SetObjectClassName removed

[u/mrichter/AliRoot.git] / TRD / AliTRDdigitizer.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.                  *
 **************************************************************************/

/* $Id$ */

///////////////////////////////////////////////////////////////////////////////
//                                                                           //
//  Creates and handles digits from TRD hits                                 //
//  Authors: C. Blume (blume@ikf.uni-frankfurt.de)                           //
//           C. Lippmann                                                     //
//           B. Vulpescu                                                     //
//                                                                           //
//  The following effects are included:                                      //
//      - Diffusion                                                          //
//      - ExB effects                                                        //
//      - Gas gain including fluctuations                                    //
//      - Pad-response (simple Gaussian approximation)                       //
//      - Time-response                                                      //
//      - Electronics noise                                                  //
//      - Electronics gain                                                   //
//      - Digitization                                                       //
//      - ADC threshold                                                      //
//  The corresponding parameter can be adjusted via the various              //
//  Set-functions. If these parameters are not explicitly set, default       //
//  values are used (see Init-function).                                     //
//                                                                           //
///////////////////////////////////////////////////////////////////////////////

#include <stdlib.h>

#include <TMath.h>
#include <TVector.h>
#include <TRandom.h>
#include <TROOT.h>
#include <TTree.h>
#include <TFile.h>
#include <TF1.h>
#include <TList.h>
#include <TTask.h>
#include <TGeoManager.h>

#include "AliRun.h"
#include "AliRunLoader.h"
#include "AliLoader.h"
#include "AliConfig.h"
#include "AliMagF.h"
#include "AliRunDigitizer.h"
#include "AliRunLoader.h"
#include "AliLoader.h"
#include "AliLog.h"

#include "AliTRD.h"
#include "AliTRDhit.h"
#include "AliTRDdigitizer.h"
#include "AliTRDdataArrayI.h"
#include "AliTRDdataArrayF.h"
#include "AliTRDsegmentArray.h"
#include "AliTRDdigitsManager.h"
#include "AliTRDgeometry.h"
#include "AliTRDpadPlane.h"
#include "AliTRDcalibDB.h"
#include "AliTRDSimParam.h"
#include "AliTRDCommonParam.h"

ClassImp(AliTRDdigitizer)

//_____________________________________________________________________________
AliTRDdigitizer::AliTRDdigitizer()
{
  //
  // AliTRDdigitizer default constructor
  //

  fRunLoader          = 0;
  fDigitsManager      = 0;
  fSDigitsManager     = 0;
  fSDigitsManagerList = 0;
  fTRD                = 0;
  fGeo                = 0;
  fEvent              = 0;
  fMasks              = 0;
  fCompress           = kTRUE;
  fSDigits            = kFALSE;
  fSDigitsScale       = 0.0;
  fMergeSignalOnly    = kFALSE;
 
  fTimeStructInfo.fLastVdrift   = 0;
  fTimeStructInfo.fTimeStruct1  = 0;
  fTimeStructInfo.fTimeStruct2  = 0;
  fTimeStructInfo.fVDlo         = 0;
  fTimeStructInfo.fVDhi         = 0;
  
  fDiffusionInfo.fLastVdrift    = 0;
  fDiffusionInfo.fDiffusionT    = 0.0;
  fDiffusionInfo.fDiffusionL    = 0.0;
  fDiffusionInfo.fLorentzFactor = 0.0;
  
  Init();

}

//_____________________________________________________________________________
AliTRDdigitizer::AliTRDdigitizer(const Text_t *name, const Text_t *title)
                :AliDigitizer(name,title)
{
  //
  // AliTRDdigitizer constructor
  //

  Init();

}

//_____________________________________________________________________________
AliTRDdigitizer::AliTRDdigitizer(AliRunDigitizer *manager
                                , const Text_t *name, const Text_t *title)
                :AliDigitizer(manager,name,title)
{
  //
  // AliTRDdigitizer constructor
  //

  Init();

}

//_____________________________________________________________________________
AliTRDdigitizer::AliTRDdigitizer(AliRunDigitizer *manager)
                :AliDigitizer(manager,"AliTRDdigitizer","TRD digitizer")
{
  //
  // AliTRDdigitizer constructor
  //

  Init();

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::Init()
{
  //
  // Initialize the digitizer with default values
  //

  fRunLoader          = 0;

  //NewIO: These data members probably are not needed anymore
  fDigitsManager      = 0;
  fSDigitsManager     = 0;
  fSDigitsManagerList = 0;
  fTRD                = 0;
  fGeo                = 0;
  //End NewIO comment

  fEvent              = 0;
  fMasks              = 0;
  fCompress           = kTRUE;
  fSDigits            = kFALSE;
  fSDigitsScale       = 100.; // For the summable digits
  fMergeSignalOnly    = kFALSE;
 
  fTimeStructInfo.fLastVdrift   = -1;
  fTimeStructInfo.fTimeStruct1  = 0;
  fTimeStructInfo.fTimeStruct2  = 0;
  fTimeStructInfo.fVDlo         = 0;
  fTimeStructInfo.fVDhi         = 0;
  
  fDiffusionInfo.fLastVdrift    = -1;
  fDiffusionInfo.fDiffusionT    = 0.0;
  fDiffusionInfo.fDiffusionL    = 0.0;
  fDiffusionInfo.fLorentzFactor = 0.0;

  return AliDigitizer::Init();

}

//_____________________________________________________________________________
AliTRDdigitizer::AliTRDdigitizer(const AliTRDdigitizer &d):AliDigitizer(d)
{
  //
  // AliTRDdigitizer copy constructor
  //

  ((AliTRDdigitizer &) d).Copy(*this);

}

//_____________________________________________________________________________
AliTRDdigitizer::~AliTRDdigitizer()
{
  //
  // AliTRDdigitizer destructor
  //

  if (fDigitsManager) {
    delete fDigitsManager;
    fDigitsManager = 0;
  }

  fSDigitsManager = 0;

  if (fSDigitsManagerList) {
    fSDigitsManagerList->Delete();
    delete fSDigitsManagerList;
    fSDigitsManagerList = 0;
  }

  if (fMasks) {
    delete [] fMasks;
    fMasks = 0;
  }

  if (fTimeStructInfo.fTimeStruct1)
  {
    delete [] fTimeStructInfo.fTimeStruct1;
    fTimeStructInfo.fTimeStruct1 = 0;
  }

  if (fTimeStructInfo.fTimeStruct2) 
  {
    delete [] fTimeStructInfo.fTimeStruct2;
    fTimeStructInfo.fTimeStruct2 = 0;
  }

}

//_____________________________________________________________________________
AliTRDdigitizer &AliTRDdigitizer::operator=(const AliTRDdigitizer &d)
{
  //
  // Assignment operator
  //

  if (this != &d) ((AliTRDdigitizer &) d).Copy(*this);
  return *this;

}

//_____________________________________________________________________________
void AliTRDdigitizer::Copy(TObject &d) const
{
  //
  // Copy function
  //

  ((AliTRDdigitizer &) d).fRunLoader          = 0;
  ((AliTRDdigitizer &) d).fDigitsManager      = 0;
  ((AliTRDdigitizer &) d).fSDigitsManager     = 0;
  ((AliTRDdigitizer &) d).fSDigitsManagerList = 0;
  ((AliTRDdigitizer &) d).fTRD                = 0;
  ((AliTRDdigitizer &) d).fGeo                = 0;
  ((AliTRDdigitizer &) d).fEvent              = 0;
  ((AliTRDdigitizer &) d).fMasks              = 0;
  ((AliTRDdigitizer &) d).fCompress           = fCompress;
  ((AliTRDdigitizer &) d).fSDigits            = fSDigits;
  ((AliTRDdigitizer &) d).fSDigitsScale       = fSDigitsScale;
  ((AliTRDdigitizer &) d).fMergeSignalOnly    = fMergeSignalOnly;
                                       
  AliTRDdigitizer& target = (AliTRDdigitizer &) d;
  
  target.fDiffusionInfo = fDiffusionInfo;
  
  // Do not copy timestructs, just invalidate lastvdrift.
  // Next time they are requested, they get recalculated
  if (target.fTimeStructInfo.fTimeStruct1)
  {
    delete[] target.fTimeStructInfo.fTimeStruct1;
    target.fTimeStructInfo.fTimeStruct1 = 0;
  }
  if (target.fTimeStructInfo.fTimeStruct2)
  {
    delete[] target.fTimeStructInfo.fTimeStruct2;
    target.fTimeStructInfo.fTimeStruct2 = 0;
  }  
  target.fTimeStructInfo.fLastVdrift = -1;

}

//_____________________________________________________________________________
void AliTRDdigitizer::Exec(Option_t* option)
{
  //
  // Executes the merging
  //

  Int_t iInput;

  AliTRDdigitsManager *sdigitsManager;

  TString optionString = option;
  if (optionString.Contains("deb")) {
    AliLog::SetClassDebugLevel("AliTRDdigitizer",1);
    AliInfo("Called with debug option\n");
  }

  // The AliRoot file is already connected by the manager
  AliRunLoader* inrl;
  
  if (gAlice) {
    AliDebug(1,"AliRun object found on file.\n");
  }
  else {
    inrl = AliRunLoader::GetRunLoader(fManager->GetInputFolderName(0));
    inrl->LoadgAlice();
    gAlice = inrl->GetAliRun();
    if (!gAlice) {
      AliError("Could not find AliRun object.\n")
      return;
    }
  }
                                                                           
  Int_t nInput = fManager->GetNinputs();
  fMasks = new Int_t[nInput];
  for (iInput = 0; iInput < nInput; iInput++) {
    fMasks[iInput] = fManager->GetMask(iInput);
  }

  //
  // Initialization
  //

  AliRunLoader* orl = AliRunLoader::GetRunLoader(fManager->GetOutputFolderName());
  if (InitDetector()) {

    AliLoader* ogime = orl->GetLoader("TRDLoader");

    TTree* tree = 0;
    if (fSDigits) { 
      // If we produce SDigits
      tree = ogime->TreeS();
      if (!tree) {
	ogime->MakeTree("S");
	tree = ogime->TreeS();
      }
    }
    else {
      // If we produce Digits
      tree = ogime->TreeD();
      if (!tree) {
	ogime->MakeTree("D");
        tree = ogime->TreeD();
      }
    }

    MakeBranch(tree);

  }
 
  for (iInput = 0; iInput < nInput; iInput++) {

    AliDebug(1,Form("Add input stream %d\n",iInput));

    // Check if the input tree exists
    inrl = AliRunLoader::GetRunLoader(fManager->GetInputFolderName(iInput));
    AliLoader* gime = inrl->GetLoader("TRDLoader");

    TTree * treees =  gime->TreeS();
    if (treees == 0x0) {
      if (gime->LoadSDigits()) {
        AliError(Form("Error Occured while loading S. Digits for input %d.",iInput));
        return;
      }
      treees =  gime->TreeS();
    }
    
    if (treees == 0x0) {
      AliError(Form("Input stream %d does not exist\n",iInput));
      return;
    } 

    // Read the s-digits via digits manager
    sdigitsManager = new AliTRDdigitsManager();
    sdigitsManager->SetSDigits(kTRUE);
    
    AliRunLoader* rl = AliRunLoader::GetRunLoader(fManager->GetInputFolderName(iInput));
    AliLoader* gimme = rl->GetLoader("TRDLoader");
    if (!gimme->TreeS()) gimme->LoadSDigits();
    sdigitsManager->ReadDigits(gimme->TreeS());

    // Add the s-digits to the input list 
    AddSDigitsManager(sdigitsManager);

  }

  // Convert the s-digits to normal digits
  AliDebug(1,"Do the conversion\n");
  SDigits2Digits();

