Int_t ITSgeoplot (char *opt="All+Rec", char *filename="galice.root") {
  /*******************************************************************
   *  This macro displays geometrical information related to the
   *  hits, digits and rec points in ITS.
   *  There are histograms that are not displayed (i.e. energy
   *  deposition) but that are saved onto a file (see below)
   *
   *  Options: Any combination of:
   *    1) subdetector name:  "SPD", "SDD", "SSD", "All" (default)
   *    2) Printouts:        "Verbose" Almost everything is printed out: 
   *                          it is wise to redirect the output onto a file
   *                    e.g.: .x ITSgeoplot.C("All+Verbose") > out.log 
   *    3) Rec Points option: "Rec"   ---> Uses Rec. Points (default)
   *                           otherwise ---> uses hits and digits only
   *    Examples:
   *       .x ITSgeoplot();  (All subdetectors; no-verbose; no-recpoints)
   *       .x ITSgeoplot("SPD+SSD+Verbose+Rec"); 
   *
   *  OUTPUT: It produces a root file with a list of histograms
   *          The list can be accessed either with the Root TBrowser
   *          or with the simple macro ITSgeoplotread.C
   *  WARNING: spatial information for SSD/DIGITS is obtained by pairing
   *          digits on p and n side originating from the same track, when
   *          possible. This (mis)use of DIGITS is tolerated for debugging 
   *          purposes only !!!!  The pairing in real life should be done
   *          starting from info really available...  
   *     
   *  M.Masera  19/3/2001 18:45
   ********************************************************************/

  extern void GetHitsCoor(TObject *its, Int_t mod, TObjArray & histos, Int_t subd,Bool_t verb);
  extern Int_t GetRecCoor(TObject *ge, TClonesArray *ITSrec, Int_t mod, TH2F *h2, TH1F *h1, Bool_t verb);
  extern void GetDigits(TObject *tmps,TObject *ge,TClonesArray *ITSdigits, Int_t subd, Int_t mod, Bool_t verbose, TObjArray & histos);

  //Options
  TString choice(opt);
  Bool_t All = choice.Contains("All");
  Bool_t verbose=choice.Contains("Verbose");
  Bool_t userec=choice.Contains("Rec");
  Int_t retcode=1; //return code
  if (gClassTable->GetID("AliRun") < 0) {
    gROOT->LoadMacro("loadlibs.C");
    loadlibs();
  }
  else {
    if(gAlice){
      delete gAlice;
      gAlice=0;
    }
  }
  // Connect the Root input  file containing Geometry, Kine and Hits
  // galice.root file by default

  TFile *file = (TFile*)gROOT->GetListOfFiles()->FindObject(filename);
  if (!file) file = new TFile(filename);
  file->ls();

  // Get AliRun object from file

  if (!gAlice) {
    gAlice = (AliRun*)file->Get("gAlice");
    if (gAlice && verbose)cout<<"AliRun object found on file "<<filename<<endl;
    if(!gAlice){
      cout<<"Can't access AliRun object on file "<<filename<<endl;
      cout<<"Macro execution stopped!!!"<<endl;
      retcode=-1;
      return retcode;
    }
  }
  Int_t nparticles = gAlice->GetEvent(0);
  if(verbose) {
    cout<<" "<<endl<<" "<<endl;
    cout<<"******* Event processing started   *******"<<endl;
    cout<<"In the following, hits with 'StatusEntering' flag active"<<endl;
    cout<<"will not be processed"<<endl; 
    cout << "Number of particles=  " << nparticles <<endl;
  }

  // HITS
  TTree *TH = gAlice->TreeH();
  Stat_t ntracks = TH->GetEntries();
  if(verbose)cout<<"Number of primary tracks= "<<ntracks<<endl;

  // ITS
  AliITS *ITS  = (AliITS*)gAlice->GetModule("ITS");
  Int_t nmodules;
  ITS->InitModules(-1,nmodules);
  cout<<"Number of ITS modules= "<<nmodules<<endl;
  cout<<"Filling modules... It takes a while, now. Please be patient"<<endl;
  ITS->FillModules(0,0,nmodules," "," ");
  cout<<"ITS modules .... DONE!"<<endl;

