[u/mrichter/AliRoot.git] / ITS / AliITSVertexerPPZ.cxx

/**************************************************************************
 * Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/
#include <AliITSVertexerPPZ.h>
#include <Riostream.h>
#include <TArrayF.h>
#include <TDirectory.h>
#include <TH1F.h>
#include <TMath.h>
#include <TObjArray.h>
#include <TTree.h>
#include <TClonesArray.h>
#include "AliRun.h"
#include "AliITS.h"
#include "AliITSgeom.h"
#include "AliITSLoader.h"
#include "AliITSRecPoint.h"
/////////////////////////////////////////////////////////////////////////
//                                                                     //
// This class is intended to compute the Z coordinate of the           //
// primary vertex for p-p interactions, or in general when the         //
// number of secondaries is too slow to use the class                  //
// AliITSVertexerIons, which in turn is optimized for A-A collsions    //
// Origin: masera@to.infn.it      9/12/2002                            //
//                                                                     //
/////////////////////////////////////////////////////////////////////////
ClassImp(AliITSVertexerPPZ)


//______________________________________________________________________
AliITSVertexerPPZ::AliITSVertexerPPZ():AliITSVertexer() {
  // Default Constructor

  SetDiffPhiMax(0);
  fX0 = 0.;
  fY0 = 0.;
  SetFirstLayerModules(0);
  SetSecondLayerModules(0);
  fZFound = 0;
  fZsig = 0.;
  fITS = 0;
  SetWindow(0);
}

AliITSVertexerPPZ::AliITSVertexerPPZ(TString fn, Float_t x0, Float_t y0):AliITSVertexer(fn) {
  // Standard constructor
  SetDiffPhiMax();
  fX0 = x0;
  fY0 = y0;
  SetFirstLayerModules();
  SetSecondLayerModules();
  fZFound = 0;
  fZsig = 0.;
  fITS = 0;
  SetWindow();
}

//______________________________________________________________________
AliITSVertexerPPZ::~AliITSVertexerPPZ() {
  // Default Destructor
  fITS = 0;
}

//________________________________________________________
void  AliITSVertexerPPZ::EvalZ(TH1F *hist,Int_t sepa, Int_t ncoinc, TArrayF *zval) {
  Float_t DeltaVal = hist->GetBinWidth(1)*fWindow; // max window in Z for searching
  fZFound=0;
  fZsig=0;
  Int_t N=0;
  Int_t NbinNotZero=0;
  Float_t totst = 0.;
  Float_t totst2 = 0.;
  Float_t curz = 0.;
  for(Int_t i=1;i<=sepa;i++){
    Float_t cont=hist->GetBinContent(i);
    if(cont!=0)curz = hist->GetBinLowEdge(i)+0.5*hist->GetBinWidth(i);
    totst+=cont;
    totst2+=cont*cont;
    N++;
    if(cont!=0)NbinNotZero++;
  }
  if(NbinNotZero==0){fZFound=-100; fZsig=-100; return;}
  if(NbinNotZero==1){
    fZFound = curz;
    fZsig=0;
    fCurrentVertex = new AliITSVertex(fZFound,fZsig,NbinNotZero);
    return;
  }
  Float_t errsq = totst2/(N-1)-totst*totst/N/(N-1);
  if(errsq>=0){
  totst2=TMath::Sqrt(errsq);
  }
  else {
    Error("EvalZ","Negative variance: %d - %12.7f - %12.7f",N,totst2,totst);
    fZFound=-100; 
    fZsig=-100;
    return;
  }
  totst /= N;
  Float_t cut = totst+totst2*2.;
  if(fDebug>1)cout<<"totst, totst2, cut: "<<totst<<", "<<totst2<<", "<<cut<<endl;
  Float_t val1=hist->GetBinLowEdge(sepa); 
  Float_t val2=hist->GetBinLowEdge(1);