  // Store the digits
  AliDebug(1,"Write the digits\n");
  fDigitsManager->WriteDigits();

  // Write parameters
  orl->CdGAFile();

  AliDebug(1,"Done\n");

  DeleteSDigitsManager();

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::Open(const Char_t *file, Int_t nEvent)
{
  //
  // Opens a ROOT-file with TRD-hits and reads in the hit-tree
  //
  // Connect the AliRoot file containing Geometry, Kine, and Hits
  //  

  TString evfoldname = AliConfig::GetDefaultEventFolderName();

  fRunLoader = AliRunLoader::GetRunLoader(evfoldname);
  if (!fRunLoader) {
    fRunLoader = AliRunLoader::Open(file,evfoldname,"UPDATE");
  }  

  if (!fRunLoader) {
     AliError(Form("Can not open session for file %s.",file));
     return kFALSE;
   }
   
  if (!fRunLoader->GetAliRun()) {
    fRunLoader->LoadgAlice();
  }
  gAlice = fRunLoader->GetAliRun();
  
  if (gAlice) {
    AliDebug(1,"AliRun object found on file.\n");
  }
  else {
    AliError("Could not find AliRun object.\n");
    return kFALSE;
  }

  fEvent = nEvent;

  // Import the Trees for the event nEvent in the file
  //fRunLoader->GetEvent(fEvent);
  
  AliLoader* loader = fRunLoader->GetLoader("TRDLoader");
  if (!loader) {
    AliError("Can not get TRD loader from Run Loader");
    return kFALSE;
  }
  
  if (InitDetector()) {
    TTree* tree = 0;
    if (fSDigits) { 
      // If we produce SDigits
      tree = loader->TreeS();
      if (!tree) {
        loader->MakeTree("S");
        tree = loader->TreeS();
       }
    }
    else {
      // If we produce Digits
      if (!tree) {
        loader->MakeTree("D");
        tree = loader->TreeD();
       }
    }
    return MakeBranch(tree);
  }
  else {
    return kFALSE;
  }

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::InitDetector()
{
  //
  // Sets the pointer to the TRD detector and the geometry
  //

  // Get the pointer to the detector class and check for version 1
  fTRD = (AliTRD *) gAlice->GetDetector("TRD");
  if (!fTRD) {
    AliFatal("No TRD module found\n");
    exit(1);
  }
  if (fTRD->IsVersion() != 1) {
    AliFatal("TRD must be version 1 (slow simulator)\n");
    exit(1);
  }

  // Get the geometry
  fGeo = fTRD->GetGeometry();
  AliDebug(1,Form("Geometry version %d\n",fGeo->IsVersion()));

  // Create a digits manager
  delete fDigitsManager;
  fDigitsManager = new AliTRDdigitsManager();
  fDigitsManager->SetSDigits(fSDigits);
  fDigitsManager->CreateArrays();
  fDigitsManager->SetEvent(fEvent);

  // The list for the input s-digits manager to be merged
  if (fSDigitsManagerList) {
    fSDigitsManagerList->Delete();
  } 
  else {
    fSDigitsManagerList = new TList();
  }

  return kTRUE;

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::MakeBranch(TTree* tree) const
{
  // 
  // Create the branches for the digits array
  //

  return fDigitsManager->MakeBranch(tree);

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::MakeDigits()
{
  //
  // Creates digits.
  //

  ///////////////////////////////////////////////////////////////
  // Parameter 
  ///////////////////////////////////////////////////////////////

  // Converts number of electrons to fC
  const Double_t kEl2fC  = 1.602E-19 * 1.0E15; 

  ///////////////////////////////////////////////////////////////

  // Number of pads included in the pad response
  const Int_t kNpad      = 3;

  // Number of track dictionary arrays
  const Int_t kNDict     = AliTRDdigitsManager::kNDict;

  // Half the width of the amplification region
  const Float_t kAmWidth = AliTRDgeometry::AmThick() / 2.;
  // Width of the drift region
  const Float_t kDrWidth = AliTRDgeometry::DrThick();
  
  Int_t    iRow, iCol, iTime, iPad;
  Int_t    iDict  = 0;
  Int_t    nBytes = 0;

  Int_t    totalSizeDigits = 0;
  Int_t    totalSizeDict0  = 0;
  Int_t    totalSizeDict1  = 0;
  Int_t    totalSizeDict2  = 0;

  Int_t    timeBinTRFend   = 1;

  Double_t pos[3];
  Double_t rot[3];
  Double_t xyz[3];
  Double_t padSignal[kNpad];
  Double_t signalOld[kNpad];

  AliTRDdataArrayF *signals  = 0;
  AliTRDdataArrayI *digits   = 0;
  AliTRDdataArrayI *dictionary[kNDict];

  AliTRDpadPlane   *padPlane = 0;

  if (!gGeoManager) {
    AliFatal("No geometry manager!");
  }

  AliTRDSimParam    *simParam    = AliTRDSimParam::Instance();
  if (!simParam) {
    AliError("Could not get simulation parameters\n");
    return kFALSE;
  }
  
  AliTRDCommonParam *commonParam = AliTRDCommonParam::Instance();
  if (!commonParam) {
    AliError("Could not get common params\n");
    return kFALSE;
  }
  
  // Create a container for the amplitudes
  AliTRDsegmentArray *signalsArray = new AliTRDsegmentArray("AliTRDdataArrayF"
                                                           ,AliTRDgeometry::Ndet());

  AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
  if (!calibration) {
    AliError("Could not get calibration object\n");  
    return kFALSE;
  }

  if (simParam->TRFOn()) {
    timeBinTRFend = ((Int_t) (simParam->GetTRFhi() 
                            * calibration->GetSamplingFrequency())) - 1;
    AliDebug(1,Form("Sample the TRF up to bin %d\n",timeBinTRFend));
  }

  Float_t elAttachProp = simParam->GetElAttachProp() / 100.; 

  if (!fGeo) {
    AliError("No geometry defined\n");
    return kFALSE;
  }

  AliDebug(1,"Start creating digits.\n");

  AliLoader* gimme = fRunLoader->GetLoader("TRDLoader");
  if (!gimme->TreeH()) {
    gimme->LoadHits();
  }
  TTree* hitTree = gimme->TreeH();
  if (hitTree == 0x0) {
    AliError("Can not get TreeH");
    return kFALSE;
  }
  fTRD->SetTreeAddress();
  
  // Get the number of entries in the hit tree
  // (Number of primary particles creating a hit somewhere)
  Int_t nTrack = (Int_t) hitTree->GetEntries();
  AliDebug(1,Form("Found %d primary particles\n",nTrack));
  AliDebug(1,Form("Sampling = %.0fMHz\n"        ,calibration->GetSamplingFrequency()));
  AliDebug(1,Form("Gain     = %d\n"             ,((Int_t) simParam->GetGasGain())));
  AliDebug(1,Form("Noise     = %d\n"            ,((Int_t) simParam->GetNoise())));
  if (simParam->TimeStructOn()) {
    AliDebug(1,"Time Structure of drift cells implemented.\n");
  } 
  else {
    AliDebug(1,"Constant drift velocity in drift cells.\n");
  }
  
  Int_t   detectorOld  = -1;
  Int_t   countHits    =  0;
 
  Int_t   nTimeTotal   = calibration->GetNumberOfTimeBins();
  Float_t samplingRate = calibration->GetSamplingFrequency();

  // Loop through all entries in the tree
  for (Int_t iTrack = 0; iTrack < nTrack; iTrack++) {

    gAlice->ResetHits();
    nBytes += hitTree->GetEvent(iTrack);

    // Loop through the TRD hits
    Int_t iHit = 0;
    AliTRDhit *hit = (AliTRDhit *) fTRD->FirstHit(-1);
    while (hit) {
 
      countHits++;
      iHit++;

              pos[0]        = hit->X();
              pos[1]        = hit->Y();
              pos[2]        = hit->Z();
      Float_t q             = hit->GetCharge();
      Int_t   track         = hit->Track();
      Int_t   detector      = hit->GetDetector();
      Int_t   plane         = fGeo->GetPlane(detector);
      Int_t   chamber       = fGeo->GetChamber(detector);
      Float_t time0         = AliTRDgeometry::GetTime0(plane);

      padPlane              = commonParam->GetPadPlane(plane,chamber);
      Float_t row0          = padPlane->GetRow0();
      Int_t   nRowMax       = padPlane->GetNrows();
      Int_t   nColMax       = padPlane->GetNcols();
      Int_t   inDrift       = 1;
       
      // Don't analyze test hits
      if (((Int_t) q) != 0) {

        if (detector != detectorOld) {

          // Compress the old one if enabled
          if ((fCompress) && (detectorOld > -1)) {
            AliDebug(1,"Compress the old container ...");
            signals->Compress(1,0);
            for (iDict = 0; iDict < kNDict; iDict++) {
              dictionary[iDict]->Compress(1,0);
	    }
	  }
	  // Get the new container
          signals = (AliTRDdataArrayF *) signalsArray->At(detector);
          if (signals->GetNtime() == 0) {
            // Allocate a new one if not yet existing
            signals->Allocate(nRowMax,nColMax,nTimeTotal);
	  }
          else {
	    // Expand an existing one
            if (fCompress) {
              signals->Expand();
	    }
	  }
	  // The same for the dictionary
          for (iDict = 0; iDict < kNDict; iDict++) {       
            dictionary[iDict] = fDigitsManager->GetDictionary(detector,iDict);
            if (dictionary[iDict]->GetNtime() == 0) {
              dictionary[iDict]->Allocate(nRowMax,nColMax,nTimeTotal);
	    }
            else {
              if (fCompress) dictionary[iDict]->Expand();
            }
          }      
          detectorOld = detector;
        }

        // Rotate the sectors on top of each other       
	// by using the geoManager
        Double_t aaa[3];
        gGeoManager->MasterToLocal(pos,aaa);
        if (inDrift) {
          aaa[2] = time0 - (kDrWidth / 2.0 + kAmWidth) + aaa[2];
	} 
        else {
          aaa[2] = time0 + aaa[2];
	}
        aaa[1] = row0 + padPlane->GetLengthRim() + fGeo->RpadW() 
               - 0.5 * fGeo->GetChamberLength(plane,chamber) 
	       + aaa[1];
        rot[0] = aaa[2];
        rot[1] = aaa[0];
        rot[2] = aaa[1];

        // The driftlength. It is negative if the hit is between pad plane and anode wires.
        Double_t driftlength = time0 - rot[0];

        // Loop over all electrons of this hit
        // TR photons produce hits with negative charge
        Int_t nEl = ((Int_t) TMath::Abs(q));
        for (Int_t iEl = 0; iEl < nEl; iEl++) {

          xyz[0] = rot[0];
          xyz[1] = rot[1];
          xyz[2] = rot[2];

	  // Stupid patch to take care of TR photons that are absorbed
	  // outside the chamber volume. A real fix would actually need
	  // a more clever implementation of the TR hit generation
          if (q < 0.0) {
	    if ((xyz[2] < padPlane->GetRowEnd()) ||
                (xyz[2] > padPlane->GetRow0())) {
              if (iEl == 0) {
                AliDebug(2,Form("Hit outside of sensitive volume, row (z=%f, row0=%f, rowE=%f)\n"
                               ,xyz[2],padPlane->GetRow0(),padPlane->GetRowEnd()));
	      }
              continue;
	    }
            Float_t tt = driftlength + kAmWidth;
            if (tt < 0.0 || tt > kDrWidth + 2.*kAmWidth) {
              if (iEl == 0) {
                AliDebug(2,Form("Hit outside of sensitive volume, time (Q = %d)\n"
                               ,((Int_t) q)));
	      }
              continue;
	    }
	  }

