Plugins/FastJet/TrackJetsTests.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 <boost/test/unit_test.hpp>
0010
0011 #include <Acts/Plugins/FastJet/TrackJets.hpp>
0012
0013 class Track {
0014  public:
0015   static constexpr float mass = 139.57061 * Acts::UnitConstants::MeV;
0016
0017   Track(float pt, float eta, float phi) {
0018     Acts::Vector3 p3 = Acts::Vector3::Zero();
0019     p3[0] = pt * std::cos(phi);
0020     p3[1] = pt * std::sin(phi);
0021     p3[2] = pt * std::sinh(eta);
0022     float e = std::sqrt(mass * mass + p3.squaredNorm());
0023     m_fourMom[0] = p3[0];
0024     m_fourMom[1] = p3[1];
0025     m_fourMom[2] = p3[2];
0026     m_fourMom[3] = e;
0027   }
0028
0029   Acts::Vector4 fourMomentum() const { return m_fourMom; }
0030
0031  private:
0032   Acts::Vector4 m_fourMom{};
0033 };
0034
0035 bool operator==(Track const& lhs, Track const& rhs) {
0036   return lhs.fourMomentum() == rhs.fourMomentum();
0037 }
0038
0039 class TrackContainer {
0040  public:
0041   using TrackProxy = Track;
0042
0043   TrackContainer() = default;
0044   void insert(Track track) { m_vec.push_back(std::move(track)); }
0045   std::size_t size() { return m_vec.size(); }
0046
0047   using ConstTrackProxy = const Track&;
0048   ConstTrackProxy getTrack(std::size_t i) {
0049     if (i < size()) {
0050       return m_vec[i];
0051     }
0052     throw std::runtime_error("Too few tracks");
0053   }
0054
0055  private:
0056   std::vector<Track> m_vec{};
0057 };
0058
0059 BOOST_AUTO_TEST_CASE(SingleTrack) {
0060   TrackContainer tracks;
0061   tracks.insert(Track(100, 0, 0));
0062
0063   Acts::FastJet::InputTracks inputTracks(tracks);
0064
0065   Acts::FastJet::TrackJetSequence jetSeq =
0066       Acts::FastJet::TrackJetSequence::create(inputTracks.fourMomenta());
0067   std::vector<fastjet::PseudoJet> jets = jetSeq.jets();
0068
0069   BOOST_CHECK_EQUAL(jets.size(), 1);
0070   BOOST_CHECK_EQUAL(jets[0].constituents().size(), 1);
0071   BOOST_CHECK_EQUAL(jets[0].constituents()[0].user_index(), 0);
0072   BOOST_CHECK_CLOSE(jets[0].pt(), 100, 1e-3);
0073   BOOST_CHECK_CLOSE(jets[0].eta(), 0, 1e-3);
0074   BOOST_CHECK_CLOSE(jets[0].phi(), 0, 1e-3);
0075   BOOST_CHECK_CLOSE(jets[0].m(), Track::mass, 1);
0076 }
0077
0078 BOOST_AUTO_TEST_CASE(TwoTracksTwoJets) {
0079   TrackContainer tracks;
0080   tracks.insert(Track(100, 0, 0.0));
0081   tracks.insert(Track(100, 0, std::numbers::pi));
0082
0083   Acts::FastJet::InputTracks inputTracks(tracks);
0084
0085   Acts::FastJet::TrackJetSequence jetSeq =
0086       Acts::FastJet::TrackJetSequence::create(inputTracks.fourMomenta());
0087   std::vector<fastjet::PseudoJet> jets = jetSeq.jets();
0088
0089   BOOST_CHECK_EQUAL(jets.size(), 2);
0090
0091   std::vector<Track> trks_0 = inputTracks.tracksInJet(jets[0]);
0092   BOOST_CHECK_EQUAL(trks_0.size(), 1);
0093   BOOST_CHECK(trks_0[0] == tracks.getTrack(0) ||
0094               trks_0[0] == tracks.getTrack(1));
0095
0096   std::vector<Track> trks_1 = inputTracks.tracksInJet(jets[1]);
