[u/mrichter/AliRoot.git] / FMD / AliFMDReconstructor.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/
/* $Id$ */
/** @file    AliFMDReconstructor.cxx
    @author  Christian Holm Christensen <cholm@nbi.dk>
    @date    Mon Mar 27 12:47:09 2006
    @brief   FMD reconstruction 
*/
//____________________________________________________________________
//
// This is a class that constructs AliFMDRecPoint objects from of Digits
// This class reads either digits from a TClonesArray or raw data from 
// a DDL file (or similar), and stores the read ADC counts in an
// internal cache (fAdcs).   The rec-points are made via the naiive
// method. 
//
//-- Authors: Evgeny Karpechev(INR) and Alla Maevsksia
//  Latest changes by Christian Holm Christensen <cholm@nbi.dk>
//
//
//____________________________________________________________________

#include <AliLog.h>                        // ALILOG_H
// #include <AliRun.h>                        // ALIRUN_H
#include <AliRunLoader.h>                  // ALIRUNLOADER_H
#include <AliHeader.h>                     // ALIHEADER_H
#include <AliGenEventHeader.h>             // ALIGENEVENTHEADER_H
#include "AliFMDGeometry.h"                // ALIFMDGEOMETRY_H
#include "AliFMDParameters.h"              // ALIFMDPARAMETERS_H
#include "AliFMDDigit.h"                   // ALIFMDDIGIT_H
#include "AliFMDReconstructor.h"           // ALIFMDRECONSTRUCTOR_H
#include "AliFMDRawReader.h"               // ALIFMDRAWREADER_H
#include "AliFMDRecPoint.h"	   	   // ALIFMDMULTNAIIVE_H
#include "AliESD.h"			   // ALIESD_H
#include <AliESDFMD.h>			   // ALIESDFMD_H
class AliRawReader;

//____________________________________________________________________
ClassImp(AliFMDReconstructor)
#if 0
  ; // This is here to keep Emacs for indenting the next line
#endif

//____________________________________________________________________
AliFMDReconstructor::AliFMDReconstructor() 
  : AliReconstructor(),
    fMult(0x0), 
    fNMult(0),
    fTreeR(0x0),
    fCurrentVertex(0),
    fESDObj(0x0),
    fESD(0x0)
{
  // Make a new FMD reconstructor object - default CTOR.  
  SetNoiseFactor();
  SetAngleCorrect();
}
  

//____________________________________________________________________
AliFMDReconstructor::AliFMDReconstructor(const AliFMDReconstructor& other) 
  : AliReconstructor(), 
    fMult(other.fMult),
    fNMult(other.fNMult),
    fTreeR(other.fTreeR),
    fCurrentVertex(other.fCurrentVertex),
    fESDObj(other.fESDObj),
    fESD(other.fESD), 
    fNoiseFactor(other.fNoiseFactor),
    fAngleCorrect(other.fAngleCorrect)
{
  // Copy constructor 
}
  

//____________________________________________________________________
AliFMDReconstructor&
AliFMDReconstructor::operator=(const AliFMDReconstructor& other) 
{
  // Assignment operator
  fMult          = other.fMult;
  fNMult         = other.fNMult;
  fTreeR         = other.fTreeR;
  fCurrentVertex = other.fCurrentVertex;
  fESDObj        = other.fESDObj;
  fESD           = other.fESD;
  fNoiseFactor   = other.fNoiseFactor;
  fAngleCorrect  = other.fAngleCorrect;
   
  return *this;
}

//____________________________________________________________________
AliFMDReconstructor::~AliFMDReconstructor() 
{
  // Destructor 
  if (fMult)   fMult->Delete();
  if (fMult)   delete fMult;
  if (fESDObj) delete fESDObj;
}

//____________________________________________________________________
void 
AliFMDReconstructor::Init(AliRunLoader* runLoader) 
{
  // Initialize the reconstructor 
  AliDebug(1, Form("Init called with runloader 0x%x", runLoader));
  // Initialize the geometry 
  AliFMDGeometry* geom = AliFMDGeometry::Instance();
  geom->Init();
  geom->InitTransformations();

  // Initialize the parameters
  AliFMDParameters* param = AliFMDParameters::Instance();
  param->Init();
  
  // Current vertex position
  fCurrentVertex = 0;
  // Create array of reconstructed strip multiplicities 
  fMult = new TClonesArray("AliFMDRecPoint", 51200);
  // Create ESD output object 
  fESDObj = new AliESDFMD;
  