          // Get row and col of unsmeared electron to retrieve drift velocity
          // The pad row (z-direction)
          Int_t    rowE       = padPlane->GetPadRowNumber(xyz[2]);
          if (rowE < 0) continue;
          Double_t rowOffset  = padPlane->GetPadRowOffset(rowE,xyz[2]);

          // The pad column (rphi-direction)
	  Double_t offsetTilt = padPlane->GetTiltOffset(rowOffset);
          Int_t    colE       = padPlane->GetPadColNumber(xyz[1]+offsetTilt,rowOffset);
          if (colE < 0) continue;	  
          Double_t colOffset  = padPlane->GetPadColOffset(colE,xyz[1]+offsetTilt);

          Float_t driftvelocity = calibration->GetVdrift(detector,colE,rowE);
                    
          // Normalised drift length
          Double_t absdriftlength = TMath::Abs(driftlength);
          if (commonParam->ExBOn()) {
            absdriftlength /= TMath::Sqrt(GetLorentzFactor(driftvelocity));
	  }

          // Electron attachment
          if (simParam->ElAttachOn()) {
            if (gRandom->Rndm() < (absdriftlength * elAttachProp)) continue;
          }
          
          // Apply the diffusion smearing
          if (simParam->DiffusionOn()) {
            if (!(Diffusion(driftvelocity, absdriftlength,xyz))) continue;
          }

          // Apply E x B effects (depends on drift direction)
          if (commonParam->ExBOn()) { 
            if (!(ExB(driftvelocity, driftlength,xyz))) continue;
          }

          // The electron position after diffusion and ExB in pad coordinates.
          // The pad row (z-direction)
          rowE       = padPlane->GetPadRowNumber(xyz[2]);
          if (rowE < 0) continue;
          rowOffset  = padPlane->GetPadRowOffset(rowE,xyz[2]);

          // The pad column (rphi-direction)
          offsetTilt = padPlane->GetTiltOffset(rowOffset);
          colE       = padPlane->GetPadColNumber(xyz[1]+offsetTilt,rowOffset);
          if (colE < 0) continue;         
          colOffset  = padPlane->GetPadColOffset(colE,xyz[1]+offsetTilt);
	  
          // Also re-retrieve drift velocity because col and row may have changed
          driftvelocity = calibration->GetVdrift(detector,colE,rowE);
          Float_t t0    = calibration->GetT0(detector,colE,rowE);
          
          // Convert the position to drift time, using either constant drift velocity or
          // time structure of drift cells (non-isochronity, GARFIELD calculation).
	  Double_t drifttime;
          if (simParam->TimeStructOn()) {
	    // Get z-position with respect to anode wire:
            Double_t Z  =  row0 - xyz[2] + simParam->GetAnodeWireOffset();
	    Z -= ((Int_t)(2*Z))/2.0;
	    if (Z > 0.25) {
              Z  = 0.5 - Z;
	    }
	    // Use drift time map (GARFIELD)
            drifttime = TimeStruct(driftvelocity,time0-xyz[0]+kAmWidth,Z);
	  } 
          else {
	    // use constant drift velocity
            drifttime = TMath::Abs(time0 - xyz[0]) / driftvelocity;
	  }

          // Apply the gas gain including fluctuations
          Double_t ggRndm = 0.0;
          do {
            ggRndm = gRandom->Rndm();
	  } while (ggRndm <= 0);
          Int_t signal = (Int_t) (-(simParam->GetGasGain()) * TMath::Log(ggRndm));

          // Apply the pad response 
          if (simParam->PRFOn()) {
  	    // The distance of the electron to the center of the pad 
	    // in units of pad width
	    Double_t dist = (colOffset - 0.5*padPlane->GetColSize(colE))
                          / padPlane->GetColSize(colE);
            if (!(calibration->PadResponse(signal,dist,plane,padSignal))) continue;
	  }
	  else {
            padSignal[0] = 0.0;
            padSignal[1] = signal;
            padSignal[2] = 0.0;
	  }

          // The time bin (always positive), with t0 correction
          Double_t timeBinIdeal = drifttime * samplingRate + t0;
	  // Protection 
          if (TMath::Abs(timeBinIdeal) > 2*nTimeTotal) {
            timeBinIdeal = 2 * nTimeTotal;
	  }
          Int_t    timeBinTruncated = (Int_t) timeBinIdeal;
          // The distance of the position to the middle of the timebin
          Double_t timeOffset       = ((Float_t) timeBinTruncated 
                                    + 0.5 - timeBinIdeal) / samplingRate;
          
	  // Sample the time response inside the drift region
	  // + additional time bins before and after.
          // The sampling is done always in the middle of the time bin
          for (Int_t iTimeBin = TMath::Max(timeBinTruncated, 0);
               iTimeBin < TMath::Min(timeBinTruncated+timeBinTRFend,nTimeTotal);
	       iTimeBin++) {

     	    // Apply the time response
            Double_t timeResponse = 1.0;
            Double_t crossTalk    = 0.0;
            Double_t time         = (iTimeBin - timeBinTruncated) / samplingRate + timeOffset;
            if (simParam->TRFOn()) {
              timeResponse = simParam->TimeResponse(time);
            }
      
            if (simParam->CTOn()) {
              crossTalk    = simParam->CrossTalk(time);
            }

            signalOld[0] = 0.0;
            signalOld[1] = 0.0;
            signalOld[2] = 0.0;

            for (iPad = 0; iPad < kNpad; iPad++) {

              Int_t colPos = colE + iPad - 1;
              if (colPos <        0) continue;
              if (colPos >= nColMax) break;

              // Add the signals
              Int_t iCurrentTimeBin = iTimeBin;
              signalOld[iPad]  = signals->GetDataUnchecked(rowE,colPos,iCurrentTimeBin);
              if( colPos != colE ) {
                signalOld[iPad] += padSignal[iPad] * (timeResponse + crossTalk);
              } 
              else {
                signalOld[iPad] += padSignal[iPad] * timeResponse;
              }
              signals->SetDataUnchecked(rowE,colPos,iCurrentTimeBin,signalOld[iPad]);

              // Store the track index in the dictionary
              // Note: We store index+1 in order to allow the array to be compressed
              if (signalOld[iPad] > 0) { 
                for (iDict = 0; iDict < kNDict; iDict++) {
                  Int_t oldTrack = dictionary[iDict]->GetDataUnchecked(rowE
                                                                      ,colPos
                                                                      ,iCurrentTimeBin);
                  if (oldTrack == track+1) break;
                  if (oldTrack ==       0) {
                    dictionary[iDict]->SetDataUnchecked(rowE,colPos,iCurrentTimeBin,track+1);
                    break;
                  }
                }
              }

	    } // Loop: pads

	  } // Loop: time bins

        } // Loop: electrons of a single hit

      } // If: detector and test hit

      hit = (AliTRDhit *) fTRD->NextHit();   

    } // Loop: hits of one primary track

  } // Loop: primary tracks

  AliDebug(1,Form("Finished analyzing %d hits\n",countHits));

  // The coupling factor
  Double_t coupling = simParam->GetPadCoupling() 
                    * simParam->GetTimeCoupling();

  // The conversion factor
  Double_t convert  = kEl2fC 
                    * simParam->GetChipGain();

  // Loop through all chambers to finalize the digits
  Int_t iDetBeg = 0;
  Int_t iDetEnd = AliTRDgeometry::Ndet();
  for (Int_t iDet = iDetBeg; iDet < iDetEnd; iDet++) {

    Int_t plane       = fGeo->GetPlane(iDet);
    Int_t sector      = fGeo->GetSector(iDet);
    Int_t chamber     = fGeo->GetChamber(iDet);
    Int_t nRowMax     = commonParam->GetRowMax(plane,chamber,sector);
    Int_t nColMax     = commonParam->GetColMax(plane);

    Double_t *inADC   = new Double_t[nTimeTotal];
    Double_t *outADC  = new Double_t[nTimeTotal];

    AliDebug(1,Form("Digitization for chamber %d\n",iDet));

    // Add a container for the digits of this detector
    digits = fDigitsManager->GetDigits(iDet);        
    // Allocate memory space for the digits buffer
    if (digits->GetNtime() == 0) {
      digits->Allocate(nRowMax,nColMax,nTimeTotal);
    }
 
    // Get the signal container
    signals = (AliTRDdataArrayF *) signalsArray->At(iDet);
    if (signals->GetNtime() == 0) {
      // Create missing containers
      signals->Allocate(nRowMax,nColMax,nTimeTotal);      
    }
    else {
      // Expand the container if neccessary
      if (fCompress) signals->Expand();
    }
    // Create the missing dictionary containers
    for (iDict = 0; iDict < kNDict; iDict++) {       
      dictionary[iDict] = fDigitsManager->GetDictionary(iDet,iDict);
      if (dictionary[iDict]->GetNtime() == 0) {
        dictionary[iDict]->Allocate(nRowMax,nColMax,nTimeTotal);
      } 
    }

    Int_t nDigits = 0;

    // Don't create noise in detectors that are switched off / not installed, etc.
    if (!calibration->GetChamberStatus(iDet)) {

      // Create the digits for this chamber
      for (iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
        for (iCol  = 0; iCol  <  nColMax;   iCol++ ) {

	  // Check whether pad is active / installed / whatever ...
          if (calibration->GetPadStatus(iDet,iCol,iRow)) continue;
	  // Check whether MCM is active / installed / whatever ...
          if (calibration->GetMCMStatus(iDet,iCol,iRow)) continue;

	  // Create summable digits
          if (fSDigits) {

            for (iTime = 0; iTime < nTimeTotal; iTime++) {         
              Float_t signalAmp = signals->GetDataUnchecked(iRow,iCol,iTime);
              signalAmp *= fSDigitsScale;
              signalAmp  = TMath::Min(signalAmp,(Float_t) 1.0e9);
              Int_t adc  = (Int_t) signalAmp;
              if (adc > 0) nDigits++;
              digits->SetDataUnchecked(iRow,iCol,iTime,adc);
	    }

	  }
	  // Create normal digits
          else {

            for (iTime = 0; iTime < nTimeTotal; iTime++) {         
              Float_t signalAmp = signals->GetDataUnchecked(iRow,iCol,iTime);

              // Pad and time coupling
              signalAmp *= coupling;

              Float_t padgain = calibration->GetGainFactor(iDet, iCol, iRow);
              if (padgain <= 0) {
                AliError(Form("Not a valid gain %f, %d %d %d\n", padgain, iDet, iCol, iRow));
              }
	      signalAmp *= padgain;

              // Add the noise, starting from minus ADC baseline in electrons
              Double_t baselineEl = simParam->GetADCbaseline() * (simParam->GetADCinRange()
                                                           / simParam->GetADCoutRange())
                                                           / convert;
              signalAmp  = TMath::Max((Double_t) gRandom->Gaus(signalAmp,simParam->GetNoise())
                                     ,-baselineEl);
              // Convert to mV
              signalAmp *= convert;
              // Add ADC baseline in mV
              signalAmp += simParam->GetADCbaseline() * (simParam->GetADCinRange()
                                                   / simParam->GetADCoutRange());
 	      // Convert to ADC counts. Set the overflow-bit fADCoutRange if the
	      // signal is larger than fADCinRange
              Int_t adc  = 0;
              if (signalAmp >= simParam->GetADCinRange()) {
                adc = ((Int_t) simParam->GetADCoutRange());
	      }
              else {
                adc = TMath::Nint(signalAmp * (simParam->GetADCoutRange()
                                           / simParam->GetADCinRange()));
	      }

              inADC[iTime]  = adc;
              outADC[iTime] = adc;
	    }

            for (iTime = 0; iTime < nTimeTotal; iTime++) {   
              // Store the amplitude of the digit if above threshold
              if (outADC[iTime] > simParam->GetADCthreshold()) {
                nDigits++;
                digits->SetDataUnchecked(iRow,iCol,iTime,((Int_t) outADC[iTime]));
  	      }
	    }

