Correct HitsToFastRecPoints

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

/**************************************************************************
 * Copyright(c) 1998-1999, 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.                  *
 **************************************************************************/

/*
$Log$
Revision 1.60  2001/10/04 22:38:10  nilsen
Changes made to support PreDigits (SDigits) plus other helpful changes.

Revision 1.59  2001/08/30 09:56:18  hristov
The operator[] is replaced by At() or AddAt() in case of TObjArray.

Revision 1.58  2001/07/26 15:05:29  hristov
Use global gRandom generator (M.Ivanov)

Revision 1.57  2001/07/24 14:26:11  mariana
Introduce the function Digits2Reco() and write the defaults for simulation and reconstruction

Revision 1.56  2001/07/05 12:49:49  mariana
Temporary patches required by root.v3.01.05

Revision 1.55  2001/06/14 14:59:00  barbera
Tracking V1 decoupled from AliITS

Revision 1.54  2001/05/31 20:37:56  barbera
Bari/Salerno model set as defaault SPD simulation

Revision 1.53  2001/05/31 18:52:24 barbera 
Bari model becomes the default

Revision 1.53  2001/05/30 07:52:24  hristov
TPC and CONTAINERS included in the search path

Revision 1.52  2001/05/30 06:04:58  hristov
Changes made to be consitant with changes in TPC tracking classes (B.Nilsen)

Revision 1.51  2001/05/16 14:57:15  alibrary
New files for folders and Stack

Revision 1.50  2001/05/11 09:15:21  barbera
Corrected to make fast point creation working with PPR geometry

Revision 1.49  2001/05/11 07:37:49  hristov
Legacy lines commented

Revision 1.48  2001/05/10 18:14:25  barbera
A typo corrected

Revision 1.47  2001/05/10 17:55:59  barbera
Modified to create rec points also for PPR geometries

Revision 1.46  2001/05/10 00:05:28  nilsen
Allowed for HitsToDigits function to work with versions 5, 7, 8, and 9. This
should probably be cleaned up to only check to make sure that fITSgeom has
been properly defined.

Revision 1.45  2001/05/01 22:35:48  nilsen
Remove/commented a number of cout<< statements. and made change needed by
SSD code.

Revision 1.44  2001/04/26 22:44:01  nilsen
Removed dependence on layer 5/6 in AliITS::HitsToDigits. This will be
done properly in AliITSv???.cxx via SetDefaults.

Revision 1.43  2001/04/26 13:22:52  barbera
TMatrix and TVector elimininated to speed up the code

Revision 1.42  2001/04/25 21:55:12  barbera
Updated version to be compatible with actual verion of STEER and TPC

Revision 1.41  2001/04/21 15:16:51  barbera
Updated with the new SSD reconstruction code

Revision 1.40  2001/03/17 15:07:06  mariana
Update SDD response parameters

Revision 1.39  2001/03/12 17:45:32  hristov
Changes needed on Sun with CC 5.0

Revision 1.38  2001/03/07 14:04:51  barbera
Some vector dimensions increased to cope with full events

Revision 1.37  2001/03/07 12:36:35  barbera
A change added in the tracking part to manage delta rays

Revision 1.36  2001/03/02 19:44:11  barbera
 modified to taking into account new version tracking v1

Revision 1.35  2001/02/28 18:16:46  mariana
Make the code compatible with the new AliRun

Revision 1.34  2001/02/11 15:51:39  mariana
Set protection in MakeBranch

Revision 1.33  2001/02/10 22:26:39  mariana
Move the initialization of the containers for raw clusters in MakeTreeC()

Revision 1.32  2001/02/08 23:55:31  nilsen
Removed fMajor/MinorVersion variables in favor of variables in derived classes.
Set arrays char *det[3] = {"SPD","SDD","SSD"} as const.

Revision 1.31  2001/02/02 23:57:28  nilsen
Added include file that are no londer included in AliITSgeom.h

Revision 1.30  2001/01/30 09:23:13  hristov
Streamers removed (R.Brun)

Revision 1.29  2001/01/26 20:01:09  hristov
Major upgrade of AliRoot code

Revision 1.28  2000/12/18 14:02:00  barbera
new version of the ITS tracking to take into account the new TPC track parametrization

Revision 1.27  2000/12/08 13:49:27  barbera
Hidden declaration in a for loop removed to be compliant with HP-UX compiler

Revision 1.26  2000/11/27 13:12:13  barbera
New version containing the files for tracking

Revision 1.25  2000/11/12 22:38:05  barbera
Added header file for the SPD Bari model

Revision 1.24  2000/10/09 22:18:12  barbera
Bug fixes from MAriana to le AliITStest.C run correctly

Revision 1.23  2000/10/05 20:47:42  nilsen
fixed dependencies of include files. Tryed but failed to get a root automaticly
generates streamer function to work. Modified SetDefaults.

Revision 1.9.2.15  2000/10/04 16:56:40  nilsen
Needed to include stdlib.h

=======
Revision 1.22  2000/10/04 19:45:52  barbera
Corrected by F. Carminati for v3.04

Revision 1.21  2000/10/02 21:28:08  fca
Removal of useless dependecies via forward declarations

Revision 1.20  2000/10/02 16:31:39  barbera
General code clean-up

Revision 1.9.2.14  2000/10/02 15:43:51  barbera
General code clean-up (e.g., printf -> cout)

Revision 1.19  2000/09/22 12:13:25  nilsen
Patches and updates for fixes to this and other routines.

Revision 1.18  2000/07/12 05:32:20  fca
Correcting several syntax problem with static members

Revision 1.17  2000/07/10 16:07:18  fca
Release version of ITS code

Revision 1.9.2.3  2000/02/02 13:42:09  barbera
fixed AliITS.cxx for new AliRun structure. Added ITS hits list to list of hits which will have their track numbers updated

Revision 1.9.2.2  2000/01/23 03:03:13  nilsen
//fixed FillModule. Removed fi(fabs(xl)<dx....

