Root/src/RootParticleWriter.cpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 #include "ActsExamples/Io/Root/RootParticleWriter.hpp"
0010
0011 #include "Acts/Definitions/TrackParametrization.hpp"
0012 #include "Acts/Definitions/Units.hpp"
0013 #include "Acts/EventData/TrackParameters.hpp"
0014 #include "Acts/Propagator/Propagator.hpp"
0015 #include "Acts/Propagator/SympyStepper.hpp"
0016 #include "Acts/Surfaces/PerigeeSurface.hpp"
0017 #include "Acts/Surfaces/Surface.hpp"
0018 #include "Acts/Utilities/Helpers.hpp"
0019 #include "Acts/Utilities/VectorHelpers.hpp"
0020 #include "ActsExamples/EventData/SimParticle.hpp"
0021 #include "ActsExamples/Framework/AlgorithmContext.hpp"
0022
0023 #include <cstdint>
0024 #include <ios>
0025 #include <ostream>
0026 #include <stdexcept>
0027
0028 #include <TFile.h>
0029 #include <TTree.h>
0030
0031 ActsExamples::RootParticleWriter::RootParticleWriter(
0032     const ActsExamples::RootParticleWriter::Config& cfg,
0033     Acts::Logging::Level lvl)
0034     : WriterT(cfg.inputParticles, "RootParticleWriter", lvl), m_cfg(cfg) {
0035   // inputParticles is already checked by base constructor
0036   if (m_cfg.filePath.empty()) {
0037     throw std::invalid_argument("Missing file path");
0038   }
0039   if (m_cfg.treeName.empty()) {
0040     throw std::invalid_argument("Missing tree name");
0041   }
0042
0043   // open root file and create the tree
0044   m_outputFile = TFile::Open(m_cfg.filePath.c_str(), m_cfg.fileMode.c_str());
0045   if (m_outputFile == nullptr) {
0046     throw std::ios_base::failure("Could not open '" + m_cfg.filePath + "'");
0047   }
0048   m_outputFile->cd();
0049   m_outputTree = new TTree(m_cfg.treeName.c_str(), m_cfg.treeName.c_str());
0050   if (m_outputTree == nullptr) {
0051     throw std::bad_alloc();
0052   }
0053
0054   // setup the branches
0055   m_outputTree->Branch("event_id", &m_eventId);
0056   m_outputTree->Branch("particle_hash", &m_particleHash);
0057   m_outputTree->Branch("particle_type", &m_particleType);
0058   m_outputTree->Branch("process", &m_process);
0059   m_outputTree->Branch("vx", &m_vx);
0060   m_outputTree->Branch("vy", &m_vy);
0061   m_outputTree->Branch("vz", &m_vz);
0062   m_outputTree->Branch("vt", &m_vt);
0063   m_outputTree->Branch("px", &m_px);
0064   m_outputTree->Branch("py", &m_py);
0065   m_outputTree->Branch("pz", &m_pz);
0066   m_outputTree->Branch("m", &m_m);
0067   m_outputTree->Branch("q", &m_q);
0068   m_outputTree->Branch("eta", &m_eta);
0069   m_outputTree->Branch("phi", &m_phi);
0070   m_outputTree->Branch("pt", &m_pt);
0071   m_outputTree->Branch("p", &m_p);
0072   m_outputTree->Branch("q_over_p", &m_qop);
0073   m_outputTree->Branch("theta", &m_theta);
0074   m_outputTree->Branch("vertex_primary", &m_vertexPrimary);
0075   m_outputTree->Branch("vertex_secondary", &m_vertexSecondary);
0076   m_outputTree->Branch("particle", &m_particle);
0077   m_outputTree->Branch("generation", &m_generation);
0078   m_outputTree->Branch("sub_particle", &m_subParticle);
0079
0080   if (m_cfg.writeHelixParameters) {
0081     m_outputTree->Branch("perigee_d0", &m_perigeeD0);
0082     m_outputTree->Branch("perigee_z0", &m_perigeeZ0);
0083     m_outputTree->Branch("perigee_phi", &m_perigeePhi);
0084     m_outputTree->Branch("perigee_theta", &m_perigeeTheta);
0085     m_outputTree->Branch("perigee_q_over_p", &m_perigeeQop);
0086     m_outputTree->Branch("perigee_p", &m_perigeeP);
0087     m_outputTree->Branch("perigee_px", &m_perigeePx);
0088     m_outputTree->Branch("perigee_py", &m_perigeePy);
0089     m_outputTree->Branch("perigee_pz", &m_perigeePz);
0090     m_outputTree->Branch("perigee_eta", &m_perigeeEta);
0091     m_outputTree->Branch("perigee_pt", &m_perigeePt);
0092   }
0093
0094   m_outputTree->Branch("e_loss", &m_eLoss);
0095   m_outputTree->Branch("total_x0", &m_pathInX0);
0096   m_outputTree->Branch("total_l0", &m_pathInL0);
0097   m_outputTree->Branch("number_of_hits", &m_numberOfHits);
0098   m_outputTree->Branch("outcome", &m_outcome);
0099 }
0100
0101 ActsExamples::RootParticleWriter::~RootParticleWriter() {
0102   if (m_outputFile != nullptr) {
0103     m_outputFile->Close();
0104   }
0105 }
0106
0107 ActsExamples::ProcessCode ActsExamples::RootParticleWriter::finalize() {
0108   m_outputFile->cd();
0109   m_outputTree->Write();
0110   m_outputFile->Close();
0111