	  }

        }
      }

    }

    // Compress the arrays
    digits->Compress(1,0);
    for (iDict = 0; iDict < kNDict; iDict++) {
      dictionary[iDict]->Compress(1,0);
    }

    totalSizeDigits += digits->GetSize();
    totalSizeDict0  += dictionary[0]->GetSize();
    totalSizeDict1  += dictionary[1]->GetSize();
    totalSizeDict2  += dictionary[2]->GetSize();

    Float_t nPixel = nRowMax * nColMax * nTimeTotal;
    AliDebug(1,Form("Found %d digits in detector %d (%3.0f).\n"
              ,nDigits,iDet
              ,100.0 * ((Float_t) nDigits) / nPixel));

    if (fCompress) {
      signals->Compress(1,0);
    }

    delete [] inADC;
    delete [] outADC;

  }

  if (signalsArray) {
    delete signalsArray;
    signalsArray = 0;
  }

  AliDebug(1,Form("Total number of analyzed hits = %d\n",countHits));
  AliDebug(1,Form("Total digits data size = %d, %d, %d, %d\n",totalSizeDigits
                                                             ,totalSizeDict0
                                                             ,totalSizeDict1
                                                             ,totalSizeDict2));

  return kTRUE;

}

//_____________________________________________________________________________
void AliTRDdigitizer::AddSDigitsManager(AliTRDdigitsManager *man)
{
  //
  // Add a digits manager for s-digits to the input list.
  //

  fSDigitsManagerList->Add(man);

}

//_____________________________________________________________________________
void AliTRDdigitizer::DeleteSDigitsManager()
{
  //
  // Removes digits manager from the input list.
  //

  fSDigitsManagerList->Delete();

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::ConvertSDigits()
{
  //
  // Converts s-digits to normal digits
  //

  // Number of track dictionary arrays
  const Int_t    kNDict = AliTRDdigitsManager::kNDict;

  // Converts number of electrons to fC
  const Double_t kEl2fC = 1.602E-19 * 1.0E15; 

  Int_t iDict = 0;
  Int_t iRow;
  Int_t iCol;
  Int_t iTime;

  AliTRDSimParam* simParam = AliTRDSimParam::Instance();
  if (!simParam) {
    AliError("Could not get simulation parameters\n");
    return kFALSE;
  }
  
  AliTRDCommonParam* commonParam = AliTRDCommonParam::Instance();
  if (!commonParam) {
    AliError("Could not get common parameters\n");
    return kFALSE;
  }
  
  AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
  if (!calibration) {
    AliError("Could not get calibration object\n");
    return kFALSE;
  }
    
  Double_t sDigitsScale = 1.0 / GetSDigitsScale();
  Double_t noise        = simParam->GetNoise();
  Double_t padCoupling  = simParam->GetPadCoupling();
  Double_t timeCoupling = simParam->GetTimeCoupling();
  Double_t chipGain     = simParam->GetChipGain();
  Double_t coupling     = padCoupling * timeCoupling;
  Double_t convert      = kEl2fC * chipGain;
  Double_t adcInRange   = simParam->GetADCinRange();
  Double_t adcOutRange  = simParam->GetADCoutRange();
  Int_t    adcThreshold = simParam->GetADCthreshold();
  Int_t    adcBaseline  = simParam->GetADCbaseline();   

  Int_t    nTimeTotal   = calibration->GetNumberOfTimeBins();

  AliTRDdataArrayI *digitsIn;
  AliTRDdataArrayI *digitsOut;
  AliTRDdataArrayI *dictionaryIn[kNDict];
  AliTRDdataArrayI *dictionaryOut[kNDict];
  
  // Loop through the detectors
  for (Int_t iDet = 0; iDet < AliTRDgeometry::Ndet(); iDet++) {

    AliDebug(1,Form("Convert detector %d to digits.\n",iDet));

    Int_t plane      = fGeo->GetPlane(iDet);
    Int_t sector     = fGeo->GetSector(iDet);
    Int_t chamber    = fGeo->GetChamber(iDet);
    Int_t nRowMax    = commonParam->GetRowMax(plane,chamber,sector);
    Int_t nColMax    = commonParam->GetColMax(plane);

    Double_t *inADC  = new Double_t[nTimeTotal];
    Double_t *outADC = new Double_t[nTimeTotal];

    digitsIn  = fSDigitsManager->GetDigits(iDet);
    digitsIn->Expand();
    digitsOut = fDigitsManager->GetDigits(iDet);
    digitsOut->Allocate(nRowMax,nColMax,nTimeTotal);
    for (iDict = 0; iDict < kNDict; iDict++) {
      dictionaryIn[iDict]  = fSDigitsManager->GetDictionary(iDet,iDict);
      dictionaryIn[iDict]->Expand();
      dictionaryOut[iDict] = fDigitsManager->GetDictionary(iDet,iDict);
      dictionaryOut[iDict]->Allocate(nRowMax,nColMax,nTimeTotal);
    }

    for (iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
      for (iCol  = 0; iCol  <  nColMax;   iCol++ ) {

        for (iTime = 0; iTime < nTimeTotal; iTime++) {

          Double_t signal = (Double_t) digitsIn->GetDataUnchecked(iRow,iCol,iTime);
          signal *= sDigitsScale;
          Float_t padgain = calibration->GetGainFactor(iDet,iCol,iRow);
          if (padgain <= 0.0) {
            AliError(Form("Not a valid gain %f, %d %d %d\n", padgain, iDet, iCol, iRow));
          }

          signal *= padgain;
          // Pad and time coupling
          signal *= coupling;
          // Add the noise, starting from minus ADC baseline in electrons
          Double_t baselineEl = adcBaseline * (adcInRange / adcOutRange) / convert;
          signal  = TMath::Max((Double_t) gRandom->Gaus(signal,noise),-baselineEl);
          // Convert to mV
          signal *= convert;
          // add ADC baseline in mV
          signal += adcBaseline * (adcInRange / adcOutRange);
	  // Convert to ADC counts. Set the overflow-bit adcOutRange if the
	  // signal is larger than adcInRange
          Int_t adc  = 0;
          if (signal >= adcInRange) {
            adc = ((Int_t) adcOutRange);
	  }
          else {
            adc = TMath::Nint(signal * (adcOutRange / adcInRange));
	  }
          inADC[iTime]  = adc;
          outADC[iTime] = adc;

	}

        for (iTime = 0; iTime < nTimeTotal; iTime++) {
          // Store the amplitude of the digit if above threshold
          if (outADC[iTime] > adcThreshold) {
            digitsOut->SetDataUnchecked(iRow,iCol,iTime,((Int_t) outADC[iTime]));
  	    // Copy the dictionary
            for (iDict = 0; iDict < kNDict; iDict++) { 
              Int_t track = dictionaryIn[iDict]->GetDataUnchecked(iRow,iCol,iTime);
              dictionaryOut[iDict]->SetDataUnchecked(iRow,iCol,iTime,track);
	    }
	  }
	}

      }
    }

    if (fCompress) {
      digitsIn->Compress(1,0);
      digitsOut->Compress(1,0);
      for (iDict = 0; iDict < kNDict; iDict++) {
        dictionaryIn[iDict]->Compress(1,0);
        dictionaryOut[iDict]->Compress(1,0);
      }
    }

    delete [] inADC;
    delete [] outADC;

  }    

  return kTRUE;

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::MergeSDigits()
{
  //
  // Merges the input s-digits:
  //   - The amplitude of the different inputs are summed up.
  //   - Of the track IDs from the input dictionaries only one is
  //     kept for each input. This works for maximal 3 different merged inputs.
  //

  // Number of track dictionary arrays
  const Int_t kNDict = AliTRDdigitsManager::kNDict;

  AliTRDSimParam*    simParam    = AliTRDSimParam::Instance();
  if (!simParam) {
    AliError("Could not get simulation parameters\n");
    return kFALSE;
  }
  
  AliTRDCommonParam* commonParam = AliTRDCommonParam::Instance();
  if (!commonParam) {
    AliError("Could not get common parameters\n");
    return kFALSE;
  }
  
  AliTRDcalibDB*     calibration = AliTRDcalibDB::Instance();
  if (!calibration) {
    AliError("Could not get calibration object\n");
    return kFALSE;
  }
  
  Int_t iDict = 0;
  Int_t jDict = 0;

  AliTRDdataArrayI *digitsA;
  AliTRDdataArrayI *digitsB;
  AliTRDdataArrayI *dictionaryA[kNDict];
  AliTRDdataArrayI *dictionaryB[kNDict];

  // Get the first s-digits
  fSDigitsManager = (AliTRDdigitsManager *) fSDigitsManagerList->First();
  if (!fSDigitsManager) { 
    AliError("No SDigits manager\n");
    return kFALSE;
  }

  // Loop through the other sets of s-digits
  AliTRDdigitsManager *mergeSDigitsManager;
  mergeSDigitsManager = (AliTRDdigitsManager *) fSDigitsManagerList->After(fSDigitsManager);

  if (mergeSDigitsManager) {
    AliDebug(1,Form("Merge %d input files.\n",fSDigitsManagerList->GetSize()));
  }
  else {
    AliDebug(1,"Only one input file.\n");
  }

  Int_t nTimeTotal = calibration->GetNumberOfTimeBins();
  
  Int_t iMerge = 0;
  while (mergeSDigitsManager) {

    iMerge++;

    // Loop through the detectors
    for (Int_t iDet = 0; iDet < AliTRDgeometry::Ndet(); iDet++) {

      Int_t plane      = fGeo->GetPlane(iDet);
      Int_t sector     = fGeo->GetSector(iDet);
      Int_t chamber    = fGeo->GetChamber(iDet);
      Int_t nRowMax    = commonParam->GetRowMax(plane,chamber,sector);
      Int_t nColMax    = commonParam->GetColMax(plane);

      // Loop through the pixels of one detector and add the signals
      digitsA = fSDigitsManager->GetDigits(iDet);
      digitsB = mergeSDigitsManager->GetDigits(iDet);
      digitsA->Expand();
      digitsB->Expand();
      for (iDict = 0; iDict < kNDict; iDict++) {
        dictionaryA[iDict] = fSDigitsManager->GetDictionary(iDet,iDict);
        dictionaryB[iDict] = mergeSDigitsManager->GetDictionary(iDet,iDict);
        dictionaryA[iDict]->Expand();
        dictionaryB[iDict]->Expand();
      }

      // Merge only detectors that contain a signal
      Bool_t doMerge = kTRUE;
      if (fMergeSignalOnly) {
        if (digitsA->GetOverThreshold(0) == 0) {
          doMerge = kFALSE;
	}
      }

      if (doMerge) {

        AliDebug(1,Form("Merge detector %d of input no.%d\n",iDet,iMerge+1));

        for (Int_t iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
          for (Int_t iCol  = 0; iCol  <  nColMax;   iCol++ ) {
            for (Int_t iTime = 0; iTime < nTimeTotal; iTime++) {         

	      // Add the amplitudes of the summable digits 
              Int_t ampA = digitsA->GetDataUnchecked(iRow,iCol,iTime);
              Int_t ampB = digitsB->GetDataUnchecked(iRow,iCol,iTime);
              ampA += ampB;
              digitsA->SetDataUnchecked(iRow,iCol,iTime,ampA);

