]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - ITS/AliITS.cxx
Fix in AliITS::MakeBranchR since fRecPoints is no longer persistent
[u/mrichter/AliRoot.git] / ITS / AliITS.cxx
index 5e2087b5ac5fba2844960eefacb3a339486618bc..5704522f2417dc9fb94c073732e8dfccfd8f8adc 100644 (file)
  * provided "as is" without express or implied warranty.                  *
  **************************************************************************/
 
-/*
-$Log$
-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
+/* $Id$ */
 
-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
-
-*/
 
 ///////////////////////////////////////////////////////////////////////////////
 //
@@ -138,1601 +64,1677 @@ the AliITS class.
 // futher information.
 //
 ///////////////////////////////////////////////////////////////////////////////
-#include <iostream.h>
-#include <iomanip.h>
-#include <fstream.h>
+
+#include <Riostream.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 <TMath.h>
+#include <TObjectTable.h>
+#include <TROOT.h>
+#include <TRandom.h>
 #include <TString.h>
+#include <TTree.h>
+#include <TVector.h>
+#include <TVirtualMC.h>
 
-
-
-#include "AliRun.h"
+#include "AliConfig.h"
+#include "AliHeader.h"
 #include "AliITS.h"
-#include "AliITSMap.h"
+#include "AliITSClusterFinderSDD.h"
+#include "AliITSClusterFinderSPD.h"
+#include "AliITSClusterFinderSSD.h"
 #include "AliITSDetType.h"
-#include "AliITSClusterFinder.h"
-//#include "AliITSsimulation.h"
-#include "AliITSsimulationSPD.h"
-#include "AliITSsimulationSDD.h"
-#include "AliITSsimulationSSD.h"
-#include "AliITSresponse.h"
-#include "AliITSsegmentationSPD.h"
+#include "AliITSLoader.h"
+#include "AliITSRawCluster.h"
+#include "AliITSRecPoint.h"
+#include "AliITSdigit.h"
+#include "AliITSgeom.h"
+#include "AliITShit.h"
+#include "AliITSmodule.h"
+#include "AliITSpList.h"
+#include "AliITSresponseSDD.h"
 #include "AliITSresponseSPD.h"
-#include "AliITSresponseSPDbari.h"
+#include "AliITSresponseSSD.h"
 #include "AliITSsegmentationSDD.h"
-#include "AliITSresponseSDD.h"
+#include "AliITSsegmentationSPD.h"
 #include "AliITSsegmentationSSD.h"
-#include "AliITSresponseSSD.h"
-#include "AliITShit.h"
-#include "AliITSgeom.h"
-#include "AliITSdigit.h"
-#include "AliITSmodule.h"
-#include "AliITSRecPoint.h"
-#include "AliITSRawCluster.h"
-#include "AliMC.h"
-#include "stdlib.h"
-
-#include "AliITStrack.h"
-#include "AliITSiotrack.h"
-#include "AliITStracking.h" 
-#include "../TPC/AliTPC.h"
-#include "../TPC/AliTPCParam.h"
-
+#include "AliITSsimulationSDD.h"
+#include "AliITSsimulationSPD.h"
+#include "AliITSsimulationSSD.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;
-  fEuclidOut  = 0;
-
-  fNDetTypes = kNTYPES;
-  fIdN        = 0;
-  fIdName     = 0;
-  fIdSens     = 0;
-  fITSmodules = 0;
-  //
-  fDetTypes   = 0;
-  //
-  fDtype  = 0;
-  fNdtype = 0;
-  fCtype  = 0;
-  fNctype = 0;
-  fRecPoints = 0;
-  fNRecPoints = 0;
-  fTreeC = 0;
-  //
-  fITSgeom=0;
-}
+    // Default initializer 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.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      Blank ITS class.
+
+    fIshunt     = 0;   // not zeroed in AliDetector.
+
+    // AliITS variables.
+    fEuclidOut  = 0;
+    fITSgeom    = 0;
+    fITSmodules = 0;
+    fOpt        = "All";
+//    SetDetectors(); // default to fOpt="All". This variable not written out.
+
+    fIdN        = 0;
+    fIdName     = 0;
+    fIdSens     = 0;
+
+    fNDetTypes  = kNTYPES;
+    fDetTypes   = 0;
+
+    fSDigits    = 0;
+    fNSDigits   = 0;
+
+    fNdtype     = 0;
+    fDtype      = 0;
+
+    fCtype      = 0;
+    fNctype     = 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.
-  //
-
-
-  fHits       = new TClonesArray("AliITShit", 1560);
-  gAlice->AddHitList(fHits);
-
-  fNDetTypes = kNTYPES;
-
-  fNdtype = new Int_t[kNTYPES];
-  fDtype = new TObjArray(kNTYPES);
-
-  fNctype = new Int_t[kNTYPES];
-  fCtype = new TObjArray(kNTYPES);
-
-
-  fRecPoints = 0;
-  fNRecPoints = 0;
-
-  fTreeC = 0;
-
-  fITSmodules = 0; 
-
-  fIshunt     = 0;
-  fEuclidOut  = 0;
-  fIdN        = 0;
-  fIdName     = 0;
-  fIdSens     = 0;
-  fDetTypes = new TObjArray(kNTYPES);  
+    //     The standard Constructor for the ITS class. In addition to 
+    // creating the AliITS class, it allocates memory for the TClonesArrays 
+    // fHits, fSDigits, fDigits, fITSpoints, and the TObjArray of fCtype 
+    // (clusters). 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.
+    // Inputs:
+    //      const char *name      Detector name. Should always be "ITS"
+    //      const char *title     Detector title.
+    // Outputs:
+    //      none.
+    // Return:
+    //      An ITS class.
+
+    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;
+    SetDetectors(); // default to fOpt="All". This variable not written out.
+
+    fIdN        = 0;
+    fIdName     = 0;
+    fIdSens     = 0;
+
+    fNDetTypes  = kNTYPES;
+    fDetTypes   = new TObjArray(fNDetTypes);
+
+    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];
+
+    fRecPoints  = new TClonesArray("AliITSRecPoint",1000);
+    fNRecPoints = 0;
 
-  Int_t i;
-  for(i=0;i<kNTYPES;i++) {
-    (*fDetTypes)[i]=new AliITSDetType(); 
-    fNdtype[i]=0;
-    fNctype[i]=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);
+    SetMarkerColor(kRed);
 
-  fITSgeom=0;
 }
-//___________________________________________________________________________
+//______________________________________________________________________
+AliITS::~AliITS(){
+    // Default destructor 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,
+    // fSDigits, fCtype, fITSmodules, fITSgeom, fRecPoints, fIdSens, fIdName, 
+    // fITSpoints, fDetType and it's contents.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    if (fHits) {
+      fHits->Delete();
+      delete fHits;
+      fHits=0;
+    }
+    if (fSDigits) {
+      fSDigits->Delete();
+      delete fSDigits;
+      fSDigits=0;
+    }
+    if (fDigits) {
+      fDigits->Delete();
+      delete fDigits;
+      fDigits=0;
+    }
+    if (fRecPoints) {
+      fRecPoints->Delete();
+      delete fRecPoints;
+      fRecPoints=0;
+    }
+    delete[] fIdName;  // Array of TStrings
+    delete[] fIdSens;
+    if(fITSmodules) {
+        this->ClearModules();
+        delete fITSmodules;
+       fITSmodules = 0;
+    }// end if fITSmodules!=0
+
+    if(fDtype) {
+        fDtype->Delete();
+        delete fDtype;
+    } // end if fDtype
+    delete [] fNdtype;
+    if (fCtype) {
+        fCtype->Delete();
+        delete fCtype;
+       fCtype = 0;
+    } // end if fCtype
+    delete [] fNctype;
+
+    if (fDetTypes) {
+        fDetTypes->Delete();
+        delete fDetTypes;
+       fDetTypes = 0;
+    } // end if fDetTypes
+
+
+    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);
+    // Copy constructor. This is a function which is not allowed to be
+    // done to the ITS. It exits with an error.
+    // Inputs:
+    //      AliITS &source  An AliITS class.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    if(this==&source) return;
+    Error("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
+    // Assignment operator. This is a function which is not allowed to be
+    // done to the ITS. It exits with an error.
+    // Inputs:
+    //      AliITS &source  An AliITS class.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    if(this==&source) return *this;
+    Error("operator=","You are not allowed to make a copy of the AliITS");
+    exit(1);
+    return *this; //fake return
 }
-//____________________________________________________________________________
-void AliITS::ClearModules(){
-  //clear the modules TObjArray
-
-  if(fITSmodules) fITSmodules->Delete();
-
+//______________________________________________________________________
+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.
+    // Inputs:
+    //      Int_t     Dummy screen coordinate.
+    //      Int_t     Dummy screen coordinate.
+    // Outputs:
+    //      none.
+    // Return:
+    //      Int_t     Dummy = 9999 distance to ITS.
+
+    return 9999;
 }
-//_____________________________________________________________________________
-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 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;
-  }
-  delete [] fNdtype;
-  if (fCtype) {
-    fCtype->Delete();
-    delete fCtype;
-  }
-  delete [] fNctype;
-  //
-
-  if (fDetTypes) {
-    fDetTypes->Delete();
-    delete fDetTypes;
-  }
-
-  if (fTreeC) delete fTreeC;
-
-  if (fITSgeom) delete fITSgeom;
+//______________________________________________________________________
+void AliITS::Init(){
+    // Initializer 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.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    Int_t i;
 
