PWG2/FLOW/AliFlowCommon/AliFlowEventSimpleMakerOnTheFly.cxx

   1 /*************************************************************************
   2 * Copyright(c) 1998-2008, ALICE Experiment at CERN, All rights reserved. *
   3 *                                                                        *
   4 * Author: The ALICE Off-line Project.                                    *
   5 * Contributors are mentioned in the code where appropriate.              *
   6 *                                                                        *
   7 * Permission to use, copy, modify and distribute this software and its   *
   8 * documentation strictly for non-commercial purposes is hereby granted   *
   9 * without fee, provided that the above copyright notice appears in all   *
  10 * copies and that both the copyright notice and this permission notice   *
  11 * appear in the supporting documentation. The authors make no claims     *
  12 * about the suitability of this software for any purpose. It is          *
  13 * provided "as is" without express or implied warranty.                  *
  14 **************************************************************************/
  15
  16 /**********************************
  17  * create an event and perform    *
  18  * flow analysis 'on the fly'     *
  19  *                                *
  20  * authors: Raimond Snellings     *
  21  *           (snelling@nikhef.nl) *
  22  *          Ante Bilandzic        *
  23  *           (anteb@nikhef.nl)    *
  24  *********************************/
  25
  26 #include "Riostream.h"
  27 #include "TMath.h"
  28 #include "TF1.h"
  29 #include "TRandom3.h"
  30
  31 #include "AliFlowEventSimpleMakerOnTheFly.h"
  32 #include "AliFlowEventSimple.h"
  33 #include "AliFlowTrackSimple.h"
  34
  35 ClassImp(AliFlowEventSimpleMakerOnTheFly)
  36
  37
  38 //========================================================================
  39
  40
  41 AliFlowEventSimpleMakerOnTheFly::AliFlowEventSimpleMakerOnTheFly(UInt_t iseed):
  42   fMultiplicityOfRP(0),
  43   fMultiplicitySpreadOfRP(0.),
  44   fV1RP(0.),
  45   fV1SpreadRP(0.),
  46   fV2RP(0.),
  47   fV2SpreadRP(0.),
  48   fPtSpectra(NULL),
  49   fPhiDistribution(NULL),
  50   fMyTRandom3(NULL),
  51   fCount(0)
  52  {
  53   // constructor
  54    fMyTRandom3 = new TRandom3(iseed);
  55  }
  56
  57
  58 //========================================================================
  59
  60
  61 AliFlowEventSimpleMakerOnTheFly::~AliFlowEventSimpleMakerOnTheFly()
  62 {
  63  // destructor
  64   if (fPtSpectra) delete fPtSpectra;
  65   if (fPhiDistribution) delete fPhiDistribution;
  66   if (fMyTRandom3) delete  fMyTRandom3;
  67 }
  68
  69
  70 //========================================================================
  71
  72
  73 AliFlowEventSimple* AliFlowEventSimpleMakerOnTheFly::CreateEventOnTheFly()
  74 {
  75   // method to create event on the fly
  76
  77   AliFlowEventSimple* pEvent = new AliFlowEventSimple(fMultiplicityOfRP);
  78
  79   //reaction plane
  80   Double_t fMCReactionPlaneAngle = fMyTRandom3->Uniform(0.,TMath::TwoPi());
  81
  82   // pt:
  83   Double_t dPtMin = 0.; // to be improved
  84   Double_t dPtMax = 10.; // to be improved
  85
  86   fPtSpectra = new TF1("fPtSpectra","[0]*x*TMath::Exp(-x*x)",dPtMin,dPtMax);
  87   fPtSpectra->SetParName(0,"Multiplicity of RPs");
  88   // sampling the multiplicity:
  89   Int_t fNewMultiplicityOfRP = fMyTRandom3->Gaus(fMultiplicityOfRP,fMultiplicitySpreadOfRP);
  90   fPtSpectra->SetParameter(0,fNewMultiplicityOfRP);
  91
  92
  93   // phi:
  94   Double_t dPhiMin = 0.; // to be improved
  95   Double_t dPhiMax = TMath::TwoPi(); // to be improved
  96
  97   fPhiDistribution = new TF1("fPhiDistribution","1+2.*[0]*TMath::Cos(x)+2.*[1]*TMath::Cos(2*x)",dPhiMin,dPhiMax);
  98
  99   // sampling the V1:
 100   fPhiDistribution->SetParName(0,"directed flow");
 101   if(fV1RP>0.0) fV1RP = fMyTRandom3->Gaus(fV1RP,fV1SpreadRP);
 102   fPhiDistribution->SetParameter(0,fV1RP);
 103
 104   // sampling the V2:
 105   fPhiDistribution->SetParName(1,"elliptic flow");
 106   fV2RP = fMyTRandom3->Gaus(fV2RP,fV2SpreadRP);
 107   fPhiDistribution->SetParameter(1,fV2RP);
 108
 109   // eta:
 110   Double_t dEtaMin = -1.; // to be improved
 111   Double_t dEtaMax = 1.; // to be improved
 112
 113   Int_t iGoodTracks = 0;
 114   Int_t iSelParticlesRP = 0;
 115   Int_t iSelParticlesPOI = 0;
 116   for(Int_t i=0;i<fNewMultiplicityOfRP;i++) {
 117     AliFlowTrackSimple* pTrack = new AliFlowTrackSimple();
 118     pTrack->SetPt(fPtSpectra->GetRandom());
 119     pTrack->SetEta(fMyTRandom3->Uniform(dEtaMin,dEtaMax));
 120     pTrack->SetPhi(fPhiDistribution->GetRandom()+fMCReactionPlaneAngle);
 121     pTrack->SetForRPSelection(kTRUE);
 122     iSelParticlesRP++;
 123     pTrack->SetForPOISelection(kTRUE);
 124     iSelParticlesPOI++;
 125
 126     pEvent->TrackCollection()->Add(pTrack);
 127     iGoodTracks++;
 128   }
 129
 130   pEvent->SetEventNSelTracksRP(iSelParticlesRP);
 131   pEvent->SetNumberOfTracks(iGoodTracks);//tracks used either for RP or for POI selection
 132   pEvent->SetMCReactionPlaneAngle(fMCReactionPlaneAngle);
 133
 134   if (!fMCReactionPlaneAngle == 0) cout<<" MC Reaction Plane Angle = "<<  fMCReactionPlaneAngle << endl;
 135   else cout<<" MC Reaction Plane Angle = unknown "<< endl;
 136
 137   cout<<" iGoodTracks = "<< iGoodTracks << endl;
 138   cout<<" # of RP selected tracks = "<<iSelParticlesRP<<endl;
 139   cout<<" # of POI selected tracks = "<<iSelParticlesPOI<<endl;
 140   cout << "# " << ++fCount << " events processed" << endl;
 141
 142   delete fPhiDistribution;
 143   delete fPtSpectra;
 144   return pEvent;
 145
 146 } // end of CreateEventOnTheFly()
 147
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 149