  // Check that we have a run loader
  if (!runLoader) { 
    Warning("Init", "No run loader");
    return;
  }

  // Check if we can get the header tree 
  AliHeader* header = runLoader->GetHeader();
  if (!header) {
    Warning("Init", "No header");
    return;
  }

  // Check if we can get a simulation header 
  AliGenEventHeader* eventHeader = header->GenEventHeader();
  if (eventHeader) {
    TArrayF vtx;
    eventHeader->PrimaryVertex(vtx);
    fCurrentVertex = vtx[2];
    AliDebug(1, Form("Primary vertex Z coordinate for event # %d/%d is %f", 
		     header->GetRun(), header->GetEvent(), fCurrentVertex));
    Warning("Init", "no generator event header");
  }
  else {
    Warning("Init", "No generator event header - "
	    "perhaps we get the vertex from ESD?");
  }
}

//____________________________________________________________________
void 
AliFMDReconstructor::ConvertDigits(AliRawReader* reader, 
				   TTree* digitsTree) const
{
  // Convert Raw digits to AliFMDDigit's in a tree 
  AliDebug(1, "Reading raw data into digits tree");
  AliFMDRawReader rawRead(reader, digitsTree);
  // rawRead.SetSampleRate(fFMD->GetSampleRate());
  rawRead.Exec();
}

//____________________________________________________________________
void 
AliFMDReconstructor::Reconstruct(TTree* digitsTree, 
				 TTree* clusterTree) const 
{
  // Reconstruct event from digits in tree 
  // Get the FMD branch holding the digits. 
  // FIXME: The vertex may not be known yet, so we may have to move
  // some of this to FillESD. 
  AliDebug(1, "Reconstructing from digits in a tree");
#if 1
  if (fESD) {
    const AliESDVertex* vertex = fESD->GetVertex();
    if (vertex) {
      AliDebug(1, Form("Got vertex from ESD: %f", vertex->GetZv()));
      fCurrentVertex = vertex->GetZv();
    }
  }
#endif  
  TBranch *digitBranch = digitsTree->GetBranch("FMD");
  if (!digitBranch) {
    Error("Exec", "No digit branch for the FMD found");
    return;
  }
  TClonesArray* digits = new TClonesArray("AliFMDDigit");
  digitBranch->SetAddress(&digits);

  if (fMult)   fMult->Clear();
  if (fESDObj) fESDObj->Clear();
  
  fNMult = 0;
  fTreeR = clusterTree;
  fTreeR->Branch("FMD", &fMult);
  
  AliDebug(5, "Getting entry 0 from digit branch");
  digitBranch->GetEntry(0);
  
  AliDebug(5, "Processing digits");
  ProcessDigits(digits);

  Int_t written = clusterTree->Fill();
  AliDebug(10, Form("Filled %d bytes into cluster tree", written));
  digits->Delete();
  delete digits;
}
 

//____________________________________________________________________
void
AliFMDReconstructor::ProcessDigits(TClonesArray* digits) const
{
  // For each digit, find the pseudo rapdity, azimuthal angle, and
  // number of corrected ADC counts, and pass it on to the algorithms
  // used. 
  Int_t nDigits = digits->GetEntries();
  AliDebug(1, Form("Got %d digits", nDigits));
  fESDObj->SetNoiseFactor(fNoiseFactor);
  fESDObj->SetAngleCorrected(fAngleCorrect);
  for (Int_t i = 0; i < nDigits; i++) {
    AliFMDDigit* digit = static_cast<AliFMDDigit*>(digits->At(i));
    AliFMDParameters* param  = AliFMDParameters::Instance();
    // Check that the strip is not marked as dead 
    if (param->IsDead(digit->Detector(), digit->Ring(), 
		      digit->Sector(), digit->Strip())) {
      AliDebug(10, Form("FMD%d%c[%2d,%3d] is dead", digit->Detector(), 
			digit->Ring(), digit->Sector(), digit->Strip()));
      continue;
    }

    // digit->Print();
    // Get eta and phi 
    Float_t eta, phi;
    PhysicalCoordinates(digit, eta, phi);
    
    // Substract pedestal. 
    UShort_t counts   = SubtractPedestal(digit);
    
    // Gain match digits. 
    Double_t edep     = Adc2Energy(digit, eta, counts);
    
    // Make rough multiplicity 
    Double_t mult     = Energy2Multiplicity(digit, edep);
    
    AliDebug(10, Form("FMD%d%c[%2d,%3d]: "
		      "ADC: %d, Counts: %d, Energy: %f, Mult: %f", 
		      digit->Detector(), digit->Ring(), digit->Sector(),
		      digit->Strip(), digit->Counts(), counts, edep, mult));
    