0112   ACTS_INFO("Wrote particles to tree '" << m_cfg.treeName << "' in '"
0113                                         << m_cfg.filePath << "'");
0114
0115   return ProcessCode::SUCCESS;
0116 }
0117
0118 ActsExamples::ProcessCode ActsExamples::RootParticleWriter::writeT(
0119     const AlgorithmContext& ctx, const SimParticleContainer& particles) {
0120   // ensure exclusive access to tree/file while writing
0121   std::lock_guard<std::mutex> lock(m_writeMutex);
0122
0123   m_eventId = ctx.eventNumber;
0124   for (const auto& particle : particles) {
0125     m_particleHash.push_back(particle.particleId().hash());
0126     m_particleType.push_back(particle.pdg());
0127     m_process.push_back(static_cast<std::uint32_t>(particle.process()));
0128     // position
0129     m_vx.push_back(Acts::clampValue<float>(particle.fourPosition().x() /
0130                                            Acts::UnitConstants::mm));
0131     m_vy.push_back(Acts::clampValue<float>(particle.fourPosition().y() /
0132                                            Acts::UnitConstants::mm));
0133     m_vz.push_back(Acts::clampValue<float>(particle.fourPosition().z() /
0134                                            Acts::UnitConstants::mm));
0135     m_vt.push_back(Acts::clampValue<float>(particle.fourPosition().w() /
0136                                            Acts::UnitConstants::mm));
0137
0138     // particle constants
0139     if (!std::isfinite(particle.mass()) || !std::isfinite(particle.charge())) {
0140       ACTS_WARNING("Particle mass or charge is not finite, can't write it");
0141     }
0142
0143     m_m.push_back(
0144         Acts::clampValue<float>(particle.mass() / Acts::UnitConstants::GeV));
0145     m_q.push_back(
0146         Acts::clampValue<float>(particle.charge() / Acts::UnitConstants::e));
0147     // decoded barcode components
0148     m_vertexPrimary.push_back(particle.particleId().vertexPrimary());
0149     m_vertexSecondary.push_back(particle.particleId().vertexSecondary());
0150     m_particle.push_back(particle.particleId().particle());
0151     m_generation.push_back(particle.particleId().generation());
0152     m_subParticle.push_back(particle.particleId().subParticle());
0153
0154     m_eLoss.push_back(Acts::clampValue<float>(particle.energyLoss() /
0155                                               Acts::UnitConstants::GeV));
0156     m_pathInX0.push_back(
0157         Acts::clampValue<float>(particle.pathInX0() / Acts::UnitConstants::mm));
0158     m_pathInL0.push_back(
0159         Acts::clampValue<float>(particle.pathInL0() / Acts::UnitConstants::mm));
0160     m_numberOfHits.push_back(particle.numberOfHits());
0161     m_outcome.push_back(static_cast<std::uint32_t>(particle.outcome()));
0162
0163     // momentum
0164     const auto p = particle.absoluteMomentum() / Acts::UnitConstants::GeV;
0165     m_p.push_back(Acts::clampValue<float>(p));
0166     m_px.push_back(Acts::clampValue<float>(p * particle.direction().x()));
0167     m_py.push_back(Acts::clampValue<float>(p * particle.direction().y()));
0168     m_pz.push_back(Acts::clampValue<float>(p * particle.direction().z()));
0169     // derived kinematic quantities
0170     m_eta.push_back(Acts::clampValue<float>(
0171         Acts::VectorHelpers::eta(particle.direction())));
0172     m_pt.push_back(Acts::clampValue<float>(
0173         p * Acts::VectorHelpers::perp(particle.direction())));
0174     m_phi.push_back(Acts::clampValue<float>(
0175         Acts::VectorHelpers::phi(particle.direction())));
0176     m_theta.push_back(Acts::clampValue<float>(
0177         Acts::VectorHelpers::theta(particle.direction())));
0178     m_qop.push_back(Acts::clampValue<float>(
0179         particle.qOverP() * Acts::UnitConstants::GeV / Acts::UnitConstants::e));
0180
0181     if (!m_cfg.writeHelixParameters) {
0182       // done with this particle
0183       continue;
0184     }
0185
0186     // Perigee surface at configured reference point
0187     auto pSurface =
0188         Acts::Surface::makeShared<Acts::PerigeeSurface>(m_cfg.referencePoint);
0189
0190     // Start from truth curvilinear parameters (direction, q/p)
0191     const Acts::Vector3 startDir = particle.direction();  // unit vector
0192     const auto qOverP = particle.qOverP();                // ACTS units
0193     auto intersection =
0194         pSurface