 	      // Add the mask to the track id if defined.
              for (iDict = 0; iDict < kNDict; iDict++) {
                Int_t trackB = dictionaryB[iDict]->GetDataUnchecked(iRow,iCol,iTime);
                if ((fMasks) && (trackB > 0)) {
                  for (jDict = 0; jDict < kNDict; jDict++) { 
                    Int_t trackA = dictionaryA[iDict]->GetDataUnchecked(iRow,iCol,iTime);
                    if (trackA == 0) {
                      trackA = trackB + fMasks[iMerge];
                      dictionaryA[iDict]->SetDataUnchecked(iRow,iCol,iTime,trackA);
		    }
	  	  }
	        }
	      }

	    }
	  }
        }

      }

      if (fCompress) {
        digitsA->Compress(1,0);
        digitsB->Compress(1,0);
        for (iDict = 0; iDict < kNDict; iDict++) {
          dictionaryA[iDict]->Compress(1,0);
          dictionaryB[iDict]->Compress(1,0);
        }
      }

    }    

    // The next set of s-digits
    mergeSDigitsManager = (AliTRDdigitsManager *) fSDigitsManagerList->After(mergeSDigitsManager);

  }

  return kTRUE;

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::SDigits2Digits()
{
  //
  // Merges the input s-digits and converts them to normal digits
  //

  if (!MergeSDigits()) return kFALSE;

  return ConvertSDigits();

}

//_____________________________________________________________________________
Bool_t AliTRDdigitizer::WriteDigits() const
{
  //
  // Writes out the TRD-digits and the dictionaries
  //

  //Write parameters
  fRunLoader->CdGAFile();

  // Store the digits and the dictionary in the tree
  return fDigitsManager->WriteDigits();

}

//_____________________________________________________________________________
void AliTRDdigitizer::InitOutput(Int_t iEvent)
{
  //
  // Initializes the output branches
  //

  fEvent = iEvent;
   
  if (!fRunLoader) {
    AliError("Run Loader is NULL");
    return;  
  }

  AliLoader* loader = fRunLoader->GetLoader("TRDLoader");
  if (!loader) {
    AliError("Can not get TRD loader from Run Loader");
    return;
  }

  TTree* tree = 0;
  
  if (fSDigits) { 
    // If we produce SDigits
    tree = loader->TreeS();
    if (!tree) {
      loader->MakeTree("S");
      tree = loader->TreeS();
    }
  }
  else {
    // If we produce Digits
    tree = loader->TreeD();
    if (!tree) {
      loader->MakeTree("D");
      tree = loader->TreeD();
    }
  }

  fDigitsManager->SetEvent(iEvent);
  fDigitsManager->MakeBranch(tree);

}

//_____________________________________________________________________________
Double_t AliTRDdigitizer::TimeStruct(Float_t vdrift, Double_t dist, Double_t z)
{
  //
  // Applies the time structure of the drift cells (by C.Lippmann).
  // The drift time of electrons to the anode wires depends on the
  // distance to the wire (z) and on the position in the drift region.
  // 
  // input :
  // dist = radial distance from (cathode) pad plane [cm]
  // z    = distance from anode wire (parallel to cathode planes) [cm]
  //
  // output :
  // tdrift = the drift time of an electron at the given position
  //
  // We interpolate between the drift time values at the two drift
  // velocities fVDlo and fVDhi, being smaller and larger than
  // fDriftVelocity. We use the two stored drift time maps fTimeStruct1
  // and fTimeStruct2, calculated for the two mentioned drift velocities.
  //

  SampleTimeStruct(vdrift);
  
  // indices:
  Int_t r1 = (Int_t)(10*dist);
  if (r1 <  0) r1 =  0;
  if (r1 > 37) r1 = 37;
  Int_t r2 = r1 + 1;
  if (r2 <  0) r2 =  0;
  if (r2 > 37) r2 = 37;
  const Int_t kz1 = ((Int_t)(100 * z / 2.5));
  const Int_t kz2 = kz1 + 1;

  if ((r1 <  0) || (r1 > 37) || (kz1 <  0) || (kz1 > 10)) {
    AliWarning(Form("Indices out of range: dist=%.2f, z=%.2f, r1=%d, kz1=%d\n"
                   ,dist,z,r1,kz1));
  }

  const Float_t ky111 = fTimeStructInfo.fTimeStruct1[r1+38*kz1];
  const Float_t ky221 = ((r2 <= 37) && (kz2 <= 10)) 
                      ? fTimeStructInfo.fTimeStruct1[r2+38*kz2] 
                      : fTimeStructInfo.fTimeStruct1[37+38*10];
  const Float_t ky121 = (kz2 <= 10)             
                      ? fTimeStructInfo.fTimeStruct1[r1+38*kz2] 
                      : fTimeStructInfo.fTimeStruct1[r1+38*10];
  const Float_t ky211 = (r2 <= 37)              
                      ? fTimeStructInfo.fTimeStruct1[r2+38*kz1] 
                      : fTimeStructInfo.fTimeStruct1[37+38*kz1];

  // 2D Interpolation, lower drift time map
  const Float_t ky11  = (ky211-ky111)*10*dist + ky111 - (ky211-ky111)*r1;
  const Float_t ky21  = (ky221-ky121)*10*dist + ky121 - (ky221-ky121)*r1;

  const Float_t ky112 = fTimeStructInfo.fTimeStruct2[r1+38*kz1];
  const Float_t ky222 = ((r2 <= 37) && (kz2 <= 10)) 
                      ? fTimeStructInfo.fTimeStruct2[r2+38*kz2] 
                      : fTimeStructInfo.fTimeStruct2[37+38*10];
  const Float_t ky122 = (kz2 <= 10)             
                      ? fTimeStructInfo.fTimeStruct2[r1+38*kz2] 
                      : fTimeStructInfo.fTimeStruct2[r1+38*10];
  const Float_t ky212 = (r2 <= 37)              
                      ? fTimeStructInfo.fTimeStruct2[r2+38*kz1] 
                      : fTimeStructInfo.fTimeStruct2[37+38*kz1];

  // 2D Interpolation, larger drift time map
  const Float_t ky12  = (ky212-ky112)*10*dist + ky112 - (ky212-ky112)*r1;
  const Float_t ky22  = (ky222-ky122)*10*dist + ky122 - (ky222-ky122)*r1;

  // dist now is the drift distance to the anode wires (negative if electrons are
  // between anode wire plane and cathode pad plane)
  dist -= AliTRDgeometry::AmThick() / 2.0;

  // Get the drift times for the drift velocities fVDlo and fVDhi
  const Float_t ktdrift1 = ((TMath::Abs(dist) > 0.005) || (z > 0.005)) 
                         ? (ky21 - ky11) * 100 * z / 2.5 + ky11 - (ky21 - ky11) * kz1 
                         : 0.0;
  const Float_t ktdrift2 = ((TMath::Abs(dist) > 0.005) || (z > 0.005)) 
                         ? (ky22 - ky12) * 100 * z / 2.5 + ky12 - (ky22 - ky12) * kz1 
                         : 0.0;

  // 1D Interpolation between the values at fVDlo and fVDhi
  Float_t a = (ktdrift2 - ktdrift1) / (fTimeStructInfo.fVDhi - fTimeStructInfo.fVDlo);
  Float_t b = ktdrift2 - a * fTimeStructInfo.fVDhi;

  return a * vdrift + b;

}

//_____________________________________________________________________________
void AliTRDdigitizer::SampleTimeStruct(Float_t vdrift)
{
  //
  // Samples the timing structure of a drift cell
  // Drift Time data calculated with Garfield (by C.Lippmann)
  //
  
  // TODO make caching proper, if same timing structure is selected: do not update timestructs!
  
  // Noting to do
  if (vdrift == fTimeStructInfo.fLastVdrift) {
    return;
  }

  fTimeStructInfo.fLastVdrift = vdrift;
  
  // Drift time maps are saved for some drift velocity values (in drift region):
  Float_t  fVDsmp[8];
  fVDsmp[0] = 1.032;
  fVDsmp[1] = 1.158;
  fVDsmp[2] = 1.299;
  fVDsmp[3] = 1.450;
  fVDsmp[4] = 1.610;
  fVDsmp[5] = 1.783;
  fVDsmp[6] = 1.959;
  fVDsmp[7] = 2.134;

  if      (vdrift < fVDsmp[0]) {
    AliWarning(Form("Drift Velocity too small (%.3f<%.3f)\n",vdrift,fVDsmp[0]));
    vdrift = fVDsmp[0];
  } 
  else if (vdrift > fVDsmp[7]) {
    AliWarning(Form("Drift Velocity too large (%.3f>%.3f)\n",vdrift,fVDsmp[6]));
    vdrift = fVDsmp[7];
  }

  const Int_t ktimebin  = 38;
  const Int_t kZbin     = 11;