+    SetDefaults();
+    // Array of TStrings
+    for(i=0;i<fIdN;i++) fIdSens[i] = gMC->VolId(fIdName[i]);
 }
-
-//___________________________________________
-AliITSDetType* AliITS::DetType(Int_t id)
-{
-  //return pointer to id detector type
-    return ((AliITSDetType*) (*fDetTypes)[id]);
-
+//______________________________________________________________________
+void AliITS::SetDefaults(){
+    // sets the default segmentation, response, digit and raw cluster classes.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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("simulated")); 
+    } // 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("simulated"));
+    } // 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 initialized!");
+    }  // end if
 }
-//___________________________________________
-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)[id])->ClassNames(digit,cluster);
-
+//______________________________________________________________________
+void AliITS::SetDefaultSimulation(){
+    // sets the default simulation.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    AliITSDetType *iDetType;
+    AliITSsimulation *sim;
+    iDetType=DetType(0);
+    sim = iDetType->GetSimulationModel();
+    if (!sim) {
+        AliITSsegmentation *seg0=
+            (AliITSsegmentation*)iDetType->GetSegmentationModel();
+        AliITSresponse *res0 = (AliITSresponse*)iDetType->GetResponseModel();
+        AliITSsimulationSPD *sim0=new AliITSsimulationSPD(seg0,res0);
+        SetSimulationModel(0,sim0);
+    }else{ // simulation exists, make sure it is set up properly.
+        ((AliITSsimulationSPD*)sim)->Init(
+            (AliITSsegmentationSPD*) iDetType->GetSegmentationModel(),
+            (AliITSresponseSPD*) iDetType->GetResponseModel());
+//        if(sim->GetResponseModel()==0) sim->SetResponseModel(
+//            (AliITSresponse*)iDetType->GetResponseModel());
+//        if(sim->GetSegmentationModel()==0) sim->SetSegmentationModel(
+//            (AliITSsegmentation*)iDetType->GetSegmentationModel());
+    } // end if
+    iDetType=DetType(1);
+    sim = iDetType->GetSimulationModel();
+    if (!sim) {
+        AliITSsegmentation *seg1=
+            (AliITSsegmentation*)iDetType->GetSegmentationModel();
+        AliITSresponse *res1 = (AliITSresponse*)iDetType->GetResponseModel();
+        AliITSsimulationSDD *sim1=new AliITSsimulationSDD(seg1,res1);
+        SetSimulationModel(1,sim1);
+    }else{ // simulation exists, make sure it is set up properly.
+        ((AliITSsimulationSDD*)sim)->Init(
+            (AliITSsegmentationSDD*) iDetType->GetSegmentationModel(),
+            (AliITSresponseSDD*) iDetType->GetResponseModel());
+//        if(sim->GetResponseModel()==0) sim->SetResponseModel(
+//            (AliITSresponse*)iDetType->GetResponseModel());
+//        if(sim->GetSegmentationModel()==0) sim->SetSegmentationModel(
+//            (AliITSsegmentation*)iDetType->GetSegmentationModel());
+    } //end if
+    iDetType=DetType(2);
+    sim = iDetType->GetSimulationModel();
+    if (!sim) {
+        AliITSsegmentation *seg2=
+            (AliITSsegmentation*)iDetType->GetSegmentationModel();
+        AliITSresponse *res2 = (AliITSresponse*)iDetType->GetResponseModel();
+        AliITSsimulationSSD *sim2=new AliITSsimulationSSD(seg2,res2);
+        SetSimulationModel(2,sim2);
+    }else{ // simulation exists, make sure it is set up properly.
+        ((AliITSsimulationSSD*)sim)->Init(
+            (AliITSsegmentationSSD*) iDetType->GetSegmentationModel(),
+            (AliITSresponseSSD*) iDetType->GetResponseModel());
+//        if(sim->GetResponseModel()==0) sim->SetResponseModel(
+//            (AliITSresponse*)iDetType->GetResponseModel());
+//        if(sim->GetSegmentationModel()==0) sim->SetSegmentationModel(
+//            (AliITSsegmentation*)iDetType->GetSegmentationModel());
+    } // end if
 }
-//___________________________________________
-void AliITS::SetResponseModel(Int_t id, AliITSresponse *response)
-{
-  //set the response model for the id detector type
-
-    ((AliITSDetType*) (*fDetTypes)[id])->ResponseModel(response);
-
+//______________________________________________________________________
+void AliITS::SetDefaultClusterFinders(){
+    // Sets the default cluster finders. Used in finding RecPoints.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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){
+    // Creates Tree branches for the ITS.
+    // Inputs:
+    //      Option_t *option    String of Tree types S,D, and/or R.
+    //      const char *file    String of the file name where these branches
+    //                          are to be stored. If blank then these branches
+    //                          are written to the same tree as the Hits were
+    //                          read from.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    Bool_t cH = (strstr(option,"H")!=0);
+    Bool_t cS = (strstr(option,"S")!=0);
+    Bool_t cD = (strstr(option,"D")!=0);
+    Bool_t cR = (strstr(option,"R")!=0);
+    Bool_t cRF = (strstr(option,"RF")!=0);
+    
+    if(cRF)cR = kFALSE;
+    if(cH && (fHits == 0x0)) fHits  = new TClonesArray("AliITShit", 1560);
+    
+    AliDetector::MakeBranch(option);
 
-//___________________________________________
-void AliITS::SetSegmentationModel(Int_t id, AliITSsegmentation *seg)
-{
-  //set the segmentation model for the id detector type
-
-    ((AliITSDetType*) (*fDetTypes)[id])->SegmentationModel(seg);
-
+    if(cS) MakeBranchS(0);
+    if(cD) MakeBranchD(0);
+    if(cR) MakeBranchR(0);
+    if(cRF) MakeBranchRF(0);
 }
+//______________________________________________________________________
+void AliITS::SetTreeAddress(){
+    // Set branch address for the Trees.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    TTree *treeS = fLoader->TreeS();
+    TTree *treeD = fLoader->TreeD();
+    TTree *treeR = fLoader->TreeR();
+    if (fLoader->TreeH() && (fHits == 0x0)) fHits = new TClonesArray("AliITShit", 1560);
+      
+    AliDetector::SetTreeAddress();
 
-//___________________________________________
-void AliITS::SetSimulationModel(Int_t id, AliITSsimulation *sim)
-{
-  //set the simulation model for the id detector type
-
-   ((AliITSDetType*) (*fDetTypes)[id])->SimulationModel(sim);
-
+    SetTreeAddressS(treeS);
+    SetTreeAddressD(treeD);
+    SetTreeAddressR(treeR);
 }
-//___________________________________________
-void AliITS::SetReconstructionModel(Int_t id, AliITSClusterFinder *reconst)
-{
-  //set the cluster finder model for the id detector type
-
-   ((AliITSDetType*) (*fDetTypes)[id])->ReconstructionModel(reconst);
-
+//______________________________________________________________________
+AliITSDetType* AliITS::DetType(Int_t id){
+    // Return pointer to id detector type.
+    // Inputs:
+    //      Int_t id   detector id number.
+    // Outputs:
+    //      none.
+    // Return:
+    //      returned, a pointer to a AliITSDetType.
+
+    return ((AliITSDetType*) fDetTypes->At(id));
 }
-
-//_____________________________________________________________________________
-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::SetResponseModel(Int_t id, AliITSresponse *response){
+    // Set the response model for the id detector type.
+    // Inputs:
+    //      Int_t id        detector id number.
+    //      AliITSresponse* a pointer containing an instance of AliITSresponse
+    //                      to be stored/owned b y AliITSDetType.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    ((AliITSDetType*) fDetTypes->At(id))->ResponseModel(response);
 }
-//_____________________________________________________________________________
-void AliITS::AddRealDigit(Int_t id, Int_t *digits) 
-{
-  // add a real digit - as coming from data
-
-  TClonesArray &ldigits = *((TClonesArray*)(*fDtype)[id]);
-  new(ldigits[fNdtype[id]++]) AliITSdigit(digits);
-
+//______________________________________________________________________
+void AliITS::SetSegmentationModel(Int_t id, AliITSsegmentation *seg){
+    // Set the segmentation model for the id detector type.
+    // Inputs:
+    //      Int_t id            detector id number.
+    //      AliITSsegmentation* a pointer containing an instance of 
+    //                          AliITSsegmentation to be stored/owned b y 
+    //                          AliITSDetType.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    ((AliITSDetType*) fDetTypes->At(id))->SegmentationModel(seg);
 }
-//_____________________________________________________________________________
-void AliITS::AddSimDigit(Int_t id, AliITSdigit *d) 
-{
-
-  // add a simulated digit
-
-  TClonesArray &ldigits = *((TClonesArray*)(*fDtype)[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;
-  }
+//______________________________________________________________________
+void AliITS::SetSimulationModel(Int_t id, AliITSsimulation *sim){
+    // Set the simulation model for the id detector type.
+    // Inputs:
+    //      Int_t id        detector id number.
+    //      AliITSresponse* a pointer containing an instance of AliITSresponse
+    //                      to be stored/owned b y AliITSDetType.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+   ((AliITSDetType*) fDetTypes->At(id))->SimulationModel(sim);
 
 }
-
-//_____________________________________________________________________________
-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)[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;
-  }
+//______________________________________________________________________
+void AliITS::SetReconstructionModel(Int_t id, AliITSClusterFinder *reconst){
+    // Set the cluster finder model for the id detector type.
+    // Inputs:
+    //      Int_t id             detector id number.
+    //      AliITSClusterFinder* a pointer containing an instance of 
+    //                           AliITSClusterFinder to be stored/owned b y 
+    //                           AliITSDetType.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    ((AliITSDetType*) fDetTypes->At(id))->ReconstructionModel(reconst);
+}
+//______________________________________________________________________
+void AliITS::SetClasses(Int_t id, const char *digit, const char *cluster){
+    // Set the digit and cluster classes name to be used for the id detector
+    // type.
+    // Inputs:
+    //      Int_t id            detector id number.
+    //      const char *digit   Digit class name for detector id.
+    //      const char *cluster Cluster class name for detector id.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    ((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.
+    // Inputs:
+    //      Int_t   track   Track number which produced this hit.
+    //      Int_t   *vol    Array of Integer Hit information. See AliITShit.h
+    //      Float_t *hits   Array of Floating Hit information.  see AliITShit.h
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    TClonesArray &lhits = *fHits;
+    new(lhits[fNhits++]) AliITShit(fIshunt,track,vol,hits);
+}
+//______________________________________________________________________
+void AliITS::InitModules(Int_t size,Int_t &nmodules){
+    // Initialize the modules array.
+    // Inputs:
+    //      Int_t size  Size of array of the number of modules to be
+    //                  created. If size <=0 then the number of modules
+    //                  is gotten from AliITSgeom class kept in fITSgeom.
+    // Outputs:
+    //      Int_t &nmodules The number of modules existing.
+    // Return:
+    //      none.
+
+    if(fITSmodules){ 
+        fITSmodules->Delete();
+        delete fITSmodules;
+    } // end fir fITSmoudles
 
