algorithms/pid_lut/PIDLookup.cc

0001 // SPDX-License-Identifier: LGPL-3.0-or-later
0002 // Copyright (C) 2024, Nathan Brei, Dmitry Kalinkin
0003
0004 #include <algorithms/service.h>
0005 #include <edm4eic/MCRecoParticleAssociationCollection.h>
0006 #include <edm4eic/ReconstructedParticleCollection.h>
0007 #include <edm4hep/MCParticleCollection.h>
0008 #include <edm4hep/utils/vector_utils.h>
0009 #include <fmt/core.h>
0010 #include <podio/podioVersion.h>
0011 #include <cmath>
0012 #include <gsl/pointers>
0013 #include <stdexcept>
0014
0015 #include "algorithms/pid_lut/PIDLookup.h"
0016 #include "algorithms/pid_lut/PIDLookupConfig.h"
0017 #include "services/pid_lut/PIDLookupTableSvc.h"
0018
0019 namespace eicrecon {
0020
0021 void PIDLookup::init() {
0022   auto& serviceSvc = algorithms::ServiceSvc::instance();
0023   auto lut_svc = serviceSvc.service<PIDLookupTableSvc>("PIDLookupTableSvc");
0024
0025   m_lut = lut_svc->load(m_cfg.filename, {
0026     .pdg_values=m_cfg.pdg_values,
0027     .charge_values=m_cfg.charge_values,
0028     .momentum_edges=m_cfg.momentum_edges,
0029     .polar_edges=m_cfg.polar_edges,
0030     .azimuthal_binning=m_cfg.azimuthal_binning,
0031     .azimuthal_bin_centers_in_lut=m_cfg.azimuthal_bin_centers_in_lut,
0032     .momentum_bin_centers_in_lut=m_cfg.momentum_bin_centers_in_lut,
0033     .polar_bin_centers_in_lut=m_cfg.polar_bin_centers_in_lut,
0034     .use_radians=m_cfg.use_radians,
0035     .missing_electron_prob=m_cfg.missing_electron_prob,
0036   });
0037   if (m_lut == nullptr) {
0038     throw std::runtime_error("LUT not available");
0039   }
0040 }
0041
0042 void PIDLookup::process(const Input& input, const Output& output) const {
0043   const auto [recoparts_in, partassocs_in]          = input;
0044   auto [recoparts_out, partassocs_out, partids_out] = output;
0045
0046   for (const auto& recopart_without_pid : *recoparts_in) {
0047     auto recopart = recopart_without_pid.clone();
0048
0049     // Find MCParticle from associations and propagate the relevant ones further
0050 #if podio_VERSION >= PODIO_VERSION(0, 17, 4)
0051     auto best_assoc = edm4eic::MCRecoParticleAssociation::makeEmpty();
0052 #else
0053     edm4eic::MCRecoParticleAssociationCollection _best_assoc_coll;
0054     edm4eic::MCRecoParticleAssociation best_assoc = _best_assoc_coll.create();
0055     best_assoc.unlink();
0056 #endif
0057     for (auto assoc_in : *partassocs_in) {
0058       if (assoc_in.getRec() == recopart_without_pid) {
0059         if ((not best_assoc.isAvailable()) || (best_assoc.getWeight() < assoc_in.getWeight())) {
0060           best_assoc = assoc_in;
0061         }
0062         auto assoc_out = assoc_in.clone();
0063         assoc_out.setRec(recopart);
0064         partassocs_out->push_back(assoc_out);
0065       }
0066     }
0067     if (not best_assoc.isAvailable()) {
0068       recoparts_out->push_back(recopart);
0069       continue;
0070     }
0071
0072     edm4hep::MCParticle mcpart = best_assoc.getSim();
0073
0074     int true_pdg    = mcpart.getPDG();
0075     int true_charge = mcpart.getCharge();
0076     int charge      = recopart.getCharge();
0077     double momentum = edm4hep::utils::magnitude(recopart.getMomentum());
0078
0079     double theta = edm4hep::utils::anglePolar(recopart.getMomentum()) / M_PI * 180.;
0080     double phi   = edm4hep::utils::angleAzimuthal(recopart.getMomentum()) / M_PI * 180.;
0081