  // DIGITS
  TTree *TD = gAlice->TreeD();

  //RECPOINTS
  TTree *TR = gAlice->TreeR();
  TClonesArray *ITSrec  = ITS->RecPoints();
  if(userec && (!TR || !ITSrec)){
    userec = kFALSE;
    cout<<" "<<endl<<"======================================================="<<endl;
    cout<<"WARNING: there are no RECPOINTS on this file ! "<<endl;
    cout<<"======================================================="<<endl<<" "<<endl;
  }
  //local variables
  Int_t mod;   //module number
  Int_t nbytes = 0; 
  Double_t pos[3];  // Global position of the current module
  Float_t ragdet; // Radius of detector (x y plane)
  Int_t first; // first module
  Int_t last; // last module
  Int_t nrecp; //number of RecPoints for a given module

  //List of histograms
  TObjArray histos(26,0);  // contains the pointers to the histograms
  // Book histograms SPD
  TH2F *rspd = new TH2F("rspd","Radii of digits - SPD",50,-10.,10.,50,-10.,10.);
  TH2F *rhspd = new TH2F("rhspd","Radii of hits - SPD",50,-10.,10.,50,-10.,10.);
  TH2F *rmspd = new TH2F("rmspd","Radii of SPD modules",50,-10.,10.,50,-10.,10.);
  TH1F *zspd = new TH1F("zspd","Z of digits - SPD",100,-30.,30.);
  TH1F *zhspd = new TH1F("zhspd","Z of hits - SPD",100,-30.,30.);
  TH1F *zmspd = new TH1F("zmspd","Z of SPD modules",100,-30,30.);
  TH2F *rrspd = new TH2F("rrspd","Radii of recpoints - SPD",50,-10.,10.,50,-10.,10.);
  TH1F *zrspd = new TH1F("zrspd","Z of recpoints - SPD",100,-30.,30.);
  TH1F *enespd = new TH1F("enespd","Energy deposition SPD (KeV)",100,0.,1000.);
  histos.AddLast(rspd);  // 0
  histos.AddLast(rhspd); // 1
  histos.AddLast(rmspd); // 2
  histos.AddLast(zspd);  // 3
  histos.AddLast(zhspd); // 4
  histos.AddLast(zmspd); // 5
  histos.AddLast(rrspd); // 6
  histos.AddLast(zrspd); // 7
  histos.AddLast(enespd); // 8
  // Book histograms SDD
  TH2F *rsdd = new TH2F("rsdd","Radii of digits - SDD",50,-40.,40.,50,-40.,40.);
  TH2F *rhsdd = new TH2F("rhsdd","Radii of hits - SDD",50,-40.,40.,50,-40.,40.);
  TH2F *rmsdd = new TH2F("rmsdd","Radii of SDD modules",50,-40.,40.,50,-40.,40.);
  TH1F *zsdd = new TH1F("zsdd","Z of digits - SDD",100,-40.,40.);
  TH1F *zhsdd = new TH1F("zhsdd","Z of hits - SDD",100,-40.,40.);
  TH1F *zmsdd = new TH1F("zmsdd","Z of SDD modules",100,-40,40.);
  TH2F *rrsdd = new TH2F("rrsdd","Radii of recpoints - SDD",50,-40.,40.,50,-40.,40.);
  TH1F *zrsdd = new TH1F("zrsdd","Z of recpoints - SDD",100,-40.,40.);
  TH1F *enesdd = new TH1F("enesdd","Energy deposition SDD (KeV)",100,0.,1000.);
  histos.AddLast(rsdd);  // 9
  histos.AddLast(rhsdd); // 10
  histos.AddLast(rmsdd); // 11
  histos.AddLast(zsdd);  // 12
  histos.AddLast(zhsdd); // 13
  histos.AddLast(zmsdd); // 14
  histos.AddLast(rrsdd); // 15
  histos.AddLast(zrsdd); // 16
  histos.AddLast(enesdd); // 17
  // Book histogram SSD
  TH2F *rssd = new TH2F("rssd","Radii of digits - SSD",50,-50.,50.,50,-50.,50.);