-//_____________________________________________________________________________
-void AliITS::AddCluster(Int_t id, AliITSRawCluster *c) 
-{
+    Int_t nl,indexMAX,index;
 
-  // add a cluster to the list
-
-  TClonesArray &lcl = *((TClonesArray*)(*fCtype)[id]);
-
-  switch(id)
-  {
-  case 0:
-     new(lcl[fNctype[id]++]) AliITSRawClusterSPD(*((AliITSRawClusterSPD*)c));
-     break;
-  case 1:
-     new(lcl[fNctype[id]++]) AliITSRawClusterSDD(*((AliITSRawClusterSDD*)c));
-     break;
-  case 2:
-     new(lcl[fNctype[id]++]) AliITSRawClusterSSD(*((AliITSRawClusterSSD*)c));
-     break;
-  }
+    if(size<=0){ // default to using data stored in AliITSgeom
+        if(fITSgeom==0) {
+            Error("InitModules","fITSgeom not defined");
+            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.
+    // Inputs:
+    //      Int_t evnt       Event to be processed.
+    //      Int_t bgrev      Background Hit tree number.
+    //      Int_t nmodules   Not used.
+    //      Option_t *option String indicating if merging hits or not. To
+    //                       merge hits set equal to "Add". Otherwise no
+    //                       background hits are considered.
+    //      Test_t *filename File name containing the background hits..
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    static TTree *trH1;                 //Tree with background hits
+    static Bool_t first=kTRUE;
+    static TFile *file;
+    const char *addBgr = strstr(option,"Add");
 
-
-//_____________________________________________________________________________
-void AliITS::AddRecPoint(const AliITSRecPoint &r)
-{
-  //
-  // Add a reconstructed space point to the list
-  //
-  TClonesArray &lrecp = *fRecPoints;
-  new(lrecp[fNRecPoints++]) AliITSRecPoint(r);
+    if (addBgr ) {
+        if(first) {
+            file=new TFile(filename);
+        } // end if first
+        first=kFALSE;
+        file->cd();
+        file->ls();
+        // Get Hits Tree header from file
+        if(trH1) delete trH1;
+        trH1=0;
+
+        char treeName[20];
+        sprintf(treeName,"TreeH%d",bgrev);
+        trH1 = (TTree*)gDirectory->Get(treeName);
+        if (!trH1) {
+            Error("FillModules","cannot find Hits Tree for event:%d",bgrev);
+        } // end if !trH1
+        // Set branch addresses
+    } // end if addBgr
+
+    FillModules(fLoader->TreeH(),0); // fill from this file's tree.
+    
+    if (addBgr ) {
+        FillModules(trH1,10000000); // Default mask 10M.
+        TTree *fAli=fLoader->GetRunLoader()->TreeK();
+        TFile *fileAli=0;
+        if (fAli) fileAli =fAli->GetCurrentFile();
+        fileAli->cd();
+    } // end if add
 }
+//______________________________________________________________________
+void AliITS::FillModules(TTree *treeH, Int_t mask) {
+    // fill the modules with the sorted by module hits; 
+    // can be called many times to do a merging
+    // Inputs:
+    //      TTree *treeH  The tree containing the hits to be copied into
+    //                    the modules.
+    //      Int_t mask    The track number mask to indecate which file
+    //                    this hits came from.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    if (treeH == 0x0)
+     {
+       Error("FillModules","Tree is NULL");
+     }
+    Int_t lay,lad,det,index;
+    AliITShit *itsHit=0;
+    AliITSmodule *mod=0;
+    char branchname[20];
+    sprintf(branchname,"%s",GetName());
+    TBranch *branch = treeH->GetBranch(branchname);
+    if (!branch) {
+        Error("FillModules","%s branch in TreeH not found",branchname);
+        return;
+    } // end if !branch
+    branch->SetAddress(&fHits);
+    Int_t nTracks =(Int_t) treeH->GetEntries();
+    Int_t iPrimTrack,h;
+    for(iPrimTrack=0; iPrimTrack<nTracks; iPrimTrack++){
+        ResetHits();
+        Int_t nBytes = treeH->GetEvent(iPrimTrack);
+        if (nBytes <= 0) continue;
+        Int_t nHits = fHits->GetEntriesFast();
+        for(h=0; h<nHits; h++){
+            itsHit = (AliITShit *)fHits->UncheckedAt(h);
+            itsHit->GetDetectorID(lay,lad,det);
+            if (fITSgeom) {
+                index = fITSgeom->GetModuleIndex(lay,lad,det);
+            } else {
+                index=det-1; // This should not be used.
+            } // end if [You must have fITSgeom for this to work!]
+            mod = GetModule(index);
+            itsHit->SetTrack(itsHit->GetTrack()+mask); // Set track mask.
+            mod->AddHit(itsHit,iPrimTrack,h);
+        } // end loop over hits 
+    } // end loop over tracks
+}
+//______________________________________________________________________
+void AliITS::ClearModules(){
+    // Clear the modules TObjArray.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
 
-//____________________________________________
-void AliITS::ResetDigits()
-{
-    //
-    // Reset number of digits and the digits array for the ITS detector
-    //
+    if(fITSmodules) fITSmodules->Delete();
+}
+//______________________________________________________________________
+void AliITS::MakeBranchS(const char *fl){
+    // Creates Tree Branch for the ITS summable digits.
+    // Inputs:
+    //      cont char *fl  File name where SDigits branch is to be written
+    //                     to. If blank it write the SDigits to the same
+    //                     file in which the Hits were found.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    Int_t buffersize = 4000;
+    char branchname[30];
 
-    if (!fDtype) return;
+    // only one branch for SDigits.
+    sprintf(branchname,"%s",GetName());
+    
 
-    Int_t i;
-    for (i=0;i<kNTYPES;i++ ) {
-       if ((*fDtype)[i])    ((TClonesArray*)(*fDtype)[i])->Clear();
-       if (fNdtype)  fNdtype[i]=0;
-    }
+    if(fSDigits && fLoader->TreeS()){
+        if (fSDigits == 0x0)  fSDigits  = new TClonesArray("AliITSpListItem",1000);
+        MakeBranchInTree(fLoader->TreeS(),branchname,&fSDigits,buffersize,fl);
+    } // end if
 }
+//______________________________________________________________________
+void AliITS::SetTreeAddressS(TTree *treeS){
+    // Set branch address for the ITS summable digits Trees.
+    // Inputs:
+    //      TTree *treeS   Tree containing the SDigits.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    char branchname[30];
 
-//____________________________________________
-void AliITS::ResetDigits(Int_t i)
-{
-    //
-    // Reset number of digits and the digits array for this branch
-    //
-  if ((*fDtype)[i])    ((TClonesArray*)(*fDtype)[i])->Clear();
-  if (fNdtype)  fNdtype[i]=0;
+    if(!treeS) return;
+    if (fSDigits == 0x0)  fSDigits = new TClonesArray("AliITSpListItem",1000);
+    TBranch *branch;
+    sprintf(branchname,"%s",GetName());
+    branch = treeS->GetBranch(branchname);
+    if (branch) branch->SetAddress(&fSDigits);
 }
+//______________________________________________________________________
+void AliITS::MakeBranchInTreeD(TTree *treeD,const char *file){
+    // Creates Tree branches for the ITS.
+    // Inputs:
+    //      TTree     *treeD Pointer to the Digits Tree.
+    //      cont char *file  File name where Digits branch is to be written
+    //                       to. If blank it write the SDigits to the same
+    //                       file in which the Hits were found.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    Int_t buffersize = 4000;
+    char branchname[30];
 
-
-//____________________________________________
-void AliITS::ResetClusters()
-{
-    //
-    // Reset number of clusters and the clusters array for ITS
-    //
-
+    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++ ) {
-       if ((*fCtype)[i])    ((TClonesArray*)(*fCtype)[i])->Clear();
-       if (fNctype)  fNctype[i]=0;
-    }
-
+    for (i=0; i<kNTYPES ;i++) {
+        DetType(i)->GetClassNames(digclass,clclass);
+        // digits
+        if (fDtype == 0x0) fDtype = new TObjArray(fNDetTypes);
+        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 && treeD) {
+            MakeBranchInTree(treeD, branchname, &((*fDtype)[i]),buffersize,file);
+        } // end if
+    } // end for i
 }
+//______________________________________________________________________
+void AliITS::SetTreeAddressD(TTree *treeD){
+    // Set branch address for the Trees.
+    // Inputs:
+    //      TTree *treeD   Tree containing the Digits.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    char branchname[30];
+    const char *det[3] = {"SPD","SDD","SSD"};
+    TBranch *branch;
+    char digclass[40];
+    char clclass[40];
+    Int_t i;
 
-//____________________________________________
-void AliITS::ResetClusters(Int_t i)
-{
-    //
-    // Reset number of clusters and the clusters array for this branch
-    //
-       if ((*fCtype)[i])    ((TClonesArray*)(*fCtype)[i])->Clear();
-       if (fNctype)  fNctype[i]=0;
-
+    if(!treeD) return;
+    for (i=0; i<kNTYPES; i++) {
+        DetType(i)->GetClassNames(digclass,clclass);
+        // digits
+        if (fDtype == 0x0) fDtype = new TObjArray(fNDetTypes);
+        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::ResetRecPoints()
-{
-    //
-    // Reset number of rec points and the rec points array 
-    //
-    if (fRecPoints) fRecPoints->Clear();
-    fNRecPoints = 0;
-
+//______________________________________________________________________
+void AliITS::Hits2SDigits(){
+    // Standard Hits to summable Digits function.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+
+//    return; // Using Hits in place of the larger sDigits.
+    AliRunLoader* rl = fLoader->GetRunLoader(); 
+    AliHeader *header=rl->GetHeader(); // Get event number from this file.
+    if (header == 0x0)
+     {
+       rl->LoadHeader();
+       header=rl->GetHeader();
+       if (header == 0x0) return;
+     }
+    // 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," ",fOpt," ");
+    
 }
-
-//_____________________________________________________________________________
-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::Hits2PreDigits(){
+    // Standard Hits to summable Digits function.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+
+    AliHeader *header=fLoader->GetRunLoader()->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," ",fOpt," ");
 }
-
-//_____________________________________________________________________________
-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;
-
+//______________________________________________________________________
+void AliITS::SDigitsToDigits(Option_t *opt){
+    // Standard Summable digits to Digits function.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+    char name[20] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+
+    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")};
+    if( !det[0] && !det[1] && !det[2] ) all = "All";
+    else all = 0;
+    static Bool_t setDef=kTRUE;
+    if (setDef) SetDefaultSimulation();
+    setDef=kFALSE;
+
+    AliITSsimulation *sim      = 0;
+    AliITSDetType    *iDetType = 0;
+    TTree            *trees    = fLoader->TreeS();
+    if( !(trees && this->GetSDigits()) ){
+        Error("SDigits2Digits","Error: No trees or SDigits. Returning.");
+        return;
+    } // end if
+    sprintf( name, "%s", this->GetName() );
+    TBranch *brchSDigits = trees->GetBranch( name );
+    
+    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("SDigit2Digits",
+                  "The simulation class was not instanciated!");
+            exit(1);
+        } // end if !sim
+        sim->InitSimulationModule(module,gAlice->GetEvNumber());
 //
-  SetDefaults();
-// Array of TStrings
-  for(i=0;i<fIdN;i++) fIdSens[i] = gMC->VolId(fIdName[i]);
+        // add summable digits to module
+        this->GetSDigits()->Clear();
+        brchSDigits->GetEvent(module);
+        sim->AddSDigitsToModule(GetSDigits(),0);
 //
-}
+        // Digitise current module sum(SDigits)->Digits
+        sim->FinishSDigitiseModule();
 