0082     trace("lookup for true_pdg={}, true_charge={}, momentum={:.2f} GeV, polar={:.2f}, aziumthal={:.2f}",
0083       true_pdg, true_charge, momentum, theta, phi);
0084     auto entry = m_lut->Lookup(true_pdg, true_charge, momentum, theta, phi);
0085
0086     int identified_pdg = 0; // unknown
0087
0088     if ((entry != nullptr) && ((entry->prob_electron != 0.) || (entry->prob_pion != 0.) || (entry->prob_kaon != 0.) || (entry->prob_electron != 0.))) {
0089       double random_unit_interval = m_dist(m_gen);
0090
0091       trace("entry with e:pi:K:P={}:{}:{}:{}", entry->prob_electron, entry->prob_pion, entry->prob_kaon, entry->prob_proton);
0092
0093       recopart.addToParticleIDs(partids_out->create(
0094         m_cfg.system,                // std::int32_t type
0095         std::copysign(11, -charge),  // std::int32_t PDG
0096         0,                           // std::int32_t algorithmType
0097         static_cast<float>(entry->prob_electron) // float likelihood
0098       ));
0099       recopart.addToParticleIDs(partids_out->create(
0100         m_cfg.system,                // std::int32_t type
0101         std::copysign(211, charge),  // std::int32_t PDG
0102         0,                           // std::int32_t algorithmType
0103         static_cast<float>(entry->prob_pion) // float likelihood
0104       ));
0105       recopart.addToParticleIDs(partids_out->create(
0106         m_cfg.system,                // std::int32_t type
0107         std::copysign(321, charge),  // std::int32_t PDG
0108         0,                           // std::int32_t algorithmType
0109         static_cast<float>(entry->prob_kaon) // float likelihood
0110       ));
0111       recopart.addToParticleIDs(partids_out->create(
0112         m_cfg.system,                // std::int32_t type
0113         std::copysign(2212, charge), // std::int32_t PDG
0114         0,                           // std::int32_t algorithmType
0115         static_cast<float>(entry->prob_proton) // float likelihood
0116       ));
0117
0118       if (random_unit_interval < entry->prob_electron) {
0119         identified_pdg = 11; // electron
0120         recopart.setParticleIDUsed((*partids_out)[partids_out->size() - 4]);
0121       } else if (random_unit_interval < (entry->prob_electron + entry->prob_pion)) {
0122         identified_pdg = 211; // pion
0123         recopart.setParticleIDUsed((*partids_out)[partids_out->size() - 3]);
0124       } else if (random_unit_interval <
0125                  (entry->prob_electron + entry->prob_pion + entry->prob_kaon)) {
0126         identified_pdg = 321; // kaon
0127         recopart.setParticleIDUsed((*partids_out)[partids_out->size() - 2]);
0128       } else if (random_unit_interval < (entry->prob_electron + entry->prob_pion +
0129                                          entry->prob_kaon + entry->prob_electron)) {
0130         identified_pdg = 2212; // proton
0131         recopart.setParticleIDUsed((*partids_out)[partids_out->size() - 1]);
0132       }
0133     }
0134
0135     if (identified_pdg != 0) {
0136       recopart.setPDG(std::copysign(identified_pdg, (identified_pdg == 11) ? -charge : charge));
0137       recopart.setMass(m_particleSvc.particle(identified_pdg).mass);
0138     }
0139
0140     if (identified_pdg != 0) {
0141       trace("randomized PDG is {}", recopart.getPDG());
0142     }
0143
0144     recoparts_out->push_back(recopart);
0145   }
0146 }
0147
0148 } // namespace eicrecon