Revision 1.9.2.1  2000/01/12 19:03:32  nilsen
This is the version of the files after the merging done in December 1999.
See the ReadMe110100.txt file for details

Revision 1.9  1999/11/14 14:33:25  fca
Correct problems with distructors and pointers, thanks to I.Hrivnacova

Revision 1.8  1999/09/29 09:24:19  fca
Introduction of the Copyright and cvs Log

*/

///////////////////////////////////////////////////////////////////////////////
//
//      An overview of the basic philosophy of the ITS code development
// and analysis is show in the figure below.
//Begin_Html
/*
<img src="picts/ITS/ITS_Analysis_schema.gif">
</pre>
<br clear=left>
<font size=+2 color=red>
<p>Roberto Barbera is in charge of the ITS Offline code (1999).
<a href="mailto:roberto.barbera@ct.infn.it">Roberto Barbera</a>.
</font>
<pre>
*/
//End_Html
//
//  AliITS. Inner Traking System base class.
//  This class contains the base procedures for the Inner Tracking System
//
//Begin_Html
/*
<img src="picts/ITS/AliITS_Class_Diagram.gif">
</pre>
<br clear=left>
<font size=+2 color=red>
<p>This show the class diagram of the different elements that are part of
the AliITS class.
</font>
<pre>
*/
//End_Html
//
// Version: 0
// Written by Rene Brun, Federico Carminati, and Roberto Barbera
//
// Version: 1
// Modified and documented by Bjorn S. Nilsen
// July 11 1999
//
// Version: 2
// Modified and documented by A. Bologna
// October 18 1999
//
// AliITS is the general base class for the ITS. Also see AliDetector for
// futher information.
//
///////////////////////////////////////////////////////////////////////////////
#include <iostream.h>
#include <iomanip.h>
#include <fstream.h>
#include <stdlib.h>
#include <TMath.h>
#include <TRandom.h>
#include <TBranch.h>
#include <TVector.h>
#include <TClonesArray.h>
#include <TROOT.h>
#include <TObjectTable.h>
#include <TFile.h>
#include <TTree.h>
#include <TString.h>

#include "AliMC.h"
#include "AliRun.h"
#include "AliHeader.h"

#include "AliITS.h"
#include "AliITSDetType.h"
#include "AliITSresponseSPD.h"
#include "AliITSresponseSDD.h"
#include "AliITSresponseSSD.h"
#include "AliITSsegmentationSPD.h"
#include "AliITSsegmentationSDD.h"
#include "AliITSsegmentationSSD.h"
#include "AliITSsimulationSPD.h"
#include "AliITSsimulationSDD.h"
#include "AliITSsimulationSSD.h"
#include "AliITSClusterFinderSPD.h"
#include "AliITSClusterFinderSDD.h"
#include "AliITSClusterFinderSSD.h"
#include "AliITShit.h"
#include "AliITSgeom.h"
#include "AliITSpList.h"
#include "AliITSdigit.h"
#include "AliITSmodule.h"
#include "AliITSRecPoint.h"
#include "AliITSRawCluster.h"

ClassImp(AliITS)

//______________________________________________________________________
AliITS::AliITS() : AliDetector() {
    // Default initialiser for ITS
    //      The default constructor of the AliITS class. In addition to
    // creating the AliITS class it zeros the variables fIshunt (a member
    // of AliDetector class), fEuclidOut, and fIdN, and zeros the pointers
    // fITSpoints, fIdSens, and fIdName. The AliDetector default constructor
    // is also called.

    fIshunt     = 0;   // not zeroed in AliDetector.

    // AliITS variables.
    fEuclidOut  = 0;
    fITSgeom    = 0;
    fITSmodules = 0;

    fIdN        = 0;
    fIdName     = 0;
    fIdSens     = 0;

    fNDetTypes  = kNTYPES;
    fDetTypes   = 0;

    fSDigits    = 0;
    fNSDigits   = 0;

    fNdtype     = 0;
    fDtype      = 0;

    fCtype      = 0;
    fNctype     = 0;
    fTreeC      = 0;

    fRecPoints  = 0;
    fNRecPoints = 0;

    SetMarkerColor(kRed);
}
//______________________________________________________________________
AliITS::AliITS(const char *name, const char *title):AliDetector(name,title){
    // Default initialiser for ITS
    //     The constructor of the AliITS class. In addition to creating the
    // AliITS class, it allocates memory for the TClonesArrays fHits and
    // fDigits, and for the TObjArray fITSpoints. It also zeros the variables
    // fIshunt (a member of AliDetector class), fEuclidOut, and fIdN, and zeros
    // the pointers fIdSens and fIdName. To help in displaying hits via the
    // ROOT macro display.C AliITS also sets the marker color to red. The
    // variables passes with this constructor, const char *name and *title,
    // are used by the constructor of AliDetector class. See AliDetector
    // class for a description of these parameters and its constructor
    // functions.

    fIshunt     = 0;  // not zeroed in AliDetector
    fHits       = new TClonesArray("AliITShit", 1560);//not done in AliDetector
    gAlice->AddHitList(fHits);  // Not done in AliDetector.

    fEuclidOut  = 0;
    fITSgeom    = 0;
    fITSmodules = 0;

    fIdN        = 0;
    fIdName     = 0;
    fIdSens     = 0;

    fNDetTypes  = kNTYPES;
    fDetTypes   = new TObjArray(fNDetTypes);

//    fSDigits    = new TObjArray(1000);
    fSDigits    = new TClonesArray("AliITSpListItem",1000);
    fNSDigits   = 0;

    fNdtype     = new Int_t[fNDetTypes];
    fDtype      = new TObjArray(fNDetTypes);

    fCtype      = new TObjArray(fNDetTypes);
    fNctype     = new Int_t[fNDetTypes];
    fTreeC      = 0;

    fRecPoints  = new TClonesArray("AliITSRecPoint",1000);
    fNRecPoints = 0;

    Int_t i;
    for(i=0;i<fNDetTypes;i++) {
	fDetTypes->AddAt(new AliITSDetType(),i); 
	fNdtype[i] = 0;
	fNctype[i] = 0;
    } // end for i

    SetMarkerColor(kRed);
}
//______________________________________________________________________
AliITS::~AliITS(){
    // Default distructor for ITS
    //     The default destructor of the AliITS class. In addition to deleting
    // the AliITS class it deletes the memory pointed to by the fHits, fDigits,
    // fIdSens, fIdName, and fITSpoints.

    delete fHits;
    delete fSDigits;
    delete fDigits;
    delete fRecPoints;
//  delete fIdName;        // TObjArray of TObjStrings
    if(fIdName!=0) delete[] fIdName;  // Array of TStrings
    if(fIdSens!=0) delete[] fIdSens;
    if(fITSmodules!=0) {
	this->ClearModules();
	delete fITSmodules;
    }// end if fITSmodules!=0

    if(fDtype) {
	fDtype->Delete();
	delete fDtype;
    } // end if fDtype
    delete [] fNdtype;
    if (fCtype) {
	fCtype->Delete();
	delete fCtype;
    } // end if fCtype
    delete [] fNctype;

    if (fDetTypes) {
	fDetTypes->Delete();
	delete fDetTypes;
    } // end if fDetTypes

    if (fTreeC) delete fTreeC;

    if (fITSgeom) delete fITSgeom;
}
//______________________________________________________________________
AliITS::AliITS(AliITS &source){
    // copy constructor

    if(this==&source) return;
    Error("AliITS::Copy constructor",
	  "You are not allowed to make a copy of the AliITS");
    exit(1);
}
//______________________________________________________________________
AliITS& AliITS::operator=(AliITS &source){
    // assignment operator

    if(this==&source) return *this;
    Error("AliITS::operator=",
	  "You are not allowed to make a copy of the AliITS");
    exit(1);
    return *this; //fake return
}
//______________________________________________________________________
Int_t AliITS::DistancetoPrimitive(Int_t , Int_t ){
    // Distance from mouse to ITS on the screen. Dummy routine
    //     A dummy routine used by the ROOT macro display.C to allow for the
    // use of the mouse (pointing device) in the macro. In general this should
    // never be called. If it is it returns the number 9999 for any value of
    // x and y.