  Float_t valm = 0.;
  Float_t zmax = 0.;
  for(Int_t i=1;i<=sepa;i++){
    Float_t cont=hist->GetBinContent(i);
    if(cont>valm){
      valm = cont;
      zmax = hist->GetBinLowEdge(i)+0.5*hist->GetBinWidth(1);
    }
    if(cont>cut){
      curz=hist->GetBinLowEdge(i);
      if(curz<val1)val1=curz;
      if(curz>val2)val2=curz;
    }
  }
  val2+=hist->GetBinWidth(1);
  if((val2-val1)>DeltaVal){
    val1 = zmax-DeltaVal/2.;
    val2 = zmax+DeltaVal/2.;
    if(fDebug>0)cout<<"val1 and val2 recomputed\n";
  }
  if(fDebug>0)cout<<"Values for Z finding: "<<val1<<" "<<val2<<" "<<val2-val1<<endl;
  fZFound=0;
  fZsig=0;
  N=0;
  for(Int_t i=0; i<ncoinc; i++){
    Float_t z=zval->At(i);
    if(z<val1)continue;
    if(z>val2)continue;
   
    fZFound+=z;
    fZsig+=z*z;
    /*   weights defined by the curvature
    Float_t wei = 1./curv->At(i);
    fZFound+=z*wei;
    fZsig+=wei;
    */
    N++;
  }
  if(N<1){fZFound=-110; fZsig=-110; return;}
  if(N==1){
    fZsig = 0;
    fCurrentVertex = new AliITSVertex(fZFound,fZsig,N);
    return;
  }
  errsq = (fZsig/(N-1)-fZFound*fZFound/N/(N-1))/N;
  if(errsq>=0.){
    fZsig=TMath::Sqrt(errsq);
  }
  else {
    Error("evalZ","Negative variance: %d - %12.7f %12.7f",N,fZsig,fZFound);
    fZsig=0;
  }
  fZFound=fZFound/N;
  /* weights defined by the curvature
  fZsig=1./fZsig;
  fZFound*=fZsig;
  fZsig = TMath::Sqrt(fZsig);
  */
  fCurrentVertex = new AliITSVertex(fZFound,fZsig,N);
}

//______________________________________________________________________
AliITSVertex* AliITSVertexerPPZ::FindVertexForCurrentEvent(Int_t evnumber){
  // Defines the AliITSVertex for the current event
  fCurrentVertex = 0;
  fZFound = -999;
  fZsig = -999;
  AliRunLoader *rl =AliRunLoader::GetRunLoader();
  AliITSLoader* ITSloader =  (AliITSLoader*) rl->GetLoader("ITSLoader");
  if(!fITS)  {
    fITS = (AliITS*)gAlice->GetModule("ITS");
    if(!fITS) {
      Error("FindVertexForCurrentEvent","AliITS object was not found");
      return fCurrentVertex;
    }
  }
  fITS->SetTreeAddress();
  AliITSgeom *geom = fITS->GetITSgeom();
  if(!geom) {
    Error("FindVertexForCurrentEvent","ITS geometry is not defined");
    return fCurrentVertex;
  }
  TTree *TR=0;
  TClonesArray *ITSrec  = 0;
  Float_t lc[3]; for(Int_t ii=0; ii<3; ii++) lc[ii]=0.;
  Float_t gc[3]; for(Int_t ii=0; ii<3; ii++) gc[ii]=0.;
  Float_t lc2[3]; for(Int_t ii=0; ii<3; ii++) lc2[ii]=0.;
  Float_t gc2[3]; for(Int_t ii=0; ii<3; ii++) gc2[ii]=0.;

  TR = ITSloader->TreeR();
  if(!TR){
    Error("FindVertexForCurrentEvent","TreeR not found");
    return fCurrentVertex;
  }
  ITSrec  = fITS->RecPoints();  // uses slow points or fast points if slow are
  // missing
  TBranch *branch = TR->GetBranch("ITSRecPoints");
  if(!branch){ 
    branch = TR->GetBranch("ITSRecPointsF");
    //   Warning("FindVertexForCurrentEvent","Using Fast points");
  }
  if(!branch){
   Error("FindVertexForCurrentEvent","branch for ITS rec points not found");
   return fCurrentVertex;
  }
  Float_t zave=0;
  Float_t rmszav=0;
  Float_t zave2=0;
  Int_t firipixe=0;
  for(Int_t module= fFirstL1; module<=fLastL1;module++){
    branch->GetEvent(module);
    Int_t nrecp1 = ITSrec->GetEntries();
