X-Git-Url: http://git.uio.no/git/?a=blobdiff_plain;f=ITS%2FAliV0Comparison.C;h=392463bcf2f5714d1e8ff78f94e52eb4af788934;hb=7b54ea5c7f4a049ae41d5026aba55d64b07bf6cf;hp=da772af851ab091ad3fa9d1d8bc898014ad78912;hpb=548b1270145e59901dd49b6ab6e195b2fcee0949;p=u%2Fmrichter%2FAliRoot.git

diff --git a/ITS/AliV0Comparison.C b/ITS/AliV0Comparison.C
index da772af851a..392463bcf2f 100644
--- a/ITS/AliV0Comparison.C
+++ b/ITS/AliV0Comparison.C
@@ -7,36 +7,44 @@
  *   Origin: I.Belikov, IReS, Strasbourg, Jouri.Belikov@cern.ch             *
  ****************************************************************************/
 
-#ifndef __CINT__
-  #include "Riostream.h"
-  #include <fstream.h>
-
-  #include "TH1.h"
-  #include "TFile.h"
-  #include "TTree.h"
-  #include "TObjArray.h"
-  #include "TStyle.h"
-  #include "TCanvas.h"
-  #include "TLine.h"
-  #include "TText.h"
-  #include "TParticle.h"
-  #include "TStopwatch.h"
-
+#if !defined(__CINT__) || defined(__MAKECINT__)
+  #include <TMath.h>
+  #include <TError.h>
+  #include <Riostream.h>
+  #include <TH1F.h>
+  #include <TTree.h>
+  #include <TParticle.h>
+  #include <TCanvas.h>
+  #include <TLine.h>
+  #include <TText.h>
+  #include <TBenchmark.h>
+  #include <TStyle.h>
+  #include <TFile.h>
+  #include <TROOT.h>
+
+  #include "AliStack.h"
+  #include "AliHeader.h"
+  #include "AliTrackReference.h"
+  #include "AliRunLoader.h"
   #include "AliRun.h"
-  #include "AliPDG.h"
-  #include "AliV0vertex.h"
+  #include "AliESD.h"
 #endif
 
-struct GoodVertex {
-  Int_t nlab,plab;
-  Int_t code;
-  Float_t px,py,pz;
-  Float_t x,y,z;
-};
-Int_t good_vertices(GoodVertex *gt, Int_t max);
+Int_t GoodV0s(const Char_t *dir=".");
+
+extern AliRun *gAlice;
+extern TBenchmark *gBenchmark;
+extern TROOT *gROOT;
+
+static Int_t allgood=0;
+static Int_t allfound=0;
+
+Int_t AliV0Comparison(Int_t code=310, const Char_t *dir=".") { 
+   //Lambda=3122, LambdaBar=-3122
+   gBenchmark->Start("AliV0Comparison");
+
+   ::Info("AliV0Comparison.C","Doing comparison...");
 
-Int_t AliV0Comparison(Int_t code=310) { //Lambda=3122, LambdaBar=-3122
-   cerr<<"Doing comparison...\n";
 
    const Double_t V0window=0.05;
    Double_t ptncut=0.13, ptpcut=0.13, kinecut=0.03; 
@@ -53,195 +61,272 @@ Int_t AliV0Comparison(Int_t code=310) { //Lambda=3122, LambdaBar=-3122
    default: cerr<<"Invalid PDG code !\n"; return 1;
    }
 