-//_____________________________________________________________________________
-void AliITS::SetDefaults()
-{
-  // sets the default segmentation, response, digit and raw cluster classes
+        // fills all branches - wasted disk space
+        fLoader->TreeD()->Fill();
+        this->ResetDigits();
+    } // end for module
 
-  printf("SetDefaults\n");
-
-  AliITSDetType *iDetType;
-
-
-  //SPD 
-
-  iDetType=DetType(0); 
-  if (!iDetType->GetSegmentationModel()) {
-    AliITSsegmentationSPD *seg0=new AliITSsegmentationSPD(fITSgeom);
-    SetSegmentationModel(0,seg0); 
-  }
-  if (!iDetType->GetResponseModel()) {
-     SetResponseModel(0,new AliITSresponseSPD()); 
-  }
-  // 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()); 
-  }
-  AliITSresponse *resp1=iDetType->GetResponseModel();
-  if (!iDetType->GetSegmentationModel()) {
-    AliITSsegmentationSDD *seg1=new AliITSsegmentationSDD(fITSgeom,resp1);
-    SetSegmentationModel(1,seg1); 
-  }
-  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); 
-  }
-  if (!iDetType->GetResponseModel()) {
-    SetResponseModel(2,new AliITSresponseSSD()); 
-  }
-  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!");
-  } 
+    fLoader->TreeD()->GetEntries();
 
+    fLoader->TreeD()->AutoSave();
+    // reset tree
+    fLoader->TreeD()->Reset();
+    
 }
-
-
-
-//_____________________________________________________________________________
-void AliITS::SetDefaultSimulation()
-{
-  // to be written
-
+//______________________________________________________________________
+void AliITS::Hits2Digits(){
+    // Standard Hits to Digits function.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+
+    AliHeader *header=fLoader->GetRunLoader()->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," ",fOpt," ");
 }
-//_____________________________________________________________________________
-void AliITS::SetDefaultClusterFinders()
-{
-  // to be written
-
+//______________________________________________________________________
+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
+    // initialized for all versions - for the moment it is only for v5 !
+    // 7 is the SDD beam test version. Dummy routine. Hits are ITS's Summable
+    // Digits.
+    // Inputs:
+    //      Int_t evnt       Event to be processed.
+    //      Int_t bgrev      Background Hit tree number.
+    //      Int_t nmodules   Not used.
+    //      Option_t *option String indicating if merging hits or not. To
+    //                       merge hits set equal to "Add". Otherwise no
+    //                       background hits are considered.
+    //      Test_t *filename File name containing the background hits..
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+//    return; // using Hits instead of the larger sdigits.
+
+    HitsToPreDigits(evNumber,bgrev,size,option,opt,filename);
 }
-//_____________________________________________________________________________
-
-void AliITS::MakeTreeC(Option_t *option)
-{
-  // create a separate tree to store the clusters
-
-  cout << "AliITS::MakeTreeC" << endl;
-
-     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);
-       //printf("i, digclass, recclass %d %s %s\n",i,digclass,clclass); 
-       // clusters
-       (*fCtype)[i] = new TClonesArray(clclass,10000); 
-        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);
-          cout << "Making Branch " << branchname;
-          cout << " for Clusters of detector type " << i+1 << endl;
-       }       
-     }
-
+//______________________________________________________________________
+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
+    // initialized for all versions - for the moment it is only for v5 !
+    // 7 is the SDD beam test version.
+    // Inputs:
+    //      Int_t evnt       Event to be processed.
+    //      Int_t bgrev      Background Hit tree number.
+    //      Int_t nmodules   Not used.
+    //      Option_t *option String indicating if merging hits or not. To
+    //                       merge hits set equal to "Add". Otherwise no
+    //                       background hits are considered.
+    //      Test_t *filename File name containing the background hits..
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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 instanciated!");
+            exit(1);
+        } // end if !sim
+        mod      = (AliITSmodule *)fITSmodules->At(module);
+        sim->SDigitiseModule(mod,module,evNumber);
+        // fills all branches - wasted disk space
+        fLoader->TreeS()->Fill(); 
+        ResetSDigits();
+    } // end for module
+
+    ClearModules();
+
+    fLoader->TreeS()->GetEntries();
+    fLoader->TreeS()->AutoSave();
+    fLoader->WriteSDigits("OVERWRITE");
+    // reset tree
+    fLoader->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
+    // initialized for all versions - for the moment it is only for v5 !
+    // 7 is the SDD beam test version.
+    // Inputs:
+    //      Int_t evnt       Event to be processed.
+    //      Int_t bgrev      Background Hit tree number.
+    //      Int_t nmodules   Not used.
+    //      Option_t *option String indicating if merging hits or not. To
+    //                       merge hits set equal to "Add". Otherwise no
+    //                       background hits are considered.
+    //      Test_t *filename File name containing the background hits..
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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 instanciated!");
+            exit(1);
+        } // end if !sim
+        mod      = (AliITSmodule *)fITSmodules->At(module);
+        sim->DigitiseModule(mod,module,evNumber);
+        // fills all branches - wasted disk space
+        fLoader->TreeD()->Fill(); 
+        ResetDigits();
+    } // end for module
+
+    ClearModules();
+
+    fLoader->TreeD()->GetEntries();
+    fLoader->TreeD()->AutoSave();
+    // reset tree
+    fLoader->TreeD()->Reset();
+}
+//______________________________________________________________________
+void AliITS::ResetSDigits(){
+    // Reset the Summable Digits array.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+
+    if (fSDigits) fSDigits->Clear();
+    fNSDigits = 0;
+}
+//______________________________________________________________________
+void AliITS::ResetDigits(){
+    // Reset number of digits and the digits array for the ITS detector.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
 
-//_____________________________________________________________________________
-void AliITS::GetTreeC(Int_t event)
-{
-
-  cout << "AliITS::GetTreeC" << endl;
-
-  // 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;
-    }
-
-    sprintf(treeName,"TreeC%d",event);
-    fTreeC = (TTree*)gDirectory->Get(treeName);
-
-    TBranch *branch;
-    if (fTreeC) {
-        Int_t i;
-       for (i=0; i<kNTYPES; 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]));
-           }
-       }
-    } else {
-       Error("AliITS::GetTreeC",
-               "cannot find Clusters Tree for event:%d\n",event);
-    }
+    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::MakeBranch(Option_t* option, char *file)
-{
-  //
-  // Creates Tree branches for the ITS.
-  //
-  //
-  Int_t buffersize = 4000;
-  char branchname[30];
-  sprintf(branchname,"%s",GetName());
-
-  AliDetector::MakeBranch(option,file);
-
-  char *cD = strstr(option,"D");
-  char *cR = strstr(option,"R");
-
-  if (cD) {
-  //
-  // 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++) {
-       AliITSDetType *iDetType=DetType(i); 
-       iDetType->GetClassNames(digclass,clclass);
-       //printf("i, digclass, recclass %d %s %s\n",i,digclass,clclass); 
-       // digits
-       (*fDtype)[i] = new TClonesArray(digclass,10000); 
-       // clusters
-       //(*fCtype)[i] = new TClonesArray(clclass,10000); 
-   }
-
-   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()) {
-        gAlice->MakeBranchInTree(gAlice->TreeD(), 
-                                 branchname, &((*fDtype)[i]), buffersize, file) ;
-           cout << "Making Branch " << branchname;
-           cout << " for digits of type "<< i+1 << endl;
-      }        
-    }
+//______________________________________________________________________
+void AliITS::ResetDigits(Int_t i){
+    // Reset number of digits and the digits array for this branch.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+
+    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.
+    // Inputs:
+    //      AliITSpListItem &sdig   SDigit to be added to SDigits tree.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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.
+    // Inputs:
+    //      Int_t id        Detector type number.
+    //      Int_t *digits   Integer array containing the digits info. See 
+    //                      AliITSdigit.h
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    TClonesArray &ldigits = *((TClonesArray*)fDtype->At(id));
+    new(ldigits[fNdtype[id]++]) AliITSdigit(digits);
+}
+//______________________________________________________________________
+void AliITS::AddSimDigit(Int_t id, AliITSdigit *d){
+    //    Add a simulated digit.
+    // Inputs:
+    //      Int_t id        Detector type number.
+    //      AliITSdigit *d  Digit to be added to the Digits Tree. See 
+    //                      AliITSdigit.h
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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.
+    // Inputs:
+    //      Int_t id        Detector type number.
+    //      Float_t phys    Physics indicator. See AliITSdigits.h
+    //      Int_t *digits   Integer array containing the digits info. See 
+    //                      AliITSdigit.h
+    //      Int_t *tracks   Integer array [AliITSdigitS?D::GetNTracks()] 
+    //                      containing the track numbers that contributed to
+    //                      this digit.
+    //      Int_t *hits     Integer array [AliITSdigitS?D::GetNTracks()]
+    //                      containing the hit numbers, from AliITSmodule, that
+    //                      contributed to this digit.
+    //      Float_t *charge Floating point array of the signals contributed
+    //                      to this digit by each track.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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.
+  // Inputs:
+  //      Option_t *option  string which must contain "C" otherwise
+  //                        no Cluster Tree is created.
+  // Outputs:
+  //      none.
+  // Return:
+  //      none.
+
+  AliITSLoader *pITSLoader = (AliITSLoader*)fLoader;    
+    
+  if (pITSLoader == 0x0) {
+    Error("MakeTreeC","fLoader == 0x0");
+    return;
   }
-
-  if (cR) {
-  //
-  // only one branch for rec points for all detector types
-  //
-    sprintf(branchname,"%sRecPoints",GetName());
-    fRecPoints=new TClonesArray("AliITSRecPoint",10000);
-
-    if (fRecPoints && gAlice->TreeR()) {
-      gAlice->MakeBranchInTree(gAlice->TreeR(), 
-                               branchname, &fRecPoints, buffersize, file) ;
-      cout << "Making Branch " << branchname;
-      cout << " for reconstructed space points" << endl;
-    }
-  }    
+  if (pITSLoader->TreeC() == 0x0) pITSLoader->MakeTree("C");
+  MakeBranchC();
 }
 