    for(Int_t i=0; i<nrecp1;i++){
      AliITSRecPoint *current = (AliITSRecPoint*)ITSrec->At(i);
      lc[0]=current->GetX();
      lc[2]=current->GetZ();
      geom->LtoG(module,lc,gc);
      zave+=gc[2];
      zave2+=gc[2]*gc[2];
      firipixe++;
    }
    fITS->ResetRecPoints();
  }
  if(firipixe>1){
    rmszav=TMath::Sqrt(zave2/(firipixe-1)-zave*zave/firipixe/(firipixe-1));
    zave=zave/firipixe;
    if(fDebug>1)cout<<"++++++++++++++++++++++++++++++++++++++++++++++++++++++\n Number of firing pixels: "<<firipixe<<endl;
  }
  else {
    fZFound = -200;
    fZsig = -200;
    Warning("FindVertexForCurrentEvent","No rec points on first layer for this event");
    return fCurrentVertex;
  }
  Float_t zlim1=zave-rmszav;
  Float_t zlim2=zave+rmszav;
  Int_t sepa=(Int_t)((zlim2-zlim1)*10.+1.);
  zlim2=zlim1 + sepa/10.;
  TH1F *zvdis = new TH1F("z_ev","zv distr",sepa,zlim1,zlim2);
  if(fDebug>0){
    cout<<"Z limits: "<<zlim1<<" "<<zlim2<<"; Bins= "<<sepa<<endl;
    cout<<"Bin width: "<<zvdis->GetBinWidth(1)*10000.<<" micron\n";
  }
  Int_t sizarr=100;
  TArrayF *zval = new TArrayF(sizarr);
  //  TArrayF *curv = new TArrayF(sizarr);
  Int_t ncoinc=0;
  for(Int_t module= fFirstL1; module<=fLastL1;module++){
    if(fDebug>0)cout<<"processing module   "<<module<<"                  \r";
    branch->GetEvent(module);
    Int_t nrecp1 = ITSrec->GetEntries();
    TObjArray *poiL1 = new TObjArray(nrecp1);
    for(Int_t i=0; i<nrecp1;i++)poiL1->AddAt(ITSrec->At(i),i);
    fITS->ResetRecPoints();
    for(Int_t i=0; i<nrecp1;i++){
      AliITSRecPoint *current = (AliITSRecPoint*)poiL1->At(i);
      lc[0]=current->GetX();
      lc[2]=current->GetZ();
      geom->LtoG(module,lc,gc);
      gc[0]-=fX0;
      gc[1]-=fY0;
      Float_t r1=TMath::Sqrt(gc[0]*gc[0]+gc[1]*gc[1]);
      Float_t phi1 = TMath::ATan2(gc[1],gc[0]);
      if(phi1<0)phi1=2*TMath::Pi()+phi1;
      if(fDebug>1)cout<<"module "<<module<<" "<<gc[0]<<" "<<gc[1]<<" "<<gc[2]<<" "<<phi1<<"     \n";
      for(Int_t modul2=fFirstL2; modul2<=fLastL2; modul2++){
	branch->GetEvent(modul2);
	Int_t nrecp2 = ITSrec->GetEntries();
	for(Int_t j=0; j<nrecp2;j++){
	  AliITSRecPoint *recp = (AliITSRecPoint*)ITSrec->At(j);
	  lc2[0]=recp->GetX();
	  lc2[2]=recp->GetZ();
	  geom->LtoG(modul2,lc2,gc2);
	  gc2[0]-=fX0;
	  gc2[1]-=fY0;
	  Float_t r2=TMath::Sqrt(gc2[0]*gc2[0]+gc2[1]*gc2[1]);
	  Float_t zr0=(r2*gc[2]-r1*gc2[2])/(r2-r1);
	  Float_t phi2 = TMath::ATan2(gc2[1],gc2[0]);
	  if(phi2<0)phi2=2.*TMath::Pi()+phi2;
	  Float_t diff = TMath::Abs(phi2-phi1);
	  if(diff>TMath::Pi())diff=2.*TMath::Pi()-diff;
	  if(zr0>zlim1 && zr0<zlim2){
	    if(diff<fDiffPhiMax ){
	      zvdis->Fill(zr0);
	      zval->AddAt(zr0,ncoinc);
	      /* uncomment these lines to use curvature as a weight
	      Float_t cu = Curv(0.,0.,gc[0],gc[1],gc2[0],gc[1]);
	      curv->AddAt(cu,ncoinc);
	      */
	      ncoinc++;
	      if(ncoinc==(sizarr-1)){
		sizarr+=100;
		zval->Set(sizarr);
		//uncomment next line to use curvature as weight
		//		curv->Set(sizarr);
	      }
	    }
	  }
	}
	fITS->ResetRecPoints();
      }
    }
    delete poiL1;
  }         // loop on modules
  if(fDebug>0){
