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   fNoOfLoops(1)
  53  {
  54   // constructor
  55    fMyTRandom3 = new TRandom3(iseed);
  56  }
  57
  58
  59 //========================================================================
  60
  61
  62 AliFlowEventSimpleMakerOnTheFly::~AliFlowEventSimpleMakerOnTheFly()
  63 {
  64  // destructor
  65   if (fPtSpectra) delete fPtSpectra;
  66   if (fPhiDistribution) delete fPhiDistribution;
  67   if (fMyTRandom3) delete  fMyTRandom3;
  68 }
  69
  70
  71 //========================================================================
  72
  73
  74 AliFlowEventSimple* AliFlowEventSimpleMakerOnTheFly::CreateEventOnTheFly()
  75 {
  76   // method to create event on the fly
  77
  78   AliFlowEventSimple* pEvent = new AliFlowEventSimple(fMultiplicityOfRP);
  79
  80   //reaction plane
  81   Double_t fMCReactionPlaneAngle = fMyTRandom3->Uniform(0.,TMath::TwoPi());
  82
  83   // pt:
  84   Double_t dPtMin = 0.; // to be improved
  85   Double_t dPtMax = 10.; // to be improved
  86
  87   fPtSpectra = new TF1("fPtSpectra","[0]*x*TMath::Exp(-x*x)",dPtMin,dPtMax);
  88   fPtSpectra->SetParName(0,"Multiplicity of RPs");
  89   // sampling the multiplicity:
  90   Int_t fNewMultiplicityOfRP = fMyTRandom3->Gaus(fMultiplicityOfRP,fMultiplicitySpreadOfRP);
  91   fPtSpectra->SetParameter(0,fNewMultiplicityOfRP);
  92
  93
  94   // phi:
  95   Double_t dPhiMin = 0.; // to be improved
  96   Double_t dPhiMax = TMath::TwoPi(); // to be improved
  97
  98   fPhiDistribution = new TF1("fPhiDistribution","1+2.*[0]*TMath::Cos(x)+2.*[1]*TMath::Cos(2*x)",dPhiMin,dPhiMax);
  99
 100   // sampling the V1:
 101   fPhiDistribution->SetParName(0,"directed flow");
 102   Double_t fNewV1RP=0.;
 103   if(fV1RP>0.0) {fNewV1RP = fMyTRandom3->Gaus(fV1RP,fV1SpreadRP);}
 104   fPhiDistribution->SetParameter(0,fNewV1RP);
 105
 106   // sampling the V2:
 107   fPhiDistribution->SetParName(1,"elliptic flow");
 108   Double_t fNewV2RP = fMyTRandom3->Gaus(fV2RP,fV2SpreadRP);
 109   fPhiDistribution->SetParameter(1,fNewV2RP);
 110
 111   // eta:
 112   Double_t dEtaMin = -1.; // to be improved
 113   Double_t dEtaMax = 1.; // to be improved
 114
 115   Int_t iGoodTracks = 0;
 116   Int_t iSelParticlesRP = 0;
 117   Int_t iSelParticlesPOI = 0;
 118   Double_t fTmpPt =0;
 119   Double_t fTmpEta =0;
 120   Double_t fTmpPhi =0;
 121   for(Int_t i=0;i<fNewMultiplicityOfRP;i++) {
 122     fTmpPt = fPtSpectra->GetRandom();
 123     fTmpEta = fMyTRandom3->Uniform(dEtaMin,dEtaMax);
 124     fTmpPhi = fPhiDistribution->GetRandom()+fMCReactionPlaneAngle;
 125     for(Int_t d=0;d<fNoOfLoops;d++) {
 126       AliFlowTrackSimple* pTrack = new AliFlowTrackSimple();
 127       pTrack->SetPt(fTmpPt);
 128       pTrack->SetEta(fTmpEta);
 129       pTrack->SetPhi(fTmpPhi);
 130       pTrack->SetForRPSelection(kTRUE);
 131       iSelParticlesRP++;
 132       pTrack->SetForPOISelection(kTRUE);
 133       iSelParticlesPOI++;
 134       pEvent->TrackCollection()->Add(pTrack);
 135       iGoodTracks++;
 136     }
 137   }
 138
 139   pEvent->SetEventNSelTracksRP(iSelParticlesRP);
 140   pEvent->SetNumberOfTracks(iGoodTracks);//tracks used either for RP or for POI selection
 141   pEvent->SetMCReactionPlaneAngle(fMCReactionPlaneAngle);
 142
 143   if (!fMCReactionPlaneAngle == 0) cout<<" MC Reaction Plane Angle = "<<  fMCReactionPlaneAngle << endl;
 144   else cout<<" MC Reaction Plane Angle = unknown "<< endl;
 145
 146   cout<<" iGoodTracks = "<< iGoodTracks << endl;
 147   cout<<" # of RP selected tracks = "<<iSelParticlesRP<<endl;
 148   cout<<" # of POI selected tracks = "<<iSelParticlesPOI<<endl;
 149   cout << "# " << ++fCount << " events processed" << endl;
 150
 151   delete fPhiDistribution;
 152   delete fPtSpectra;
 153   return pEvent;
 154
 155 } // end of CreateEventOnTheFly()
 156
 157
 158