0195             ->intersect(ctx.geoContext, particle.position(), startDir,
0196                         Acts::BoundaryTolerance::Infinite())
0197             .closest();
0198
0199     // Neutral particles have no helix -> linearly extrapolate to perigee
0200     if (particle.charge() == 0) {
0201       ACTS_WARNING(
0202           "Particle has zero charge, linearly extrapolating to perigee");
0203       // Initialize the truth particle info
0204       auto perigeeD0 = NaNfloat;
0205       auto perigeeZ0 = NaNfloat;
0206
0207       const auto position = intersection.position();
0208
0209       // get the truth perigee parameter
0210       auto lpResult =
0211           pSurface->globalToLocal(ctx.geoContext, position, startDir);
0212       if (lpResult.ok()) {
0213         perigeeD0 = lpResult.value()[Acts::BoundIndices::eBoundLoc0];
0214         perigeeZ0 = lpResult.value()[Acts::BoundIndices::eBoundLoc1];
0215       } else {
0216         ACTS_ERROR("Global to local transformation did not succeed.");
0217       }
0218       // truth parameters at perigee are the same as at production vertex
0219       m_perigeePhi.push_back(Acts::clampValue<float>(particle.phi()));
0220       m_perigeeTheta.push_back(Acts::clampValue<float>(particle.theta()));
0221       m_perigeeQop.push_back(Acts::clampValue<float>(
0222           qOverP * Acts::UnitConstants::GeV / Acts::UnitConstants::e));
0223       m_perigeeP.push_back(Acts::clampValue<float>(particle.absoluteMomentum() /
0224                                                    Acts::UnitConstants::GeV));
0225       m_perigeePx.push_back(Acts::clampValue<float>(m_p.back() * startDir.x()));
0226       m_perigeePy.push_back(Acts::clampValue<float>(m_p.back() * startDir.y()));
0227       m_perigeePz.push_back(Acts::clampValue<float>(m_p.back() * startDir.z()));
0228       m_perigeeEta.push_back(Acts::clampValue<float>(
0229           Acts::VectorHelpers::eta(particle.direction())));
0230       m_perigeePt.push_back(Acts::clampValue<float>(
0231           m_p.back() * Acts::VectorHelpers::perp(particle.direction())));
0232
0233       // Push the extrapolated parameters
0234       m_perigeeD0.push_back(
0235           Acts::clampValue<float>(perigeeD0 / Acts::UnitConstants::mm));
0236       m_perigeeZ0.push_back(
0237           Acts::clampValue<float>(perigeeZ0 / Acts::UnitConstants::mm));
0238       continue;
0239     }
0240
0241     // Charged particles: propagate helix to perigee
0242     // Build a propagator and propagate the *truth parameters* to the
0243     // perigee Stepper + propagator
0244     using Stepper = Acts::SympyStepper;
0245     Stepper stepper(m_cfg.bField);
0246     using PropagatorT = Acts::Propagator<Stepper>;
0247     auto propagator = std::make_shared<PropagatorT>(stepper);
0248
0249     Acts::BoundTrackParameters startParams =
0250         Acts::BoundTrackParameters::createCurvilinear(
0251             particle.fourPosition(), startDir, qOverP, std::nullopt,
0252             Acts::ParticleHypothesis::pion());
0253
0254     // Propagation options (need event contexts)
0255     using PropOptions = PropagatorT::Options<>;
0256     PropOptions pOptions(ctx.geoContext, ctx.magFieldContext);
0257
0258     // Choose propagation direction based on the closest intersection
0259     pOptions.direction =
0260         Acts::Direction::fromScalarZeroAsPositive(intersection.pathLength());
0261
0262     // Do the propagation to the perigee surface
0263     auto propRes = propagator->propagate(startParams, *pSurface, pOptions);
0264     if (!propRes.ok() || !propRes->endParameters.has_value()) {
0265       ACTS_ERROR("Propagation to perigee surface failed.");
0266       m_perigeePhi.push_back(NaNfloat);
0267       m_perigeeTheta.push_back(NaNfloat);
0268       m_perigeeQop.push_back(NaNfloat);
0269       m_perigeeD0.push_back(NaNfloat);
0270       m_perigeeZ0.push_back(NaNfloat);
0271       m_perigeeP.push_back(NaNfloat);
0272       m_perigeePx.push_back(NaNfloat);
0273       m_perigeePy.push_back(NaNfloat);
0274       m_perigeePz.push_back(NaNfloat);
0275       m_perigeeEta.push_back(NaNfloat);
0276       m_perigeePt.push_back(NaNfloat);
0277       continue;
0278     }
0279     const Acts::BoundTrackParameters& atPerigee = *propRes->endParameters;
0280
0281     // By construction, atPerigee is *bound on the perigee surface*.
