[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 "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(TFile *infile, TFile *outfile, Float_t x0, Float_t y0):AliITSVertexer(infile,outfile) {
  // Standard constructor
  if(!fInFile)Fatal("AliITSVertexerPPZ","No inputfile has been defined!");
  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;
  if(!gAlice)gAlice = (AliRun*)fInFile->Get("gAlice");
  if(!gAlice){
    Error("FindVertexForCurrentEvent","The AliRun object is not available - nothing done");
    return fCurrentVertex;
  }
  if(!fITS)  {
    fITS = (AliITS*)gAlice->GetModule("ITS");
    if(!fITS) {
      Error("FindVertexForCurrentEvent","AliITS object was not found");
      return fCurrentVertex;
    }
  }
  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 = gAlice->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
  if(!fOutFile){
    Error("FindVertices","The output file is not available - nothing done");
    return;
  }
  if(!gAlice)gAlice = (AliRun*)fInFile->Get("gAlice");
  if(!gAlice){
    Error("FindVertices","The AliRun object is not available - nothing done");
    return;
  }
  TDirectory *curdir = gDirectory;
  fInFile->cd();
  for(Int_t i=fFirstEvent;i<=fLastEvent;i++){
    gAlice->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;
      }
    }
  }
  curdir->cd();
}

//________________________________________________________
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;
  if(fInFile)cout <<" The input file is open\n";
  if(!fInFile)cout <<"The input file is not open\n";
  if(fOutFile)cout <<"The output file is open\n";
  if(!fOutFile)cout <<"The output file is not open\n";
  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"
	27	#include "AliITSRecPoint.h"
	28	/////////////////////////////////////////////////////////////////////////
	29	// //
	30	// This class is intended to compute the Z coordinate of the //
	31	// primary vertex for p-p interactions, or in general when the //
	32	// number of secondaries is too slow to use the class //
	33	// AliITSVertexerIons, which in turn is optimized for A-A collsions //
	34	// Origin: masera@to.infn.it 9/12/2002 //
	35	// //
	36	/////////////////////////////////////////////////////////////////////////
	37	ClassImp(AliITSVertexerPPZ)
	38
	39
	40
	41	//______________________________________________________________________
	42	AliITSVertexerPPZ::AliITSVertexerPPZ():AliITSVertexer() {
	43	// Default Constructor
	44
	45	SetDiffPhiMax(0);
	46	fX0 = 0.;
	47	fY0 = 0.;
	48	SetFirstLayerModules(0);
	49	SetSecondLayerModules(0);
	50	fZFound = 0;
	51	fZsig = 0.;
	52	fITS = 0;
c95d6417	53	SetWindow(0);
c5f0f3c1	54	}
	55
	56	AliITSVertexerPPZ::AliITSVertexerPPZ(TFile infile, TFile outfile, Float_t x0, Float_t y0):AliITSVertexer(infile,outfile) {
	57	// Standard constructor
	58	if(!fInFile)Fatal("AliITSVertexerPPZ","No inputfile has been defined!");
	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;
	183	if(!gAlice)gAlice = (AliRun*)fInFile->Get("gAlice");
	184	if(!gAlice){
	185	Error("FindVertexForCurrentEvent","The AliRun object is not available - nothing done");
	186	return fCurrentVertex;
	187	}
	188	if(!fITS) {
	189	fITS = (AliITS*)gAlice->GetModule("ITS");
	190	if(!fITS) {
	191	Error("FindVertexForCurrentEvent","AliITS object was not found");
	192	return fCurrentVertex;
	193	}
	194	}
	195	AliITSgeom *geom = fITS->GetITSgeom();
	196	if(!geom) {
	197	Error("FindVertexForCurrentEvent","ITS geometry is not defined");
	198	return fCurrentVertex;
	199	}
	200	TTree *TR=0;
	201	TClonesArray *ITSrec = 0;
	202	Float_t lc[3]; for(Int_t ii=0; ii<3; ii++) lc[ii]=0.;
	203	Float_t gc[3]; for(Int_t ii=0; ii<3; ii++) gc[ii]=0.;