-//___________________________________________
-void AliITS::SetTreeAddress()
+void AliITS::MakeBranchC()
 {
+//Makes barnches in treeC
+  AliITSLoader *pITSLoader = (AliITSLoader*)fLoader;    
+  if (pITSLoader == 0x0) 
+   {
+    Error("MakeTreeC","fLoader == 0x0");
+    return;
+   }
+  TTree * TC = pITSLoader->TreeC();
+  if (TC == 0x0)
+   {
+     Error("MakeTreeC","Can not get TreeC from Loader");
+     return;
+   }
 
-  // Set branch address for the Trees.
-
+  Int_t buffersize = 4000;
   char branchname[30];
-  AliDetector::SetTreeAddress();
-
   const char *det[3] = {"SPD","SDD","SSD"};
-
-  TBranch *branch;
-  TTree *treeD = gAlice->TreeD();
-  TTree *treeR = gAlice->TreeR();
-
-  Int_t i;
-  if (treeD) {
-      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) {
-             branch = treeD->GetBranch(branchname);
-             if (branch) branch->SetAddress(&((*fDtype)[i]));
-         }
-      }
-  }
-
-  if (treeR) {
-    sprintf(branchname,"%sRecPoints",GetName());
-    if (fRecPoints) {
-      branch = treeR->GetBranch(branchname);
-      if (branch) branch->SetAddress(&fRecPoints);
-    }
-  }
-  
-
+  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
+        if (fCtype == 0x0) fCtype  = new TObjArray(fNDetTypes);
+        if(!ClustersAddress(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  && TC) 
+         {
+           if (TC->GetBranch(branchname))
+            {
+              Warning("MakeBranchC","Branch %s alread exists in TreeC",branchname);
+            }
+           else
+            {
+              Info("MakeBranchC","Creating branch %s in TreeC",branchname);
+              TC->Branch(branchname,&((*fCtype)[i]), buffersize);
+            }
+         } // end if fCtype && TC
+  } // end for i
 }
 
-//____________________________________________________________________________
-void AliITS::InitModules(Int_t size,Int_t &nmodules){
+//______________________________________________________________________
+void AliITS::GetTreeC(Int_t event){
+  //    Get the clusters tree for this event and set the branch address.
+  // Inputs:
+  //      Int_t event    Event number for the cluster tree.
+  // Outputs:
+  //      none.
+  // Return:
+  //      none.
+  char branchname[30];
+  const char *det[3] = {"SPD","SDD","SSD"};
 
-  //initialize the modules array
+  AliITSLoader *pITSLoader = (AliITSLoader*)fLoader;
+  TTree * TC = pITSLoader->TreeC();
 
-  if(fITSmodules){ 
-      fITSmodules->Delete();
-      delete fITSmodules;
-  }
+  ResetClusters();
+  if (TC) {
+    pITSLoader->CleanRawClusters();
+  } // end if TreeC()
 
-    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);
-       }
+  TBranch *branch;
 
-        nmodules = size;
-    } // end i size<=0
+  if (TC) {
+    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 == 0x0) fCtype  = new TObjArray(fNDetTypes);
+      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 = TC->GetBranch(branchname);
+        if (branch) branch->SetAddress(&((*fCtype)[i]));
+      } // end if fCtype
+        } // end for i
+  } else {
+        Error("GetTreeC","cannot find Clusters Tree for event:%d",event);
+  } // end if TC
 }
-
-//____________________________________________________________________________
-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;
-    char *addBgr = strstr(option,"Add");
-
-
-    if (addBgr ) {
-       if(first) {
-           cout<<"filename "<<filename<<endl;
-           file=new TFile(filename);
-           cout<<"I have opened "<<filename<<" file "<<endl;
-           fHits2     = new TClonesArray("AliITShit",1000  );
-       }           
-       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);
-        //printf("TrH1 %p of treename %s for event %d \n",trH1,treeName,bgrev);
-       
-       if (!trH1) {
-           Error("AliITS::FillModules",
-           "cannot find Hits Tree for event:%d\n",bgrev);
-       }
-       // Set branch addresses
-       TBranch *branch;
-       char branchname[20];
-       sprintf(branchname,"%s",GetName());
-       if (trH1 && fHits2) {
-           branch = trH1->GetBranch(branchname);
-           if (branch) branch->SetAddress(&fHits2);
-       }
-
-        // test
-       //Int_t ntracks1 =(Int_t)TrH1->GetEntries();
-       //printf("background - ntracks1 - %d\n",ntracks1);
-   }
-
-    //Int_t npart = gAlice->GetEvent(evnt);
-    //if(npart<=0) return;
-    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();
-       //printf("nhits %d\n",nhits);
-        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();
-           //printf("background - ntracks1 %d\n",ntracks);
-           //printf("background - Start loop over tracks \n");     
-            //   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
-
-    //gObjectTable->Print();
-
+//______________________________________________________________________
+void AliITS::AddCluster(Int_t id, AliITSRawCluster *c){
+    //   Add a cluster to the list.
+    // Inputs:
+    //      Int_t id             Detector type number.
+    //      AliITSRawCluster *c  Cluster class to be added to the tree of
+    //                           clusters.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    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.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
 
-//____________________________________________________________________________
-
-void AliITS::SDigits2Digits()
-{
-  
-  AliITSgeom *geom = GetITSgeom();
-  
-  // SPD
-  AliITSDetType *iDetType;
-  iDetType=DetType(0);
-  AliITSsegmentationSPD *seg0=(AliITSsegmentationSPD*)iDetType->GetSegmentationModel();
-  AliITSresponseSPD *res0 = (AliITSresponseSPD*)iDetType->GetResponseModel();
-  AliITSsimulationSPD *sim0=new AliITSsimulationSPD(seg0,res0);
-  SetSimulationModel(0,sim0);
-  // test
-  // printf("SPD dimensions %f %f \n",seg0->Dx(),seg0->Dz());
-  // printf("SPD npixels %d %d \n",seg0->Npz(),seg0->Npx());
-  // printf("SPD pitches %d %d \n",seg0->Dpz(0),seg0->Dpx(0));
-  // end test
-  // 
-  // SDD
-  //Set response functions
-  Float_t baseline = 10.;
-  Float_t noise = 1.75;
-  
-  // SDD compression param: 2 fDecrease, 2fTmin, 2fTmax or disable, 2 fTolerance
-
-  iDetType=DetType(1);
-  AliITSresponseSDD *res1 = (AliITSresponseSDD*)iDetType->GetResponseModel();
-  if (!res1) {
-    res1=new AliITSresponseSDD();
-    SetResponseModel(1,res1);
-  }
-   res1->SetMagicValue(900.);
-   Float_t maxadc = res1->MaxAdc();    
-   Float_t topValue = res1->MagicValue();
-   Float_t norm = maxadc/topValue;
-
-   Float_t fCutAmp = baseline + 2.*noise;
-   fCutAmp *= norm;
-   Int_t cp[8]={0,0,(int)fCutAmp,(int)fCutAmp,0,0,0,0}; //1D
-
-  //res1->SetZeroSupp("2D");
-  res1->SetZeroSupp("1D");
-  res1->SetNoiseParam(noise,baseline);
-  res1->SetDo10to8(kTRUE);
-  res1->SetCompressParam(cp);
-  res1->SetMinVal(4);
-  res1->SetDiffCoeff(3.6,40.);
-  //res1->SetMagicValue(96.95);
-  AliITSsegmentationSDD *seg1=(AliITSsegmentationSDD*)iDetType->GetSegmentationModel();
-  if (!seg1) {
-    seg1 = new AliITSsegmentationSDD(geom,res1);
-    SetSegmentationModel(1,seg1);
-  }
-  AliITSsimulationSDD *sim1=new AliITSsimulationSDD(seg1,res1);
-  sim1->SetDoFFT(1);
-  sim1->SetCheckNoise(kFALSE);
-  SetSimulationModel(1,sim1);
-
-  // SSD
-  iDetType=DetType(2);
-  AliITSsegmentationSSD *seg2=(AliITSsegmentationSSD*)iDetType->GetSegmentationModel();
-  AliITSresponseSSD *res2 = (AliITSresponseSSD*)iDetType->GetResponseModel();
-  res2->SetSigmaSpread(3.,2.);
-  AliITSsimulationSSD *sim2=new AliITSsimulationSSD(seg2,res2);
-  SetSimulationModel(2,sim2);
-  cerr<<"Digitizing ITS...\n";
-  TStopwatch timer;
-  timer.Start();
-  HitsToDigits(0,0,-1," ","All"," ");
-  timer.Stop(); timer.Print();
-
-  delete sim0;
-  delete sim1;
-  delete sim2;
+    Int_t i;
+    for (i=0;i<kNTYPES;i++ ) ResetClusters(i);
 }
-
-
-//____________________________________________________________________________
-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) return; 
-
-   char *all = strstr(opt,"All");
-   char *det[3] = {strstr(opt,"SPD"),strstr(opt,"SDD"),strstr(opt,"SSD")};
-
-   Int_t nmodules;
-   InitModules(size,nmodules); 
-   FillModules(evNumber,bgrev,nmodules,option,filename);
-
-   //TBranch *branch;
-   AliITSsimulation* sim;
-   //TObjArray *branches=gAlice->TreeD()->GetListOfBranches();
-   AliITSgeom *geom = GetITSgeom();
-
-   Int_t id,module;
-   Int_t first,last;
-   for (id=0;id<kNTYPES;id++) {
-        if (!all && !det[id]) continue;
-       //branch = (TBranch*)branches->UncheckedAt(id);
-       AliITSDetType *iDetType=DetType(id); 
-       sim = (AliITSsimulation*)iDetType->GetSimulationModel();
-       if (!sim) {
-           Error("HitsToDigits","The simulation class was not instantiated!");
-           exit(1);
-          // or SetDefaultSimulation();
-       }
-       if(geom) {
-         first = geom->GetStartDet(id);
-         last = geom->GetLastDet(id);
-       } else first=last=0;
-       cout << "det type " << id << " first, last "<< first << last << endl;
-       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();
-           // try and fill only the branch 
-           //branch->Fill();
-           //ResetDigits(id);
-       } // loop over modules
-   } // loop over detector types
-
-   ClearModules();
-
-   Int_t nentries=(Int_t)gAlice->TreeD()->GetEntries();
-   cout << "nentries in TreeD" << nentries << endl;
-
-   char hname[30];
-   sprintf(hname,"TreeD%d",evNumber);
-   gAlice->TreeD()->Write(hname,TObject::kOverwrite);
-   // reset tree
-   gAlice->TreeD()->Reset();
-
+//______________________________________________________________________
+void AliITS::ResetClusters(Int_t i){
+    //    Reset number of clusters and the clusters array for this branch.
+    // Inputs:
+    //      Int_t i        Detector type number.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    if (fCtype->At(i))    ((TClonesArray*)fCtype->At(i))->Clear();
+    if (fNctype)  fNctype[i]=0;
 }
+//______________________________________________________________________
+void AliITS::MakeBranchR(const char *file, Option_t *opt){
+    // Creates Tree branches for the ITS Reconstructed points.
+    // Inputs:
+    //      cont char *file  File name where RecPoints branch is to be written
+    //                       to. If blank it write the SDigits to the same
+    //                       file in which the Hits were found.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    Int_t buffsz = 4000;
+    char branchname[30];
 
