PWG2/FLOW/AliFlowCommon/AliFittingFunctionsForQDistribution.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  * integrated flow estimate by  *
  18  *   fitting q-distribution     *
  19  *                              *
  20  * author: Ante Bilandzic       *
  21  *          (anteb@nikhef.nl)   *
  22  *                              *
  23  * based on the macro written   *
  24  *     by Sergei Voloshin       *
  25  *******************************/
  26
  27 #define AliFittingFunctionsForQDistribution_cxx
  28
  29 #include "Riostream.h"
  30 #include "TChain.h"
  31 #include "TFile.h"
  32 #include "TList.h"
  33 #include "TParticle.h"
  34
  35 #include "TProfile.h"
  36 #include "TF1.h"
  37 #include "TAxis.h"
  38 #include "TH1.h"
  39 #include "TH1D.h"
  40 #include "TMath.h"
  41
  42 #include "AliFlowEventSimple.h"
  43 #include "AliFlowTrackSimple.h"
  44 #include "AliFittingQDistribution.h"
  45 #include "AliFlowCommonConstants.h"
  46 #include "AliFlowCommonHistResults.h"
  47 #include "AliFittingFunctionsForQDistribution.h"
  48
  49 ClassImp(AliFittingFunctionsForQDistribution)
  50
  51 //================================================================================================================_
  52
  53 AliFittingFunctionsForQDistribution::AliFittingFunctionsForQDistribution():
  54  fAvMultFQD(NULL),
  55  fQDistributionFQD(NULL),
  56  fIntFlowResFQD(NULL),
  57  fSigma2(NULL),
  58  fchrFQD(NULL)
  59 {
  60  //default constructor
  61 }
  62
  63 AliFittingFunctionsForQDistribution::~AliFittingFunctionsForQDistribution()
  64 {
  65  //destructor
  66 }
  67
  68 AliFittingFunctionsForQDistribution::AliFittingFunctionsForQDistribution(TProfile *AvMult, TH1D *QDistribution, TH1D *intFlowRes, TH1D *sigma2, AliFlowCommonHistResults *chr):
  69  fAvMultFQD(AvMult),
  70  fQDistributionFQD(QDistribution),
  71  fIntFlowResFQD(intFlowRes),
  72  fSigma2(sigma2),
  73  fchrFQD(chr)
  74 {
  75  //custom constructor
  76 }
  77
  78 //================================================================================================================
  79
  80 void AliFittingFunctionsForQDistribution::Calculate()
  81 {
  82  //fitting q-distribution
  83
  84  Int_t n=2;//harmonic (to be improved)
  85
  86  Double_t AvM = fAvMultFQD->GetBinContent(1);
  87
  88  Int_t nEvts = (Int_t)(fAvMultFQD->GetBinEntries(1));
  89
  90  Double_t qmin=(fQDistributionFQD->GetXaxis())->GetXmin();
  91  Double_t qmax=(fQDistributionFQD->GetXaxis())->GetXmax();
  92  Double_t bin=fQDistributionFQD->GetBinWidth(4);//assuming that all bins have the same width
  93  Double_t ent=fQDistributionFQD->GetEntries();
  94  Double_t norm=bin*ent;//assuming that all bins have the same width
  95
  96  TF1 *fittingFun = new TF1("fittingFun","[2]*(x/[1])*exp(-(x*x+[0]*[0])/(2.*[1]))*TMath::BesselI0(x*[0]/[1])",qmin,qmax);
  97
  98  fittingFun->SetParNames("V","sigma","norm");
  99  fittingFun->SetParameters(0.1*pow(AvM,0.5),0.5,norm);
 100
 101  fittingFun->SetParLimits(0,0.,10.);//to be improved (limits)
 102  fittingFun->SetParLimits(1,0.,5.5);//to be improved (limits)
 103  fittingFun->FixParameter(2,norm);
 104
 105  Double_t v=0.,errorv=0.,sigma2=0.,errorsigma2=0.;
 106
 107  if(fQDistributionFQD->GetEntries()>50)//to be improved (only a pragmatic fix)
 108  {
 109   fQDistributionFQD->Fit("fittingFun","NQ","",qmin,qmax);
 110   if(AvM)
 111   {
 112    v = fittingFun->GetParameter(0)/pow(AvM,0.5);
 113    errorv = fittingFun->GetParError(0)/pow(AvM,0.5);
 114   }
 115   sigma2 = fittingFun->GetParameter(1);
 116   errorsigma2 = fittingFun->GetParError(1);
 117  }
 118
 119  cout<<" "<<endl;
 120  cout<<"***************************************"<<endl;
 121  cout<<"***************************************"<<endl;
 122  cout<<"      integrated flow by fitting "<<endl;
 123  cout<<"           q-distribution:      "<<endl;
 124  cout<<""<<endl;
 125  cout<<"   v_"<<n<<"{FQD} = "<<v<<" +/- "<<errorv<<endl;
 126  cout<<"   sigma^2  = "<<sigma2<<" +/- "<<errorsigma2<<endl;
 127  //cout<<"vm       = "<<v*pow(AvM,0.5)<<endl;
 128  cout<<" "<<endl;
 129  cout<<"      nEvts = "<<nEvts<<", AvM = "<<AvM<<endl;
 130  cout<<"***************************************"<<endl;
 131  cout<<"***************************************"<<endl;
 132  fIntFlowResFQD->SetBinContent(1,v);
 133  fIntFlowResFQD->SetBinError(1,errorv);
 134  fSigma2->SetBinContent(1,sigma2);
 135  fSigma2->SetBinError(1,errorsigma2);
 136
 137  //common histograms:
 138  fchrFQD->FillIntegratedFlow(v,errorv);
 139  fchrFQD->FillChi(v*pow(AvM,0.5));
 140  //RP:
 141  fchrFQD->FillIntegratedFlowRP(v,errorv);
 142  fchrFQD->FillChiRP(v*pow(AvM,0.5));
 143
 144  cout<<" "<<endl;
 145
 146  //fQDistributionFQD->Draw("");
 147  //fittingFun->Draw("SAME");
 148
 149 }//end of Calculate()
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