  // Garfield simulation at UD = -1500V; vd = 1.032cm/microsec, <driftfield> = 525V/cm
  Float_t time1500[ktimebin][kZbin] =
      {{0.09170, 0.09205, 0.09306, 0.09475, 0.09716, 0.10035,
        0.10445, 0.10993, 0.11838, 0.13986, 0.37858},
       {0.06588, 0.06626, 0.06739, 0.06926, 0.07186, 0.07524,
        0.07951, 0.08515, 0.09381, 0.11601, 0.35673},
       {0.03946, 0.04003, 0.04171, 0.04435, 0.04780, 0.05193,
        0.05680, 0.06306, 0.07290, 0.09873, 0.34748},
       {0.01151, 0.01283, 0.01718, 0.02282, 0.02880, 0.03479,
        0.04098, 0.04910, 0.06413, 0.10567, 0.36897},
       {0.01116, 0.01290, 0.01721, 0.02299, 0.02863, 0.03447,
        0.04074, 0.04984, 0.06839, 0.11625, 0.37277},
       {0.03919, 0.03974, 0.04131, 0.04380, 0.04703, 0.05102,
        0.05602, 0.06309, 0.07651, 0.10938, 0.36838},
       {0.06493, 0.06560, 0.06640, 0.06802, 0.07051, 0.07392,
        0.07853, 0.08510, 0.09690, 0.12621, 0.38058},
       {0.09174, 0.09186, 0.09225, 0.09303, 0.09477, 0.00000,
        0.11205, 0.11952, 0.13461, 0.16984, 0.43017},
       {0.14356, 0.14494, 0.14959, 0.16002, 0.18328, 0.27981,
        0.22785, 0.21240, 0.21948, 0.25965, 0.52392},
       {0.23120, 0.23366, 0.24046, 0.25422, 0.28071, 0.36914,
        0.32999, 0.31208, 0.31772, 0.35804, 0.62249},
       {0.32686, 0.32916, 0.33646, 0.35053, 0.37710, 0.46292,
        0.42773, 0.40948, 0.41497, 0.45527, 0.71955},
       {0.42353, 0.42583, 0.43317, 0.44727, 0.47380, 0.55884,
        0.52479, 0.50650, 0.51194, 0.55225, 0.81658},
       {0.52038, 0.52271, 0.53000, 0.54415, 0.57064, 0.65545,
        0.62172, 0.60341, 0.60885, 0.64915, 0.91339},
       {0.61724, 0.61953, 0.62694, 0.64098, 0.66756, 0.75226,
        0.71862, 0.70030, 0.70575, 0.74604, 1.01035},
       {0.71460, 0.71678, 0.72376, 0.73786, 0.76447, 0.84913,
        0.81551, 0.79720, 0.80264, 0.84292, 1.10723},
       {0.81101, 0.81334, 0.82066, 0.83475, 0.86127, 0.94599,
        0.91240, 0.89408, 0.89952, 0.93981, 1.20409},
       {0.90788, 0.91023, 0.91752, 0.93163, 0.95815, 1.04293,
        1.00929, 0.99096, 0.99640, 1.03669, 1.30106},
       {1.00477, 1.00707, 1.01449, 1.02852, 1.05504, 1.13976,
        1.10617, 1.08784, 1.09329, 1.13358, 1.39796},
       {1.10166, 1.10397, 1.11130, 1.12541, 1.15257, 1.23672,
        1.20307, 1.18472, 1.19018, 1.23046, 1.49486},
       {1.19854, 1.20084, 1.20818, 1.22235, 1.24885, 1.33355,
        1.29992, 1.28156, 1.28707, 1.32735, 1.59177},
       {1.29544, 1.29780, 1.30507, 1.31917, 1.34575, 1.43073,
        1.39681, 1.37851, 1.38396, 1.42377, 1.68854},
       {1.39236, 1.39462, 1.40205, 1.41607, 1.44259, 1.52745,
        1.49368, 1.47541, 1.48083, 1.52112, 1.78546},
       {1.49314, 1.49149, 1.49885, 1.51297, 1.53949, 1.62420,
        1.59016, 1.57231, 1.57772, 1.61800, 1.88048},
       {1.58610, 1.58839, 1.59572, 1.60983, 1.63635, 1.72109,
        1.68651, 1.66921, 1.67463, 1.71489, 1.97918},
       {1.68400, 1.68529, 1.69261, 1.70671, 1.73331, 1.81830,
        1.78341, 1.76605, 1.77150, 1.81179, 2.07608},
       {1.77991, 1.78215, 1.78952, 1.80385, 1.83014, 1.91486,
        1.88128, 1.86215, 1.86837, 1.90865, 2.17304},
       {1.87674, 1.87904, 1.88647, 1.90052, 1.92712, 2.01173,
        1.97812, 1.95905, 1.96527, 2.00710, 2.26979},
       {1.97369, 1.97594, 1.98326, 1.99869, 2.02442, 2.10865,
        2.07501, 2.05666, 2.06214, 2.10243, 2.36669},
       {2.07052, 2.07281, 2.08016, 2.09425, 2.12132, 2.20555,
        2.17182, 2.15341, 2.15904, 2.19933, 2.46363},
       {2.16742, 2.16971, 2.17707, 2.19114, 2.21766, 2.30240,
        2.26877, 2.25015, 2.25573, 2.29586, 2.56060},
       {2.26423, 2.26659, 2.27396, 2.28803, 2.31456, 2.40828,
        2.36567, 2.34705, 2.35282, 2.39765, 2.65744},
       {2.36153, 2.36349, 2.37330, 2.38501, 2.41159, 2.49940,
        2.46257, 2.44420, 2.44843, 2.48987, 2.75431},
       {2.46558, 2.46035, 2.46822, 2.48181, 2.50849, 2.59630,
        2.55947, 2.54112, 2.54513, 2.58677, 2.85094},
       {2.56248, 2.55723, 2.56486, 2.57871, 2.60520, 2.68998,
        2.65626, 2.63790, 2.64316, 2.68360, 2.94813},
       {2.65178, 2.65441, 2.66153, 2.67556, 2.70210, 2.78687,
        2.75319, 2.73463, 2.74032, 2.78060, 3.04503},
       {2.74868, 2.75131, 2.75870, 2.77245, 2.79385, 2.88700,
        2.85009, 2.83177, 2.83723, 2.87750, 3.14193},
       {2.84574, 2.84789, 2.85560, 2.86935, 2.89075, 2.98060,
        2.94576, 2.92868, 2.93356, 2.97436, 3.23868},
       {2.94239, 2.94469, 2.95221, 2.96625, 2.99345, 3.07747,
        3.04266, 3.02545, 3.03051, 3.07118, 3.33555}};
  
  // Garfield simulation at UD = -1600V; vd = 1.158cm/microsec, <driftfield> = 558V/cm
  Float_t time1600[ktimebin][kZbin] =
      {{0.09169, 0.09203, 0.09305, 0.09473, 0.09714, 0.10032,
        0.10441, 0.10990, 0.11835, 0.13986, 0.37845},
       {0.06589, 0.06626, 0.06738, 0.06924, 0.07184, 0.07521,
        0.07947, 0.08512, 0.09379, 0.11603, 0.35648},
       {0.03947, 0.04003, 0.04171, 0.04434, 0.04778, 0.05190,
        0.05678, 0.06304, 0.07292, 0.09876, 0.34759},
       {0.01111, 0.01281, 0.01718, 0.02281, 0.02879, 0.03477,
        0.04097, 0.04910, 0.06415, 0.10573, 0.36896},
       {0.01120, 0.01311, 0.01721, 0.02279, 0.02862, 0.03446,
        0.04074, 0.04981, 0.06825, 0.11595, 0.37255},
       {0.03919, 0.03980, 0.04132, 0.04380, 0.04704, 0.05102,
        0.05602, 0.06302, 0.07633, 0.10896, 0.36743},
       {0.06531, 0.06528, 0.06631, 0.06805, 0.07053, 0.07392,
        0.07853, 0.08505, 0.09669, 0.12578, 0.37967},
       {0.09157, 0.09171, 0.09216, 0.09301, 0.09475, 0.00000,
        0.11152, 0.11879, 0.13352, 0.16802, 0.42750},
       {0.13977, 0.14095, 0.14509, 0.15433, 0.17534, 0.26406,
        0.21660, 0.20345, 0.21113, 0.25067, 0.51434},
       {0.21816, 0.22041, 0.22631, 0.23850, 0.26208, 0.34340,
        0.30755, 0.29237, 0.29878, 0.33863, 0.60258},
       {0.30344, 0.30547, 0.31241, 0.32444, 0.34809, 0.42696,
        0.39464, 0.37919, 0.38546, 0.42530, 0.68926},
       {0.38969, 0.39164, 0.39810, 0.41059, 0.43441, 0.51246,
        0.48112, 0.46562, 0.47191, 0.51172, 0.77558},
       {0.47592, 0.47799, 0.48442, 0.49689, 0.52061, 0.59855,
        0.56752, 0.55201, 0.55826, 0.59808, 0.86202},
       {0.56226, 0.56428, 0.57074, 0.58324, 0.60696, 0.68483,
        0.65388, 0.63837, 0.64461, 0.68445, 0.94830},
       {0.64881, 0.65063, 0.65709, 0.66958, 0.69331, 0.77117,
        0.74023, 0.72472, 0.73098, 0.77079, 1.03486},
       {0.73506, 0.73698, 0.74344, 0.75596, 0.77964, 0.85751,
        0.82658, 0.81107, 0.81731, 0.85712, 1.12106},
       {0.82132, 0.82333, 0.82979, 0.84228, 0.86608, 0.94386,
        0.91293, 0.89742, 0.90367, 0.94335, 1.20737},
       {0.90767, 0.90968, 0.91614, 0.92863, 0.95236, 1.03021,
        0.99928, 0.98377, 0.99001, 1.02984, 1.29371},
       {0.99410, 0.99602, 1.00257, 1.01498, 1.03869, 1.11720,
        1.08563, 1.07011, 1.07637, 1.11621, 1.37873},
       {1.08036, 1.08240, 1.08884, 1.10138, 1.12504, 1.20301,
        1.17198, 1.15647, 1.16272, 1.20255, 1.46651},
       {1.16670, 1.16872, 1.17525, 1.18783, 1.21139, 1.28934,
        1.25833, 1.24281, 1.24909, 1.28889, 1.55275},
       {1.25307, 1.25510, 1.26153, 1.27404, 1.29773, 1.37584,
        1.34469, 1.32916, 1.33536, 1.37524, 1.63915},
       {1.33942, 1.34146, 1.34788, 1.36040, 1.38410, 1.46438,
        1.43105, 1.41537, 1.42176, 1.46158, 1.72538},
       {1.42579, 1.42782, 1.43458, 1.44674, 1.47043, 1.55085,
        1.51675, 1.50168, 1.50810, 1.54793, 1.81174},
       {1.51207, 1.51454, 1.52060, 1.53307, 1.55684, 1.63478,
        1.60336, 1.58820, 1.59446, 1.63414, 1.89814},
       {1.59856, 1.60047, 1.60693, 1.61942, 1.64317, 1.72257,
        1.69008, 1.67454, 1.68080, 1.72063, 1.98433},
       {1.68481, 1.68682, 1.69330, 1.70584, 1.72949, 1.80752,
        1.77643, 1.76089, 1.76716, 1.80692, 2.07069},
       {1.77117, 1.77319, 1.77969, 1.79260, 1.81583, 1.89376,
        1.86226, 1.84720, 1.85355, 1.89256, 2.15343},
       {1.85748, 1.85967, 1.86605, 1.87848, 1.90222, 1.98010,
        1.94913, 1.93271, 1.93981, 1.97968, 2.24355},
       {1.94386, 1.94587, 1.95233, 1.96484, 1.98854, 2.06646,
        2.03542, 2.01755, 2.02617, 2.06604, 2.32993},
       {2.03022, 2.03230, 2.03868, 2.05134, 2.07488, 2.15367,
        2.12178, 2.10391, 2.11252, 2.15432, 2.41623},
       {2.11656, 2.11857, 2.12505, 2.13772, 2.16147, 2.23919,
        2.20817, 2.19265, 2.20744, 2.23872, 2.49996},
       {2.20291, 2.20611, 2.21137, 2.22387, 2.24758, 2.32563,
        2.29450, 2.27901, 2.28525, 2.32507, 2.58897},
       {2.28922, 2.29172, 2.29774, 2.31345, 2.33400, 2.41287,
        2.38086, 2.36535, 2.37160, 2.40869, 2.67113},
       {2.37572, 2.37764, 2.38410, 2.39803, 2.42046, 2.49817,
        2.46721, 2.45171, 2.45794, 2.49505, 2.76061},
       {2.46190, 2.46396, 2.47043, 2.48340, 2.50665, 2.58453,
        2.55357, 2.53728, 2.54430, 2.58407, 2.84816},
       {2.54833, 2.55032, 2.55679, 2.56976, 2.59312, 2.67103,
        2.63993, 2.62364, 2.63062, 2.67040, 2.93444},
       {2.63456, 2.63660, 2.64304, 2.65555, 2.67938, 2.75739,
        2.72629, 2.71064, 2.71688, 2.75671, 3.01886}};
  