-   TStopwatch timer;
-
-   /*** Load reconstructed vertices ***/
-   TFile *vf=TFile::Open("AliV0vertices.root");
-   if (!vf->IsOpen()) {cerr<<"Can't open AliV0vertices.root !\n"; return 2;}
-   TObjArray varray(1000);
-   TTree *vTree=(TTree*)vf->Get("TreeV0");
-   TBranch *branch=vTree->GetBranch("vertices");
-   Int_t nentr=(Int_t)vTree->GetEntries();
-   for (Int_t i=0; i<nentr; i++) {
-       AliV0vertex *iovertex=new AliV0vertex; branch->SetAddress(&iovertex);
-       vTree->GetEvent(i);
-       varray.AddLast(iovertex);
-   }
-
-   /*** Check if the file with the "good" vertices exists ***/
-   GoodVertex gv[1000];
-   Int_t ngood=0;
-   ifstream in("good_vertices");
-   if (in) {
-      cerr<<"Reading good vertices...\n";
-      while (in>>gv[ngood].nlab>>gv[ngood].plab>>gv[ngood].code>>
-                 gv[ngood].px>>gv[ngood].py>>gv[ngood].pz>>
-                 gv[ngood].x >>gv[ngood].y >>gv[ngood].z) {
-         ngood++;
-         cerr<<ngood<<'\r';
-         if (ngood==1000) {
-            cerr<<"Too many good vertices !\n";
-            break;
-         }
-      }
-      if (!in.eof()) cerr<<"Read error (good_vertices) !\n";
-   } else {
-     /*** generate a file with the "good" vertices ***/
-      cerr<<"Marking good vertices (this will take a while)...\n";
-      ngood=good_vertices(gv,1000);
-      ofstream out("good_vertices");
-      if (out) {
-         for (Int_t ngd=0; ngd<ngood; ngd++)            
-	    out<<gv[ngd].nlab<<' '<<gv[ngd].plab<<' '<<gv[ngd].code<<' '<<
-                 gv[ngd].px<<' '<<gv[ngd].py<<' '<<gv[ngd].pz<<' '<<
-                 gv[ngd].x <<' '<<gv[ngd].y <<' '<<gv[ngd].z <<endl;
-      } else cerr<<"Can not open file (good_vertices) !\n";
-      out.close();
-   }
-
-   vf->Close();
-
-
-   TH1F *hp=new TH1F("hp","Angular Resolution",30,-30.,30.); //phi resolution 
+   TH1F *hp=(TH1F*)gROOT->FindObject("hp");
+   if (!hp) hp=new TH1F("hp","PHI Resolution",30,-30.,30.);
    hp->SetXTitle("(mrad)"); hp->SetFillColor(2);
-   TH1F *hl=new TH1F("hl","Lambda Resolution",30,-30,30);
-   hl->SetXTitle("(mrad)"); hl->SetFillColor(1); hl->SetFillStyle(3013); 
-   TH1F *hpt=new TH1F("hpt","Relative Pt Resolution",30,-10.,10.); 
+
+   TH1F *hl=(TH1F*)gROOT->FindObject("hl");
+   if (!hl) hl=new TH1F("hl","LAMBDA Resolution",30,-30,30);
+   hl->SetXTitle("(mrad)"); hl->SetFillColor(1); hl->SetFillStyle(3013);
+ 
+   TH1F *hpt=(TH1F*)gROOT->FindObject("hpt");
+   if (!hpt) hpt=new TH1F("hpt","Relative Pt Resolution",30,-10.,10.); 
    hpt->SetXTitle("(%)"); hpt->SetFillColor(2); 
 
-   TH1F *hx=new TH1F("hx","Position Resolution (X,Y)",30,-3.,3.); //x res. 
+   TH1F *hx=(TH1F*)gROOT->FindObject("hx");
+   if (!hx) hx=new TH1F("hx","Position Resolution (X)",30,-3.,3.);
    hx->SetXTitle("(mm)"); hx->SetFillColor(6);
-   TH1F *hy=new TH1F("hy","Position Resolution (Y)",30,-3.,3.);   //y res
+
+   TH1F *hy=(TH1F*)gROOT->FindObject("hy");
+   if (!hy) hy=new TH1F("hy","Position Resolution (Y)",30,-3.,3.); 
    hy->SetXTitle("(mm)"); hy->SetFillColor(1); hy->SetFillStyle(3013);
-   TH1F *hz=new TH1F("hz","Position Resolution (Z)",30,-3.,3.);   //z res. 
+
+   TH1F *hz=(TH1F*)gROOT->FindObject("hz");
+   if (!hz) hz=new TH1F("hz","Position Resolution (Z)",30,-3.,3.);
    hz->SetXTitle("(mm)"); hz->SetFillColor(6);
 