-
-//____________________________________________________________________________
-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!=7) return; 
-
-   char *all = strstr(opt,"All");
-   char *det[3] = {strstr(opt,"SPD"),strstr(opt,"SDD"),strstr(opt,"SSD")};
-
-   static Bool_t first=kTRUE;
-   if (!TreeC() && first) {
-       MakeTreeC("C");
-       first=kFALSE;
-   }
-
-   TTree *treeC=TreeC();
-
-   //TBranch *branch;
-   AliITSClusterFinder* rec;
-
-   //TObjArray *branches=gAlice->TreeR()->GetListOfBranches();
-   AliITSgeom *geom = GetITSgeom();
-
-   Int_t id,module;
-   for (id=0;id<kNTYPES;id++) {
-        if (!all && !det[id]) continue;
-       //branch = (TBranch*)branches->UncheckedAt(id);
-       AliITSDetType *iDetType=DetType(id); 
-       rec = (AliITSClusterFinder*)iDetType->GetReconstructionModel();
-       if (!rec) {
-           Error("DigitsToRecPoints","The cluster finder class was not instantiated!");
-           exit(1);
-          // or SetDefaultClusterFinders();
-       }
-        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 last %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();
-             gAlice->TreeR()->Fill(); 
-             ResetRecPoints();
-             treeC->Fill();
-              ResetClusters();
-             // try and fill only the branch 
-             //branch->Fill();
-             //ResetRecPoints(id);
-       } // loop over modules
-   } // loop over detector types
-
-
-   Int_t nentries=(Int_t)gAlice->TreeR()->GetEntries();
-   Int_t ncentries=(Int_t)treeC->GetEntries();
-   cout << " nentries ncentries " << nentries << ncentries <<  endl;
-
-   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();
+    // only one branch for rec points for all detector types
+    Bool_t oFast= (strstr(opt,"Fast")!=0);
+    if(oFast){
+      sprintf(branchname,"%sRecPointsF",GetName());
+    } else {
+      sprintf(branchname,"%sRecPoints",GetName());
+    }
+    
+    
+    if(!fRecPoints)fRecPoints = new TClonesArray("AliITSRecPoint",1000);
+    if (fLoader->TreeR()) {
+        if (fRecPoints == 0x0) fRecPoints = new TClonesArray("AliITSRecPoint",1000);
+        MakeBranchInTree(fLoader->TreeR(),branchname,&fRecPoints,buffsz,file);
+    } // end if
 }
+//______________________________________________________________________
+void AliITS::SetTreeAddressR(TTree *treeR){
+    // Set branch address for the Reconstructed points Trees.
+    // Inputs:
+    //      TTree *treeR   Tree containing the RecPoints.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+    char branchname[30];
 
-
-//____________________________________________________________________________
+    if(!treeR) return;
+    if (fRecPoints == 0x0) fRecPoints = new TClonesArray("AliITSRecPoint",1000);
+    TBranch *branch;
+    sprintf(branchname,"%sRecPoints",GetName());
+    branch = treeR->GetBranch(branchname);
+    if (branch) {
+      branch->SetAddress(&fRecPoints);
+    }
+    else {
+      sprintf(branchname,"%sRecPointsF",GetName());
+      branch = treeR->GetBranch(branchname);
+      if (branch) {
+        branch->SetAddress(&fRecPoints);
+      }
+    }
+}
+//______________________________________________________________________
+void AliITS::AddRecPoint(const AliITSRecPoint &r){
+    // Add a reconstructed space point to the list
+    // Inputs:
+    //      const AliITSRecPoint &r RecPoint class to be added to the tree
+    //                              of reconstructed points TreeR.
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    TClonesArray &lrecp = *fRecPoints;
+    new(lrecp[fNRecPoints++]) AliITSRecPoint(r);
+}
+//______________________________________________________________________
 void AliITS::HitsToFastRecPoints(Int_t evNumber,Int_t bgrev,Int_t size,
-Option_t *option,Option_t *opt,Text_t *filename)
-{
+                                  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) return; 
-
-   char *all = strstr(opt,"All");
-   char *det[3] = {strstr(opt,"SPD"),strstr(opt,"SDD"),strstr(opt,"SSD")};
-
-   Int_t nmodules;
-   InitModules(size,nmodules);
-   FillModules(evNumber,bgrev,nmodules,option,filename);
-
-
-   AliITSsimulation* sim;
-   AliITSgeom *geom = GetITSgeom();
-
-   TRandom *random=new TRandom[9];
-   random[0].SetSeed(111);
-   random[1].SetSeed(222);
-   random[2].SetSeed(333);             
-   random[3].SetSeed(444);
-   random[4].SetSeed(555);
-   random[5].SetSeed(666);             
-   random[6].SetSeed(777);
-   random[7].SetSeed(888);
-   random[8].SetSeed(999);             
-
-
-   Int_t id,module;
-   for (id=0;id<kNTYPES;id++) {
+    // the condition below will disappear when the geom class will be
+    // initialized for all versions - for the moment it is only for v5 !
+    // Inputs:
+    //      Int_t evnt       Event to be processed.
+    //      Int_t bgrev      Background Hit tree number.
+    //      Int_t size       Size used by InitModules. See InitModules.
+    //      Option_t *opt0   Option passed to FillModules. See FillModules.
+    //      Option_t *opt1   String indicating if merging hits or not. To
+    //                       merge hits set equal to "Add". Otherwise no
+    //                       background hits are considered.
+    //      Test_t *flnm     File name containing the background hits..
+    // Outputs:
+    //      none.
+    // Return:
+    //      none.
+
+    if(!GetITSgeom()) return;
+    AliITSLoader *pITSloader = (AliITSLoader*)fLoader;
+    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 !
+    
+    cout<<"HitsToFastRecPoints: N mod = "<<geom->GetIndexMax()<<endl;
+    
+    for(module=0;module<geom->GetIndexMax();module++)
+     {
+        id       = geom->GetModuleType(module);
         if (!all && !det[id]) continue;
-       AliITSDetType *iDetType=DetType(id); 
-       sim = (AliITSsimulation*)iDetType->GetSimulationModel();
-       if (!sim) {
-           Error("HitsToFastPoints","The simulation class was not instantiated!");
+        iDetType = DetType(id);
+        sim      = (AliITSsimulation*)iDetType->GetSimulationModel();
+        if (!sim) 
+         {
+           Error("HitsToFastPoints","The simulation class was not instanciated!");
            exit(1);
-          // or SetDefaultSimulation();
-       }
-       Int_t first = geom->GetStartDet(id);
-       Int_t last = geom->GetLastDet(id);
-       for(module=first;module<=last;module++) {
-           AliITSmodule *mod = (AliITSmodule *)fITSmodules->At(module);
-           sim->CreateFastRecPoints(mod,module,random);
-           gAlice->TreeR()->Fill(); 
-           ResetRecPoints();
-       } // loop over modules
-   } // loop over detector types
-
-
-   ClearModules();
-
-   //Int_t nentries=(Int_t)gAlice->TreeR()->GetEntries();
-
-   char hname[30];
-   sprintf(hname,"TreeR%d",evNumber);
-   gAlice->TreeR()->Write(hname,TObject::kOverwrite);
-   // reset tree
-   gAlice->TreeR()->Reset();
-
-   delete [] random;
-
-}
-
-//________________________________________________________________
-
-AliITStrack  AliITS::Tracking(AliITStrack &track, AliITStrack *reference,TObjArray *fastpoints, Int_t
-**vettid, Bool_t flagvert ) { 
-                                                                               
-//Origin  A. Badala' and G.S. Pappalardo:  e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it 
-
-                                                                                   
-  TList *list= new TList();   
-
-  AliITStrack tr(track);
-  
-  list->AddLast(&tr);
-  
-  Double_t Pt=(tr).GetPt();
-  //cout << "\n Pt = " << Pt <<"\n";
-
-  AliITStracking obj(list, reference, this, fastpoints,TMath::Abs(Pt),vettid, flagvert);
-  list->Delete();
-  delete list;
-
-  Int_t itot=-1;
-  TVector VecTotLabref(18);
-  Int_t lay, k;
-  for(lay=5; lay>=0; lay--) {
-    TVector VecLabref(3); 
-    VecLabref=(*reference).GetLabTrack(lay);
-    for(k=0; k<3; k++) {itot++; VecTotLabref(itot)=VecLabref(k);}    
-  }
-  Long_t labref;
-  Int_t freq;  
-  (*reference).Search(VecTotLabref, labref, freq);
+         } // end if !sim
+        mod      = (AliITSmodule *)fITSmodules->At(module);
+        sim->CreateFastRecPoints(mod,module,gRandom);
+        cout<<module<<"\r";fflush(0);
+        //gAlice->TreeR()->Fill();
+       TTree *TR = pITSloader->TreeR();
+        TBranch *br=TR->GetBranch("ITSRecPointsF");
+        br->Fill();
+        ResetRecPoints();
+    } // end for module
+
+    ClearModules();
     
