algorithms/calorimetry/CalorimeterIslandCluster.h

0001 // Copyright (C) 2022, 2023 Chao Peng, Wouter Deconinck, Sylvester Joosten, Thomas Britton
0002 // SPDX-License-Identifier: LGPL-3.0-or-later
0003
0004 #pragma once
0005
0006 #include <DD4hep/Detector.h>
0007 #include <DD4hep/IDDescriptor.h>
0008 #include <algorithms/algorithm.h>
0009 #include <algorithms/geo.h>
0010 #include <edm4eic/CalorimeterHitCollection.h>
0011 #include <edm4eic/ProtoClusterCollection.h>
0012 #include <edm4hep/Vector2f.h>
0013 #include <array>
0014 #include <cstddef>
0015 #include <functional>
0016 #include <gsl/pointers>
0017 #include <set>
0018 #include <string>
0019 #include <string_view>
0020 #include <vector>
0021
0022 #include "CalorimeterIslandClusterConfig.h"
0023 #include "algorithms/interfaces/WithPodConfig.h"
0024
0025 namespace eicrecon {
0026
0027 using CaloHit = edm4eic::CalorimeterHit;
0028
0029 using CalorimeterIslandClusterAlgorithm =
0030     algorithms::Algorithm<algorithms::Input<edm4eic::CalorimeterHitCollection>,
0031                           algorithms::Output<edm4eic::ProtoClusterCollection>>;
0032
0033 class CalorimeterIslandCluster : public CalorimeterIslandClusterAlgorithm,
0034                                  public WithPodConfig<CalorimeterIslandClusterConfig> {
0035
0036 public:
0037   CalorimeterIslandCluster(std::string_view name)
0038       : CalorimeterIslandClusterAlgorithm{name,
0039                                           {"inputProtoClusterCollection"},
0040                                           {"outputClusterCollection"},
0041                                           "Island clustering."} {}
0042
0043   void init() final;
0044   void process(const Input&, const Output&) const final;
0045
0046 private:
0047   const dd4hep::Detector* m_detector{algorithms::GeoSvc::instance().detector()};
0048   std::vector<double> m_localDistXY;
0049
0050 public:
0051   // neighbor checking function
0052   std::function<edm4hep::Vector2f(const CaloHit&, const CaloHit&)> hitsDist;
0053
0054   std::function<edm4hep::Vector2f(const CaloHit& h1, const CaloHit& h2)>
0055       transverseEnergyProfileMetric;
0056   double u_transverseEnergyProfileScale;
0057   double transverseEnergyProfileScaleUnits;
0058
0059   // helper function to group hits
0060   std::function<bool(const CaloHit& h1, const CaloHit& h2)> is_neighbour;
0061
0062   // helper function to define hit maximum
0063   std::function<bool(const CaloHit& maximum, const CaloHit& other)> is_maximum_neighbourhood;
0064
0065   // unitless counterparts of the input parameters
0066   std::array<double, 2> neighbourDist;
0067
0068   // Pointer to the geometry service
0069   dd4hep::IDDescriptor m_idSpec;
0070
0071 private:
0072   // grouping function with Breadth-First Search
0073   void bfs_group(const edm4eic::CalorimeterHitCollection& hits, std::set<std::size_t>& group,
0074                  std::size_t idx, std::vector<bool>& visits) const;
0075
0076   // find local maxima that above a certain threshold
0077   std::vector<std::size_t> find_maxima(const edm4eic::CalorimeterHitCollection& hits,
0078                                        const std::set<std::size_t>& group,
0079                                        bool global = false) const;
0080
0081   // helper function
0082   inline static void vec_normalize(std::vector<double>& vals) {
0083     double total = 0.;
0084     for (auto& val : vals) {
0085       total += val;
0086     }
0087     for (auto& val : vals) {
0088       val /= total;
0089     }
0090   }
0091
0092   // split a group of hits according to the local maxima
0093   void split_group(const edm4eic::CalorimeterHitCollection& hits, std::set<std::size_t>& group,
0094                    const std::vector<std::size_t>& maxima,
0095                    edm4eic::ProtoClusterCollection* protoClusters) const;
0096 };
0097
0098 } // namespace eicrecon