    cout<<endl<<"Number of coincidences = "<<ncoinc<<endl;
  }
  //  EvalZ(zvdis,sepa,ncoinc,zval,curv);
  EvalZ(zvdis,sepa,ncoinc,zval);
  delete zvdis;
  delete zval;
  //  delete curv;
  if(fCurrentVertex){
    char name[30];
    sprintf(name,"Vertex_%d",evnumber);
    //    fCurrentVertex->SetName(name);
    fCurrentVertex->SetTitle("vertexer: PPZ");
  }
  return fCurrentVertex;
}

//______________________________________________________________________
void AliITSVertexerPPZ::FindVertices(){
  // computes the vertices of the events in the range FirstEvent - LastEvent
  AliRunLoader *rl = AliRunLoader::GetRunLoader();
  AliITSLoader* ITSloader =  (AliITSLoader*) rl->GetLoader("ITSLoader");
  ITSloader->ReloadRecPoints();
  for(Int_t i=fFirstEvent;i<=fLastEvent;i++){
    cout<<"Processing event "<<i<<endl;
    rl->GetEvent(i);
    FindVertexForCurrentEvent(i);
    if(fCurrentVertex){
      WriteCurrentVertex();
    }
    else {
      if(fDebug>0){
	cout<<"Vertex not found for event "<<i<<endl;
	cout<<"fZFound = "<<fZFound<<", fZsig= "<<fZsig<<endl;
      }
    }
  }
}

//________________________________________________________
void AliITSVertexerPPZ::PrintStatus() const {
  // Print current status
  cout <<"=======================================================\n";
  cout <<" First layer first and last modules: "<<fFirstL1<<", ";
  cout <<fLastL1<<endl;
  cout <<" Second layer first and last modules: "<<fFirstL2<<", ";
  cout <<fLastL2<<endl;
  cout <<" Max Phi difference: "<<fDiffPhiMax<<endl;
  cout <<" Window for Z search: "<<fWindow<<endl;
  cout <<" Current Z "<<fZFound<<"; Z sig "<<fZsig<<endl;
  cout <<" Debug flag: "<<fDebug<<endl;
  cout<<"First event to be processed "<<fFirstEvent;
  cout<<"\n Last event to be processed "<<fLastEvent<<endl;
}

//________________________________________________________
Float_t AliITSVertexerPPZ::Curv(Double_t x1,Double_t y1,
                   Double_t x2,Double_t y2,
                   Double_t x3,Double_t y3) 
{
  //-----------------------------------------------------------------
  // Initial approximation of the track curvature (Y. Belikov) squared
  //-----------------------------------------------------------------
  Double_t d=(x2-x1)*(y3-y2)-(x3-x2)*(y2-y1);
  Double_t a=0.5*((y3-y2)*(y2*y2-y1*y1+x2*x2-x1*x1)-
                  (y2-y1)*(y3*y3-y2*y2+x3*x3-x2*x2));
  Double_t b=0.5*((x2-x1)*(y3*y3-y2*y2+x3*x3-x2*x2)-
                  (x3-x2)*(y2*y2-y1*y1+x2*x2-x1*x1));

  Double_t xr=TMath::Abs(d/(d*x1-a)), yr=d/(d*y1-b);

  Float_t val = (Float_t)(( -xr*yr/TMath::Sqrt(xr*xr+yr*yr))
			  *( -xr*yr/TMath::Sqrt(xr*xr+yr*yr)));
  return val; 
}
Commit	Line	Data
c95d6417	1	/**************************************************************************
	2	* Copyright(c) 1998-2003, 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	**************************************************************************/
c5f0f3c1	15	#include <AliITSVertexerPPZ.h>
	16	#include <Riostream.h>
	17	#include <TArrayF.h>
	18	#include <TDirectory.h>
	19	#include <TH1F.h>
	20	#include <TMath.h>
	21	#include <TObjArray.h>
	22	#include <TTree.h>
	23	#include <TClonesArray.h>
	24	#include "AliRun.h"
	25	#include "AliITS.h"