 
    Double_t pmin=0.2, pmax=4.2; Int_t nchan=20;
-   TH1F *hgood=new TH1F("hgood","Good Vertices",nchan,pmin,pmax);    
-   TH1F *hfound=new TH1F("hfound","Found Vertices",nchan,pmin,pmax);
-   TH1F *hfake=new TH1F("hfake","Fake Vertices",nchan,pmin,pmax);
-   TH1F *hg=new TH1F("hg","Efficiency for Good Vertices",nchan,pmin,pmax);
+   TH1F *hgood=(TH1F*)gROOT->FindObject("hgood");    
+   if (!hgood) hgood=new TH1F("hgood","Good Vertices",nchan,pmin,pmax);
+    
+   TH1F *hfound=(TH1F*)gROOT->FindObject("hfound");
+   if (!hfound) hfound=new TH1F("hfound","Found Vertices",nchan,pmin,pmax);
+
+   TH1F *hfake=(TH1F*)gROOT->FindObject("hfake");
+   if (!hfake) hfake=new TH1F("hfake","Fake Vertices",nchan,pmin,pmax);
+
+   TH1F *hg=(TH1F*)gROOT->FindObject("hg");
+   if (!hg) hg=new TH1F("hg","Efficiency for Good Vertices",nchan,pmin,pmax);
    hg->SetLineColor(4); hg->SetLineWidth(2);
-   TH1F *hf=new TH1F("hf","Probability of Fake Vertices",nchan,pmin,pmax);
+
+   TH1F *hf=(TH1F*)gROOT->FindObject("hf");
+   if (!hf) hf=new TH1F("hf","Probability of Fake Vertices",nchan,pmin,pmax);
    hf->SetFillColor(1); hf->SetFillStyle(3013); hf->SetLineWidth(2);
 
+
    Double_t mmin=V0mass-V0window, mmax=V0mass+V0window;
-   TH1F *v0s =new TH1F("v0s","V0s Effective Mass",40, mmin, mmax);
-   v0s->SetXTitle("(GeV)");
-   v0s->SetLineColor(4); v0s->SetLineWidth(4);
-   TH1F *v0sf =new TH1F("v0sf","Fake V0s Effective Mass",40, mmin, mmax);
+   TH1F *v0s=(TH1F*)gROOT->FindObject("v0s");
+   if (!v0s) v0s=new TH1F("v0s","V0s Effective Mass",40, mmin, mmax);
+   v0s->SetXTitle("(GeV)"); v0s->SetLineColor(4); v0s->SetLineWidth(4);
+
+   TH1F *v0sf=(TH1F*)gROOT->FindObject("v0sf");
+   if (!v0sf) v0sf=new TH1F("v0sf","Fake V0s Effective Mass",40, mmin, mmax);
    v0sf->SetXTitle("(GeV)"); v0sf->SetFillColor(6);
 
 
-   Double_t pxg=0.,pyg=0.,ptg=0.;
-   Int_t nlab=-1, plab=-1;
-   Int_t i;
-   for (i=0; i<nentr; i++) {
-       AliV0vertex *vertex=(AliV0vertex*)varray.UncheckedAt(i);
-       nlab=TMath::Abs(vertex->GetNlabel());
-       plab=TMath::Abs(vertex->GetPlabel());
-
-       /** Kinematical cuts **/
-       Double_t pxn,pyn,pzn; vertex->GetNPxPyPz(pxn,pyn,pzn); 
-       Double_t ptn=TMath::Sqrt(pxn*pxn + pyn*pyn);
-       if (ptn < ptncut) continue;
-       Double_t pxp,pyp,pzp; vertex->GetPPxPyPz(pxp,pyp,pzp); 
-       Double_t ptp=TMath::Sqrt(pxp*pxp + pyp*pyp);
-       if (ptp < ptpcut) continue;
-       Double_t kine=vertex->ChangeMassHypothesis(code);
-       //if (TMath::Abs(kine)>kinecut) continue;
-
-       Double_t mass=vertex->GetEffMass();
-       v0s->Fill(mass);
-       v0sf->Fill(mass);
-
-       Int_t j;
-       for (j=0; j<ngood; j++) {
-          if (gv[j].code != vertex->GetPdgCode()) continue;
-          if (gv[j].nlab == nlab)
-          if (gv[j].plab == plab) break;
-       }
-
-       if (TMath::Abs(mass-V0mass)>V0width) continue;
-
-       Double_t px,py,pz; vertex->GetPxPyPz(px,py,pz);
-       Double_t pt=TMath::Sqrt(px*px+py*py);
-
-       if (j==ngood) {
-          hfake->Fill(pt);
-          cerr<<"Fake vertex: ("<<nlab<<","<<plab<<")\n";
-          continue;
-       }
-       v0sf->Fill(mass,-1);
-
-       pxg=gv[j].px; pyg=gv[j].py; ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
-       Double_t phig=TMath::ATan2(pyg,pxg), phi=TMath::ATan2(py,px);
-       Double_t lamg=TMath::ATan2(gv[j].pz,ptg), lam=TMath::ATan2(pz,pt);
-       hp->Fill((phi - phig)*1000.);
-       hl->Fill((lam - lamg)*1000.);
-       hpt->Fill((1/pt - 1/ptg)/(1/ptg)*100.);
-
-       Double_t x,y,z; vertex->GetXYZ(x,y,z);
-       hx->Fill((x-gv[j].x)*10);
-       hy->Fill((y-gv[j].y)*10);
-       hz->Fill((z-gv[j].z)*10);
-
-       hfound->Fill(ptg);
-       gv[j].nlab=-1;
+   Char_t fname[100];
+   sprintf(fname,"%s/GoodV0s.root",dir);
 