    // Create a `RecPoint' on the output branch. 
    AliFMDRecPoint* m = 
      new ((*fMult)[fNMult]) AliFMDRecPoint(digit->Detector(), 
					    digit->Ring(), 
					    digit->Sector(),
					    digit->Strip(),
					    eta, phi, 
					    edep, mult);
    (void)m; // Suppress warnings about unused variables. 
    fNMult++;

    fESDObj->SetMultiplicity(digit->Detector(), digit->Ring(), 
			     digit->Sector(),  digit->Strip(), mult);
    fESDObj->SetEta(digit->Detector(), digit->Ring(), 
		    digit->Sector(),  digit->Strip(), eta);
  }
}

//____________________________________________________________________
UShort_t
AliFMDReconstructor::SubtractPedestal(AliFMDDigit* digit) const
{
  // Member function to subtract the pedestal from a digit
  // This implementation does nothing, but a derived class could over
  // load this to subtract a pedestal that was given in a database or
  // something like that. 

  Int_t             counts = 0;
  AliFMDParameters* param  = AliFMDParameters::Instance();
  Float_t           ped    = param->GetPedestal(digit->Detector(), 
						digit->Ring(), 
						digit->Sector(), 
						digit->Strip());
  Float_t           noise  = param->GetPedestalWidth(digit->Detector(), 
						     digit->Ring(), 
						     digit->Sector(), 
						     digit->Strip());
  AliDebug(15, Form("Subtracting pedestal %f from signal %d", 
		   ped, digit->Counts()));
  if (digit->Count3() > 0)      counts = digit->Count3();
  else if (digit->Count2() > 0) counts = digit->Count2();
  else                          counts = digit->Count1();
  counts = TMath::Max(Int_t(counts - ped), 0);
  if (counts < noise * fNoiseFactor) counts = 0;
  if (counts > 0) AliDebug(15, "Got a hit strip");
  
  return  UShort_t(counts);
}

//____________________________________________________________________
Float_t
AliFMDReconstructor::Adc2Energy(AliFMDDigit* digit, 
				Float_t      eta, 
				UShort_t     count) const
{
  // Converts number of ADC counts to energy deposited. 
  // Note, that this member function can be overloaded by derived
  // classes to do strip-specific look-ups in databases or the like,
  // to find the proper gain for a strip. 
  // 
  // In this simple version, we calculate the energy deposited as 
  // 
  //    EnergyDeposited = cos(theta) * gain * count
  // 
  // where 
  // 
  //           Pre_amp_MIP_Range
  //    gain = ----------------- * Energy_deposited_per_MIP
  //           ADC_channel_size    
  // 
  // is constant and the same for all strips.

  if (count <= 0) return 0;
  AliFMDParameters* param = AliFMDParameters::Instance();
  Float_t           gain  = param->GetPulseGain(digit->Detector(), 
						digit->Ring(), 
						digit->Sector(), 
						digit->Strip());
  AliDebug(15, Form("Converting counts %d to energy via factor %f", 
		    count, gain));

  Double_t edep  = count * gain;
  if (fAngleCorrect) {
    Double_t theta =  2 * TMath::ATan(TMath::Exp(-eta));
    edep           *= TMath::Abs(TMath::Cos(theta));
  }
  return edep;
}

//____________________________________________________________________
Float_t
AliFMDReconstructor::Energy2Multiplicity(AliFMDDigit* /* digit */, 
					 Float_t      edep) const
{
  // Converts an energy signal to number of particles. 
  // Note, that this member function can be overloaded by derived
  // classes to do strip-specific look-ups in databases or the like,
  // to find the proper gain for a strip. 
  // 
  // In this simple version, we calculate the multiplicity as 
  // 
  //   multiplicity = Energy_deposited / Energy_deposited_per_MIP
  // 
  // where 
  //
  //   Energy_deposited_per_MIP = 1.664 * SI_density * SI_thickness 
  // 
  // is constant and the same for all strips 
  AliFMDParameters* param   = AliFMDParameters::Instance();
  Double_t          edepMIP = param->GetEdepMip();
  Float_t           mult    = edep / edepMIP;
  if (edep > 0) 
    AliDebug(15, Form("Translating energy %f to multiplicity via "
		     "divider %f->%f", edep, edepMIP, mult));
  return mult;
}

