PWG2/FLOW/AliFlowAnalysisWithMCEventPlane.cxx

   1 /*************************************************************************
   2 * Copyright(c) 1998-2008, ALICE Experiment at CERN, All rights reserved. *
   3 *                                                                        *
   4 * Author: The ALICE Off-line Project.                                    *
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  10 * copies and that both the copyright notice and this permission notice   *
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  12 * about the suitability of this software for any purpose. It is          *
  13 * provided "as is" without express or implied warranty.                  *
  14 **************************************************************************/
  15
  16 #define AliFlowAnalysisWithMCEventPlane_cxx
  17
  18 #include "Riostream.h"  //needed as include
  19 #include "TFile.h"      //needed as include
  20 #include "TProfile.h"   //needed as include
  21 #include "TComplex.h"   //needed as include
  22 #include "TList.h"
  23
  24 class TH1F;
  25
  26 #include "AliFlowCommonConstants.h"    //needed as include
  27 #include "AliFlowEventSimple.h"
  28 #include "AliFlowTrackSimple.h"
  29 #include "AliFlowCommonHist.h"
  30 #include "AliFlowCommonHistResults.h"
  31 #include "AliFlowAnalysisWithMCEventPlane.h"
  32
  33 class AliFlowVector;
  34
  35 // AliFlowAnalysisWithMCEventPlane:
  36 // Description: Maker to analyze Flow from the generated MC reaction plane.
  37 //              This class is used to get the real value of the flow
  38 //              to compare the other methods to when analysing simulated events
  39 // author: N. van der Kolk (kolk@nikhef.nl)
  40
  41 ClassImp(AliFlowAnalysisWithMCEventPlane)
  42
  43   //-----------------------------------------------------------------------
  44
  45  AliFlowAnalysisWithMCEventPlane::AliFlowAnalysisWithMCEventPlane():
  46    fQsum(NULL),
  47    fQ2sum(0),
  48    fEventNumber(0),
  49    fDebug(kFALSE),
  50    fHistList(NULL),
  51    fCommonHists(NULL),
  52    fCommonHistsRes(NULL),
  53    fHistProFlow(NULL),
  54    fHistRP(NULL)
  55
  56 {
  57
  58   // Constructor.
  59   fHistList = new TList();
  60
  61   fQsum = new TVector2;        // flow vector sum
  62 }
  63
  64
  65  //-----------------------------------------------------------------------
  66
  67
  68  AliFlowAnalysisWithMCEventPlane::~AliFlowAnalysisWithMCEventPlane()
  69  {
  70    //destructor
  71    delete fHistList;
  72    delete fQsum;
  73  }
  74
  75
  76 //-----------------------------------------------------------------------
  77 void AliFlowAnalysisWithMCEventPlane::Init() {
  78
  79   //Define all histograms
  80   cout<<"---Analysis with the real MC Event Plane---"<<endl;
  81
  82   Int_t iNbinsPt = AliFlowCommonConstants::GetNbinsPt();
  83   Double_t  dPtMin = AliFlowCommonConstants::GetPtMin();
  84   Double_t  dPtMax = AliFlowCommonConstants::GetPtMax();
  85
  86   fCommonHists = new AliFlowCommonHist("MC");
  87   fHistList->Add(fCommonHists->GetHistMultOrig());
  88   fHistList->Add(fCommonHists->GetHistMultInt());
  89   fHistList->Add(fCommonHists->GetHistMultDiff());
  90   fHistList->Add(fCommonHists->GetHistPtInt());
  91   fHistList->Add(fCommonHists->GetHistPtDiff());
  92   fHistList->Add(fCommonHists->GetHistPhiInt());
  93   fHistList->Add(fCommonHists->GetHistPhiDiff());
  94   fHistList->Add(fCommonHists->GetHistEtaInt());
  95   fHistList->Add(fCommonHists->GetHistEtaDiff());
  96   fHistList->Add(fCommonHists->GetHistProMeanPtperBin());
  97   fHistList->Add(fCommonHists->GetHistQ());
  98   fCommonHistsRes = new AliFlowCommonHistResults("MC");