+   TFile *refFile=TFile::Open(fname,"old");
+   if (!refFile || !refFile->IsOpen()) {
+   ::Info("AliV0Comparison.C","Marking good V0s (will take a while)...");
+     if (GoodV0s(dir)) {
+        ::Error("AliV0Comparison.C","Can't generate the reference file !");
+        return 1;
+     }
+   }
+   refFile=TFile::Open(fname,"old");
+   if (!refFile || !refFile->IsOpen()) {
+     ::Error("AliV0Comparison.C","Can't open the reference file !");
+     return 1;
+   }   
+  
+   TTree *v0Tree=(TTree*)refFile->Get("v0Tree");
+   if (!v0Tree) {
+     ::Error("AliV0Comparison.C","Can't get the reference tree !");
+     return 2;
    }
-   for (i=0; i<ngood; i++) {
-      if (gv[i].code != code) continue;
-      pxg=gv[i].px; pyg=gv[i].py; ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
-      hgood->Fill(ptg);
-      nlab=gv[i].nlab; plab=gv[i].plab;
-      if (nlab < 0) continue;
-      cerr<<"Vertex ("<<nlab<<','<<plab<<") has not been found !\n";
+   TBranch *pbranch=v0Tree->GetBranch("positive");
+   if (!pbranch) {
+     ::Error("AliV0Comparison.C","Can't get the positive daughter branch !");
+     return 3;
    }
+   TClonesArray dummy("AliTrackReference",1000), *prefs=&dummy;
+   pbranch->SetAddress(&prefs);
 
-   varray.Delete();
+   TBranch *nbranch=v0Tree->GetBranch("negative");
+   if (!nbranch) {
+     ::Error("AliV0Comparison.C","Can't get the negative daughter branch !");
+     return 4;
+   }
+   TClonesArray dumm("AliTrackReference",1000), *nrefs=&dumm;
+   nbranch->SetAddress(&nrefs);
+
+   
+   sprintf(fname,"%s/AliESDs.root",dir);
+   TFile *ef=TFile::Open(fname);
+   if ((!ef)||(!ef->IsOpen())) {
+      sprintf(fname,"%s/AliESDv0.root",dir);
+      ef=TFile::Open(fname);
+      if ((!ef)||(!ef->IsOpen())) {
+         ::Error("AliV0Comparison.C","Can't open AliESDv0.root !");
+         return 5;
+      }
+   }
+   AliESD* event = new AliESD;
+   TTree* esdTree = (TTree*) ef->Get("esdTree");
+   if (!esdTree) {
+      ::Error("AliV0Comparison.C", "no ESD tree found");
+      return 6;
+   }
+   esdTree->SetBranchAddress("ESD", &event);
 
-   Stat_t ng=hgood->GetEntries();
-   Stat_t nf=hfound->GetEntries();
 