//____________________________________________________________________
void
AliFMDReconstructor::PhysicalCoordinates(AliFMDDigit* digit, 
					 Float_t& eta, 
					 Float_t& phi) const
{
  // Get the eta and phi of a digit 
  // 
  // Get geometry. 
  AliFMDGeometry* geom = AliFMDGeometry::Instance();
  Double_t x, y, z, r, theta;
  geom->Detector2XYZ(digit->Detector(), digit->Ring(), digit->Sector(), 
		    digit->Strip(), x, y, z);
  // Correct for vertex offset. 
  z     += fCurrentVertex;
  phi   =  TMath::ATan2(y, x);
  r     =  TMath::Sqrt(y * y + x * x);
  theta =  TMath::ATan2(r, z);
  eta   = -TMath::Log(TMath::Tan(theta / 2));
}

      
//____________________________________________________________________
void 
AliFMDReconstructor::FillESD(TTree*  /* digitsTree */, 
			     TTree*  /* clusterTree */,
			     AliESD* esd) const
{
  // nothing to be done
  // FIXME: The vertex may not be known when Reconstruct is executed,
  // so we may have to move some of that member function here. 
  AliDebug(1, Form("Calling FillESD with two trees and one ESD"));
  // fESDObj->Print();

  if (esd) { 
    AliDebug(1, Form("Writing FMD data to ESD tree"));
    esd->SetFMDData(fESDObj);
  }
}


//____________________________________________________________________
void 
AliFMDReconstructor::Reconstruct(AliRawReader*,TTree*) const 
{
  // Cannot be used.  See member function with same name but with 2
  // TTree arguments.   Make sure you do local reconstrucion 
  AliDebug(1, Form("Calling FillESD with loader and tree"));
  AliError("MayNotUse");
}
//____________________________________________________________________
void 
AliFMDReconstructor::Reconstruct(AliRunLoader*) const 
{
  // Cannot be used.  See member function with same name but with 2
  // TTree arguments.   Make sure you do local reconstrucion 
  AliDebug(1, Form("Calling FillESD with loader"));
  AliError("MayNotUse");
}
//____________________________________________________________________
void 
AliFMDReconstructor::Reconstruct(AliRunLoader*, AliRawReader*) const 
{
  // Cannot be used.  See member function with same name but with 2
  // TTree arguments.   Make sure you do local reconstrucion 
  AliDebug(1, Form("Calling FillESD with loader and raw reader"));
  AliError("MayNotUse");
}
//____________________________________________________________________
void 
AliFMDReconstructor::FillESD(AliRawReader*,TTree*,AliESD*) const 
{
  // Cannot be used.  See member function with same name but with 2
  // TTree arguments.   Make sure you do local reconstrucion 
  AliDebug(1, Form("Calling FillESD with raw reader, tree, and ESD"));
  AliError("MayNotUse");
}
//____________________________________________________________________
void 
AliFMDReconstructor::FillESD(AliRunLoader*,AliESD*) const
{
  // Cannot be used.  See member function with same name but with 2
  // TTree arguments.   Make sure you do local reconstrucion 
  AliDebug(1, Form("Calling FillESD with loader and ESD"));
  AliError("MayNotUse");
}
//____________________________________________________________________
void 
AliFMDReconstructor::FillESD(AliRunLoader*,AliRawReader*,AliESD*) const 
{
  // Cannot be used.  See member function with same name but with 2
  // TTree arguments.   Make sure you do local reconstrucion 
  AliDebug(1, Form("Calling FillESD with loader, raw reader, and ESD"));
  AliError("MayNotUse");
}