  // Garfield simulation at UD = -1700V; vd = 1.299cm/microsec, <driftfield> = 590V/cm
  Float_t time1700[ktimebin][kZbin] =
      {{0.09167, 0.09201, 0.09302, 0.09471, 0.09712, 0.10029,
        0.10438, 0.10986, 0.11832, 0.13986, 0.37824},
       {0.06591, 0.06626, 0.06736, 0.06923, 0.07183, 0.07519,
        0.07944, 0.08511, 0.09378, 0.11603, 0.35625},
       {0.03946, 0.04003, 0.04170, 0.04433, 0.04777, 0.05189,
        0.05676, 0.06301, 0.07291, 0.09880, 0.34724},
       {0.01110, 0.01281, 0.01718, 0.02280, 0.02879, 0.03476,
        0.04096, 0.04910, 0.06417, 0.10582, 0.36861},
       {0.01115, 0.01294, 0.01721, 0.02276, 0.02862, 0.03447,
        0.04074, 0.04980, 0.06812, 0.11565, 0.37231},
       {0.03920, 0.03974, 0.04133, 0.04381, 0.04706, 0.05105,
        0.05603, 0.06299, 0.07618, 0.10860, 0.36646},
       {0.06498, 0.06529, 0.06634, 0.06808, 0.07055, 0.07395,
        0.07852, 0.08500, 0.09650, 0.12532, 0.37850},
       {0.09143, 0.09159, 0.09207, 0.09297, 0.09473, 0.00000,
        0.11102, 0.11809, 0.13245, 0.16627, 0.42496},
       {0.13646, 0.13750, 0.14112, 0.14926, 0.16806, 0.24960,
        0.20627, 0.19536, 0.20366, 0.24256, 0.50557},
       {0.20678, 0.20848, 0.21384, 0.22450, 0.24552, 0.32018,
        0.28740, 0.27477, 0.28196, 0.32128, 0.58475},
       {0.28287, 0.28461, 0.29020, 0.30108, 0.32224, 0.39467,
        0.36500, 0.35217, 0.35926, 0.39860, 0.66194},
       {0.35972, 0.36145, 0.36713, 0.37797, 0.39912, 0.47091,
        0.44212, 0.42925, 0.43632, 0.47563, 0.73892},
       {0.43667, 0.43841, 0.44413, 0.45494, 0.47607, 0.54780,
        0.51912, 0.50627, 0.51334, 0.55254, 0.81595},
       {0.51365, 0.51540, 0.52101, 0.53193, 0.55305, 0.62463,
        0.59617, 0.58328, 0.59035, 0.62965, 0.89303},
       {0.59064, 0.59240, 0.59801, 0.60893, 0.63009, 0.70169,
        0.67317, 0.66028, 0.66735, 0.70666, 0.96995},
       {0.66765, 0.66939, 0.67501, 0.68592, 0.70724, 0.77863,
        0.75016, 0.73728, 0.74435, 0.78366, 1.04696},
       {0.74464, 0.74636, 0.75200, 0.76293, 0.78405, 0.85561,
        0.82716, 0.81427, 0.82133, 0.86064, 1.12396},
       {0.82165, 0.82340, 0.82902, 0.83991, 0.86104, 0.93266,
        0.90414, 0.89128, 0.89834, 0.93763, 1.20100},
       {0.89863, 0.90042, 0.90659, 0.91705, 0.93805, 1.00960,
        0.98115, 0.96825, 0.97533, 1.01462, 1.27801},
       {0.97563, 0.97740, 0.98310, 0.99391, 1.01504, 1.08659,
        1.05814, 1.04526, 1.05233, 1.09163, 1.35503},
       {1.05276, 1.05451, 1.06002, 1.07090, 1.09099, 1.16357,
        1.13516, 1.12225, 1.12933, 1.16863, 1.43195},
       {1.12977, 1.13138, 1.13700, 1.14792, 1.16797, 1.24061,
        1.21212, 1.19926, 1.20626, 1.24554, 1.50900},
       {1.20664, 1.20839, 1.21400, 1.22490, 1.24606, 1.31772,
        1.28914, 1.27382, 1.28329, 1.32262, 1.58550},
       {1.28367, 1.28541, 1.29099, 1.30189, 1.32312, 1.39460,
        1.36612, 1.34924, 1.36030, 1.39961, 1.66310},
       {1.36064, 1.36249, 1.36799, 1.37896, 1.40004, 1.48030,
        1.44314, 1.43032, 1.43731, 1.47659, 1.73442},
       {1.43762, 1.43937, 1.44497, 1.45618, 1.47704, 1.54932,
        1.52012, 1.50725, 1.51430, 1.55357, 1.81708},
       {1.51462, 1.51937, 1.52203, 1.53316, 1.55403, 1.62572,
        1.59713, 1.58424, 1.59128, 1.63061, 1.89406},
       {1.59162, 1.59338, 1.59947, 1.60989, 1.63103, 1.70270,
        1.67411, 1.66124, 1.66799, 1.70759, 1.97103},
       {1.66874, 1.67037, 1.67597, 1.68687, 1.70814, 1.77969,
        1.75112, 1.73806, 1.74530, 1.78457, 2.04794},
       {1.74693, 1.74749, 1.75297, 1.76476, 1.78500, 1.85667,
        1.82811, 1.81504, 1.82101, 1.86161, 2.12492},
       {1.82260, 1.82437, 1.82995, 1.84174, 1.86202, 1.93372,
        1.90509, 1.89202, 1.89930, 1.93859, 2.20189},
       {1.89964, 1.90135, 1.90693, 1.91789, 1.93952, 2.01080,
        1.98207, 1.96921, 1.97628, 2.01384, 2.27887},
       {1.97662, 1.97917, 1.98611, 1.99487, 2.01601, 2.08778,
        2.05846, 2.04623, 2.05330, 2.09244, 2.35585},
       {2.05359, 2.05615, 2.06309, 2.07187, 2.09867, 2.16459,
        2.13610, 2.12322, 2.13029, 2.16942, 2.43199},
       {2.13063, 2.13233, 2.13795, 2.14886, 2.17008, 2.24199,
        2.21310, 2.20020, 2.20727, 2.24659, 2.50983},
       {2.20761, 2.20931, 2.21955, 2.22624, 2.24708, 2.32147,
        2.29009, 2.27725, 2.28276, 2.32359, 2.58680},
       {2.28459, 2.29108, 2.29202, 2.30286, 2.32007, 2.39559,
        2.36683, 2.35422, 2.36119, 2.40058, 2.66081},
       {2.36153, 2.36806, 2.36889, 2.37985, 2.40092, 2.47828,
        2.44381, 2.43099, 2.43819, 2.47750, 2.73779}};
  
  // Garfield simulation at UD = -1800V; vd = 1.450cm/microsec, <driftfield> = 623V/cm
  Float_t time1800[ktimebin][kZbin] =
      {{0.09166, 0.09199, 0.09300, 0.09470, 0.09709, 0.10026,
        0.10434, 0.10983, 0.11831, 0.13987, 0.37802},
       {0.06585, 0.06623, 0.06735, 0.06921, 0.07180, 0.07520,
        0.07941, 0.08507, 0.09376, 0.11604, 0.35624},
       {0.03945, 0.04004, 0.04169, 0.04432, 0.04776, 0.05187,
        0.05674, 0.06300, 0.07290, 0.09884, 0.34704},
       {0.01108, 0.01287, 0.01717, 0.02280, 0.02880, 0.03476,
        0.04095, 0.04909, 0.06419, 0.10589, 0.36843},
       {0.01115, 0.01287, 0.01720, 0.02276, 0.02862, 0.03448,
        0.04073, 0.04973, 0.06799, 0.11535, 0.37224},
       {0.03918, 0.03975, 0.04134, 0.04382, 0.04707, 0.05105,
        0.05603, 0.06296, 0.07605, 0.10822, 0.36560},
       {0.06498, 0.06532, 0.06635, 0.06809, 0.07058, 0.07395,
        0.07855, 0.08495, 0.09632, 0.12488, 0.37730},
       {0.09130, 0.09160, 0.09199, 0.09300, 0.09472, 0.00000,
        0.11059, 0.11747, 0.13146, 0.16462, 0.42233},
       {0.13364, 0.13449, 0.13767, 0.14481, 0.16147, 0.23635,
        0.19706, 0.18812, 0.19704, 0.23520, 0.49749},
       {0.19698, 0.19844, 0.20311, 0.21236, 0.23082, 0.29920,
        0.26936, 0.25927, 0.26732, 0.30601, 0.56871},
       {0.26518, 0.26670, 0.27160, 0.28099, 0.29955, 0.36597,
        0.33885, 0.32858, 0.33653, 0.37524, 0.63801},
       {0.33441, 0.33553, 0.34040, 0.34987, 0.36841, 0.43428,
        0.40797, 0.39763, 0.40556, 0.44425, 0.70698},
       {0.40296, 0.40447, 0.40934, 0.41881, 0.43737, 0.50306,
        0.47695, 0.46662, 0.47455, 0.51329, 0.77600},
       {0.47296, 0.47344, 0.47830, 0.48779, 0.50632, 0.57200,
        0.54593, 0.53559, 0.54351, 0.58222, 0.84489},
       {0.54089, 0.54264, 0.54727, 0.55673, 0.57529, 0.64094,
        0.61490, 0.60457, 0.61249, 0.65118, 0.91394},
       {0.60987, 0.61138, 0.61624, 0.62573, 0.64428, 0.70989,
        0.68397, 0.67354, 0.68147, 0.72015, 0.98291},
       {0.67883, 0.68035, 0.68521, 0.69469, 0.71324, 0.77896,
        0.75287, 0.74251, 0.75043, 0.78912, 1.04458},
       {0.74780, 0.74932, 0.75421, 0.76367, 0.78221, 0.84785,
        0.82185, 0.81148, 0.81941, 0.85811, 1.12085},
       {0.81690, 0.81830, 0.82316, 0.83263, 0.85120, 0.91683,
        0.89077, 0.88045, 0.88837, 0.92707, 1.18976},
       {0.88574, 0.88726, 0.89228, 0.90198, 0.92017, 0.98578,
        0.95974, 0.94947, 0.95734, 0.99604, 1.25873},
       {0.95493, 0.95624, 0.96110, 0.97058, 0.98913, 1.05481,
        1.02873, 1.01839, 1.02631, 1.06503, 1.32772},
       {1.02392, 1.02524, 1.03008, 1.03955, 1.05810, 1.12378,
        1.09757, 1.08605, 1.09530, 1.13399, 1.39669},
       {1.09270, 1.09418, 1.09911, 1.10854, 1.12714, 1.19281,
        1.16502, 1.15633, 1.16427, 1.20271, 1.46574},
       {1.16168, 1.16323, 1.16801, 1.17772, 1.19604, 1.26190,
        1.23399, 1.22531, 1.23323, 1.27194, 1.53475},
       {1.23061, 1.23214, 1.23698, 1.24669, 1.26503, 1.33073,
        1.30461, 1.29428, 1.30220, 1.34091, 1.60372},
       {1.29960, 1.30110, 1.30596, 1.31544, 1.33398, 1.39962,
        1.37228, 1.36323, 1.37121, 1.40988, 1.67273},
       {1.36851, 1.37007, 1.37512, 1.38441, 1.40297, 1.46865,
        1.44256, 1.43222, 1.44017, 1.47878, 1.74155},
       {1.43752, 1.43904, 1.44773, 1.45338, 1.47220, 1.53759,
        1.51136, 1.50119, 1.50914, 1.54775, 1.81050},
       {1.50646, 1.50802, 1.51288, 1.52237, 1.54097, 1.60697,
        1.58049, 1.57018, 1.57811, 1.61678, 1.87947},
       {1.57545, 1.57720, 1.58185, 1.59134, 1.60996, 1.67787,
        1.64929, 1.63914, 1.64707, 1.68570, 1.94851},
       {1.64442, 1.64617, 1.65081, 1.66035, 1.67893, 1.74684,
        1.71826, 1.70745, 1.71604, 1.75310, 2.01748},
       {1.71337, 1.71513, 1.71978, 1.72932, 1.74645, 1.81346,
        1.78739, 1.77642, 1.78501, 1.82151, 2.08644},
       {1.78238, 1.78410, 1.78876, 1.79824, 1.81678, 1.88332,
        1.85639, 1.84262, 1.85397, 1.89270, 2.15533},
       {1.85135, 1.85306, 1.85778, 1.86728, 1.88580, 1.95615,
        1.92536, 1.91171, 1.92283, 1.96165, 2.22428},
       {1.92774, 1.92184, 1.92672, 1.93618, 1.95477, 2.02048,
        1.99427, 1.98068, 1.99192, 2.03062, 2.29338},
       {1.98929, 1.99081, 1.99567, 2.00515, 2.02373, 2.08987,
        2.06332, 2.05249, 2.05939, 2.09928, 2.36227},
       {2.05829, 2.05978, 2.06464, 2.07414, 2.09272, 2.15850,
        2.12928, 2.12194, 2.12987, 2.16825, 2.43083},
       {2.12726, 2.12869, 2.13360, 2.14425, 2.16160, 2.22872,
        2.20118, 2.19078, 2.19876, 2.23416, 2.50007}};
  
