fForceDecay initialized to kAll in constructors
[u/mrichter/AliRoot.git] / STEER / AliESDanalysis.C
index 7593cb6..4e9f967 100644 (file)
 //********************************************************************
 //     Example (very naive for the moment) of the data analysis 
 //                    using the ESD classes
-//       It demonstrates the idea of the "combined PID".
-// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
+//     Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
 //********************************************************************
 
-#ifndef __CINT__
+#if !defined( __CINT__) || defined(__MAKECINT__)
   #include <Riostream.h>
   #include "TKey.h"
   #include "TFile.h"
-  #include "TH2F.h"
+  #include "TH1F.h"
   #include "TCanvas.h"
+  #include "TStyle.h"
   #include "TStopwatch.h"
 
   #include "AliESD.h"
 #endif
 
-Int_t AliESDanalysis(Int_t nev=1) { 
-  TH2F *tpcHist=
-     new TH2F("tpcHist","TPC dE/dX vs momentum",100,0.,4.,100,0.,500.);
-  tpcHist->SetXTitle("p (GeV/c)"); tpcHist->SetYTitle("dE/dx (Arb. Units)");
-     tpcHist->SetMarkerStyle(8); 
-     tpcHist->SetMarkerSize(0.3);
-  TH2F *elHist=new TH2F("elHist","dE/dX vs momentum",100,0.,4.,50,0.,500.);
-     elHist->SetMarkerStyle(8); 
-     elHist->SetMarkerSize(0.3);
-
-  TH2F *piHist=new TH2F("piHist","dE/dX vs momentum",100,0.,4.,50,0.,500.);
-     piHist->SetMarkerColor(2); 
-     piHist->SetMarkerStyle(8); 
-     piHist->SetMarkerSize(0.3);
-
-  TH2F *kaHist=new TH2F("kaHist","dE/dX vs momentum",100,0.,4.,100,0.,500.);
-     kaHist->SetMarkerColor(4); 
-     kaHist->SetMarkerStyle(8); 
-     kaHist->SetMarkerSize(0.3);
-
-  TH2F *prHist=new 
-   TH2F("prHist","Classification into e, pi, K and p",100,0.,4.,100,0.,500.);
-   prHist->SetXTitle("p (GeV/c)"); prHist->SetYTitle("dE/dx (Arb. Units)");
-     prHist->SetMarkerColor(6); 
-     prHist->SetMarkerStyle(8); 
-     prHist->SetMarkerSize(0.3);
-   
-   TFile *ef=TFile::Open("AliESDs.root");
-   if (!ef->IsOpen()) {cerr<<"Can't AliESDs.root !\n"; return 1;}
+extern TStyle *gStyle;
 
+Int_t AliESDanalysis() { 
    TStopwatch timer;
-   Int_t rc=0,n=0;
+
+   gStyle->SetOptStat(111110);
+   gStyle->SetOptFit(1);
+
+   Double_t V0mass=0.497672, V0width=0.020, V0window=0.05; 
+   Double_t mmin=V0mass-V0window, mmax=V0mass+V0window;
+   TH1F *hm =new TH1F("hm","K0s",40, mmin, mmax);
+   hm->SetXTitle("Mass (GeV/c**2)"); hm->SetLineColor(2);
+   TH1F *hp =new TH1F("hp","Momentum of the positive daughter",40, 0, 2);
+   hp->SetXTitle("P (GeV/c)"); hp->SetLineColor(4);
+
+//****** File with the ESD
+   TFile *ef=TFile::Open("AliESDs.root");
+   if (!ef || !ef->IsOpen()) {cerr<<"Can't AliESDs.root !\n"; return 1;}
+
+   Int_t n=0;
    TKey *key=0;
    TIter next(ef->GetListOfKeys());
 
-   //****** Tentative particle type "concentrations"
-   Double_t c[5]={0.05, 0., 0.85, 0.10, 0.05};
-
-   //******* The loop over events
+//******* The loop over events
    while ((key=(TKey*)next())!=0) {
-     cerr<<"Processing event number : "<<n++<<endl;
+     cout<<endl<<"Processing event number : "<<n++<<endl;
+
      AliESD *event=(AliESD*)key->ReadObj();
 