-  if(freq < 5) labref=-labref;         
-  (*reference).SetLabel(labref);
-
-  return *reference; 
-
+    fLoader->WriteRecPoints("OVERWRITE");
 }
-
-
-
-//________________________________________________________________
-
-
-
-void AliITS::DoTracking(Int_t evNumber, Int_t min_t, Int_t max_t, TFile *file, Bool_t flagvert) {
-
-//   ex macro for tracking ITS
-
-  printf("begin DoTracking - file %p\n",file);
-
-  const char *pname="75x40_100x60";
-  
-  struct GoodTrack {
-    Int_t lab,code;
-    Float_t px,py,pz,x,y,z,pxg,pyg,pzg,ptg;
-    Bool_t flag;
-  };
-  
-
-  gAlice->GetEvent(0);
-
-  AliTPC *TPC=(AliTPC*)gAlice->GetDetector("TPC");
-  AliTPCParam *digp = (AliTPCParam*)file->Get(pname);
-  if (digp!=0) TPC->SetParam(digp);
-  
-  GoodTrack gt[7000];
-  Int_t ngood=0;
-  ifstream in("good_tracks");
-
-  cerr<<"Reading good tracks...\n";
-  while (in>>gt[ngood].lab>>gt[ngood].code
-         >>gt[ngood].px >>gt[ngood].py>>gt[ngood].pz
-         >>gt[ngood].x  >>gt[ngood].y >>gt[ngood].z
-         >>gt[ngood].pxg  >>gt[ngood].pyg >>gt[ngood].pzg
-         >>gt[ngood].ptg >>gt[ngood].flag) {
-    ngood++;
-    cerr<<ngood<<'\r';
-    if (ngood==7000) {
-      cerr<<"Too many good tracks !\n";
-      break;
+//______________________________________________________________________
+void AliITS::Digits2Reco(){
+    // Find clusters and reconstruct space points.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
+
+    AliHeader *header=fLoader->GetRunLoader()->GetHeader();
+    // to Digits to RecPoints for event in file, all digits in file, and
+    // all ITS detectors.
+    DigitsToRecPoints(header->GetEvent(),0,fOpt);
+}
+//______________________________________________________________________
+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
+  // initialized for all versions - for the moment it is only for v5 !
+  // 7 is the SDD beam test version
+  // Inputs:
+  //      Int_t evNumber   Event number to be processed.
+  //      Int_t lastentry  Offset for module when not all of the modules
+  //                       are processed.
+  //      Option_t *opt    String indicating which ITS sub-detectors should
+  //                       be processed. If ="All" then all of the ITS
+  //                       sub detectors are processed.
+  // Outputs:
+  //      none.
+  // Return:
+  //      none.
+
+  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;
+
+  AliITSLoader *pITSloader = (AliITSLoader*)fLoader;
+  TTree *treeC=pITSloader->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 instanciated!");
+      exit(1);
+        } // end if !rec
+        this->ResetDigits();
+    TTree *TD = pITSloader->TreeD();
+        if (all) {
+      TD->GetEvent(lastentry+module);
     }
-  }
-  if (!in.eof()) cerr<<"Read error (good_tracks) !\n";
-  
-  
-// Load tracks
-  TFile *tf=TFile::Open("tpctracks.root");
-  if (!tf->IsOpen()) {cerr<<"Can't open tpctracks.root !\n"; return ;}
-  TObjArray tracks(200000);
-  TTree *tracktree=(TTree*)tf->Get("TreeT");
-  TBranch *tbranch=tracktree->GetBranch("tracks");
-  Int_t nentr=(Int_t)tracktree->GetEntries();
-  Int_t kk;
-  for (kk=0; kk<nentr; kk++) {
-    AliTPCtrack *iotrack=new AliTPCtrack;
-    tbranch->SetAddress(&iotrack);
-    tracktree->GetEvent(kk);
-    tracks.AddLast(iotrack);
-  }   
-  tf->Close();
-
-
-  Int_t nt = tracks.GetEntriesFast();
-  cerr<<"Number of found tracks "<<nt<<endl;
-  
-  TVector DataOut(9);
-  Int_t kkk=0;
-  
-  Double_t ptg=0.,pxg=0.,pyg=0.,pzg=0.;
-
-  //////////////////////////////  good tracks definition in TPC  ////////////////////////////////
-      
-  ofstream out1 ("AliITSTrag.out");
-  Int_t i;
-  for (i=0; i<ngood; i++) out1 << gt[i].ptg << "\n";
-  out1.close();
-
-
-  TVector vec(5);
-  TTree *TR=gAlice->TreeR();
-  Int_t nent=(Int_t)TR->GetEntries();
-  TClonesArray  *recPoints = RecPoints();
-  Int_t numbpoints;
-  Int_t totalpoints=0;
-  Int_t *np = new Int_t[nent];
-  Int_t **vettid = new Int_t* [nent];
-  Int_t mod;
-  for (mod=0; mod<nent; mod++) {
-    vettid[mod]=0;
-    this->ResetRecPoints();
-    gAlice->TreeR()->GetEvent(mod+1); //first entry in TreeR is empty
-    numbpoints = recPoints->GetEntries();
-    totalpoints+=numbpoints;
-    np[mod] = numbpoints;
-  //cout<<" mod = "<<mod<<"   numbpoints = "<<numbpoints<<"\n"; getchar();
-    vettid[mod] = new Int_t[numbpoints];
-    Int_t ii;
-    for (ii=0;ii<numbpoints; ii++) *(vettid[mod]+ii)=0;
-  }
+    else {
+      TD->GetEvent(lastentry+(module-first));
+    }
+        Int_t ndigits = itsDigits->GetEntriesFast();
+        if (ndigits) rec->FindRawClusters(module);
+    pITSloader->TreeR()->Fill(); 
+        ResetRecPoints();
+        treeC->Fill();
+    ResetClusters();
+  } // end for module
 
-  AliTPCtrack *track;
 
-     
-  if(min_t < 0) {min_t = 0; max_t = nt-1;}   
+  pITSloader->WriteRecPoints("OVERWRITE");
+  pITSloader->WriteRawClusters("OVERWRITE");
+}
+//______________________________________________________________________
+void AliITS::ResetRecPoints(){
+    // Reset number of rec points and the rec points array.
+    // Inputs:
+    //      none.
+    // Outputs:
+    //      none.
 