  99   fHistList->Add(fCommonHistsRes->GetHistDiffFlow());
 100   fHistList->Add(fCommonHistsRes->GetHistChi());
 101   fHistList->Add(fCommonHistsRes->GetHistIntFlow());
 102
 103   fHistProFlow = new TProfile("FlowPro_VPt_MC","FlowPro_VPt_MC",iNbinsPt,dPtMin,dPtMax);
 104   fHistProFlow->SetXTitle("Pt");
 105   fHistProFlow->SetYTitle("v2 (%)");
 106   fHistList->Add(fHistProFlow);
 107
 108   fHistRP = new TH1F("Flow_RP_MC","Flow_RP_MC",100,0.,3.14);
 109   fHistRP->SetXTitle("Reaction Plane Angle");
 110   fHistRP->SetYTitle("Counts");
 111   fHistList->Add(fHistRP);
 112
 113
 114   fEventNumber = 0;  //set number of events to zero
 115
 116 }
 117
 118 //-----------------------------------------------------------------------
 119
 120 void AliFlowAnalysisWithMCEventPlane::Make(AliFlowEventSimple* anEvent, Double_t aRP) {
 121
 122   //Calculate v2 from the MC reaction plane
 123   if (anEvent) {
 124
 125     //fill control histograms
 126     fCommonHists->FillControlHistograms(anEvent);
 127
 128     //get the Q vector from the FlowEvent
 129     AliFlowVector vQ = anEvent->GetQ();
 130     //cout<<"vQ.Mod() = " << vQ.Mod() << endl;
 131     //for chi calculation:
 132     *fQsum += vQ;
 133     //cout<<"fQsum.Mod() = "<<fQsum.Mod()<<endl;
 134     fQ2sum += vQ.Mod2();
 135     cout<<"fQ2sum = "<<fQ2sum<<endl;
 136
 137     fHistRP->Fill(aRP);
 138
 139     //calculate flow
 140     //loop over the tracks of the event
 141     Int_t iNumberOfTracks = anEvent->NumberOfTracks();
 142     for (Int_t i=0;i<iNumberOfTracks;i++)
 143       {
 144         AliFlowTrackSimple* pTrack = anEvent->GetTrack(i) ;
 145         if (pTrack){
 146           if (pTrack->UseForDifferentialFlow()) {
 147             Double_t dPhi = pTrack->Phi();
 148             //if (dPhi<0.) dPhi+=2*TMath::Pi();
 149             //calculate flow v2:
 150             Double_t dv2 = TMath::Cos(2*(dPhi-aRP));
 151             Double_t dPt = pTrack->Pt();
 152             //fill histogram
 153             fHistProFlow->Fill(dPt,100*dv2);
 154           }
 155         }//track selected
 156       }//loop over tracks
 157
 158     fEventNumber++;
 159     cout<<"@@@@@ "<<fEventNumber<<" events processed"<<endl;
 160   }
 161 }
 162
 163   //--------------------------------------------------------------------
 164 void AliFlowAnalysisWithMCEventPlane::Finish() {
 165
 166   //*************make histograms etc.
 167   if (fDebug) cout<<"AliFlowAnalysisWithMCEventPlane::Terminate()"<<endl;
 168
 169   Int_t iNbinsPt = AliFlowCommonConstants::GetNbinsPt();
 170
 171   TH1F* fHistPtDiff = fCommonHists->GetHistPtDiff();
 172   Double_t dV = 0.;
 173   Double_t dErrV = 0.;
 174   Double_t dSum = 0.;
 175   for(Int_t b=0;b<iNbinsPt;b++){
 176     Double_t dv2pro = 0.;
 177     Double_t dErrdifcomb = 0.; //in case error from profile is correct
 178     if(fHistProFlow) {
 179       dv2pro = fHistProFlow->GetBinContent(b);
 180       dErrdifcomb = fHistProFlow->GetBinError(b);
 181       //fill TH1D
 182       fCommonHistsRes->FillDifferentialFlow(b, dv2pro, dErrdifcomb);
 183       if (fHistPtDiff){
 184         //integrated flow
 185         Double_t dYield = fHistPtDiff->GetBinContent(b);
 186         dV += dv2pro/100*dYield ;
 187         dSum += dYield;
 188         //error on integrated flow
 189         dErrV += dYield*dYield*(dErrdifcomb/100)*(dErrdifcomb/100);
 190       }
 191     }
 192   }
 193   dV /= dSum;  //because pt distribution should be normalised
 194   dErrV /= dSum*dSum;
 195   dErrV = TMath::Sqrt(dErrV);
 196   cout<<"dV is "<<dV<<" +- "<<dErrV<<endl;
 197   fCommonHistsRes->FillIntegratedFlow(dV,dErrV);
 198
 199   cout<<".....finished"<<endl;
 200  }
 201
 202