    return 9999;
}
//______________________________________________________________________
void AliITS::Init(){
    // Initialise ITS after it has been built
    //     This routine initializes the AliITS class. It is intended to be
    // called from the Init function in AliITSv?. Besides displaying a banner
    // indicating that it has been called it initializes the array fIdSens
    // and sets the default segmentation, response, digit and raw cluster
    // classes therefore it should be called after a call to CreateGeometry.
    Int_t i;

    SetDefaults();
    // Array of TStrings
    for(i=0;i<fIdN;i++) fIdSens[i] = gMC->VolId(fIdName[i]);
}
//______________________________________________________________________
void AliITS::SetDefaults(){
    // sets the default segmentation, response, digit and raw cluster classes

    if(fDebug) printf("%s: SetDefaults\n",ClassName());

    AliITSDetType *iDetType;

    //SPD
    iDetType=DetType(0); 
    if (!iDetType->GetSegmentationModel()) {
	AliITSsegmentationSPD *seg0=new AliITSsegmentationSPD(fITSgeom);
	SetSegmentationModel(0,seg0); 
    } // end if
    if (!iDetType->GetResponseModel()) {
	SetResponseModel(0,new AliITSresponseSPD()); 
    } // end if
    // set digit and raw cluster classes to be used

    const char *kData0=(iDetType->GetResponseModel())->DataType();
    if (strstr(kData0,"real")) {
	iDetType->ClassNames("AliITSdigit","AliITSRawClusterSPD");
    } else iDetType->ClassNames("AliITSdigitSPD","AliITSRawClusterSPD");

    // SDD
    iDetType=DetType(1); 
    if (!iDetType->GetResponseModel()) {
	SetResponseModel(1,new AliITSresponseSDD()); 
    } // end if
    AliITSresponse *resp1=iDetType->GetResponseModel();
    if (!iDetType->GetSegmentationModel()) {
	AliITSsegmentationSDD *seg1=new AliITSsegmentationSDD(fITSgeom,resp1);
	SetSegmentationModel(1,seg1); 
    } // end if
    const char *kData1=(iDetType->GetResponseModel())->DataType();
    const char *kopt=iDetType->GetResponseModel()->ZeroSuppOption();
    if((!strstr(kopt,"2D")) && (!strstr(kopt,"1D")) || strstr(kData1,"real") ){
	iDetType->ClassNames("AliITSdigit","AliITSRawClusterSDD");
    } else iDetType->ClassNames("AliITSdigitSDD","AliITSRawClusterSDD");

    // SSD
    iDetType=DetType(2); 
    if (!iDetType->GetSegmentationModel()) {
	AliITSsegmentationSSD *seg2=new AliITSsegmentationSSD(fITSgeom);
	SetSegmentationModel(2,seg2); 
    } // end if
    if (!iDetType->GetResponseModel()) {
	SetResponseModel(2,new AliITSresponseSSD()); 
    } // end if
    const char *kData2=(iDetType->GetResponseModel())->DataType();
    if (strstr(kData2,"real")) {
	iDetType->ClassNames("AliITSdigit","AliITSRawClusterSSD");
    } else iDetType->ClassNames("AliITSdigitSSD","AliITSRawClusterSSD");

    if (kNTYPES>3) {
	Warning("SetDefaults",
		"Only the three basic detector types are initialised!");
    }  // end if
}
//______________________________________________________________________
void AliITS::SetDefaultSimulation(){
    // sets the default simulation

    AliITSDetType *iDetType;
    iDetType=DetType(0);
    if (!iDetType->GetSimulationModel()) {
	AliITSsegmentation *seg0=
	    (AliITSsegmentation*)iDetType->GetSegmentationModel();
	AliITSresponse *res0 = (AliITSresponse*)iDetType->GetResponseModel();
	AliITSsimulationSPD *sim0=new AliITSsimulationSPD(seg0,res0);
	SetSimulationModel(0,sim0);
    } // end if
    iDetType=DetType(1);
    if (!iDetType->GetSimulationModel()) {
	AliITSsegmentation *seg1=
	    (AliITSsegmentation*)iDetType->GetSegmentationModel();
	AliITSresponse *res1 = (AliITSresponse*)iDetType->GetResponseModel();
	AliITSsimulationSDD *sim1=new AliITSsimulationSDD(seg1,res1);
	SetSimulationModel(1,sim1);
    } //end if
    iDetType=DetType(2);
    if (!iDetType->GetSimulationModel()) {
	AliITSsegmentation *seg2=
	    (AliITSsegmentation*)iDetType->GetSegmentationModel();
	AliITSresponse *res2 = (AliITSresponse*)iDetType->GetResponseModel();
	AliITSsimulationSSD *sim2=new AliITSsimulationSSD(seg2,res2);
	SetSimulationModel(2,sim2);
    } // end if
}
//______________________________________________________________________
void AliITS::SetDefaultClusterFinders(){
    // sets the default cluster finders

    MakeTreeC();
    AliITSDetType *iDetType;

    // SPD
    iDetType=DetType(0);
    if (!iDetType->GetReconstructionModel()) {
	AliITSsegmentation *seg0 =
	    (AliITSsegmentation*)iDetType->GetSegmentationModel();
	TClonesArray *dig0=DigitsAddress(0);
	TClonesArray *recp0=ClustersAddress(0);
	AliITSClusterFinderSPD *rec0 = new AliITSClusterFinderSPD(seg0,dig0,
								  recp0);
	SetReconstructionModel(0,rec0);
    } // end if

    // SDD
    iDetType=DetType(1);
    if (!iDetType->GetReconstructionModel()) {
	AliITSsegmentation *seg1 =
	    (AliITSsegmentation*)iDetType->GetSegmentationModel();
	AliITSresponse *res1 = (AliITSresponse*)iDetType->GetResponseModel();
	TClonesArray *dig1=DigitsAddress(1);
	TClonesArray *recp1=ClustersAddress(1);
	AliITSClusterFinderSDD *rec1 =
	    new AliITSClusterFinderSDD(seg1,res1,dig1,recp1);
      SetReconstructionModel(1,rec1);
    } // end if