      Int_t ntrk=event->GetNumberOfTracks();
-     cerr<<"Number of ESD tracks : "<<ntrk<<endl; 
+     cout<<"Number of ESD tracks : "<<ntrk<<endl; 
+     Int_t nv0=event->GetNumberOfV0s();
+     cout<<"Number of ESD V0s : "<<nv0<<endl; 
+     Int_t ncas=event->GetNumberOfCascades();
+     cout<<"Number of ESD cascades : "<<ncas<<endl; 
+
      //****** The loop over tracks
+     Int_t nk=0;
      while (ntrk--) {
-       AliESDtrack *t=event->GetTrack(ntrk);
-
-       Double_t p=t->GetP();
-
-       if (t->GetStatus()&AliESDtrack::kTPCin) {
-        Double_t dedx=t->GetTPCsignal();
-         tpcHist->Fill(p,dedx,1);
-       }
-
-       if (t->GetStatus()&AliESDtrack::kESDpid) {
-         Double_t dedx=t->GetTPCsignal();
-        Double_t r[10]; t->GetESDpid(r);
-         Double_t rc=0.;
-         Int_t i;
-         for (i=0; i<AliESDtrack::kSPECIES; i++) rc+=(c[i]*r[i]);
-         if (rc==0.) continue;
-
-        //Here we apply Bayes' formula
-         Double_t w[10];
-         for (i=0; i<AliESDtrack::kSPECIES; i++) w[i]=c[i]*r[i]/rc;
-
-         if (w[4]>w[3] && w[4]>w[2] && w[4]>w[0]) prHist->Fill(p,dedx,1);
-         if (w[3]>w[4] && w[3]>w[2] && w[3]>w[0]) kaHist->Fill(p,dedx,1);
-         if (w[2]>w[3] && w[2]>w[4] && w[2]>w[0]) piHist->Fill(p,dedx,1);
-         if (w[0]>w[3] && w[0]>w[2] && w[0]>w[4]) elHist->Fill(p,dedx,1);
-       }
-
-     } 
-     delete event;
+        AliESDtrack *track=event->GetTrack(ntrk);
+        UInt_t status=track->GetStatus();
+
+       //select only tracks with the "combined PID"
+        if ((status&AliESDtrack::kESDpid)==0) continue;
+
+        Double_t w[10]; track->GetESDpid(w);
+        //count only "Kaon-like" tracks
+        if (w[3]>w[4] && w[3]>w[2] && w[3]>w[1] && w[3]>w[0]) nk++;        
+     }
+     cout<<"Number of \"Kaon-like\" tracks : "<<nk<<endl;
+
+     //****** The loop over V0s
+     while (nv0--) {
+        AliESDv0 *v0=event->GetV0(nv0);
+        v0->ChangeMassHypothesis(310); // K0s
+        Double_t mass=v0->GetEffMass();
+        hm->Fill(mass);
+
+        Int_t pidx=v0->GetPindex();               // now let's get an access  
+        AliESDtrack *track=event->GetTrack(pidx); // to the positive daughter
+        Double_t p=track->GetP();
+        hp->Fill(p);
+     }
+
+     //****** The loop over cascades
+     while (ncas--) {
+        AliESDcascade *cas=event->GetCascade(ncas);
+        Double_t q; //"quality" of the associated Lambda
+        cas->ChangeMassHypothesis(q,3312); // Xi-
+        // Here you do something with your Xis
+        //  ...
+        // You can get the access to the daughters
+     }
+
    }
+
    timer.Stop(); timer.Print();
 
    TCanvas *c1=new TCanvas("c1","",0,0,600,1200);
    c1->Divide(1,2);
 
    c1->cd(1);
-   tpcHist->Draw();
-   c1->cd(2);
-   prHist->Draw();
-   kaHist->Draw("same");
-   piHist->Draw("same");
-   elHist->Draw("same");
+   hm->Fit("gaus","","",V0mass-V0width,V0mass+V0width);
 
-   ef->Close();
+   c1->cd(2);
+   hp->Fit("expo","","",0.3,2); 
 
-   return rc;
+   return 0;
 }