//____________________________________________________________________
//
// EOF
//
Commit	Line	Data
	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15	/* $Id$ */
	16	/** @file AliFMDReconstructor.cxx
	17	@author Christian Holm Christensen <cholm@nbi.dk>
	18	@date Mon Mar 27 12:47:09 2006
	19	@brief FMD reconstruction
	20	*/
	21	//____________________________________________________________________
	22	//
	23	// This is a class that constructs AliFMDRecPoint objects from of Digits
	24	// This class reads either digits from a TClonesArray or raw data from
	25	// a DDL file (or similar), and stores the read ADC counts in an
	26	// internal cache (fAdcs). The rec-points are made via the naiive
	27	// method.
	28	//
	29	//-- Authors: Evgeny Karpechev(INR) and Alla Maevsksia
	30	// Latest changes by Christian Holm Christensen <cholm@nbi.dk>
	31	//
	32	//
	33	//____________________________________________________________________
	34
	35	#include <AliLog.h> // ALILOG_H
	36	// #include <AliRun.h> // ALIRUN_H
	37	#include <AliRunLoader.h> // ALIRUNLOADER_H
	38	#include <AliHeader.h> // ALIHEADER_H
	39	#include <AliGenEventHeader.h> // ALIGENEVENTHEADER_H
	40	#include "AliFMDGeometry.h" // ALIFMDGEOMETRY_H
	41	#include "AliFMDParameters.h" // ALIFMDPARAMETERS_H
	42	#include "AliFMDDigit.h" // ALIFMDDIGIT_H
	43	#include "AliFMDReconstructor.h" // ALIFMDRECONSTRUCTOR_H
	44	#include "AliFMDRawReader.h" // ALIFMDRAWREADER_H
	45	#include "AliFMDRecPoint.h" // ALIFMDMULTNAIIVE_H
	46	#include "AliESD.h" // ALIESD_H
	47	#include <AliESDFMD.h> // ALIESDFMD_H
	48	class AliRawReader;
	49
	50	//____________________________________________________________________
	51	ClassImp(AliFMDReconstructor)
	52	#if 0
	53	; // This is here to keep Emacs for indenting the next line
	54	#endif
	55
	56	//____________________________________________________________________
	57	AliFMDReconstructor::AliFMDReconstructor()
	58	: AliReconstructor(),
	59	fMult(0x0),
	60	fNMult(0),
	61	fTreeR(0x0),
	62	fCurrentVertex(0),
	63	fESDObj(0x0),
	64	fESD(0x0)
	65	{
	66	// Make a new FMD reconstructor object - default CTOR.
	67	SetNoiseFactor();
	68	SetAngleCorrect();
	69	}
	70
	71
	72	//____________________________________________________________________
	73	AliFMDReconstructor::AliFMDReconstructor(const AliFMDReconstructor& other)
	74	: AliReconstructor(),
	75	fMult(other.fMult),
	76	fNMult(other.fNMult),
	77	fTreeR(other.fTreeR),
	78	fCurrentVertex(other.fCurrentVertex),
	79	fESDObj(other.fESDObj),
	80	fESD(other.fESD),
	81	fNoiseFactor(other.fNoiseFactor),
	82	fAngleCorrect(other.fAngleCorrect)
	83	{
	84	// Copy constructor
	85	}
	86
	87
	88	//____________________________________________________________________
	89	AliFMDReconstructor&
	90	AliFMDReconstructor::operator=(const AliFMDReconstructor& other)
	91	{
	92	// Assignment operator
	93	fMult = other.fMult;
	94	fNMult = other.fNMult;
	95	fTreeR = other.fTreeR;
	96	fCurrentVertex = other.fCurrentVertex;
	97	fESDObj = other.fESDObj;
	98	fESD = other.fESD;
	99	fNoiseFactor = other.fNoiseFactor;
	100	fAngleCorrect = other.fAngleCorrect;
	101
	102	return *this;
	103	}
	104
	105	//____________________________________________________________________
	106	AliFMDReconstructor::~AliFMDReconstructor()
	107	{
	108	// Destructor
	109	if (fMult) fMult->Delete();
	110	if (fMult) delete fMult;
	111	if (fESDObj) delete fESDObj;
	112	}
	113
	114	//____________________________________________________________________
	115	void
	116	AliFMDReconstructor::Init(AliRunLoader* runLoader)
	117	{
	118	// Initialize the reconstructor
	119	AliDebug(1, Form("Init called with runloader 0x%x", runLoader));
	120	// Initialize the geometry
	121	AliFMDGeometry* geom = AliFMDGeometry::Instance();
	122	geom->Init();
	123	geom->InitTransformations();
	124
	125	// Initialize the parameters
	126	AliFMDParameters* param = AliFMDParameters::Instance();
	127	param->Init();
	128
	129	// Current vertex position
	130	fCurrentVertex = 0;
	131	// Create array of reconstructed strip multiplicities
	132	fMult = new TClonesArray("AliFMDRecPoint", 51200);