    // SSD
    iDetType=DetType(2);
    if (!iDetType->GetReconstructionModel()) {
	AliITSsegmentation *seg2=
	    (AliITSsegmentation*)iDetType->GetSegmentationModel();
	TClonesArray *dig2=DigitsAddress(2);
	AliITSClusterFinderSSD *rec2= new AliITSClusterFinderSSD(seg2,dig2);
	SetReconstructionModel(2,rec2);
    } // end if
}
//______________________________________________________________________
void AliITS::MakeBranch(Option_t* option, const char *file){
    // Creates Tree branches for the ITS.
    const char *cS = strstr(option,"S");
    const char *cD = strstr(option,"D");
    const char *cR = strstr(option,"R");

    AliDetector::MakeBranch(option,file);

    if(cS) MakeBranchS(file);
    if(cD) MakeBranchD(file);
    if(cR) MakeBranchR(file);
}
//______________________________________________________________________
void AliITS::SetTreeAddress(){
    // Set branch address for the Trees.
    TTree *treeS = gAlice->TreeS();
    TTree *treeD = gAlice->TreeD();
    TTree *treeR = gAlice->TreeR();

    AliDetector::SetTreeAddress();

    SetTreeAddressS(treeS);
    SetTreeAddressD(treeD);
    SetTreeAddressR(treeR);
}
//______________________________________________________________________
AliITSDetType* AliITS::DetType(Int_t id){
    //return pointer to id detector type

    return ((AliITSDetType*) fDetTypes->At(id));
}
//______________________________________________________________________
void AliITS::SetResponseModel(Int_t id, AliITSresponse *response){
    //set the response model for the id detector type

    ((AliITSDetType*) fDetTypes->At(id))->ResponseModel(response);
}
//______________________________________________________________________
void AliITS::SetSegmentationModel(Int_t id, AliITSsegmentation *seg){
    //set the segmentation model for the id detector type

    ((AliITSDetType*) fDetTypes->At(id))->SegmentationModel(seg);
}
//______________________________________________________________________
void AliITS::SetSimulationModel(Int_t id, AliITSsimulation *sim){
    //set the simulation model for the id detector type

   ((AliITSDetType*) fDetTypes->At(id))->SimulationModel(sim);

}
//______________________________________________________________________
void AliITS::SetReconstructionModel(Int_t id, AliITSClusterFinder *reconst){
    //set the cluster finder model for the id detector type

    ((AliITSDetType*) fDetTypes->At(id))->ReconstructionModel(reconst);
}
//______________________________________________________________________
void AliITS::SetClasses(Int_t id, const char *digit, const char *cluster){
    //set the digit and cluster classes to be used for the id detector type

    ((AliITSDetType*) fDetTypes->At(id))->ClassNames(digit,cluster);
}
//______________________________________________________________________
void AliITS::AddHit(Int_t track, Int_t *vol, Float_t *hits){
    // Add an ITS hit
    //     The function to add information to the AliITShit class. See the
    // AliITShit class for a full description. This function allocates the
    // necessary new space for the hit information and passes the variable
    // track, and the pointers *vol and *hits to the AliITShit constructor
    // function.

    TClonesArray &lhits = *fHits;
    new(lhits[fNhits++]) AliITShit(fIshunt,track,vol,hits);
}
//______________________________________________________________________
void AliITS::InitModules(Int_t size,Int_t &nmodules){
    //initialize the modules array

    if(fITSmodules){ 
	fITSmodules->Delete();
	delete fITSmodules;
    } // end fir fITSmoudles

    Int_t nl,indexMAX,index;

    if(size<=0){ // default to using data stored in AliITSgeom
	if(fITSgeom==0) {
	    Error("AliITS::InitModules",
		  "in AliITS::InitModule fITSgeom not defined\n");
	    return;
	} // end if fITSgeom==0
	nl = fITSgeom->GetNlayers();
	indexMAX = fITSgeom->GetModuleIndex(nl,fITSgeom->GetNladders(nl),
					    fITSgeom->GetNdetectors(nl))+1;
	nmodules = indexMAX;
	fITSmodules = new TObjArray(indexMAX);
	for(index=0;index<indexMAX;index++){
	    fITSmodules->AddAt( new AliITSmodule(index),index);
	} // end for index
    }else{
	fITSmodules = new TObjArray(size);
	for(index=0;index<size;index++) {
	    fITSmodules->AddAt( new AliITSmodule(index),index);
	} // end for index

        nmodules = size;
    } // end i size<=0
}
//______________________________________________________________________
void AliITS::FillModules(Int_t evnt,Int_t bgrev,Int_t nmodules,
			 Option_t *option,Text_t *filename){
    // fill the modules with the sorted by module hits; add hits from
    // background if option=Add
    static TTree *trH1;                 //Tree with background hits
    static TClonesArray *fHits2;        //List of hits for one track only
    static Bool_t first=kTRUE;
    static TFile *file;
    const char *addBgr = strstr(option,"Add");

    if (addBgr ) {
	if(first) {
	    file=new TFile(filename);
	    fHits2     = new TClonesArray("AliITShit",1000  );
	} // end if first
	first=kFALSE;
	file->cd();
	file->ls();
	// Get Hits Tree header from file
	if(fHits2) fHits2->Clear();
	if(trH1) delete trH1;
	trH1=0;

	char treeName[20];
	sprintf(treeName,"TreeH%d",bgrev);
	trH1 = (TTree*)gDirectory->Get(treeName);
	if (!trH1) {
	    Error("AliITS::FillModules","cannot find Hits Tree for event:%d\n",
		  bgrev);
	} // end if !trH1
	// Set branch addresses
	TBranch *branch;
	char branchname[20];
	sprintf(branchname,"%s",GetName());
	if (trH1 && fHits2) {
	    branch = trH1->GetBranch(branchname);
	    if (branch) branch->SetAddress(&fHits2);
	} // end if trH1 && fHits
    } // end if addBgr