-   cerr<<"Number of found vertices: "<<nentr<<" ("<<nf<<" in the peak)\n";
-   cerr<<"Number of good vertices: "<<ng<<endl;
+   //******* Loop over events *********
+   Int_t e=0;
+   while (esdTree->GetEvent(e)) {
+      cout<<endl<<endl<<"********* Processing event number: "<<e<<"*******\n";
+ 
+      Int_t nentr=event->GetNumberOfV0s();
+      allfound+=nentr;
 
-   if (ng!=0) 
-      cerr<<"Integral efficiency is about "<<nf/ng*100.<<" %\n";
+      if (v0Tree->GetEvent(e++)==0) {
+         cerr<<"No reconstructable V0s !\n";
+         continue;
+      }
+
+      Int_t ngood=prefs->GetEntriesFast(),ng=0; 
+
+      Double_t pxg=0.,pyg=0.,pzg=0.,ptg=0.;
+      Int_t nlab=-1, plab=-1;
+      Int_t i;
+      for (i=0; i<nentr; i++) {
+          AliESDv0 *vertex=event->GetV0(i);
+
+          Int_t nidx=TMath::Abs(vertex->GetNindex());
+          Int_t pidx=TMath::Abs(vertex->GetPindex());
+
+          AliESDtrack *ntrack=event->GetTrack(nidx);
+          AliESDtrack *ptrack=event->GetTrack(pidx);
+
+          nlab=TMath::Abs(ntrack->GetLabel());
+          plab=TMath::Abs(ptrack->GetLabel());
+
+          /** Kinematical cuts **/
+          Double_t pxn,pyn,pzn; vertex->GetNPxPyPz(pxn,pyn,pzn); 
+          Double_t ptn=TMath::Sqrt(pxn*pxn + pyn*pyn);
+          if (ptn < ptncut) continue;
+          Double_t pxp,pyp,pzp; vertex->GetPPxPyPz(pxp,pyp,pzp); 
+          Double_t ptp=TMath::Sqrt(pxp*pxp + pyp*pyp);
+          if (ptp < ptpcut) continue;
+          Double_t kine=vertex->ChangeMassHypothesis(code);
+          //if (TMath::Abs(kine)>kinecut) continue;
+
+          Double_t mass=vertex->GetEffMass();
+          v0s->Fill(mass);
+          v0sf->Fill(mass);
+
+          AliTrackReference *nref=0, *pref=0;
+          Int_t j;
+          for (j=0; j<ngood; j++) {
+              nref=(AliTrackReference*)nrefs->UncheckedAt(j);
+              pref=(AliTrackReference*)prefs->UncheckedAt(j);
+              if (nref->Label() == nlab)
+              if (pref->Label() == plab) break;
+          }
+
+          if (TMath::Abs(mass-V0mass)>V0width) continue;
+
+          Double_t px,py,pz; vertex->GetPxPyPz(px,py,pz);
+          Double_t pt=TMath::Sqrt(px*px+py*py);
+
+          if (j==ngood) {
+             hfake->Fill(pt);
+             cout<<"Fake vertex: ("<<nlab<<","<<plab<<")\n";
+             continue;
+          }
+          v0sf->Fill(mass,-1);
+
+          pxg=nref->Px()+pref->Px(); pyg=nref->Py()+pref->Py();
+          pzg=nref->Pz()+pref->Pz(); 
+          ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
+          Double_t phig=TMath::ATan2(pyg,pxg), phi=TMath::ATan2(py,px);
+          Double_t lamg=TMath::ATan2(pzg,ptg), lam=TMath::ATan2(pz,pt);
+          hp->Fill((phi - phig)*1000.);
+          hl->Fill((lam - lamg)*1000.);
+          hpt->Fill((1/pt - 1/ptg)/(1/ptg)*100.);
+
+          Double_t x,y,z; vertex->GetXYZ(x,y,z);
+          hx->Fill((x - nref->X())*10);
+          hy->Fill((y - nref->Y())*10);
+          hz->Fill((z - nref->Z())*10);
+
+          hfound->Fill(ptg);
+          nref->SetLabel(-1);
+
+      }
+      for (i=0; i<ngood; i++) {
+         AliTrackReference *nref=(AliTrackReference*)nrefs->UncheckedAt(i);
+         AliTrackReference *pref=(AliTrackReference*)prefs->UncheckedAt(i);
+         Int_t pdg=(Int_t)nref->GetLength();//this is the mother's PDG !
+         if (code!=pdg) continue;
+         ng++;
+         pxg=nref->Px()+pref->Px(); pyg=nref->Py()+pref->Py(); 
+         ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
+         hgood->Fill(ptg);
+         nlab=nref->Label(); plab=pref->Label();
+         if (nlab < 0) continue;
+         cout<<"Vertex ("<<nlab<<','<<plab<<") has not been found !\n";
+      }
+      allgood+=ng;
+
+      cout<<"Number of found V0s : "<<nentr<<endl;
+      cout<<"Number of \"good\" V0s : "<<ng<<endl;
+
+      prefs->Clear();
+      nrefs->Clear();
+
+   } //**** End of the loop over events
+
+   delete event;
+   ef->Close();
+   
+   delete v0Tree;
+   refFile->Close();
+
+   Stat_t ng=hgood->GetEntries(), nf=hfound->GetEntries();
+   if (ng!=0) cout<<"Integral efficiency is about "<<nf/ng*100.<<" %\n";
+   cout<<"Total number of found V0s: "<<allfound<<" ("<<nf<<" in the peak)\n";
+   cout<<"Total number of \"good\" V0s: "<<allgood<<endl;
 