0282     // Its parameter vector is [loc0, loc1, phi, theta, q/p, t]
0283     const auto& perigee_pars = atPerigee.parameters();
0284
0285     const auto perigeeD0 = perigee_pars[Acts::BoundIndices::eBoundLoc0];
0286     const auto perigeeZ0 = perigee_pars[Acts::BoundIndices::eBoundLoc1];
0287
0288     // truth phi;theta;q/p *at the perigee*,
0289     const auto perigeePhi = perigee_pars[Acts::BoundIndices::eBoundPhi];
0290     const auto perigeeTheta = perigee_pars[Acts::BoundIndices::eBoundTheta];
0291     const auto perigeeQop = perigee_pars[Acts::BoundIndices::eBoundQOverP];
0292
0293     m_perigeePhi.push_back(Acts::clampValue<float>(perigeePhi));
0294     m_perigeeTheta.push_back(Acts::clampValue<float>(perigeeTheta));
0295     m_perigeeQop.push_back(Acts::clampValue<float>(
0296         perigeeQop * Acts::UnitConstants::GeV / Acts::UnitConstants::e));
0297     // update p, px, py, pz, eta, pt
0298     const auto perigeeP =
0299         atPerigee.absoluteMomentum() / Acts::UnitConstants::GeV;
0300     m_perigeeP.push_back(Acts::clampValue<float>(perigeeP));
0301     const auto dir = atPerigee.direction();
0302     m_perigeePx.push_back(Acts::clampValue<float>(perigeeP * dir.x()));
0303     m_perigeePy.push_back(Acts::clampValue<float>(perigeeP * dir.y()));
0304     m_perigeePz.push_back(Acts::clampValue<float>(perigeeP * dir.z()));
0305     m_perigeeEta.push_back(Acts::clampValue<float>(
0306         Acts::VectorHelpers::eta(atPerigee.direction())));
0307     m_perigeePt.push_back(Acts::clampValue<float>(
0308         perigeeP * Acts::VectorHelpers::perp(atPerigee.direction())));
0309
0310     // Push the perigee parameters
0311     m_perigeeD0.push_back(
0312         Acts::clampValue<float>(perigeeD0 / Acts::UnitConstants::mm));
0313     m_perigeeZ0.push_back(
0314         Acts::clampValue<float>(perigeeZ0 / Acts::UnitConstants::mm));
0315   }
0316
0317   m_outputTree->Fill();
0318
0319   m_particleHash.clear();
0320   m_particleType.clear();
0321   m_process.clear();
0322   m_vx.clear();
0323   m_vy.clear();
0324   m_vz.clear();
0325   m_vt.clear();
0326   m_p.clear();
0327   m_px.clear();
0328   m_py.clear();
0329   m_pz.clear();
0330   m_m.clear();
0331   m_q.clear();
0332   m_eta.clear();
0333   m_phi.clear();
0334   m_pt.clear();
0335   m_theta.clear();
0336   m_qop.clear();
0337   m_vertexPrimary.clear();
0338   m_vertexSecondary.clear();
0339   m_particle.clear();
0340   m_generation.clear();
0341   m_subParticle.clear();
0342   m_eLoss.clear();
0343   m_numberOfHits.clear();
0344   m_outcome.clear();
0345   m_pathInX0.clear();
0346   m_pathInL0.clear();
0347
0348   if (m_cfg.writeHelixParameters) {
0349     m_perigeeD0.clear();
0350     m_perigeeZ0.clear();
0351     m_perigeePhi.clear();
0352     m_perigeeTheta.clear();
0353     m_perigeeQop.clear();
0354     m_perigeeP.clear();
0355     m_perigeePx.clear();
0356     m_perigeePy.clear();
0357     m_perigeePz.clear();
0358     m_perigeeEta.clear();
0359     m_perigeePt.clear();
0360   }
0361
0362   return ProcessCode::SUCCESS;
0363 }