    TClonesArray *itsHits = this->Hits();
    Int_t lay,lad,det,index;
    AliITShit *itsHit=0;
    AliITSmodule *mod=0;
    TTree *iTH = gAlice->TreeH();
    Int_t ntracks =(Int_t) iTH->GetEntries();
    Int_t t,h;
    for(t=0; t<ntracks; t++){
	gAlice->ResetHits();
	iTH->GetEvent(t);
	Int_t nhits = itsHits->GetEntriesFast();
        if (!nhits) continue;
	for(h=0; h<nhits; h++){
	    itsHit = (AliITShit *)itsHits->UncheckedAt(h);
	    itsHit->GetDetectorID(lay,lad,det);
	    // temporarily index=det-1 !!!
	    if(fITSgeom) index = fITSgeom->GetModuleIndex(lay,lad,det);
	    else index=det-1;
	    //
	    mod = this->GetModule(index);
	    mod->AddHit(itsHit,t,h);
	} // end loop over hits 
    } // end loop over tracks

    // open the file with background
    
    if (addBgr ) {
	Int_t track,i;
	ntracks =(Int_t)trH1->GetEntries();     
	// Loop over tracks
	for (track=0; track<ntracks; track++) {
	    if (fHits2)       fHits2->Clear();
	    trH1->GetEvent(track);
	    //   Loop over hits
	    for(i=0;i<fHits2->GetEntriesFast();++i) {
		itsHit=(AliITShit*) (*fHits2)[i];
		itsHit->GetDetectorID(lay,lad,det);
		// temporarily index=det-1 !!!
		if(fITSgeom) index = fITSgeom->GetModuleIndex(lay,lad,det);
		else index=det-1;
		//
		mod = this->GetModule(index);
		mod->AddHit(itsHit,track,i);
	    }  // end loop over hits
	} // end loop over tracks
	TTree *fAli=gAlice->TreeK();
	TFile *fileAli=0;
	if (fAli) fileAli =fAli->GetCurrentFile();
	fileAli->cd();
    } // end if add
}
//______________________________________________________________________
void AliITS::ClearModules(){
    //clear the modules TObjArray

    if(fITSmodules) fITSmodules->Delete();
}
//______________________________________________________________________
void AliITS::MakeBranchS(const char *file){
    // Creates Tree branche for the ITS summable digits.
    Int_t buffersize = 4000;
    char branchname[30];

    // only one branch for SDigits.
    sprintf(branchname,"%s",GetName());
    if(fSDigits && gAlice->TreeS()){
	MakeBranchInTree(gAlice->TreeS(),branchname,&fSDigits,buffersize,file);
    } // end if
}
//______________________________________________________________________
void AliITS::SetTreeAddressS(TTree *treeS){
    // Set branch address for the ITS summable digits Trees.
    char branchname[30];

    if(!treeS) return;
    TBranch *branch;
    sprintf(branchname,"%s",GetName());
    branch = treeS->GetBranch(branchname);
    if (branch) branch->SetAddress(&fSDigits);
}
//______________________________________________________________________
void AliITS::MakeBranchD(const char *file){
    // Creates Tree branches for the ITS.
    Int_t buffersize = 4000;
    char branchname[30];

    sprintf(branchname,"%s",GetName());
    // one branch for digits per type of detector
    const char *det[3] = {"SPD","SDD","SSD"};
    char digclass[40];
    char clclass[40];
    Int_t i;
    for (i=0; i<kNTYPES ;i++) {
	DetType(i)->GetClassNames(digclass,clclass);
	// digits
	if(!(fDtype->At(i))) fDtype->AddAt(new TClonesArray(digclass,1000),i);
	else ResetDigits(i);
    } // end for i
    for (i=0; i<kNTYPES ;i++) {
	if (kNTYPES==3) sprintf(branchname,"%sDigits%s",GetName(),det[i]);
	else  sprintf(branchname,"%sDigits%d",GetName(),i+1);      
	if (fDtype && gAlice->TreeD()) {
	    MakeBranchInTree(gAlice->TreeD(), 
			     branchname, &((*fDtype)[i]),buffersize,file);
	} // end if
    } // end for i
}
//______________________________________________________________________
void AliITS::SetTreeAddressD(TTree *treeD){
    // Set branch address for the Trees.
    char branchname[30];
    const char *det[3] = {"SPD","SDD","SSD"};
    TBranch *branch;
    char digclass[40];
    char clclass[40];
    Int_t i;

    if(!treeD) return;
    for (i=0; i<kNTYPES; i++) {
	DetType(i)->GetClassNames(digclass,clclass);
	// digits
	if(!(fDtype->At(i))) fDtype->AddAt(new TClonesArray(digclass,1000),i);
	else ResetDigits(i);
	if (kNTYPES==3) sprintf(branchname,"%sDigits%s",GetName(),det[i]);
	else  sprintf(branchname,"%sDigits%d",GetName(),i+1);
	if (fDtype) {
	    branch = treeD->GetBranch(branchname);
	    if (branch) branch->SetAddress(&((*fDtype)[i]));
	} // end if fDtype
    } // end for i
}
//______________________________________________________________________
void AliITS::Hits2SDigits(){
    // Standard Hits to summable Digits function.

    return; // Using Hits inplace of the larger sDigits.
    AliHeader *header=gAlice->GetHeader(); // Get event number from this file.
    // Do the Hits to Digits operation. Use Standard input values.
    // Event number from file, no background hit merging , use size from
    // AliITSgeom class, option="All", input from this file only.
    HitsToSDigits(header->GetEvent(),0,-1," ","All"," ");
}
//______________________________________________________________________
void AliITS::Hits2PreDigits(){
    // Standard Hits to summable Digits function.

    AliHeader *header=gAlice->GetHeader(); // Get event number from this file.
    // Do the Hits to Digits operation. Use Standard input values.
    // Event number from file, no background hit merging , use size from
    // AliITSgeom class, option="All", input from this file only.
    HitsToPreDigits(header->GetEvent(),0,-1," ","All"," ");
}
//______________________________________________________________________
void AliITS::SDigits2Digits(){
    // Standard Summable digits to Digits function.

    Hits2Digits();
}
//______________________________________________________________________
void AliITS::Hits2Digits(){
    // Standard Hits to Digits function.