  TH2F *rhssd = new TH2F("rhssd","Radii of hits - SSD",50,-50.,50.,50,-50.,50.);
  TH2F *rmssd = new TH2F("rmssd","Radii of SSD modules",50,-50.,50.,50,-50.,50.);
  TH1F *zssd = new TH1F("zssd","Z of digits - SSD",100,-70.,70.);
  TH1F *zhssd = new TH1F("zhssd","Z of hits - SSD",100,-70.,70.);
  TH1F *zmssd = new TH1F("zmssd","Z of SSD modules",100,-70,70.);
  TH2F *rrssd = new TH2F("rrssd","Radii of recpoints - SSD",50,-50.,50.,50,-50.,50.);
  TH1F *zrssd = new TH1F("zrssd","Z of recpoints - SSD",100,-70.,70.);
  TH1F *enessd = new TH1F("enessd","Energy deposition SSD (KeV)",100,0.,1000.);
  histos.AddLast(rssd);  // 18
  histos.AddLast(rhssd); // 19
  histos.AddLast(rmssd); // 20
  histos.AddLast(zssd);  // 21
  histos.AddLast(zhssd); // 22
  histos.AddLast(zmssd); // 23
  histos.AddLast(rrssd); // 24
  histos.AddLast(zrssd); // 25
  histos.AddLast(enessd); // 26
  //
  // Loop on subdetectors
  // 
  AliITSgeom *geom = ITS->GetITSgeom();
  for(Int_t subd=0;subd<3;subd++){
    if(All || (choice.Contains("SPD") && subd==0) || (choice.Contains("SDD") && subd==1) || (choice.Contains("SSD") && subd==2)){
      // Prepare array for the digits
      TClonesArray *ITSdigits  = ITS->DigitsAddress(subd);
      Bool_t usedigits = kTRUE;
      if(!ITSdigits){
        usedigits = kFALSE;
        cout<<" "<<endl<<"======================================================="<<endl;
        cout<<"WARNING: there are no DIGITS on this file ! "<<endl;
        cout<<"======================================================="<<endl<<" "<<endl;
      }
      // Get segmentation model
      AliITSDetType *iDetType=ITS->DetType(subd);
      TString detna; // subdetector name 
      if(subd==0)detna="SPD";
      if(subd==1)detna="SDD";
      if(subd==2)detna="SSD";
      AliITSsegmentation *seg=(AliITSsegmentation*)iDetType->GetSegmentationModel();
      // Loop on modules
      first = geom->GetStartDet(subd);
      last = geom->GetLastDet(subd);
      if(verbose){
        cout<<"     "<<endl<<"-------------------------------------"<<endl;
        cout<<"Start processing subdetector "<<detna<<endl;
        cout<<detna<<" first module "<<first<<endl;
        cout<<detna<<" last module "<<last<<endl;
        cout<<" "<<endl<<" "<<endl;
      }
      for (mod=first; mod<=last; mod++){
        geom->GetTrans(mod,pos);  // position of the module in the MRS
        ragdet=sqrt(pos[0]*pos[0]+pos[1]*pos[1]);
        // The following 2 histos are a check of the geometry
        TH2F *bidi = (TH2F*)histos.At(2+subd*9);
        TH1F *uni = (TH1F*)histos.At(5+subd*9);
        bidi->Fill(pos[0],pos[1]);
        uni->Fill(pos[2]);
        if(verbose){
          cout<<"==========================================================="<<endl;
          cout<<detna<<" module="<<mod<<endl;
          cout<<"Mod. coordinates: "<<pos[0]<<", "<<pos[1]<<", "<<pos[2]<<" Radius "<<ragdet<<endl;
        }

