 = m_cfg.maxVertices;
0101   finderCfg.reassignTracksAfterFirstFit = m_cfg.reassignTracksAfterFirstFit;
0102   finderCfg.extractParameters.connect<&Acts::InputTrack::extractParameters>();
0103   finderCfg.trackLinearizer.connect<&Linearizer::linearizeTrack>(&linearizer);
0104   finderCfg.field = m_BField;
0105   VertexFinder finder(std::move(finderCfg));
0106   Acts::IVertexFinder::State state(std::in_place_type<VertexFinder::State>, *m_BField, m_fieldctx);
0107   VertexFinderOptions finderOpts(m_geoctx, m_fieldctx);
0108
0109   std::vector<Acts::InputTrack> inputTracks;
0110
0111   for (const auto& trajectory : trajectories) {
0112     auto tips = trajectory->tips();
0113     if (tips.empty()) {
0114       continue;
0115     }
0116     /// CKF can provide multiple track trajectories for a single input seed
0117     for (auto& tip : tips) {
0118       ActsExamples::TrackParameters par = trajectory->trackParameters(tip);
0119
0120       inputTracks.emplace_back(&(trajectory->trackParameters(tip)));
0121       m_log->trace("Track local position at input = {} mm, {} mm",
0122                    par.localPosition().x() / Acts::UnitConstants::mm,
0123                    par.localPosition().y() / Acts::UnitConstants::mm);
0124     }
0125   }
0126
0127   std::vector<Acts::Vertex> vertices;
0128   auto result = finder.find(inputTracks, finderOpts, state);
0129   if (result.ok()) {
0130     vertices = std::move(result.value());
0131   }
0132
0133   for (const auto& vtx : vertices) {
0134     edm4eic::Cov4f cov(vtx.fullCovariance()(0, 0), vtx.fullCovariance()(1, 1),
0135                        vtx.fullCovariance()(2, 2), vtx.fullCovariance()(3, 3),
0136                        vtx.fullCovariance()(0, 1), vtx.fullCovariance()(0, 2),
0137                        vtx.fullCovariance()(0, 3), vtx.fullCovariance()(1, 2),
0138                        vtx.fullCovariance()(1, 3), vtx.fullCovariance()(2, 3));
0139     auto eicvertex = outputVertices->create();
0140     eicvertex.setType(1); // boolean flag if vertex is primary vertex of event
0141     eicvertex.setChi2((float)vtx.fitQuality().first); // chi2
0142     eicvertex.setNdf((float)vtx.fitQuality().second); // ndf
0143     eicvertex.setPosition({
0144         (float)vtx.position().x(),
0145         (float)vtx.position().y(),
0146         (float)vtx.position().z(),
0147         (float)vtx.time(),
0148     });                              // vtxposition
0149     eicvertex.setPositionError(cov); // covariance
0150
0151     for (const auto& t : vtx.tracks()) {
0152       const auto& par = Acts::InputTrack::extractParameters(t.originalParams);
0153       m_log->trace("Track local position from vertex = {} mm, {} mm",
0154                    par.localPosition().x() / Acts::UnitConstants::mm,
0155                    par.localPosition().y() / Acts::UnitConstants::mm);
0156       float loc_a = par.localPosition().x();
0157       float loc_b = par.localPosition().y();
0158
0159       for (const auto& part : *reconParticles) {
0160         const auto& tracks = part.getTracks();
0161         for (const auto& trk : tracks) {
0162           const auto& traj    = trk.getTrajectory();
0163           const auto& trkPars = traj.getTrackParameters();
0164           for (const auto& par : trkPars) {
0165             const double EPSILON = 1.0e-4; // mm
0166             if (std::abs((par.getLoc().a / edm4eic::unit::mm) - (loc_a / Acts::UnitConstants::mm)) <
0167                     EPSILON &&
0168                 std::abs((par.getLoc().b / edm4eic::unit::mm) - (loc_b / Acts::UnitConstants::mm)) <
0169                     EPSILON) {
0170               m_log->trace(
0171                   "From ReconParticles, track local position [Loc a, Loc b] = {} mm, {} mm",
0172                   par.getLoc().a / edm4eic::unit::mm, par.getLoc().b / edm4eic::unit::mm);
0173               eicvertex.addToAssociatedParticles(part);
0174             } // endif
0175           } // end for par
0176         } // end for trk
0177       } // end for part
0178     } // end for t
0179     m_log->debug("One vertex found at (x,y,z) = ({}, {}, {}) mm.",
0180                  vtx.position().x() / Acts::UnitConstants::mm,
0181                  vtx.position().y() / Acts::UnitConstants::mm,
0182                  vtx.position().z() / Acts::UnitConstants::mm);
0183
0184   } // end for vtx
0185
0186   return outputVertices;
0187 }