    AliHeader *header=gAlice->GetHeader(); // Get event number from this file.
    // Do the Hits to Digits operation. Use Standard input values.
    // Event number from file, no background hit merging , use size from
    // AliITSgeom class, option="All", input from this file only.
    HitsToDigits(header->GetEvent(),0,-1," ","All"," ");
}
//______________________________________________________________________
void AliITS::HitsToSDigits(Int_t evNumber,Int_t bgrev,Int_t size,
			  Option_t *option, Option_t *opt,Text_t *filename){
    // keep galice.root for signal and name differently the file for 
    // background when add! otherwise the track info for signal will be lost !
    // the condition below will disappear when the geom class will be
    // initialised for all versions - for the moment it is only for v5 !
    // 7 is the SDD beam test version
    return; // using Hits instead of the larger sdigits.
}
//______________________________________________________________________
void AliITS::HitsToPreDigits(Int_t evNumber,Int_t bgrev,Int_t size,
			  Option_t *option, Option_t *opt,Text_t *filename){
    // keep galice.root for signal and name differently the file for 
    // background when add! otherwise the track info for signal will be lost !
    // the condition below will disappear when the geom class will be
    // initialised for all versions - for the moment it is only for v5 !
    // 7 is the SDD beam test version

    if(!GetITSgeom()) return; // need transformations to do digitization.
    AliITSgeom *geom = GetITSgeom();

    const char *all = strstr(opt,"All");
    const char *det[3] = {strstr(opt,"SPD"),strstr(opt,"SDD"),
			  strstr(opt,"SSD")};
    static Bool_t setDef=kTRUE;
    if (setDef) SetDefaultSimulation();
    setDef=kFALSE;

    Int_t nmodules;
    InitModules(size,nmodules);
    FillModules(evNumber,bgrev,nmodules,option,filename);

    AliITSsimulation *sim      = 0;
    AliITSDetType    *iDetType = 0;
    AliITSmodule     *mod      = 0;
    Int_t id,module;
    for(module=0;module<geom->GetIndexMax();module++){
	id       = geom->GetModuleType(module);
        if (!all && !det[id]) continue;
	iDetType = DetType(id);
	sim      = (AliITSsimulation*)iDetType->GetSimulationModel();
	if (!sim) {
	    Error("HitsToSDigits",
		  "The simulation class was not instantiated!");
	    exit(1);
	} // end if !sim
	mod      = (AliITSmodule *)fITSmodules->At(module);
	sim->SDigitiseModule(mod,module,evNumber);
	// fills all branches - wasted disk space
	gAlice->TreeS()->Fill(); 
	ResetSDigits();
    } // end for module

    ClearModules();

    gAlice->TreeS()->GetEntries();

    char hname[30];
    sprintf(hname,"TreeS%d",evNumber);
    gAlice->TreeS()->Write(hname,TObject::kOverwrite);
    // reset tree
    gAlice->TreeS()->Reset();
}
//______________________________________________________________________
void AliITS::HitsToDigits(Int_t evNumber,Int_t bgrev,Int_t size,
			  Option_t *option, Option_t *opt,Text_t *filename){
    // keep galice.root for signal and name differently the file for 
    // background when add! otherwise the track info for signal will be lost !
    // the condition below will disappear when the geom class will be
    // initialised for all versions - for the moment it is only for v5 !
    // 7 is the SDD beam test version  
/*    Int_t ver = this->IsVersion(); 
    if(ver!=5 && ver!=7 && ver!=8 && ver!=9) return; 
*/
    if(!GetITSgeom()) return; // need transformations to do digitization.
    AliITSgeom *geom = GetITSgeom();

    const char *all = strstr(opt,"All");
    const char *det[3] = {strstr(opt,"SPD"),strstr(opt,"SDD"),
			  strstr(opt,"SSD")};
    static Bool_t setDef=kTRUE;
    if (setDef) SetDefaultSimulation();
    setDef=kFALSE;

    Int_t nmodules;
    InitModules(size,nmodules);
    FillModules(evNumber,bgrev,nmodules,option,filename);

    AliITSsimulation *sim      = 0;
    AliITSDetType    *iDetType = 0;
    AliITSmodule     *mod      = 0;
    Int_t id,module;
    for(module=0;module<geom->GetIndexMax();module++){
	id       = geom->GetModuleType(module);
        if (!all && !det[id]) continue;
	iDetType = DetType(id);
	sim      = (AliITSsimulation*)iDetType->GetSimulationModel();
	if (!sim) {
	    Error("HitsToDigits",
		  "The simulation class was not instantiated!");
	    exit(1);
	} // end if !sim
	mod      = (AliITSmodule *)fITSmodules->At(module);
	sim->DigitiseModule(mod,module,evNumber);
	// fills all branches - wasted disk space
	gAlice->TreeD()->Fill(); 
	ResetDigits();
    } // end for module
/*
    Int_t id,module;
    Int_t first,last;
    for (id=0;id<kNTYPES;id++) {
        if (!all && !det[id]) continue;
	AliITSDetType *iDetType=DetType(id); 
	sim = (AliITSsimulation*)iDetType->GetSimulationModel();
	if(geom) {
	    first = geom->GetStartDet(id);
	    last = geom->GetLastDet(id);
	} else first=last=0;
	for(module=first;module<=last;module++) {
	    AliITSmodule *mod = (AliITSmodule *)fITSmodules->At(module);
	    sim->DigitiseModule(mod,module,evNumber);
	    // fills all branches - wasted disk space
	    gAlice->TreeD()->Fill(); 
	    ResetDigits();
	} // loop over modules
    } // loop over detector types
*/
    ClearModules();

    gAlice->TreeD()->GetEntries();

    char hname[30];
    sprintf(hname,"TreeD%d",evNumber);
    gAlice->TreeD()->Write(hname,TObject::kOverwrite);
    // reset tree
    gAlice->TreeD()->Reset();
}
//______________________________________________________________________
void AliITS::ResetSDigits(){
    // Reset the Summable Digits array

    if (fSDigits) fSDigits->Clear();
    fNSDigits = 0;
}
//______________________________________________________________________
void AliITS::ResetDigits(){
    // Reset number of digits and the digits array for the ITS detector

    if (!fDtype) return;

    Int_t i;
    for (i=0;i<kNTYPES;i++ ) {
	if (fDtype->At(i))    ((TClonesArray*)fDtype->At(i))->Clear();
	if (fNdtype)  fNdtype[i]=0;
    } // end for i
}
//______________________________________________________________________
void AliITS::ResetDigits(Int_t i){
    // Reset number of digits and the digits array for this branch

    if (fDtype->At(i))    ((TClonesArray*)fDtype->At(i))->Clear();
    if (fNdtype)  fNdtype[i]=0;
}
//______________________________________________________________________
void AliITS::AddSumDigit(AliITSpListItem &sdig){
    // adds the a module full of summable digits to the summable digits tree.