        // Hits
        GetHitsCoor(ITS,mod,histos,subd,verbose);

        //RecPoints     
        if(userec){
          ITS->ResetRecPoints();
          TR->GetEvent(mod);
          TH2F *bidi=(TH2F*)histos.At(6+subd*9);
          TH1F *uni=(TH1F*)histos.At(7+subd*9);
          nrecp=GetRecCoor(geom,ITSrec,mod,bidi,uni,verbose);
        }
     
        // Digits
        if(usedigits){
          ITS->ResetDigits();
          nbytes += TD->GetEvent(mod);
          GetDigits(seg,geom,ITSdigits,subd,mod,verbose,histos);
        }

      } // End of loop on the modules
      TH1F *h1tmp;
      TH2F *h2tmp;
      //  Plot the histograms
      TCanvas *current=0; // current Canvas (1--> SPD, 2---> SDD, 3---> SSD)
      if(subd==0){
        // Prepare canvas 1
        TCanvas *c1 = new TCanvas("c1","SPD",10,10,600,900);
        c1->Divide(2,3);
        current=c1;
      }
      if(subd==1){
        // Prepare canvas 2
        TCanvas *c2 = new TCanvas("c2","SDD",40,40,600,900);
        c2->Divide(2,3);
        current=c2;
      }
      if(subd==2){
        // Prepare canvas 3
        TCanvas *c3 = new TCanvas("c3","SSD",70,70,600,900);
        c3->Divide(2,3);
        current=c3;
      }
      current->cd(1);
      h2tmp = (TH2F*)histos.At(9*subd);
      h2tmp->Draw();
      current->cd(2);
      h1tmp=(TH1F*)histos.At(3+subd*9);
      h1tmp->Draw();
      current->cd(3);
      h2tmp=(TH2F*)histos.At(1+9*subd);
      h2tmp->Draw();
      current->cd(4);
      h1tmp=(TH1F*)histos.At(4+subd*9);
      h1tmp->Draw();
   
      if(userec){
        current->cd(5);
        h2tmp=(TH2F*)histos.At(6+9*subd);
        h2tmp->Draw();
        current->cd(6);
        h1tmp=(TH1F*)histos.At(7+subd*9);
        h1tmp->Draw();
      }
  
      else {
        current->cd(5);
        h2tmp=(TH2F*)histos.At(2+9*subd);
        h2tmp->Draw();
        current->cd(6);
        h2tmp=(TH2F*)histos.At(5+9*subd);
        h2tmp->Draw();
      }
    } // if(All.....
  } // end of loop on subdetectors
  // Save the histograms
  TFile *fh = new TFile("ITSgeoplot.root","recreate");
  // The list is written to file as a single entry
  TList *lihi = new TList();
  // copy the pointers to the histograms to a TList object.
  // The histograms concerning recpoints are not copied if
  // 'userec' is false.
  for(Int_t i=0;i<histos.GetEntriesFast();i++){
    if(choice.Contains("All") || (choice.Contains("SPD") && i<8) || (choice.Contains("SDD") && i>7 && i<16) || (choice.Contains("SSD") && i>15)){
      if(!(!userec && ((i+2)%9==0 || (i+1)%9==0)))lihi->Add(histos.At(i));
    }
  }
  lihi->Write("Histograms ITS hits+digits+recpoints",TObject::kSingleKey);
  fh->Close();