	204	Float_t lc2[3]; for(Int_t ii=0; ii<3; ii++) lc2[ii]=0.;
	205	Float_t gc2[3]; for(Int_t ii=0; ii<3; ii++) gc2[ii]=0.;
	206
	207	TR = gAlice->TreeR();
	208	if(!TR){
	209	Error("FindVertexForCurrentEvent","TreeR not found");
	210	return fCurrentVertex;
	211	}
	212	ITSrec = fITS->RecPoints(); // uses slow points or fast points if slow are
	213	// missing
	214	TBranch *branch = TR->GetBranch("ITSRecPoints");
	215	if(!branch){
	216	branch = TR->GetBranch("ITSRecPointsF");
	217	// Warning("FindVertexForCurrentEvent","Using Fast points");
	218	}
	219	if(!branch){
	220	Error("FindVertexForCurrentEvent","branch for ITS rec points not found");
	221	return fCurrentVertex;
	222	}
	223	Float_t zave=0;
	224	Float_t rmszav=0;
	225	Float_t zave2=0;
	226	Int_t firipixe=0;
	227	for(Int_t module= fFirstL1; module<=fLastL1;module++){
	228	branch->GetEvent(module);
	229	Int_t nrecp1 = ITSrec->GetEntries();
	230	for(Int_t i=0; i<nrecp1;i++){
	231	AliITSRecPoint current = (AliITSRecPoint)ITSrec->At(i);
	232	lc[0]=current->GetX();
	233	lc[2]=current->GetZ();
	234	geom->LtoG(module,lc,gc);
	235	zave+=gc[2];
	236	zave2+=gc[2]*gc[2];
	237	firipixe++;
238	}
239	fITS->ResetRecPoints();
240	}
241	if(firipixe>1){
242	rmszav=TMath::Sqrt(zave2/(firipixe-1)-zave*zave/firipixe/(firipixe-1));
243	zave=zave/firipixe;
c95d6417	244	if(fDebug>1)cout<<"++++++++++++++++++++++++++++++++++++++++++++++++++++++\n Number of firing pixels: "<<firipixe<<endl;
c5f0f3c1	245	}
	246	else {
	247	fZFound = -200;
	248	fZsig = -200;
	249	Warning("FindVertexForCurrentEvent","No rec points on first layer for this event");
	250	return fCurrentVertex;
	251	}
	252	Float_t zlim1=zave-rmszav;
	253	Float_t zlim2=zave+rmszav;
	254	Int_t sepa=(Int_t)((zlim2-zlim1)*10.+1.);
	255	zlim2=zlim1 + sepa/10.;
	256	TH1F *zvdis = new TH1F("z_ev","zv distr",sepa,zlim1,zlim2);
c95d6417	257	if(fDebug>0){
	258	cout<<"Z limits: "<<zlim1<<" "<<zlim2<<"; Bins= "<<sepa<<endl;
	259	cout<<"Bin width: "<<zvdis->GetBinWidth(1)*10000.<<" micron\n";
	260	}
c5f0f3c1	261	Int_t sizarr=100;
c5f0f3c1	262	TArrayF *zval = new TArrayF(sizarr);
c95d6417	263	// TArrayF *curv = new TArrayF(sizarr);
c5f0f3c1	264	Int_t ncoinc=0;
	265	for(Int_t module= fFirstL1; module<=fLastL1;module++){
	266	if(fDebug>0)cout<<"processing module "<<module<<" \r";
	267	branch->GetEvent(module);
	268	Int_t nrecp1 = ITSrec->GetEntries();
	269	TObjArray *poiL1 = new TObjArray(nrecp1);
	270	for(Int_t i=0; i<nrecp1;i++)poiL1->AddAt(ITSrec->At(i),i);
	271	fITS->ResetRecPoints();
	272	for(Int_t i=0; i<nrecp1;i++){
	273	AliITSRecPoint current = (AliITSRecPoint)poiL1->At(i);
	274	lc[0]=current->GetX();
	275	lc[2]=current->GetZ();
	276	geom->LtoG(module,lc,gc);
	277	gc[0]-=fX0;
	278	gc[1]-=fY0;
	279	Float_t r1=TMath::Sqrt(gc[0]gc[0]+gc[1]gc[1]);
	280	Float_t phi1 = TMath::ATan2(gc[1],gc[0]);
	281	if(phi1<0)phi1=2*TMath::Pi()+phi1;
	282	if(fDebug>1)cout<<"module "<<module<<" "<<gc[0]<<" "<<gc[1]<<" "<<gc[2]<<" "<<phi1<<" \n";
	283	for(Int_t modul2=fFirstL2; modul2<=fLastL2; modul2++){
	284	branch->GetEvent(modul2);
	285	Int_t nrecp2 = ITSrec->GetEntries();
	286	for(Int_t j=0; j<nrecp2;j++){
	287	AliITSRecPoint recp = (AliITSRecPoint)ITSrec->At(j);
	288	lc2[0]=recp->GetX();
	289	lc2[2]=recp->GetZ();
	290	geom->LtoG(modul2,lc2,gc2);
	291	gc2[0]-=fX0;
	292	gc2[1]-=fY0;
	293	Float_t r2=TMath::Sqrt(gc2[0]gc2[0]+gc2[1]gc2[1]);
	294	Float_t zr0=(r2gc[2]-r1gc2[2])/(r2-r1);
	295	Float_t phi2 = TMath::ATan2(gc2[1],gc2[0]);
	296	if(phi2<0)phi2=2.*TMath::Pi()+phi2;
	297	Float_t diff = TMath::Abs(phi2-phi1);
	298	if(diff>TMath::Pi())diff=2.*TMath::Pi()-diff;
	299	if(zr0>zlim1 && zr0<zlim2){
	300	if(diff<fDiffPhiMax ){
	301	zvdis->Fill(zr0);
	302	zval->AddAt(zr0,ncoinc);