	26	#include "AliITSgeom.h"
88cb7938	27	#include "AliITSLoader.h"
c5f0f3c1	28	#include "AliITSRecPoint.h"
	29	/////////////////////////////////////////////////////////////////////////
	30	// //
	31	// This class is intended to compute the Z coordinate of the //
	32	// primary vertex for p-p interactions, or in general when the //
	33	// number of secondaries is too slow to use the class //
	34	// AliITSVertexerIons, which in turn is optimized for A-A collsions //
	35	// Origin: masera@to.infn.it 9/12/2002 //
	36	// //
	37	/////////////////////////////////////////////////////////////////////////
	38	ClassImp(AliITSVertexerPPZ)
	39
	40
	41
	42	//______________________________________________________________________
	43	AliITSVertexerPPZ::AliITSVertexerPPZ():AliITSVertexer() {
	44	// Default Constructor
	45
	46	SetDiffPhiMax(0);
	47	fX0 = 0.;
	48	fY0 = 0.;
	49	SetFirstLayerModules(0);
	50	SetSecondLayerModules(0);
	51	fZFound = 0;
	52	fZsig = 0.;
	53	fITS = 0;
c95d6417	54	SetWindow(0);
c5f0f3c1	55	}
c5f0f3c1	56
88cb7938	57	AliITSVertexerPPZ::AliITSVertexerPPZ(TString fn, Float_t x0, Float_t y0):AliITSVertexer(fn) {
c5f0f3c1	58	// Standard constructor
c5f0f3c1	59	SetDiffPhiMax();
	60	fX0 = x0;
	61	fY0 = y0;
	62	SetFirstLayerModules();
	63	SetSecondLayerModules();
	64	fZFound = 0;
	65	fZsig = 0.;
	66	fITS = 0;
c95d6417	67	SetWindow();
c5f0f3c1	68	}
	69
	70	//______________________________________________________________________
	71	AliITSVertexerPPZ::~AliITSVertexerPPZ() {
	72	// Default Destructor
	73	fITS = 0;
	74	}
	75
	76	//________________________________________________________
	77	void AliITSVertexerPPZ::EvalZ(TH1F hist,Int_t sepa, Int_t ncoinc, TArrayF zval) {
c95d6417	78	Float_t DeltaVal = hist->GetBinWidth(1)*fWindow; // max window in Z for searching
c5f0f3c1	79	fZFound=0;
	80	fZsig=0;
	81	Int_t N=0;
	82	Int_t NbinNotZero=0;
	83	Float_t totst = 0.;
	84	Float_t totst2 = 0.;
	85	Float_t curz = 0.;
	86	for(Int_t i=1;i<=sepa;i++){
	87	Float_t cont=hist->GetBinContent(i);
c95d6417	88	if(cont!=0)curz = hist->GetBinLowEdge(i)+0.5*hist->GetBinWidth(i);
c5f0f3c1	89	totst+=cont;
	90	totst2+=cont*cont;
	91	N++;
	92	if(cont!=0)NbinNotZero++;
	93	}
	94	if(NbinNotZero==0){fZFound=-100; fZsig=-100; return;}
c95d6417	95	if(NbinNotZero==1){
	96	fZFound = curz;
	97	fZsig=0;
	98	fCurrentVertex = new AliITSVertex(fZFound,fZsig,NbinNotZero);
	99	return;
	100	}
	101	Float_t errsq = totst2/(N-1)-totst*totst/N/(N-1);
	102	if(errsq>=0){
	103	totst2=TMath::Sqrt(errsq);
	104	}
	105	else {
	106	Error("EvalZ","Negative variance: %d - %12.7f - %12.7f",N,totst2,totst);
	107	fZFound=-100;
	108	fZsig=-100;
	109	return;
	110	}
c5f0f3c1	111	totst /= N;
c95d6417	112	Float_t cut = totst+totst2*2.;
c95d6417	113	if(fDebug>1)cout<<"totst, totst2, cut: "<<totst<<", "<<totst2<<", "<<cut<<endl;
c5f0f3c1	114	Float_t val1=hist->GetBinLowEdge(sepa);
c5f0f3c1	115	Float_t val2=hist->GetBinLowEdge(1);
c95d6417	116	Float_t valm = 0.;
c95d6417	117	Float_t zmax = 0.;
c5f0f3c1	118	for(Int_t i=1;i<=sepa;i++){
c5f0f3c1	119	Float_t cont=hist->GetBinContent(i);
c95d6417	120	if(cont>valm){
	121	valm = cont;
	122	zmax = hist->GetBinLowEdge(i)+0.5*hist->GetBinWidth(1);
	123	}