	133	// Create ESD output object
	134	fESDObj = new AliESDFMD;
	135
	136	// Check that we have a run loader
	137	if (!runLoader) {
	138	Warning("Init", "No run loader");
	139	return;
	140	}
	141
	142	// Check if we can get the header tree
	143	AliHeader* header = runLoader->GetHeader();
	144	if (!header) {
	145	Warning("Init", "No header");
	146	return;
	147	}
	148
	149	// Check if we can get a simulation header
	150	AliGenEventHeader* eventHeader = header->GenEventHeader();
	151	if (eventHeader) {
	152	TArrayF vtx;
	153	eventHeader->PrimaryVertex(vtx);
	154	fCurrentVertex = vtx[2];
	155	AliDebug(1, Form("Primary vertex Z coordinate for event # %d/%d is %f",
	156	header->GetRun(), header->GetEvent(), fCurrentVertex));
	157	Warning("Init", "no generator event header");
	158	}
	159	else {
	160	Warning("Init", "No generator event header - "
	161	"perhaps we get the vertex from ESD?");
	162	}
	163	}
	164
	165	//____________________________________________________________________
	166	void
	167	AliFMDReconstructor::ConvertDigits(AliRawReader* reader,
	168	TTree* digitsTree) const
	169	{
	170	// Convert Raw digits to AliFMDDigit's in a tree
	171	AliDebug(1, "Reading raw data into digits tree");
	172	AliFMDRawReader rawRead(reader, digitsTree);
	173	// rawRead.SetSampleRate(fFMD->GetSampleRate());
	174	rawRead.Exec();
	175	}
	176
	177	//____________________________________________________________________
	178	void
	179	AliFMDReconstructor::Reconstruct(TTree* digitsTree,
	180	TTree* clusterTree) const
	181	{
	182	// Reconstruct event from digits in tree
	183	// Get the FMD branch holding the digits.
	184	// FIXME: The vertex may not be known yet, so we may have to move
	185	// some of this to FillESD.
	186	AliDebug(1, "Reconstructing from digits in a tree");
	187	#if 1
	188	if (fESD) {
	189	const AliESDVertex* vertex = fESD->GetVertex();
	190	if (vertex) {
	191	AliDebug(1, Form("Got vertex from ESD: %f", vertex->GetZv()));
	192	fCurrentVertex = vertex->GetZv();
	193	}
	194	}
	195	#endif
	196	TBranch *digitBranch = digitsTree->GetBranch("FMD");
	197	if (!digitBranch) {
	198	Error("Exec", "No digit branch for the FMD found");
	199	return;
	200	}
	201	TClonesArray* digits = new TClonesArray("AliFMDDigit");
	202	digitBranch->SetAddress(&digits);
	203
	204	if (fMult) fMult->Clear();
	205	if (fESDObj) fESDObj->Clear();
	206
	207	fNMult = 0;
	208	fTreeR = clusterTree;
	209	fTreeR->Branch("FMD", &fMult);
	210
	211	AliDebug(5, "Getting entry 0 from digit branch");
	212	digitBranch->GetEntry(0);
	213
	214	AliDebug(5, "Processing digits");
	215	ProcessDigits(digits);
	216
	217	Int_t written = clusterTree->Fill();
	218	AliDebug(10, Form("Filled %d bytes into cluster tree", written));
	219	digits->Delete();
	220	delete digits;
	221	}
	222
	223
	224	//____________________________________________________________________
	225	void
	226	AliFMDReconstructor::ProcessDigits(TClonesArray* digits) const
	227	{
	228	// For each digit, find the pseudo rapdity, azimuthal angle, and
	229	// number of corrected ADC counts, and pass it on to the algorithms
	230	// used.
	231	Int_t nDigits = digits->GetEntries();
	232	AliDebug(1, Form("Got %d digits", nDigits));
	233	fESDObj->SetNoiseFactor(fNoiseFactor);
	234	fESDObj->SetAngleCorrected(fAngleCorrect);
	235	for (Int_t i = 0; i < nDigits; i++) {
	236	AliFMDDigit* digit = static_cast<AliFMDDigit*>(digits->At(i));
	237	AliFMDParameters* param = AliFMDParameters::Instance();
	238	// Check that the strip is not marked as dead
	239	if (param->IsDead(digit->Detector(), digit->Ring(),
	240	digit->Sector(), digit->Strip())) {
	241	AliDebug(10, Form("FMD%d%c[%2d,%3d] is dead", digit->Detector(),
	242	digit->Ring(), digit->Sector(), digit->Strip()));
	243	continue;
	244	}
	245
	246	// digit->Print();
	247	// Get eta and phi
	248	Float_t eta, phi;
	249	PhysicalCoordinates(digit, eta, phi);
	250
	251	// Substract pedestal.
	252	UShort_t counts = SubtractPedestal(digit);
	253
	254	// Gain match digits.
	255	Double_t edep = Adc2Energy(digit, eta, counts);
	256