c95d6417	303	/* uncomment these lines to use curvature as a weight
	304	Float_t cu = Curv(0.,0.,gc[0],gc[1],gc2[0],gc[1]);
	305	curv->AddAt(cu,ncoinc);
	306	*/
c5f0f3c1	307	ncoinc++;
	308	if(ncoinc==(sizarr-1)){
	309	sizarr+=100;
	310	zval->Set(sizarr);
c95d6417	311	//uncomment next line to use curvature as weight
c95d6417	312	// curv->Set(sizarr);
c5f0f3c1	313	}
	314	}
	315	}
	316	}
	317	fITS->ResetRecPoints();
	318	}
	319	}
	320	delete poiL1;
	321	} // loop on modules
	322	if(fDebug>0){
	323	cout<<endl<<"Number of coincidences = "<<ncoinc<<endl;
	324	}
c95d6417	325	// EvalZ(zvdis,sepa,ncoinc,zval,curv);
c5f0f3c1	326	EvalZ(zvdis,sepa,ncoinc,zval);
	327	delete zvdis;
	328	delete zval;
c95d6417	329	// delete curv;
c5f0f3c1	330	if(fCurrentVertex){
	331	char name[30];
	332	sprintf(name,"Vertex_%d",evnumber);
	333	fCurrentVertex->SetName(name);
	334	fCurrentVertex->SetTitle("vertexer: PPZ");
	335	}
	336	return fCurrentVertex;
	337	}
	338
	339	//______________________________________________________________________
	340	void AliITSVertexerPPZ::FindVertices(){
	341	// computes the vertices of the events in the range FirstEvent - LastEvent
	342	if(!fOutFile){
	343	Error("FindVertices","The output file is not available - nothing done");
	344	return;
	345	}
	346	if(!gAlice)gAlice = (AliRun*)fInFile->Get("gAlice");
	347	if(!gAlice){
	348	Error("FindVertices","The AliRun object is not available - nothing done");
	349	return;
	350	}
	351	TDirectory *curdir = gDirectory;
	352	fInFile->cd();
ab6a6f40	353	for(Int_t i=fFirstEvent;i<=fLastEvent;i++){
c5f0f3c1	354	gAlice->GetEvent(i);
	355	FindVertexForCurrentEvent(i);
	356	if(fCurrentVertex){
	357	WriteCurrentVertex();
	358	}
	359	else {
	360	if(fDebug>0){
	361	cout<<"Vertex not found for event "<<i<<endl;
	362	cout<<"fZFound = "<<fZFound<<", fZsig= "<<fZsig<<endl;
	363	}
	364	}
	365	}
	366	curdir->cd();
	367	}
	368
	369	//________________________________________________________
	370	void AliITSVertexerPPZ::PrintStatus() const {
	371	// Print current status
	372	cout <<"=======================================================\n";
	373	cout <<" First layer first and last modules: "<<fFirstL1<<", ";
	374	cout <<fLastL1<<endl;
	375	cout <<" Second layer first and last modules: "<<fFirstL2<<", ";
	376	cout <<fLastL2<<endl;
	377	cout <<" Max Phi difference: "<<fDiffPhiMax<<endl;
c95d6417	378	cout <<" Window for Z search: "<<fWindow<<endl;
c5f0f3c1	379	cout <<" Current Z "<<fZFound<<"; Z sig "<<fZsig<<endl;
	380	cout <<" Debug flag: "<<fDebug<<endl;
	381	if(fInFile)cout <<" The input file is open\n";
	382	if(!fInFile)cout <<"The input file is not open\n";
	383	if(fOutFile)cout <<"The output file is open\n";
ab6a6f40	384	if(!fOutFile)cout <<"The output file is not open\n";
c5f0f3c1	385	cout<<"First event to be processed "<<fFirstEvent;
	386	cout<<"\n Last event to be processed "<<fLastEvent<<endl;
	387	}
c95d6417	388
	389	//________________________________________________________
	390	Float_t AliITSVertexerPPZ::Curv(Double_t x1,Double_t y1,
	391	Double_t x2,Double_t y2,
	392	Double_t x3,Double_t y3)
	393	{
	394	//-----------------------------------------------------------------
	395	// Initial approximation of the track curvature (Y. Belikov) squared
	396	//-----------------------------------------------------------------
	397	Double_t d=(x2-x1)(y3-y2)-(x3-x2)(y2-y1);
	398	Double_t a=0.5((y3-y2)(y2y2-y1y1+x2x2-x1x1)-
	399	(y2-y1)(y3y3-y2y2+x3x3-x2*x2));
	400	Double_t b=0.5((x2-x1)(y3y3-y2y2+x3x3-x2x2)-
	401	(x3-x2)(y2y2-y1y1+x2x2-x1*x1));
	402
	403	Double_t xr=TMath::Abs(d/(dx1-a)), yr=d/(dy1-b);
	404
	405	Float_t val = (Float_t)(( -xryr/TMath::Sqrt(xrxr+yr*yr))
	406	( -xryr/TMath::Sqrt(xrxr+yryr)));
	407	return val;
	408	}