	124	if(cont>cut){
c5f0f3c1	125	curz=hist->GetBinLowEdge(i);
	126	if(curz<val1)val1=curz;
	127	if(curz>val2)val2=curz;
	128	}
	129	}
	130	val2+=hist->GetBinWidth(1);
c95d6417	131	if((val2-val1)>DeltaVal){
	132	val1 = zmax-DeltaVal/2.;
	133	val2 = zmax+DeltaVal/2.;
	134	if(fDebug>0)cout<<"val1 and val2 recomputed\n";
	135	}
	136	if(fDebug>0)cout<<"Values for Z finding: "<<val1<<" "<<val2<<" "<<val2-val1<<endl;
c5f0f3c1	137	fZFound=0;
	138	fZsig=0;
	139	N=0;
	140	for(Int_t i=0; i<ncoinc; i++){
	141	Float_t z=zval->At(i);
	142	if(z<val1)continue;
	143	if(z>val2)continue;
c95d6417	144
c5f0f3c1	145	fZFound+=z;
c5f0f3c1	146	fZsig+=z*z;
c95d6417	147	/* weights defined by the curvature
	148	Float_t wei = 1./curv->At(i);
	149	fZFound+=z*wei;
	150	fZsig+=wei;
	151	*/
c5f0f3c1	152	N++;
c5f0f3c1	153	}
c95d6417	154	if(N<1){fZFound=-110; fZsig=-110; return;}
	155	if(N==1){
	156	fZsig = 0;
	157	fCurrentVertex = new AliITSVertex(fZFound,fZsig,N);
	158	return;
	159	}
	160	errsq = (fZsig/(N-1)-fZFound*fZFound/N/(N-1))/N;
	161	if(errsq>=0.){
	162	fZsig=TMath::Sqrt(errsq);
	163	}
	164	else {
	165	Error("evalZ","Negative variance: %d - %12.7f %12.7f",N,fZsig,fZFound);
	166	fZsig=0;
	167	}
c5f0f3c1	168	fZFound=fZFound/N;
c95d6417	169	/* weights defined by the curvature
	170	fZsig=1./fZsig;
	171	fZFound*=fZsig;
	172	fZsig = TMath::Sqrt(fZsig);
	173	*/
c5f0f3c1	174	fCurrentVertex = new AliITSVertex(fZFound,fZsig,N);
	175	}
	176
	177	//______________________________________________________________________
	178	AliITSVertex* AliITSVertexerPPZ::FindVertexForCurrentEvent(Int_t evnumber){
	179	// Defines the AliITSVertex for the current event
	180	fCurrentVertex = 0;
	181	fZFound = -999;
	182	fZsig = -999;
88cb7938	183	AliRunLoader *rl =AliRunLoader::GetRunLoader();
88cb7938	184	AliITSLoader* ITSloader = (AliITSLoader*) rl->GetLoader("ITSLoader");
c5f0f3c1	185	if(!fITS) {
	186	fITS = (AliITS*)gAlice->GetModule("ITS");
	187	if(!fITS) {
	188	Error("FindVertexForCurrentEvent","AliITS object was not found");
	189	return fCurrentVertex;
	190	}
	191	}
88cb7938	192	fITS->SetTreeAddress();
c5f0f3c1	193	AliITSgeom *geom = fITS->GetITSgeom();
	194	if(!geom) {
	195	Error("FindVertexForCurrentEvent","ITS geometry is not defined");
	196	return fCurrentVertex;
	197	}
	198	TTree *TR=0;
	199	TClonesArray *ITSrec = 0;
	200	Float_t lc[3]; for(Int_t ii=0; ii<3; ii++) lc[ii]=0.;
	201	Float_t gc[3]; for(Int_t ii=0; ii<3; ii++) gc[ii]=0.;
	202	Float_t lc2[3]; for(Int_t ii=0; ii<3; ii++) lc2[ii]=0.;
	203	Float_t gc2[3]; for(Int_t ii=0; ii<3; ii++) gc2[ii]=0.;
	204
88cb7938	205	TR = ITSloader->TreeR();
c5f0f3c1	206	if(!TR){
	207	Error("FindVertexForCurrentEvent","TreeR not found");
	208	return fCurrentVertex;
	209	}
	210	ITSrec = fITS->RecPoints(); // uses slow points or fast points if slow are
	211	// missing
	212	TBranch *branch = TR->GetBranch("ITSRecPoints");
	213	if(!branch){
	214	branch = TR->GetBranch("ITSRecPointsF");
	215	// Warning("FindVertexForCurrentEvent","Using Fast points");
	216	}
	217	if(!branch){
	218	Error("FindVertexForCurrentEvent","branch for ITS rec points not found");
	219	return fCurrentVertex;
	220	}
	221	Float_t zave=0;
	222	Float_t rmszav=0;