    TClonesArray &lsdig = *fSDigits;
    new(lsdig[fNSDigits++]) AliITSpListItem(sdig);
}
//______________________________________________________________________
void AliITS::AddRealDigit(Int_t id, Int_t *digits){
    // add a real digit - as coming from data

    TClonesArray &ldigits = *((TClonesArray*)fDtype->At(id));
    new(ldigits[fNdtype[id]++]) AliITSdigit(digits);
}
//______________________________________________________________________
void AliITS::AddSimDigit(Int_t id, AliITSdigit *d){
    // add a simulated digit

    TClonesArray &ldigits = *((TClonesArray*)fDtype->At(id));

    switch(id){
    case 0:
	new(ldigits[fNdtype[id]++]) AliITSdigitSPD(*((AliITSdigitSPD*)d));
	break;
    case 1:
	new(ldigits[fNdtype[id]++]) AliITSdigitSDD(*((AliITSdigitSDD*)d));
	break;
    case 2:
	new(ldigits[fNdtype[id]++]) AliITSdigitSSD(*((AliITSdigitSSD*)d));
	break;
    } // end switch id
}
//______________________________________________________________________
void AliITS::AddSimDigit(Int_t id,Float_t phys,Int_t *digits,Int_t *tracks,
			 Int_t *hits,Float_t *charges){
    // add a simulated digit to the list

    TClonesArray &ldigits = *((TClonesArray*)fDtype->At(id));
    switch(id){
    case 0:
	new(ldigits[fNdtype[id]++]) AliITSdigitSPD(digits,tracks,hits);
	break;
    case 1:
	new(ldigits[fNdtype[id]++]) AliITSdigitSDD(phys,digits,tracks,
						   hits,charges);
	break;
    case 2:
	new(ldigits[fNdtype[id]++]) AliITSdigitSSD(digits,tracks,hits);
	break;
    } // end switch id
}
//______________________________________________________________________
void AliITS::MakeTreeC(Option_t *option){
    // create a separate tree to store the clusters

    const char *optC = strstr(option,"C");
    if (optC && !fTreeC) fTreeC = new TTree("TC","Clusters in ITS");
    else return;

    Int_t buffersize = 4000;
    char branchname[30];
    const char *det[3] = {"SPD","SDD","SSD"};
    char digclass[40];
    char clclass[40];

    // one branch for Clusters per type of detector
    Int_t i;
    for (i=0; i<kNTYPES ;i++) {
        AliITSDetType *iDetType=DetType(i); 
        iDetType->GetClassNames(digclass,clclass);
	// clusters
        fCtype->AddAt(new TClonesArray(clclass,1000),i);
        if (kNTYPES==3) sprintf(branchname,"%sClusters%s",GetName(),det[i]);
	else  sprintf(branchname,"%sClusters%d",GetName(),i+1);
	if (fCtype   && fTreeC) {
	    TreeC()->Branch(branchname,&((*fCtype)[i]), buffersize);
	} // end if fCtype && fTreeC
    } // end for i
}
//______________________________________________________________________
void AliITS::GetTreeC(Int_t event){
    // get the clusters tree for this event and set the branch address
    char treeName[20];
    char branchname[30];
    const char *det[3] = {"SPD","SDD","SSD"};

    ResetClusters();
    if (fTreeC) {
	delete fTreeC;
    } // end if fTreeC

    sprintf(treeName,"TreeC%d",event);
    fTreeC = (TTree*)gDirectory->Get(treeName);

    TBranch *branch;

    if (fTreeC) {
        Int_t i;
	char digclass[40];
	char clclass[40];
	for (i=0; i<kNTYPES; i++) {
	    AliITSDetType *iDetType=DetType(i); 
	    iDetType->GetClassNames(digclass,clclass);
	    // clusters
	    if(!fCtype->At(i)) fCtype->AddAt(new TClonesArray(clclass,1000),i);
	    if(kNTYPES==3) sprintf(branchname,"%sClusters%s",GetName(),det[i]);
	    else  sprintf(branchname,"%sClusters%d",GetName(),i+1);
	    if (fCtype) {
		branch = fTreeC->GetBranch(branchname);
                if (branch) branch->SetAddress(&((*fCtype)[i]));
	    } // end if fCtype
	} // end for i
    } else {
	Error("AliITS::GetTreeC",
	      "cannot find Clusters Tree for event:%d\n",event);
    } // end if fTreeC
}
//______________________________________________________________________
void AliITS::AddCluster(Int_t id, AliITSRawCluster *c){
    // add a cluster to the list

    TClonesArray &lc = *((TClonesArray*)fCtype->At(id));

    switch(id){
    case 0:
	new(lc[fNctype[id]++]) AliITSRawClusterSPD(*((AliITSRawClusterSPD*)c));
	break;
    case 1:
	new(lc[fNctype[id]++]) AliITSRawClusterSDD(*((AliITSRawClusterSDD*)c));
	break;
    case 2:
	new(lc[fNctype[id]++]) AliITSRawClusterSSD(*((AliITSRawClusterSSD*)c));
	break;
    } // end switch id
}
//______________________________________________________________________
void AliITS::ResetClusters(){
    // Reset number of clusters and the clusters array for ITS

    Int_t i;
    for (i=0;i<kNTYPES;i++ ) {
	if (fCtype->At(i))    ((TClonesArray*)fCtype->At(i))->Clear();
	if (fNctype)  fNctype[i]=0;
    } // end for i
}
//______________________________________________________________________
void AliITS::ResetClusters(Int_t i){
    // Reset number of clusters and the clusters array for this branch

    if (fCtype->At(i))    ((TClonesArray*)fCtype->At(i))->Clear();
    if (fNctype)  fNctype[i]=0;
}
//______________________________________________________________________
void AliITS::MakeBranchR(const char *file){
    // Creates Tree branches for the ITS Reconstructed points.
    Int_t buffersize = 4000;
    char branchname[30];

//    sprintf(branchname,"%s",GetName());
    // only one branch for rec points for all detector types
    sprintf(branchname,"%sRecPoints",GetName());
    if (fRecPoints && gAlice->TreeR()) {
	MakeBranchInTree(gAlice->TreeR(),branchname, &fRecPoints,
			 buffersize,file) ;
    } // end if
}
//______________________________________________________________________
void AliITS::SetTreeAddressR(TTree *treeR){
    // Set branch address for the Reconstructed points Trees.
    char branchname[30];

    if(!treeR) return;
    TBranch *branch;
//    sprintf(branchname,"%s",GetName());
    sprintf(branchname,"%sRecPoints",GetName());
    branch = treeR->GetBranch(branchname);
    if (branch) branch->SetAddress(&fRecPoints);
}
//______________________________________________________________________
void AliITS::AddRecPoint(const AliITSRecPoint &r){
    // Add a reconstructed space point to the list