  return retcode;
}


void GetHitsCoor(TObject *its, Int_t mod, TObjArray & histos, Int_t subd,Bool_t verb){
  TH2F *h2=(TH2F*)histos.At(1+subd*9);
  TH1F *h1=(TH1F*)histos.At(4+subd*9);
  TH1F *ener=(TH1F*)histos.At(8+subd*9);
  AliITS *ITS= (AliITS*)its;
  AliITSmodule *modu = ITS->GetModule(mod);
  TObjArray *fHits = modu->GetHits();
  Int_t nhits = fHits->GetEntriesFast();
  if(nhits>0){
    if(verb){
      cout<<"-------------------------------------------------------"<<endl;
      cout<<"Number of HITS for module "<<mod<<": "<<nhits<<endl;
    }
    for (Int_t hit=0;hit<nhits;hit++) {
      AliITShit *iHit = (AliITShit*) fHits->At(hit);
      if(!iHit->StatusEntering()){
        Float_t x=iHit->GetXG();
        Float_t y=iHit->GetYG();
        Float_t z=iHit->GetZG();
        Float_t edep=iHit->GetIonization()*1000000;
        h2->Fill(x,y);
        h1->Fill(z);
        ener->Fill(edep);
        if(verb){
          cout<<"hit # "<<hit<<" Global coordinates "<<x<<" "<<y<<" "<<z<<endl;
          cout<<"track # "<<iHit->GetTrack()<<" energy deposition (KeV)= "<<edep<<endl;
        }
      }
    }
  }
}


Int_t GetRecCoor(TObject *ge, TClonesArray *ITSrec, Int_t mod, TH2F *h2, TH1F *h1, Bool_t verb){
  AliITSgeom *geom = (AliITSgeom*)ge;
  Int_t nrecp = ITSrec->GetEntries();
  if(nrecp>0){
    Float_t lc[3]; for(Int_t i=0; i<3; i++) lc[i]=0.;
    Float_t gc[3]; for(Int_t i=0; i<3; i++) gc[i]=0.;
    if(verb){
      cout<<"-------------------------------------------------------"<<endl;
      cout<<"Number of REC POINTS for module "<<mod<<": "<<nrecp<<endl;
    }
    for(Int_t irec=0;irec<nrecp;irec++) {
      AliITSRecPoint *recp = (AliITSRecPoint*)ITSrec->At(irec);
      lc[0]=recp->GetX();
      lc[2]=recp->GetZ();
      geom->LtoG(mod,lc,gc);
      if(verb){
        cout<<"recp # "<<irec<<" local coordinates. lx= "<<lc[0]<<" lz= "<<lc[2]<<endl;
        Float_t r=sqrt(gc[0]*gc[0]+gc[1]*gc[1]);
        cout<<"Global coor. + radius "<<gc[0]<<" "<<gc[1]<<" "<<gc[2]<<" "<<r<<endl;
      }
      h2->Fill(gc[0],gc[1]);
      h1->Fill(gc[2]);
    }
  }
  return nrecp;
}