	223	Float_t zave2=0;
	224	Int_t firipixe=0;
	225	for(Int_t module= fFirstL1; module<=fLastL1;module++){
	226	branch->GetEvent(module);
	227	Int_t nrecp1 = ITSrec->GetEntries();
	228	for(Int_t i=0; i<nrecp1;i++){
	229	AliITSRecPoint current = (AliITSRecPoint)ITSrec->At(i);
	230	lc[0]=current->GetX();
	231	lc[2]=current->GetZ();
	232	geom->LtoG(module,lc,gc);
	233	zave+=gc[2];
	234	zave2+=gc[2]*gc[2];
	235	firipixe++;
	236	}
	237	fITS->ResetRecPoints();
	238	}
	239	if(firipixe>1){
	240	rmszav=TMath::Sqrt(zave2/(firipixe-1)-zave*zave/firipixe/(firipixe-1));
	241	zave=zave/firipixe;
c95d6417	242	if(fDebug>1)cout<<"++++++++++++++++++++++++++++++++++++++++++++++++++++++\n Number of firing pixels: "<<firipixe<<endl;
c5f0f3c1	243	}
	244	else {
	245	fZFound = -200;
	246	fZsig = -200;
	247	Warning("FindVertexForCurrentEvent","No rec points on first layer for this event");
	248	return fCurrentVertex;
	249	}
	250	Float_t zlim1=zave-rmszav;
	251	Float_t zlim2=zave+rmszav;
	252	Int_t sepa=(Int_t)((zlim2-zlim1)*10.+1.);
	253	zlim2=zlim1 + sepa/10.;
	254	TH1F *zvdis = new TH1F("z_ev","zv distr",sepa,zlim1,zlim2);
c95d6417	255	if(fDebug>0){
	256	cout<<"Z limits: "<<zlim1<<" "<<zlim2<<"; Bins= "<<sepa<<endl;
	257	cout<<"Bin width: "<<zvdis->GetBinWidth(1)*10000.<<" micron\n";
	258	}
c5f0f3c1	259	Int_t sizarr=100;
c5f0f3c1	260	TArrayF *zval = new TArrayF(sizarr);
c95d6417	261	// TArrayF *curv = new TArrayF(sizarr);
c5f0f3c1	262	Int_t ncoinc=0;
	263	for(Int_t module= fFirstL1; module<=fLastL1;module++){
	264	if(fDebug>0)cout<<"processing module "<<module<<" \r";
	265	branch->GetEvent(module);
	266	Int_t nrecp1 = ITSrec->GetEntries();
	267	TObjArray *poiL1 = new TObjArray(nrecp1);
	268	for(Int_t i=0; i<nrecp1;i++)poiL1->AddAt(ITSrec->At(i),i);
	269	fITS->ResetRecPoints();
	270	for(Int_t i=0; i<nrecp1;i++){
	271	AliITSRecPoint current = (AliITSRecPoint)poiL1->At(i);
	272	lc[0]=current->GetX();
	273	lc[2]=current->GetZ();
	274	geom->LtoG(module,lc,gc);
	275	gc[0]-=fX0;
	276	gc[1]-=fY0;
	277	Float_t r1=TMath::Sqrt(gc[0]gc[0]+gc[1]gc[1]);
	278	Float_t phi1 = TMath::ATan2(gc[1],gc[0]);
	279	if(phi1<0)phi1=2*TMath::Pi()+phi1;
	280	if(fDebug>1)cout<<"module "<<module<<" "<<gc[0]<<" "<<gc[1]<<" "<<gc[2]<<" "<<phi1<<" \n";
	281	for(Int_t modul2=fFirstL2; modul2<=fLastL2; modul2++){
	282	branch->GetEvent(modul2);
	283	Int_t nrecp2 = ITSrec->GetEntries();
	284	for(Int_t j=0; j<nrecp2;j++){
	285	AliITSRecPoint recp = (AliITSRecPoint)ITSrec->At(j);
	286	lc2[0]=recp->GetX();
	287	lc2[2]=recp->GetZ();
	288	geom->LtoG(modul2,lc2,gc2);
	289	gc2[0]-=fX0;
	290	gc2[1]-=fY0;
	291	Float_t r2=TMath::Sqrt(gc2[0]gc2[0]+gc2[1]gc2[1]);
	292	Float_t zr0=(r2gc[2]-r1gc2[2])/(r2-r1);
	293	Float_t phi2 = TMath::ATan2(gc2[1],gc2[0]);
	294	if(phi2<0)phi2=2.*TMath::Pi()+phi2;
	295	Float_t diff = TMath::Abs(phi2-phi1);
	296	if(diff>TMath::Pi())diff=2.*TMath::Pi()-diff;
	297	if(zr0>zlim1 && zr0<zlim2){
	298	if(diff<fDiffPhiMax ){
	299	zvdis->Fill(zr0);
	300	zval->AddAt(zr0,ncoinc);
c95d6417	301	/* uncomment these lines to use curvature as a weight
	302	Float_t cu = Curv(0.,0.,gc[0],gc[1],gc2[0],gc[1]);
	303	curv->AddAt(cu,ncoinc);
	304	*/
c5f0f3c1	305	ncoinc++;
	306	if(ncoinc==(sizarr-1)){
