Add 3D histogram for eta, pT, and Centrality

Author: Luzhiyongg

PWGCF/Flow/Tasks/flowTask.cxx

@@ -361,6 +361,7 @@ struct FlowTask {
       registry.add("centFT0CVar_centFT0C", "after cut;Centrality T0C;Centrality T0C Var", {HistType::kTH2D, {axisCentForQA, axisCentForQA}});
       registry.add("centFT0M_centFT0C", "after cut;Centrality T0C;Centrality T0M", {HistType::kTH2D, {axisCentForQA, axisCentForQA}});
       registry.add("centFV0A_centFT0C", "after cut;Centrality T0C;Centrality V0A", {HistType::kTH2D, {axisCentForQA, axisCentForQA}});
+      registry.add("hEtaPtCent", "after cut;#eta;p_{T};Centrality;", {HistType::kTH3D, {{16, -0.8, 0.8}, axisPt, {10, 0, 100}}});
     }
     // Track QA
     registry.add("hPhi", "#phi distribution", {HistType::kTH1D, {axisPhi}});
@@ -1295,6 +1296,9 @@ struct FlowTask {
       registry.fill(HIST("hPt"), track.pt());
       if (cfgAdditionObs.cfgDptDisEnable)
         ptVec.push_back(track.pt());
+      if (!cfgUserIO.cfgUseSmallMemory) {
+        registry.fill(HIST("hEtaPtCent"), track.eta(), track.pt(), cent);
+      }
       if (cfgAdditionObs.cfgV02Enabled && track.eta() >= cfgAdditionObs.cfgV02FracEtaMin && track.eta() <= cfgAdditionObs.cfgV02FracEtaMax) {
         cfgAdditionObs.listPtX[0]->Fill(independent, track.pt(), weff);
         cfgAdditionObs.listPtX[sampleIndex + 1]->Fill(independent, track.pt(), weff);