-/*
-  ///////////////////////////////// Definition of vertex end its error ////////////////////////////
-  ////////////////////////// In the future it will be given by a method ///////////////////////////
-  Double_t Vx=0.;
-  Double_t Vy=0.;
-  Double_t Vz=0.;
-  
-  Float_t sigmavx=0.0050;      // 50  microns
-  Float_t sigmavy=0.0050;      // 50  microns
-  Float_t sigmavz=0.010;       // 100 microns
-
-  //Vx+=gRandom->Gaus(0,sigmavx);  Vy+=gRandom->Gaus(0,sigmavy);  Vz+=gRandom->Gaus(0,sigmavz);
-  TVector vertex(3), ervertex(3)
-  vertex(0)=Vx; vertex(1)=Vy; vertex(2)=Vz;
-  ervertex(0)=sigmavx;  ervertex(1)=sigmavy;  ervertex(2)=sigmavz;
-  /////////////////////////////////////////////////////////////////////////////////////////////////
-*/      
-
-  //TDirectory *savedir=gDirectory; 
-
-  TTree tracktree1("TreeT","Tree with ITS tracks");
-  AliITSiotrack *iotrack=0;
-  tracktree1.Branch("ITStracks","AliITSiotrack",&iotrack,32000,0);
-
-  ofstream out ("AliITSTra.out");
-  
-  Int_t j;       
-  for (j=min_t; j<=max_t; j++) {     
-    track=(AliTPCtrack*)tracks.UncheckedAt(j);
-    Int_t flaglab=0;
-    if (!track) continue;
-    ////// elimination of not good tracks ////////////  
-    Int_t ilab=TMath::Abs(track->GetLabel());
-    Int_t iii;
-    for (iii=0;iii<ngood;iii++) {
-        //cout<<" ilab, gt[iii].lab = "<<ilab<<" "<<gt[iii].lab<<"\n"; getchar();
-      if (ilab==gt[iii].lab) { 
-       flaglab=1;
-       ptg=gt[iii].ptg; 
-       pxg=gt[iii].pxg;
-       pyg=gt[iii].pyg;
-       pzg=gt[iii].pzg;        
-       break;
-      }
-    }
-        //cout<<" j flaglab =  " <<j<<" "<<flaglab<<"\n";  getchar();
-    if (!flaglab) continue;
-        //cout<<" j =  " <<j<<"\n";  getchar();
-  /*           
-    ////// old propagation to the end of TPC //////////////       
-    Double_t xk=76.;
-    track->PropagateTo(xk);
-    xk-=0.11;
-    track->PropagateTo(xk,42.7,2.27); //C
-    xk-=2.6;
-    track->PropagateTo(xk,36.2,1.98e-3); //C02
-    xk-=0.051;
-    track->PropagateTo(xk,42.7,2.27); //C 
-    /////////////////////////////////////////////////// 
-        */
-                
-        ////// new propagation to the end of TPC //////////////
-    Double_t xk=77.415;
-    track->PropagateTo(xk, 28.94, 1.204e-3);    //Ne
-        xk -=0.01;
-    track->PropagateTo(xk, 44.77, 1.71);        //Tedlar
-        xk -=0.04;
-    track->PropagateTo(xk, 44.86, 1.45);        //Kevlar
-        xk -=2.0;
-    track->PropagateTo(xk, 41.28, 0.029);       //Nomex         
-    xk-=16;
-    track->PropagateTo(xk,36.2,1.98e-3); //C02
-        xk -=0.01;
-    track->PropagateTo(xk, 24.01, 2.7);         //Al    
-        xk -=0.01;
-    track->PropagateTo(xk, 44.77, 1.71);        //Tedlar
-        xk -=0.04;
-    track->PropagateTo(xk, 44.86, 1.45);        //Kevlar
-        xk -=0.5;
-    track->PropagateTo(xk, 41.28, 0.029);       //Nomex                                                 
-                    
-       ///////////////////////////////////////////////////////////////                          
-  
-   ///////////////////////////////////////////////////////////////
-    AliITStrack trackITS(*track);
-    AliITStrack result(*track);
-    AliITStrack primarytrack(*track); 
-    
-///////////////////////////////////////////////////////////////////////////////////////////////
-        TVector Vgeant(3);
-        Vgeant=result.GetVertex(); 
-                         
-  // Definition of Dv and Zv for vertex constraint     
-     Double_t sigmaDv=0.0050;  Double_t sigmaZv=0.010; 
-    //Double_t sigmaDv=0.0015;  Double_t sigmaZv=0.0015;                                 
-       Double_t uniform= gRandom->Uniform();
-       Double_t signdv;
-       if(uniform<=0.5) signdv=-1.;
-          else
-                signdv=1.;
-        
-       Double_t Vr=TMath::Sqrt(Vgeant(0)*Vgeant(0)+ Vgeant(1)*Vgeant(1));
-         Double_t Dv=gRandom->Gaus(signdv*Vr,(Float_t)sigmaDv); 
-    Double_t Zv=gRandom->Gaus(Vgeant(2),(Float_t)sigmaZv);
-                               
-  //cout<<" Dv e Zv = "<<Dv<<" "<<Zv<<"\n";                            
-    trackITS.SetDv(Dv);  trackITS.SetZv(Zv);
-    trackITS.SetsigmaDv(sigmaDv); trackITS.SetsigmaZv(sigmaZv); 
-    result.SetDv(Dv);  result.SetZv(Zv);
-    result.SetsigmaDv(sigmaDv); result.SetsigmaZv(sigmaZv);
-    primarytrack.SetDv(Dv);  primarytrack.SetZv(Zv);
-    primarytrack.SetsigmaDv(sigmaDv); primarytrack.SetsigmaZv(sigmaZv);                                                                
-
-/////////////////////////////////////////////////////////////////////////////////////////////////       
-               
-    primarytrack.PrimaryTrack();
-    TVector  d2=primarytrack.Getd2();
-    TVector  tgl2=primarytrack.Gettgl2();
-    TVector  dtgl=primarytrack.Getdtgl();
-    trackITS.Setd2(d2); trackITS.Settgl2(tgl2);  trackITS.Setdtgl(dtgl); 
-    result.Setd2(d2); result.Settgl2(tgl2);  result.Setdtgl(dtgl);        
-        /*                      
-    trackITS.SetVertex(vertex); trackITS.SetErrorVertex(ervertex);
-    result.SetVertex(vertex);   result.SetErrorVertex(ervertex);   
-    */                         
-    Tracking(trackITS,&result,recPoints,vettid, flagvert);  
-            
-     cout<<" progressive track number = "<<j<<"\r";
-   // cout<<j<<"\r";
-    //cout<<" progressive track number = "<<j<<"\n";
-    Long_t labITS=result.GetLabel();
-    //cout << " ITS track label = " << labITS << "\n";                     
-    int lab=track->GetLabel();             
-  //  cout << " TPC track label = " << lab <<"\n";
-    //result.GetClusters(); getchar();  //to print the cluster matrix
-        
-//propagation to vertex
-       
-    Double_t rbeam=3.;
+    if (fRecPoints) fRecPoints->Clear();
+    fNRecPoints = 0;
+}
+//______________________________________________________________________
+AliLoader* AliITS::MakeLoader(const char* topfoldername)
+{ 
+  //builds ITSgetter (AliLoader type)
+  //if detector wants to use castomized getter, it must overload this method
+
+  cout<<"AliITS::MakeLoader: Creating standard getter for detector "<<GetName()
+      <<". top folder is "<<topfoldername<<endl;
      
-    result.Propagation(rbeam);
-       
-    TMatrix *cov;
-        cov=&result.GetCMatrix();       
-    Double_t pt=TMath::Abs(result.GetPt());
-    Double_t Dr=result.GetD();
-    Double_t Z=result.GetZ();
-    Double_t tgl=result.GetTgl();
-    Double_t C=result.GetC();
-    Double_t Cy=C/2.;
-    Double_t Dz=Z-(tgl/Cy)*TMath::ASin(result.arga(rbeam));
-         Dz-=Vgeant(2);
-         
-        // cout<<" Dr e dz alla fine = "<<Dr<<" "<<Dz<<"\n"; getchar();
-    Double_t phi=result.Getphi();
-    Double_t phivertex = phi - TMath::ASin(result.argA(rbeam));
-    Double_t duepi=2.*TMath::Pi();      
-    if(phivertex>duepi) phivertex-=duepi;
-    if(phivertex<0.) phivertex+=duepi;
-    Double_t Dtot=TMath::Sqrt(Dr*Dr+Dz*Dz);
-        
-//////////////////////////////////////////////////////////////////////////////////////////     
-    Int_t NumofCluster, idmodule,idpoint;
-    NumofCluster=result.GetNumClust();
-    if(NumofCluster >=5)  {     
-
-
-      AliITSiotrack outtrack;
-
-      iotrack=&outtrack;
-
-      iotrack->SetStatePhi(phi);
-      iotrack->SetStateZ(Z);
-      iotrack->SetStateD(Dr);
-      iotrack->SetStateTgl(tgl);
-      iotrack->SetStateC(C);
-               Double_t radius=result.Getrtrack();
-               iotrack->SetRadius(radius);
-               Int_t charge;
-               if(C>0.) charge=-1;  else charge=1;
-               iotrack->SetCharge(charge);
-               
-               
-
-      iotrack->SetCovMatrix(cov);         
-
-      Double_t px=pt*TMath::Cos(phi);
-      Double_t py=pt*TMath::Sin(phi);
-      Double_t pz=pt*tgl;
-               
-      Double_t xtrack=Dr*TMath::Sin(phi);
-      Double_t ytrack=Dr*TMath::Cos(phi);
-      Double_t ztrack=Dz+Vgeant(2);
-
-
-      iotrack->SetPx(px);
-      iotrack->SetPy(py);
-      iotrack->SetPz(pz);
-      iotrack->SetX(xtrack);
-      iotrack->SetY(ytrack);
-      iotrack->SetZ(ztrack);
-      iotrack->SetLabel(labITS);
-               
-      Int_t il;                
-               for(il=0;il<6; il++){
-                 iotrack->SetIdPoint(il,result.GetIdPoint(il));
-                 iotrack->SetIdModule(il,result.GetIdModule(il));              
-               }
-      tracktree1.Fill();
-
-   //cout<<" labITS = "<<labITS<<"\n";
-       //cout<<" phi z Dr tgl C = "<<phi<<" "<<Z<<" "<<Dr<<" "<<tgl<<" "<<C<<"\n";  getchar();    
-
-     DataOut(kkk) = ptg; kkk++; DataOut(kkk)=labITS; kkk++; DataOut(kkk)=lab; kkk++;           
-
-      for (il=0;il<6;il++) {
-        idpoint=result.GetIdPoint(il);
-        idmodule=result.GetIdModule(il);
-       *(vettid[idmodule]+idpoint)=1; 
-       iotrack->SetIdPoint(il,idpoint);
-        iotrack->SetIdModule(il,idmodule);
-      }
-      
-    //  cout<<"  +++++++++++++  pt e ptg = "<<pt<<" "<<ptg<<"  ++++++++++\n";
-      Double_t difpt= (pt-ptg)/ptg*100.;                                       
-      DataOut(kkk)=difpt; kkk++;                                             
-      Double_t lambdag=TMath::ATan(pzg/ptg);
-      Double_t   lam=TMath::ATan(tgl);      
-      Double_t diflam = (lam - lambdag)*1000.;
-      DataOut(kkk) = diflam; kkk++;                                        
-      Double_t phig=TMath::ATan(pyg/pxg);
-      Double_t phi=phivertex;  
-      Double_t difphi = (phi - phig)*1000.;
-      DataOut(kkk)=difphi; kkk++;
-      DataOut(kkk)=Dtot*1.e4; kkk++;
-      DataOut(kkk)=Dr*1.e4; kkk++;
-      DataOut(kkk)=Dz*1.e4; kkk++;
-      Int_t r;
-      for (r=0; r<9; r++) { out<<DataOut(r)<<" ";}
-      out<<"\n";
-      kkk=0;  
-               
-           
-    } // end if on NumofCluster
-  //gObjectTable->Print();    // stampa memoria     
-  }  //  end for (int j=min_t; j<=max_t; j++)
-  
-  out.close();  
-  
+  fLoader = new AliITSLoader(GetName(),topfoldername);
+  return fLoader;
  
-  static Bool_t first=kTRUE;
-  static TFile *tfile;
-
-       if(first) {
-           tfile=new TFile("itstracks.root","RECREATE");
-           //cout<<"I have opened itstracks.root file "<<endl;
-       }           
-       first=kFALSE;
-       tfile->cd();
-       tfile->ls();
-
-   char hname[30];
-   sprintf(hname,"TreeT%d",evNumber);
-
-  tracktree1.Write(hname);
-
+}
 
-  
-           TTree *fAli=gAlice->TreeK();
-            TFile *fileAli=0;
-           
-           if (fAli) fileAli =fAli->GetCurrentFile();
-           fileAli->cd();
-     
-  ////////////////////////////////////////////////////////////////////////////////////////////////
 
-  printf("delete vectors\n");
-  if(np) delete [] np;
-  if(vettid) delete [] vettid;
-  
-}