	307	sizarr+=100;
	308	zval->Set(sizarr);
c95d6417	309	//uncomment next line to use curvature as weight
c95d6417	310	// curv->Set(sizarr);
c5f0f3c1	311	}
	312	}
	313	}
	314	}
	315	fITS->ResetRecPoints();
	316	}
	317	}
	318	delete poiL1;
	319	} // loop on modules
	320	if(fDebug>0){
	321	cout<<endl<<"Number of coincidences = "<<ncoinc<<endl;
	322	}
c95d6417	323	// EvalZ(zvdis,sepa,ncoinc,zval,curv);
c5f0f3c1	324	EvalZ(zvdis,sepa,ncoinc,zval);
	325	delete zvdis;
	326	delete zval;
c95d6417	327	// delete curv;
c5f0f3c1	328	if(fCurrentVertex){
	329	char name[30];
	330	sprintf(name,"Vertex_%d",evnumber);
88cb7938	331	// fCurrentVertex->SetName(name);
c5f0f3c1	332	fCurrentVertex->SetTitle("vertexer: PPZ");
	333	}
	334	return fCurrentVertex;
	335	}
	336
	337	//______________________________________________________________________
	338	void AliITSVertexerPPZ::FindVertices(){
	339	// computes the vertices of the events in the range FirstEvent - LastEvent
88cb7938	340	AliRunLoader *rl = AliRunLoader::GetRunLoader();
	341	AliITSLoader* ITSloader = (AliITSLoader*) rl->GetLoader("ITSLoader");
	342	ITSloader->ReloadRecPoints();
ab6a6f40	343	for(Int_t i=fFirstEvent;i<=fLastEvent;i++){
88cb7938	344	cout<<"Processing event "<<i<<endl;
88cb7938	345	rl->GetEvent(i);
c5f0f3c1	346	FindVertexForCurrentEvent(i);
	347	if(fCurrentVertex){
	348	WriteCurrentVertex();
	349	}
	350	else {
	351	if(fDebug>0){
	352	cout<<"Vertex not found for event "<<i<<endl;
	353	cout<<"fZFound = "<<fZFound<<", fZsig= "<<fZsig<<endl;
	354	}
	355	}
	356	}
c5f0f3c1	357	}
	358
	359	//________________________________________________________
	360	void AliITSVertexerPPZ::PrintStatus() const {
	361	// Print current status
	362	cout <<"=======================================================\n";
	363	cout <<" First layer first and last modules: "<<fFirstL1<<", ";
	364	cout <<fLastL1<<endl;
	365	cout <<" Second layer first and last modules: "<<fFirstL2<<", ";
	366	cout <<fLastL2<<endl;
	367	cout <<" Max Phi difference: "<<fDiffPhiMax<<endl;
c95d6417	368	cout <<" Window for Z search: "<<fWindow<<endl;
c5f0f3c1	369	cout <<" Current Z "<<fZFound<<"; Z sig "<<fZsig<<endl;
c5f0f3c1	370	cout <<" Debug flag: "<<fDebug<<endl;
c5f0f3c1	371	cout<<"First event to be processed "<<fFirstEvent;
	372	cout<<"\n Last event to be processed "<<fLastEvent<<endl;
	373	}
c95d6417	374
	375	//________________________________________________________
	376	Float_t AliITSVertexerPPZ::Curv(Double_t x1,Double_t y1,
	377	Double_t x2,Double_t y2,
	378	Double_t x3,Double_t y3)
	379	{
	380	//-----------------------------------------------------------------
	381	// Initial approximation of the track curvature (Y. Belikov) squared
	382	//-----------------------------------------------------------------
	383	Double_t d=(x2-x1)(y3-y2)-(x3-x2)(y2-y1);
	384	Double_t a=0.5((y3-y2)(y2y2-y1y1+x2x2-x1x1)-
	385	(y2-y1)(y3y3-y2y2+x3x3-x2*x2));
	386	Double_t b=0.5((x2-x1)(y3y3-y2y2+x3x3-x2x2)-
	387	(x3-x2)(y2y2-y1y1+x2x2-x1*x1));
	388
	389	Double_t xr=TMath::Abs(d/(dx1-a)), yr=d/(dy1-b);
	390
	391	Float_t val = (Float_t)(( -xryr/TMath::Sqrt(xrxr+yr*yr))
	392	( -xryr/TMath::Sqrt(xrxr+yryr)));
	393	return val;
	394	}