void GetDigits(TObject *tmps,TObject *ge,TClonesArray *ITSdigits, Int_t subd, Int_t mod, Bool_t verbose, TObjArray & histos){
  AliITSsegmentation *seg = (AliITSsegmentation*)tmps;
  AliITSgeom *geom = (AliITSgeom*)ge;
  Float_t lcoor[3]; for(Int_t j=0; j<3; j++) lcoor[j]=0.;  //local coord dig.
  Float_t gcoor[3]; for(Int_t j=0; j<3; j++) gcoor[j]=0.; // global coo. dig.
  Float_t ragdig; // Radius digit
  TArrayI ssdone(5000);  // used to match p and n side digits of strips
  TArrayI pair(5000);    // as above 
  Int_t ndigits = ITSdigits->GetEntries();
  AliITSdigit *digs;
  if(ndigits){ 
    if(verbose){
      cout<<"-------------------------------------------------------"<<endl;
      cout<<"Number of DIGITS for module "<<mod<<": "<<ndigits<<endl;
    }
    // Get the coordinates of the module
    if(subd==2){
      for (Int_t digit=0;digit<ndigits;digit++){
        ssdone[digit]=0;
        pair[digit]=0;
      }
    }
    for (Int_t digit=0;digit<ndigits;digit++) {
      digs = (AliITSdigit*)ITSdigits->UncheckedAt(digit);
      Int_t iz=digs->fCoord1;  // cell number z
      Int_t ix=digs->fCoord2;  // cell number x
      // Get local coordinates of the element (microns)
      if(subd<2){
        seg->GetPadCxz(ix,iz,lcoor[0],lcoor[2]);
      }
      else{
        // SSD: if iz==0 ---> N side; if iz==1 P side
        if(ssdone[digit]==0){
          ssdone[digit]=1;
          pair[digit]=-1;
          Bool_t pside=(iz==1);
          Bool_t impaired=kTRUE;
          Int_t pstrip=0;
          Int_t nstrip=0;
          if(pside)pstrip=ix;
          if(!pside)nstrip=ix;
          for(Int_t digi2=0;digi2<ndigits;digi2++){
            if(ssdone[digi2]==0 && impaired){
              AliITSdigitSSD *dig2=(AliITSdigitSSD*)ITSdigits->UncheckedAt(digi2);
              if(dig2->fCoord1 != iz && dig2->GetTracks()[0]==digs->GetTracks()[0]){
                ssdone[digi2]=2;
                pair[digit]=digi2;
                if(pside)nstrip=dig2->fCoord2;
                if(!pside)pstrip=dig2->fCoord2;
                impaired=kFALSE;
              }
            }
          }
          if(!impaired)seg->GetPadCxz(pstrip,nstrip,lcoor[0],lcoor[2]);
        }
      }
      if(subd==0){
        // !!!THIS CONVERSION TO HIT LRS SHOULD BE REMOVED AS SOON AS THE CODE IS FIXED
        lcoor[0]=lcoor[0]-seg->Dx()/2;
        lcoor[2]=lcoor[2]-seg->Dz()/2;
      }
      if(subd<2 || (subd==2 && ssdone[digit]==1)){
        Int_t coor1=digs->fCoord1;
        Int_t coor2=digs->fCoord2;
        Int_t tra0=digs->GetTracks()[0];
        if(verbose){
          cout<<"digit # "<<digit<<" fCoord1= "<<coor1<<" fCoord2= "<<coor2<<" track "<<tra0<<" "<<endl;
          if(subd<2)cout<<"local coordinates -- x="<<lcoor[0]<<", z="<<lcoor[2]<<endl;
          if(subd==2){
            if(pair[digit]==-1){
              cout<<"(digit  not paired)"<<endl;
            }
            else {
              cout<<"local coordinates -- x="<<lcoor[0]<<", z="<<lcoor[2]<<endl;
              Int_t dtmp=pair[digit];
              AliITSdigitSSD *dig2=(AliITSdigitSSD*)ITSdigits->UncheckedAt(dtmp);
              Int_t coor1b=dig2->fCoord1;
              Int_t coor2b=dig2->fCoord2;
              Int_t tra0b=dig2->GetTracks()[0];
              cout<<"(digit paired with digit #"<<dtmp<<endl;
              cout<<"with fCoord1= "<<coor1b<<" fCoord2= "<<coor2b<<" track "<<tra0b<<")"<<endl;
            }
          }
        }
        if(subd<2 || (subd==2 && pair[digit]!=-1)){
          // Global coordinates of the element
          //SDD uses cm, SPD and SSD microns
          if(subd!=1)for(Int_t j=0;j<3;j++)lcoor[j]=lcoor[j]/10000.;
          lcoor[1]=0.;
          geom->LtoG(mod,lcoor,gcoor);  // global coord. in cm
          ragdig=sqrt(gcoor[0]*gcoor[0]+gcoor[1]*gcoor[1]);
          if(verbose)cout<<"global coordinates "<<gcoor[0]<<" "<<gcoor[1]<<" "<<gcoor[2]<<" Radius "<<ragdig<<endl;
          //Fill histograms
          TH2F *bidi = (TH2F*)histos.At(subd*9);
          TH1F *uni = (TH1F*)histos.At(3+subd*9);
          bidi->Fill(gcoor[0],gcoor[1]);
          uni->Fill(gcoor[2]);
        }
      }
    } // loop on digits for this module
  } // if(ndigits>0....
}