    gStyle->SetOptStat(111110);
    gStyle->SetOptFit(1);
 
-   TCanvas *c1=new TCanvas("c1","",0,0,580,610);
-   c1->Divide(2,2);
+   TCanvas *c1=(TCanvas*)gROOT->FindObject("c1");
+   if (!c1) {
+      c1=new TCanvas("c1","",0,0,580,610);
+      c1->Divide(2,2);
+   }
+
+   Int_t minc=33; 
 
    c1->cd(1);
    gPad->SetFillColor(42); gPad->SetFrameFillColor(10); 
-   //hp->Fit("gaus");
-   hp->Draw();
+   if (hp->GetEntries()<minc) hp->Draw(); else hp->Fit("gaus");
    hl->Draw("same"); c1->cd();
 
    c1->cd(2);
    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
-   //hpt->Fit("gaus"); c1->cd();
-   hpt->Draw(); c1->cd();
+   if (hpt->GetEntries()<minc) hpt->Draw(); else hpt->Fit("gaus");
+   c1->cd();
 
    c1->cd(3);
    gPad->SetFillColor(42); gPad->SetFrameFillColor(10); 
-   //hx->Fit("gaus"); 
-   hx->Draw(); 
+   if (hx->GetEntries()<minc) hx->Draw(); else hx->Fit("gaus"); 
    hy->Draw("same"); c1->cd();
 
    c1->cd(4);
    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
-   //hz->Fit("gaus");
-   hz->Draw();
+   if (hz->GetEntries()<minc) hz->Draw(); else hz->Fit("gaus");
 
+   c1->Update();   
 
-   TCanvas *c2=new TCanvas("c2","",600,0,580,610);
-   c2->Divide(1,2);
+   TCanvas *c2=(TCanvas*)gROOT->FindObject("c2");
+   if (!c2) {
+      c2=new TCanvas("c2","",600,0,580,610);
+      c2->Divide(1,2);
+   }
 
    c2->cd(1);
    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
@@ -273,8 +358,8 @@ Int_t AliV0Comparison(Int_t code=310) { //Lambda=3122, LambdaBar=-3122
 
    c2->cd(2);
    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
-   //v0s->Fit("gaus","","",V0mass-V0width,V0mass+V0width);
-   v0s->Draw();
+   if (v0s->GetEntries()<minc) v0s->Draw();
+   else v0s->Fit("gaus","","",V0mass-V0width,V0mass+V0width);
    v0sf->Draw("same");
    Double_t max=v0s->GetMaximum();
    TLine *line3 = new TLine(V0mass-V0width,0.,V0mass-V0width,max);
@@ -282,88 +367,155 @@ Int_t AliV0Comparison(Int_t code=310) { //Lambda=3122, LambdaBar=-3122
    TLine *line4 = new TLine(V0mass+V0width,0.,V0mass+V0width,max);
    line4->Draw("same");
 
