[PWGCF] Add event weight configuration (#16669)

Author: Luzhiyongg

PWGCF/Flow/Tasks/flowTask.cxx

@@ -76,6 +76,7 @@ using namespace o2;
 using namespace o2::framework;
 using namespace o2::framework::expressions;
 using namespace o2::analysis::genericframework;
+using namespace o2::analysis::genericframework::eventweight;
 using namespace o2::aod::rctsel;
 
 #define O2_DEFINE_CONFIGURABLE(NAME, TYPE, DEFAULT, HELP) Configurable<TYPE> NAME{#NAME, DEFAULT, HELP};
@@ -158,6 +159,7 @@ struct FlowTask {
     O2_DEFINE_CONFIGURABLE(cfgEfficiency, std::string, "", "CCDB path to efficiency object")
     O2_DEFINE_CONFIGURABLE(cfgEfficiencyForNch, std::string, "", "CCDB path to efficiency object, only for Nch correction")
     O2_DEFINE_CONFIGURABLE(cfgAcceptance, std::string, "", "CCDB path to acceptance object")
+    O2_DEFINE_CONFIGURABLE(cfgUserPtVnEvWeightEnabled, bool, false, "0: use unity weight; 1: use multiplicity weight")
     O2_DEFINE_CONFIGURABLE(cfgUseSmallMemory, bool, false, "Use small memory mode")
     O2_DEFINE_CONFIGURABLE(cfgConsistentEventFlag, int, 0, "Flag to select consistent events - 0: off, 1: v2{2} gap calculable, 2: v2{4} full calculable, 4: v2{4} gap calculable, 8: v2{4} 3sub calculable")
     Configurable<std::vector<float>> cfgConsistentEventVector{"cfgConsistentEventVector", std::vector<float>{-0.8, -0.5, -0.4, 0.4, 0.5, 0.8}, "eta regions: left(min,max), mid(min,max), right(min,max)"};
@@ -659,6 +661,10 @@ struct FlowTask {
     gfwConfigs.Print();
     fFCpt->setUseCentralMoments(cfgUseCentralMoments);
     fFCpt->setUseGapMethod(true);
+    if (!cfgUserIO.cfgUserPtVnEvWeightEnabled)
+      fFCpt->setEventWeight(EventWeight::UnityWeight);
+    else
+      fFCpt->setEventWeight(EventWeight::TupleWeight);
     fFCpt->initialise(axisIndependent, cfgMpar, gfwConfigs, cfgNbootstrap);
     if (cfgEtaGapPtPtEnabled) {
       for (int i = 0; i < 4; ++i) { // o2-linter: disable=magic-number (maximum of 4 subevents)
@@ -677,6 +683,10 @@ struct FlowTask {
     if (doprocessMCGen) {
       fFCptgen->setUseCentralMoments(cfgUseCentralMoments);
       fFCptgen->setUseGapMethod(true);
+      if (!cfgUserIO.cfgUserPtVnEvWeightEnabled)
+        fFCptgen->setEventWeight(EventWeight::UnityWeight);
+      else
+        fFCptgen->setEventWeight(EventWeight::TupleWeight);
       fFCptgen->initialise(axisIndependent, cfgMpar, gfwConfigs, cfgNbootstrap);
       if (cfgEtaGapPtPtEnabled)
         fFCptgen->initialiseSubevent(axisIndependent, cfgMpar, etagapsPtPt.size(), cfgNbootstrap);