0097   BOOST_CHECK_EQUAL(trks_1.size(), 1);
0098   BOOST_CHECK(trks_1[0] == tracks.getTrack(0) ||
0099               trks_1[0] == tracks.getTrack(1));
0100   BOOST_CHECK(trks_0[0] != trks_1[0]);
0101 }
0102
0103 BOOST_AUTO_TEST_CASE(TwoTracksOneJet) {
0104   TrackContainer tracks;
0105   tracks.insert(Track(100, 0, 0.0));
0106   tracks.insert(Track(100, 0, 0.2));
0107
0108   Acts::FastJet::InputTracks inputTracks(tracks);
0109
0110   Acts::FastJet::TrackJetSequence jetSeq =
0111       Acts::FastJet::TrackJetSequence::create(inputTracks.fourMomenta());
0112   std::vector<fastjet::PseudoJet> jets = jetSeq.jets();
0113
0114   BOOST_CHECK_EQUAL(jets.size(), 1);
0115
0116   std::vector<Track> trks_0 = inputTracks.tracksInJet(jets[0]);
0117   BOOST_CHECK_EQUAL(trks_0.size(), 2);
0118   BOOST_CHECK(trks_0[0] == tracks.getTrack(0) ||
0119               trks_0[0] == tracks.getTrack(1));
0120   BOOST_CHECK(trks_0[1] == tracks.getTrack(0) ||
0121               trks_0[1] == tracks.getTrack(1));
0122   BOOST_CHECK(trks_0[0] != trks_0[1]);
0123 }
0124
0125 BOOST_AUTO_TEST_CASE(TracksInJetCore) {
0126   TrackContainer tracks;
0127   tracks.insert(Track(100, 0, 0));
0128   tracks.insert(Track(10, 0.05, 0));
0129   tracks.insert(Track(10, -0.05, 0));
0130   tracks.insert(Track(10, 0.2, 0));
0131   tracks.insert(Track(10, -0.2, 0));
0132
0133   Acts::FastJet::InputTracks inputTracks(tracks);
0134
0135   Acts::FastJet::TrackJetSequence jetSeq =
0136       Acts::FastJet::TrackJetSequence::create(inputTracks.fourMomenta());
0137   std::vector<fastjet::PseudoJet> jets = jetSeq.jets();
0138
0139   BOOST_REQUIRE_EQUAL(jets.size(), 1);
0140
0141   std::vector<Track> trks = inputTracks.tracksInJet(jets[0], 0.1);
0142   BOOST_CHECK_EQUAL(trks.size(), 3);
0143
0144   BOOST_CHECK(std::find(trks.begin(), trks.end(), tracks.getTrack(0)) !=
0145               trks.end());
0146   BOOST_CHECK(std::find(trks.begin(), trks.end(), tracks.getTrack(1)) !=
0147               trks.end());
0148   BOOST_CHECK(std::find(trks.begin(), trks.end(), tracks.getTrack(2)) !=
0149               trks.end());
0150   BOOST_CHECK(std::find(trks.begin(), trks.end(), tracks.getTrack(3)) ==
0151               trks.end());
0152   BOOST_CHECK(std::find(trks.begin(), trks.end(), tracks.getTrack(4)) ==
0153               trks.end());
0154 }
0155
0156 BOOST_AUTO_TEST_CASE(EmptyTrackContainer) {
0157   Acts::FastJet::TrackJetSequence jetSeq =
0158       Acts::FastJet::TrackJetSequence::create(
0159           std::vector<fastjet::PseudoJet>());
0160   BOOST_CHECK_EQUAL(jetSeq.jets().size(), 0);
0161 }
0162
0163 BOOST_AUTO_TEST_CASE(InvalidCoreRadius) {
0164   TrackContainer tracks;
0165   tracks.insert(Track(100, 0, 0));
0166   Acts::FastJet::InputTracks inputTracks(tracks);
0167   Acts::FastJet::TrackJetSequence jetSeq =
0168       Acts::FastJet::TrackJetSequence::create(inputTracks.fourMomenta());
0169   BOOST_CHECK_THROW(inputTracks.tracksInJet(jetSeq.jets()[0], -1.0),
0170                     std::invalid_argument);
0171 }