-   timer.Stop(); timer.Print();
+   c2->Update();
+
+   TFile fc("AliV0Comparison.root","RECREATE");
+   c1->Write();
+   c2->Write();
+   fc.Close();
+
+   gBenchmark->Stop("AliV0Comparison");
+   gBenchmark->Show("AliV0Comparison");
 
    return 0;
 }
 
-Int_t good_vertices(GoodVertex *gv, Int_t max) {
-   Int_t nv=0;
-   /*** Get information about the cuts ***/
-   Double_t r2min=0.9*0.9;
-   Double_t r2max=2.9*2.9;
 
-   /*** Get labels of the "good" tracks ***/
-   Double_t dd; Int_t id, label[15000], ngt=0;
-   ifstream in("good_tracks_its");
-   if (!in) {
-     cerr<<"Can't open the file good_tracks_its \n";
-     return nv;
+Int_t GoodV0s(const Char_t *dir) {
+   if (gAlice) { 
+       delete gAlice->GetRunLoader();
+       delete gAlice;//if everything was OK here it is already NULL
+       gAlice = 0x0;
    }
-   while (in>>label[ngt]>>id>>dd>>dd>>dd>>dd>>dd>>dd) {
-     ngt++;
-     if (ngt>=15000) {
-       cerr<<"Too many good ITS tracks !\n";
-       return nv;
-     }
-   }   
-   if (!in.eof()) {
-      cerr<<"Read error (good_tracks_its) !\n";
-      return nv;
+
+   Char_t fname[100];
+   sprintf(fname,"%s/galice.root",dir);
+
+   AliRunLoader *rl = AliRunLoader::Open(fname,"COMPARISON");
+   if (!rl) {
+      ::Error("GoodTracksITS","Can't start session !");
+      return 1;
    }
 
-   /*** Get an access to the kinematics ***/
-   if (gAlice) {delete gAlice; gAlice=0;}
+   rl->LoadgAlice();
+   rl->LoadHeader();
+   rl->LoadKinematics();
+
 
-   TFile *file=TFile::Open("galice.root");
-   if (!file->IsOpen()) {cerr<<"Can't open galice.root !\n"; exit(4);}
-   if (!(gAlice=(AliRun*)file->Get("gAlice"))) {
-     cerr<<"gAlice has not been found on galice.root !\n";
-     exit(5);
+   Int_t nev=rl->GetNumberOfEvents();
+   ::Info("GoodV0s","Number of events : %d\n",nev);  
+
+   sprintf(fname,"%s/GoodTracksITS.root",dir);
+   TFile *itsFile=TFile::Open(fname);
+   if ((!itsFile)||(!itsFile->IsOpen())) {
+       ::Error("GoodV0s","Can't open the GoodTracksITS.root !");
+       delete rl;
+       return 5; 
+   }
+   TClonesArray dum("AliTrackReference",1000), *itsRefs=&dum;
+   TTree *itsTree=(TTree*)itsFile->Get("itsTree");
+   if (!itsTree) {
+       ::Error("GoodV0s","Can't get the ITS reference tree !");
+       delete rl;
+       return 6;
+   }
+   TBranch *itsBranch=itsTree->GetBranch("ITS");
+   if (!itsBranch) {
+      ::Error("GoodV0s","Can't get the ITS reference branch !");
+      delete rl;
+      return 7;
    }
+   itsBranch->SetAddress(&itsRefs);
 