	257	// Make rough multiplicity
	258	Double_t mult = Energy2Multiplicity(digit, edep);
	259
	260	AliDebug(10, Form("FMD%d%c[%2d,%3d]: "
	261	"ADC: %d, Counts: %d, Energy: %f, Mult: %f",
	262	digit->Detector(), digit->Ring(), digit->Sector(),
	263	digit->Strip(), digit->Counts(), counts, edep, mult));
	264
	265	// Create a `RecPoint' on the output branch.
	266	AliFMDRecPoint* m =
	267	new ((*fMult)[fNMult]) AliFMDRecPoint(digit->Detector(),
	268	digit->Ring(),
	269	digit->Sector(),
	270	digit->Strip(),
	271	eta, phi,
	272	edep, mult);
	273	(void)m; // Suppress warnings about unused variables.
	274	fNMult++;
	275
	276	fESDObj->SetMultiplicity(digit->Detector(), digit->Ring(),
	277	digit->Sector(), digit->Strip(), mult);
	278	fESDObj->SetEta(digit->Detector(), digit->Ring(),
	279	digit->Sector(), digit->Strip(), eta);
	280	}
	281	}
	282
	283	//____________________________________________________________________
	284	UShort_t
	285	AliFMDReconstructor::SubtractPedestal(AliFMDDigit* digit) const
	286	{
	287	// Member function to subtract the pedestal from a digit
	288	// This implementation does nothing, but a derived class could over
	289	// load this to subtract a pedestal that was given in a database or
	290	// something like that.
	291
	292	Int_t counts = 0;
	293	AliFMDParameters* param = AliFMDParameters::Instance();
	294	Float_t ped = param->GetPedestal(digit->Detector(),
	295	digit->Ring(),
	296	digit->Sector(),
	297	digit->Strip());
	298	Float_t noise = param->GetPedestalWidth(digit->Detector(),
	299	digit->Ring(),
	300	digit->Sector(),
	301	digit->Strip());
	302	AliDebug(15, Form("Subtracting pedestal %f from signal %d",
	303	ped, digit->Counts()));
	304	if (digit->Count3() > 0) counts = digit->Count3();
	305	else if (digit->Count2() > 0) counts = digit->Count2();
	306	else counts = digit->Count1();
	307	counts = TMath::Max(Int_t(counts - ped), 0);
	308	if (counts < noise * fNoiseFactor) counts = 0;
	309	if (counts > 0) AliDebug(15, "Got a hit strip");
	310
	311	return UShort_t(counts);
	312	}
	313
	314	//____________________________________________________________________
	315	Float_t
	316	AliFMDReconstructor::Adc2Energy(AliFMDDigit* digit,
	317	Float_t eta,
	318	UShort_t count) const
	319	{
	320	// Converts number of ADC counts to energy deposited.
	321	// Note, that this member function can be overloaded by derived
	322	// classes to do strip-specific look-ups in databases or the like,
	323	// to find the proper gain for a strip.
	324	//
	325	// In this simple version, we calculate the energy deposited as
	326	//
	327	// EnergyDeposited = cos(theta) * gain * count
	328	//
	329	// where
	330	//
	331	// Pre_amp_MIP_Range
	332	// gain = ----------------- * Energy_deposited_per_MIP
	333	// ADC_channel_size
	334	//
	335	// is constant and the same for all strips.
	336
	337	if (count <= 0) return 0;
	338	AliFMDParameters* param = AliFMDParameters::Instance();
	339	Float_t gain = param->GetPulseGain(digit->Detector(),
	340	digit->Ring(),
	341	digit->Sector(),
	342	digit->Strip());
	343	AliDebug(15, Form("Converting counts %d to energy via factor %f",
	344	count, gain));
	345
	346	Double_t edep = count * gain;
	347	if (fAngleCorrect) {
	348	Double_t theta = 2 * TMath::ATan(TMath::Exp(-eta));
	349	edep *= TMath::Abs(TMath::Cos(theta));
	350	}
	351	return edep;
	352	}
	353
	354	//____________________________________________________________________
	355	Float_t
	356	AliFMDReconstructor::Energy2Multiplicity(AliFMDDigit* /* digit */,
	357	Float_t edep) const
	358	{
	359	// Converts an energy signal to number of particles.
	360	// Note, that this member function can be overloaded by derived
	361	// classes to do strip-specific look-ups in databases or the like,
	362	// to find the proper gain for a strip.
	363	//
	364	// In this simple version, we calculate the multiplicity as
	365	//
	366	// multiplicity = Energy_deposited / Energy_deposited_per_MIP
	367	//
	368	// where
	369	//
	370	// Energy_deposited_per_MIP = 1.664 * SI_density * SI_thickness
	371	//
	372	// is constant and the same for all strips
