[PWGLF] Add hybrid generator for strangeness in jets

Author: alcaliva

MC/config/PWGLF/ini/GeneratorLFStrangenessInJets_gap4.ini

@@ -0,0 +1,5 @@
+[GeneratorHybrid]
+configFile=${O2DPG_MC_CONFIG_ROOT}/MC/config/common/external/generator/pythia8_inel_plus_jets_ropes_13p6TeV.json
+
+[DecayerPythia8]
+config[0]=${O2DPG_MC_CONFIG_ROOT}/MC/config/common/pythia8/decayer/base.cfg

MC/config/PWGLF/ini/tests/GeneratorLFStrangenessInJets_gap4.C

@@ -0,0 +1,67 @@
+int Hybrid()
+{
+  std::string path{"o2sim_Kine.root"};
+
+  TFile file(path.c_str(), "READ");
+  if (file.IsZombie()) {
+    std::cerr << "Cannot open ROOT file " << path << "\n";
+    return 1;
+  }
+
+  auto tree = (TTree*)file.Get("o2sim");
+  if (!tree) {
+    std::cerr << "Cannot find tree o2sim in file " << path << "\n";
+    return 1;
+  }
+
+  std::vector<o2::MCTrack>* tracks{};
+  o2::MCEventHeader* header{};
+
+  tree->SetBranchAddress("MCTrack", &tracks);
+  tree->SetBranchAddress("MCEventHeader.", &header);
+
+  int nEvents = tree->GetEntries();
+
+  int nMB = 0;
+  int nHard = 0;
+
+  long long multMB = 0;
+  long long multHard = 0;
+
+  for (int i = 0; i < nEvents; ++i) {
+    tree->GetEntry(i);
+
+    int genId = header->getGeneratorId();
+    int mult = tracks->size();
+
+    if (genId == 0) {
+      nMB++;
+      multMB += mult;
+    } else if (genId == 1) {
+      nHard++;
+      multHard += mult;
+    }
+  }
+
+  std::cout << "--------------------------------\n";
+  std::cout << "# Events total: " << nEvents << "\n";
+  std::cout << "# MB events   : " << nMB << "\n";
+  std::cout << "# Hard events : " << nHard << "\n";
+
+  if (nHard == 0 || nMB == 0) {
+    std::cerr << "One of the generators was never used\n";
+    return 1;
+  }
+
+  std::cout << "Avg multiplicity MB   : "
+            << double(multMB) / nMB << "\n";
+  std::cout << "Avg multiplicity Hard : "
+            << double(multHard) / nHard << "\n";
+
+  if (multHard <= multMB) {
+    std::cerr << "Hard events not harder than MB ones\n";
+    return 1;
+  }
+
+  return 0;
+}

MC/config/common/external/generator/pythia8_inel_plus_jets_ropes_13p6TeV.json

@@ -0,0 +1,30 @@
+{
+    "generators": [
+        {
+            "name": "pythia8",
+            "config": {
+                "config": "${O2_ROOT}/share/Generators/egconfig/pythia8_inel.cfg",
+                "hooksFileName": "",
+                "hooksFuncName": "",
+                "includePartonEvent": false,
+                "particleFilter": "",
+                "verbose": 0
+            }
+        },
+        {
+            "name": "pythia8",
+            "config": {
+                "config": "${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGLF/pythia8/generator/pythia8_jet_ropes_136tev.cfg",
+                "hooksFileName": "",
+                "hooksFuncName": "",
+                "includePartonEvent": false,
+                "particleFilter": "",
+                "verbose": 0
+            }
+        }
+    ],
+    "fractions": [
+        4,
+        1
+    ]
+}