-   Int_t np=gAlice->GetEvent(0);
-   while (np--) {
-      cerr<<np<<'\r';
-      TParticle *p0=gAlice->Particle(np);
-
-      /*** only these V0s are "good" ***/
-      Int_t code=p0->GetPdgCode();
-      if (code!=kK0Short)
-      if (code!=kLambda0)
-      if (code!=kLambda0Bar) continue; 
-
-      /*** daughter tracks should be "good" ***/
-      Int_t plab=p0->GetFirstDaughter(), nlab=p0->GetLastDaughter();
-      if (nlab==plab) continue;
-      if (nlab<0) continue;
-      if (plab<0) continue;
-      Int_t i;
-      for (i=0; i<ngt; i++) if (label[i]==nlab) break;
-      if (i==ngt) continue;
-      for (i=0; i<ngt; i++) if (label[i]==plab) break;
-      if (i==ngt) continue;
-
-      /*** fiducial volume ***/
-      TParticle *p=gAlice->Particle(nlab);
-      Double_t x=p->Vx(), y=p->Vy(), z=p->Vz(), r2=x*x+y*y;
-      if (r2<r2min) continue;
-      if (r2>r2max) continue;
+
+   sprintf(fname,"%s/GoodV0s.root",dir);
+   TFile *v0File=TFile::Open(fname,"recreate");
+   TClonesArray dummy("AliTrackReference",1000), *nrefs=&dummy;
+   TClonesArray dumm("AliTrackReference",1000), *prefs=&dumm;
+   TTree v0Tree("v0Tree","Tree with info about the reconstructable V0s");
+   v0Tree.Branch("negative",&nrefs);
+   v0Tree.Branch("positive",&prefs);
+
+
+   /*** Some information about the cuts ***/
+   Double_t r2min=0.9*0.9;
+   Double_t r2max=2.9*2.9;
+
+
+
+   //********  Loop over generated events
+   for (Int_t e=0; e<nev; e++) {
+      rl->GetEvent(e);  v0File->cd();
+
+      Int_t np = rl->GetHeader()->GetNtrack();
+      cout<<"Event "<<e<<" Number of particles: "<<np<<endl;
+
+      itsTree->GetEvent(e);
+      Int_t nk=itsRefs->GetEntriesFast();
+
+      AliStack *stack=rl->Stack();
+
+      AliTrackReference *nref=0, *pref=0;
+
+      Int_t nv=0;
+      while (np--) {
+	//cerr<<np<<'\r';
+         TParticle *p0=stack->Particle(np);
+
+         /*** only these V0s are "good" ***/
+         Int_t code=p0->GetPdgCode();
+         if (code!=kK0Short)
+         if (code!=kLambda0)
+         if (code!=kLambda0Bar) continue; 
+
+         /*** daughter tracks should be "good" ***/
+         Int_t plab=p0->GetFirstDaughter(), nlab=p0->GetLastDaughter();
+         if (nlab==plab) continue;
+         if (nlab<0) continue;
+         if (plab<0) continue;
+         Int_t i;
+         if (stack->Particle(plab)->GetPDG()->Charge() < 0.) {
+            i=plab; plab=nlab; nlab=i;
+         }
+
+         for (i=0; i<nk; i++) {
+	     nref=(AliTrackReference*)itsRefs->UncheckedAt(i);
+             if (nref->Label()==nlab) break;
+         }
+         if (i==nk) continue;
+         for (i=0; i<nk; i++) {
+	     pref=(AliTrackReference*)itsRefs->UncheckedAt(i);
+             if (pref->Label()==plab) break;
+         }
+         if (i==nk) continue;
+
+         /*** fiducial volume ***/
+         TParticle *p=stack->Particle(nlab);
+         Double_t x=p->Vx(), y=p->Vy(), z=p->Vz(), r2=x*x+y*y;
+         if (r2<r2min) continue;
+         if (r2>r2max) continue;
        
-      if (gAlice->Particle(plab)->GetPDG()->Charge() < 0.) {
-         i=plab; plab=nlab; nlab=i;
+         Int_t pdg=p0->GetPdgCode();
+         nref->SetLength(pdg);  //This will the V0's PDG !
+
+         new((*nrefs)[nv]) AliTrackReference(*nref);
+         new((*prefs)[nv]) AliTrackReference(*pref);
+
+         nv++;
       }
-      
-      gv[nv].code=code;
-      gv[nv].plab=plab; gv[nv].nlab=nlab;
-      gv[nv].px=p0->Px(); gv[nv].py=p0->Py(); gv[nv].pz=p0->Pz();
-      gv[nv].x=x; gv[nv].y=y; gv[nv].z=z;
-      nv++;
-   }
- 
-   delete gAlice; gAlice=0;
+      itsRefs->Clear();
+
+      v0Tree.Fill();
+      nrefs->Clear(); prefs->Clear();
+
+   }  //**** end of the loop over generated events
 
-   file->Close();  
+   v0Tree.Write();
+   v0File->Close();
 
-   return nv;
+   delete itsTree;
+   itsFile->Close();
+
+   delete rl;
+   return 0;
 }