    TClonesArray &lrecp = *fRecPoints;
    new(lrecp[fNRecPoints++]) AliITSRecPoint(r);
}
//______________________________________________________________________
void AliITS::HitsToFastRecPoints(Int_t evNumber,Int_t bgrev,Int_t size,
				 Option_t *opt0,Option_t *opt1,Text_t *flnm){
    // keep galice.root for signal and name differently the file for 
    // background when add! otherwise the track info for signal will be lost !
    // the condition below will disappear when the geom class will be
    // initialised for all versions - for the moment it is only for v5 !
/*    Int_t ver = this->IsVersion(); 
    if(ver!=5 && ver!=8 && ver!=9) return;
*/
    if(!GetITSgeom()) return;
    AliITSgeom *geom = GetITSgeom();

    const char *all = strstr(opt1,"All");
    const char *det[3] ={strstr(opt1,"SPD"),strstr(opt1,"SDD"),
			 strstr(opt1,"SSD")};
    Int_t nmodules;
    InitModules(size,nmodules);
    FillModules(evNumber,bgrev,nmodules,opt0,flnm);

    AliITSsimulation *sim      = 0;
    AliITSDetType    *iDetType = 0;
    AliITSmodule     *mod      = 0;
    Int_t id,module;

    //m.b. : this change is nothing but a nice way to make sure
    //the CPU goes up !
    for(module=0;module<geom->GetIndexMax();module++){
	id       = geom->GetModuleType(module);
        if (!all && !det[id]) continue;
	iDetType = DetType(id);
	sim      = (AliITSsimulation*)iDetType->GetSimulationModel();
	if (!sim) {
	    Error("HitsToFastPoints",
		  "The simulation class was not instantiated!");
	    exit(1);
	} // end if !sim
	mod      = (AliITSmodule *)fITSmodules->At(module);
	sim->CreateFastRecPoints(mod,module,gRandom);
	gAlice->TreeR()->Fill(); 
	ResetRecPoints();
    } // end for module
/*
    Int_t id,module;
    for (id=0;id<kNTYPES;id++) {
        if (!all && !det[id]) continue;
	AliITSDetType *iDetType=DetType(id); 
	sim = (AliITSsimulation*)iDetType->GetSimulationModel();
	if (!sim) {
	    Error("HitsToFastPoints",
		  "The simulation class was not instantiated!");
	    exit(1);
	} // end if !sim
        Int_t first,last;
        if(geom) {
	    first = geom->GetStartDet(id);
	    last = geom->GetLastDet(id);
        } else first=last=0;
	for(module=first;module<=last;module++) {
	    AliITSmodule *mod = (AliITSmodule *)fITSmodules->At(module);
	    sim->CreateFastRecPoints(mod,module,gRandom);
	    gAlice->TreeR()->Fill(); 
	    ResetRecPoints();
	} // loop over modules
    } // loop over detector types
*/
    ClearModules();

    char hname[30];
    sprintf(hname,"TreeR%d",evNumber);
    gAlice->TreeR()->Write(hname,TObject::kOverwrite);
    // reset tree
    gAlice->TreeR()->Reset();
}
//______________________________________________________________________
void AliITS::Digits2Reco(){
    // find clusters and reconstruct space points

    AliHeader *header=gAlice->GetHeader();
    // to Digits to RecPoints for event in file, all digits in file, and
    // all ITS detectors.
    DigitsToRecPoints(header->GetEvent(),0,"All");
}
//______________________________________________________________________
void AliITS::DigitsToRecPoints(Int_t evNumber,Int_t lastentry,Option_t *opt){
    // cluster finding and reconstruction of space points
    // the condition below will disappear when the geom class will be
    // initialised for all versions - for the moment it is only for v5 !
    // 7 is the SDD beam test version  
/*    Int_t ver = this->IsVersion(); 
    if(ver!=5 && ver!=8 && ver!=9) return;
*/
    if(!GetITSgeom()) return;
    AliITSgeom *geom = GetITSgeom();
    
    const char *all = strstr(opt,"All");
    const char *det[3] = {strstr(opt,"SPD"),strstr(opt,"SDD"),
			  strstr(opt,"SSD")};
    static Bool_t setRec=kTRUE;
    if (setRec) SetDefaultClusterFinders();
    setRec=kFALSE;

    TTree *treeC=TreeC();

    AliITSClusterFinder *rec     = 0;
    AliITSDetType      *iDetType = 0;
    Int_t id,module,first=0;
    for(module=0;module<geom->GetIndexMax();module++){
	id       = geom->GetModuleType(module);
        if (!all && !det[id]) continue;
	if(det[id]) first = geom->GetStartDet(id);
	iDetType = DetType(id);
	rec = (AliITSClusterFinder*)iDetType->GetReconstructionModel();
        TClonesArray *itsDigits  = this->DigitsAddress(id);
	if (!rec) {
	    Error("DigitsToRecPoints",
		  "The reconstruction class was not instantiated!");
	    exit(1);
	} // end if !rec
	this->ResetDigits();
	if (all) gAlice->TreeD()->GetEvent(lastentry+module);
	else gAlice->TreeD()->GetEvent(lastentry+(module-first));
	Int_t ndigits = itsDigits->GetEntriesFast();
	if (ndigits) rec->FindRawClusters(module);
	gAlice->TreeR()->Fill(); 
	ResetRecPoints();
	treeC->Fill();
	ResetClusters();
    } // end for module

/*
    Int_t id,module;
    for (id=0;id<kNTYPES;id++) {
        if (!all && !det[id]) continue;
	AliITSDetType *iDetType=DetType(id); 
	rec = (AliITSClusterFinder*)iDetType->GetReconstructionModel();
        TClonesArray *itsDigits  = this->DigitsAddress(id);
        Int_t first,last;
	if(geom) {
	    first = geom->GetStartDet(id);
	    last = geom->GetLastDet(id);
	} else first=last=0;
	printf("first module - last module %d %d\n",first,last);
	for(module=first;module<=last;module++) {
	    this->ResetDigits();
	    if (all) gAlice->TreeD()->GetEvent(lastentry+module);
	    else gAlice->TreeD()->GetEvent(lastentry+(module-first));
	    Int_t ndigits = itsDigits->GetEntriesFast();
	    if (ndigits) rec->FindRawClusters(module);
	    gAlice->TreeR()->Fill(); 
	    ResetRecPoints();
	    treeC->Fill();
	    ResetClusters();
	} // loop over modules
    } // loop over detector types
*/
    gAlice->TreeR()->GetEntries();
    treeC->GetEntries();

    char hname[30];
    sprintf(hname,"TreeR%d",evNumber);
    gAlice->TreeR()->Write(hname,TObject::kOverwrite);
    // reset tree
    gAlice->TreeR()->Reset();

    sprintf(hname,"TreeC%d",evNumber);
    treeC->Write(hname,TObject::kOverwrite);
    treeC->Reset();
}
//______________________________________________________________________
void AliITS::ResetRecPoints(){
    // Reset number of rec points and the rec points array

    if (fRecPoints) fRecPoints->Clear();
    fNRecPoints = 0;
}