	373	AliFMDParameters* param = AliFMDParameters::Instance();
	374	Double_t edepMIP = param->GetEdepMip();
	375	Float_t mult = edep / edepMIP;
	376	if (edep > 0)
	377	AliDebug(15, Form("Translating energy %f to multiplicity via "
	378	"divider %f->%f", edep, edepMIP, mult));
	379	return mult;
	380	}
	381
	382	//____________________________________________________________________
	383	void
	384	AliFMDReconstructor::PhysicalCoordinates(AliFMDDigit* digit,
	385	Float_t& eta,
	386	Float_t& phi) const
	387	{
	388	// Get the eta and phi of a digit
	389	//
	390	// Get geometry.
	391	AliFMDGeometry* geom = AliFMDGeometry::Instance();
	392	Double_t x, y, z, r, theta;
	393	geom->Detector2XYZ(digit->Detector(), digit->Ring(), digit->Sector(),
	394	digit->Strip(), x, y, z);
	395	// Correct for vertex offset.
	396	z += fCurrentVertex;
	397	phi = TMath::ATan2(y, x);
	398	r = TMath::Sqrt(y * y + x * x);
	399	theta = TMath::ATan2(r, z);
	400	eta = -TMath::Log(TMath::Tan(theta / 2));
	401	}
	402
	403
	404
	405	//____________________________________________________________________
	406	void
	407	AliFMDReconstructor::FillESD(TTree* /* digitsTree */,
	408	TTree* /* clusterTree */,
	409	AliESD* esd) const
	410	{
	411	// nothing to be done
	412	// FIXME: The vertex may not be known when Reconstruct is executed,
	413	// so we may have to move some of that member function here.
	414	AliDebug(1, Form("Calling FillESD with two trees and one ESD"));
	415	// fESDObj->Print();
	416
	417	if (esd) {
	418	AliDebug(1, Form("Writing FMD data to ESD tree"));
	419	esd->SetFMDData(fESDObj);
	420	}
	421	}
	422
	423
	424	//____________________________________________________________________
	425	void
	426	AliFMDReconstructor::Reconstruct(AliRawReader,TTree) const
	427	{
	428	// Cannot be used. See member function with same name but with 2
	429	// TTree arguments. Make sure you do local reconstrucion
	430	AliDebug(1, Form("Calling FillESD with loader and tree"));
	431	AliError("MayNotUse");
	432	}
	433	//____________________________________________________________________
	434	void
	435	AliFMDReconstructor::Reconstruct(AliRunLoader*) const
	436	{
	437	// Cannot be used. See member function with same name but with 2
	438	// TTree arguments. Make sure you do local reconstrucion
	439	AliDebug(1, Form("Calling FillESD with loader"));
	440	AliError("MayNotUse");
	441	}
	442	//____________________________________________________________________
	443	void
	444	AliFMDReconstructor::Reconstruct(AliRunLoader, AliRawReader) const
	445	{
	446	// Cannot be used. See member function with same name but with 2
	447	// TTree arguments. Make sure you do local reconstrucion
	448	AliDebug(1, Form("Calling FillESD with loader and raw reader"));
	449	AliError("MayNotUse");
	450	}
	451	//____________________________________________________________________
	452	void
	453	AliFMDReconstructor::FillESD(AliRawReader,TTree,AliESD*) const
	454	{
	455	// Cannot be used. See member function with same name but with 2
	456	// TTree arguments. Make sure you do local reconstrucion
	457	AliDebug(1, Form("Calling FillESD with raw reader, tree, and ESD"));
	458	AliError("MayNotUse");
	459	}
	460	//____________________________________________________________________
	461	void
	462	AliFMDReconstructor::FillESD(AliRunLoader,AliESD) const
	463	{
	464	// Cannot be used. See member function with same name but with 2
	465	// TTree arguments. Make sure you do local reconstrucion
	466	AliDebug(1, Form("Calling FillESD with loader and ESD"));
	467	AliError("MayNotUse");
	468	}
	469	//____________________________________________________________________
	470	void
	471	AliFMDReconstructor::FillESD(AliRunLoader,AliRawReader,AliESD*) const
	472	{
	473	// Cannot be used. See member function with same name but with 2
	474	// TTree arguments. Make sure you do local reconstrucion
	475	AliDebug(1, Form("Calling FillESD with loader, raw reader, and ESD"));
	476	AliError("MayNotUse");
	477	}
	478
	479	//____________________________________________________________________
	480	//
	481	// EOF
	482	//