  // Garfield simulation at UD = -1900V; vd = 1.610cm/microsec, <driftfield> = 655V/cm
  Float_t time1900[ktimebin][kZbin] =
      {{0.09166, 0.09198, 0.09298, 0.09467, 0.09707, 0.10023,
        0.10431, 0.10980, 0.11828, 0.13988, 0.37789},
       {0.06584, 0.06622, 0.06735, 0.06920, 0.07179, 0.07514,
        0.07938, 0.08505, 0.09374, 0.11606, 0.35599},
       {0.03945, 0.04002, 0.04169, 0.04432, 0.04775, 0.05185,
        0.05672, 0.06298, 0.07290, 0.09888, 0.34695},
       {0.01109, 0.01281, 0.01717, 0.02279, 0.02878, 0.03476,
        0.04094, 0.04909, 0.06421, 0.10597, 0.36823},
       {0.01115, 0.01287, 0.01720, 0.02294, 0.02862, 0.03448,
        0.04074, 0.04973, 0.06783, 0.11506, 0.37206},
       {0.03940, 0.03975, 0.04135, 0.04386, 0.04708, 0.05106,
        0.05604, 0.06293, 0.07592, 0.10787, 0.36484},
       {0.06500, 0.06534, 0.06638, 0.06811, 0.07060, 0.07413,
        0.07852, 0.08491, 0.09614, 0.12446, 0.37626},
       {0.09119, 0.09140, 0.09194, 0.09293, 0.09471, 0.00000,
        0.11013, 0.11685, 0.13050, 0.16302, 0.41991},
       {0.13111, 0.13190, 0.13466, 0.14091, 0.15554, 0.22409,
        0.18846, 0.18167, 0.19113, 0.22854, 0.48995},
       {0.18849, 0.18975, 0.19380, 0.20185, 0.21797, 0.28050,
        0.25368, 0.24575, 0.25446, 0.29249, 0.55442},
       {0.24995, 0.25125, 0.25563, 0.26366, 0.27986, 0.34065,
        0.31605, 0.30815, 0.31680, 0.35482, 0.61697},
       {0.31187, 0.31324, 0.31745, 0.32580, 0.34205, 0.40217,
        0.37825, 0.37031, 0.37897, 0.41696, 0.67890},
       {0.37401, 0.37531, 0.37955, 0.38777, 0.40395, 0.46408,
        0.44037, 0.43242, 0.44108, 0.47906, 0.74122},
       {0.43610, 0.43741, 0.44161, 0.44986, 0.46604, 0.52614,
        0.50248, 0.49452, 0.50316, 0.54116, 0.80326},
       {0.49820, 0.49988, 0.50372, 0.51196, 0.52814, 0.58822,
        0.56459, 0.55661, 0.56527, 0.60326, 0.86526},
       {0.56032, 0.56161, 0.56582, 0.57408, 0.59024, 0.65032,
        0.62670, 0.61872, 0.62737, 0.66537, 0.92749},
       {0.62240, 0.62371, 0.62792, 0.63624, 0.65236, 0.71241,
        0.68881, 0.68081, 0.68947, 0.72750, 0.98941},
       {0.68449, 0.68581, 0.69002, 0.69828, 0.71444, 0.77452,
        0.75089, 0.74295, 0.75157, 0.78957, 1.05157},
       {0.74660, 0.74790, 0.75212, 0.76036, 0.77654, 0.83748,
        0.81299, 0.80501, 0.81193, 0.85168, 1.11375},
       {0.80870, 0.81017, 0.81423, 0.82246, 0.83867, 0.89908,
        0.87509, 0.86660, 0.87577, 0.91376, 1.17586},
       {0.87080, 0.87233, 0.87632, 0.88458, 0.90074, 0.96083,
        0.93718, 0.92922, 0.93787, 0.97588, 1.23794},
       {0.93291, 0.93422, 0.93844, 0.94667, 0.96293, 1.02295,
        0.99929, 0.99127, 0.99997, 1.03797, 1.29995},
       {0.99500, 0.99645, 1.00308, 1.00877, 1.02497, 1.08504,
        1.06140, 1.05343, 1.06203, 1.10006, 1.36216},
       {1.05712, 1.05926, 1.06262, 1.07092, 1.08706, 1.14754,
        1.12350, 1.11550, 1.12417, 1.16218, 1.42427},
       {1.11921, 1.12059, 1.12473, 1.13297, 1.14916, 1.21140,
        1.18560, 1.17284, 1.18625, 1.22414, 1.48629},
       {1.18140, 1.18262, 1.18690, 1.19508, 1.21125, 1.27139,
        1.24164, 1.23495, 1.24838, 1.28634, 1.54852},
       {1.24340, 1.24473, 1.24901, 1.25732, 1.27336, 1.33358,
        1.30793, 1.30179, 1.31047, 1.34848, 1.61066},
       {1.30551, 1.30684, 1.31104, 1.32056, 1.33553, 1.39609,
        1.37004, 1.36392, 1.37045, 1.41057, 1.67259},
       {1.36755, 1.36892, 1.37315, 1.39148, 1.39755, 1.45820,
        1.43215, 1.42602, 1.43467, 1.47268, 1.73477},
       {1.42966, 1.43101, 1.43549, 1.45359, 1.45976, 1.52031,
        1.49601, 1.48811, 1.49677, 1.53477, 1.79691},
       {1.49180, 1.49321, 1.49760, 1.51570, 1.52175, 1.58185,
        1.55771, 1.55023, 1.55888, 1.59672, 1.85501},
       {1.55391, 1.55527, 1.55943, 1.57782, 1.58391, 1.64395,
        1.62008, 1.61233, 1.62085, 1.65883, 1.92091},
       {1.61599, 1.61732, 1.62154, 1.63993, 1.64612, 1.70608,
        1.68237, 1.67108, 1.68301, 1.72110, 1.97931},
       {1.67808, 1.67948, 1.68364, 1.70204, 1.70823, 1.76858,
        1.74404, 1.73539, 1.74512, 1.78321, 2.04522},
       {1.74019, 1.74152, 1.74573, 1.76415, 1.77015, 1.83040,
        1.80615, 1.79366, 1.80723, 1.84509, 2.10742},
       {1.80235, 1.80362, 1.80783, 1.82626, 1.83227, 1.89246,
        1.86795, 1.85405, 1.86938, 1.90720, 2.16953},
       {1.86442, 1.86572, 1.86994, 1.88837, 1.89438, 1.95445,
        1.93006, 1.92283, 1.93148, 1.96931, 2.23147},
       {1.92700, 1.92783, 1.93197, 1.95049, 1.95649, 2.01668,
        1.99217, 1.98486, 1.99352, 2.03143, 2.29358}};

  // Garfield simulation at UD = -2000V; vd = 1.783cm/microsec, <driftfield> = 688V/cm
  Float_t time2000[ktimebin][kZbin] =
      {{0.09176, 0.09196, 0.09296, 0.09465, 0.09704, 0.10020,
        0.10427, 0.10977, 0.11825, 0.13988, 0.37774},
       {0.06583, 0.06620, 0.06735, 0.06918, 0.07177, 0.07513,
        0.07936, 0.08503, 0.09372, 0.11606, 0.35586},
       {0.03944, 0.04001, 0.04170, 0.04431, 0.04774, 0.05184,
        0.05670, 0.06296, 0.07291, 0.09893, 0.34680},
       {0.01108, 0.01281, 0.01719, 0.02279, 0.02879, 0.03474,
        0.04093, 0.04908, 0.06422, 0.10605, 0.36800},
       {0.01114, 0.01287, 0.01720, 0.02276, 0.02863, 0.03449,
        0.04073, 0.04970, 0.06774, 0.11478, 0.37179},
       {0.03925, 0.03977, 0.04135, 0.04386, 0.04711, 0.05108,
        0.05604, 0.06290, 0.07580, 0.10748, 0.36386},
       {0.06501, 0.06536, 0.06640, 0.06814, 0.07062, 0.07398,
        0.07852, 0.08487, 0.09598, 0.12405, 0.37519},
       {0.09109, 0.09127, 0.09188, 0.09292, 0.09472, 0.00000,
        0.10964, 0.11630, 0.12960, 0.16150, 0.41765},
       {0.12898, 0.12968, 0.13209, 0.13749, 0.15034, 0.21286,
        0.18088, 0.17590, 0.18591, 0.22254, 0.48315},
       {0.18122, 0.18227, 0.18574, 0.19263, 0.20674, 0.26376,
        0.23960, 0.23375, 0.24316, 0.28047, 0.54179},
       {0.23674, 0.23784, 0.24142, 0.24847, 0.26264, 0.31810,
        0.29602, 0.29008, 0.29944, 0.33675, 0.59795},
       {0.29279, 0.29382, 0.29742, 0.30448, 0.31865, 0.37364,
        0.35215, 0.34629, 0.35555, 0.39286, 0.65411},
       {0.34875, 0.34987, 0.35346, 0.36054, 0.37472, 0.42956,
        0.40825, 0.40229, 0.41167, 0.44894, 0.71033},
       {0.40484, 0.40594, 0.40954, 0.41660, 0.43077, 0.48560,
        0.46433, 0.45840, 0.46772, 0.50500, 0.76632},
       {0.46090, 0.46201, 0.46560, 0.47267, 0.48684, 0.54167,
        0.52041, 0.51449, 0.52382, 0.56108, 0.82227},
       {0.51698, 0.51809, 0.52173, 0.52874, 0.54291, 0.59776,
        0.57646, 0.57052, 0.57986, 0.61717, 0.87836},
       {0.57306, 0.57418, 0.57782, 0.58513, 0.59899, 0.65380,
        0.63255, 0.62661, 0.63594, 0.67325, 0.93460},
       {0.62912, 0.63024, 0.63383, 0.64103, 0.65506, 0.70988,
        0.68484, 0.68267, 0.69202, 0.72878, 0.99046},
       {0.68521, 0.68633, 0.68990, 0.69699, 0.71115, 0.76595,
        0.74468, 0.73872, 0.74814, 0.78538, 1.04674},
       {0.74127, 0.74239, 0.74605, 0.75303, 0.77022, 0.82204,
        0.80078, 0.79484, 0.80416, 0.84147, 1.10261},
       {0.79736, 0.79846, 0.80206, 0.80947, 0.82330, 0.87813,
        0.85688, 0.85087, 0.86023, 0.89752, 1.15874},
       {0.85342, 0.85454, 0.85815, 0.86519, 0.87936, 0.93417,
        0.91293, 0.90428, 0.91631, 0.95360, 1.20760},
       {0.90949, 0.91061, 0.91423, 0.92128, 0.93544, 0.99026,
        0.96807, 0.96305, 0.97239, 1.00967, 1.27078},
       {0.96556, 0.96669, 0.97111, 0.97734, 0.99151, 1.04664,
        1.02508, 1.01879, 1.02846, 1.06167, 1.32695},
       {1.02167, 1.02279, 1.02656, 1.03341, 1.04759, 1.10242,
        1.08115, 1.07003, 1.08453, 1.12184, 1.38304},
       {1.07776, 1.07883, 1.08242, 1.08950, 1.10384, 1.16422,
        1.13725, 1.13133, 1.14061, 1.17793, 1.43910},
       {1.13379, 1.13492, 1.13864, 1.14567, 1.15973, 1.21455,
        1.19323, 1.18734, 1.19668, 1.23401, 1.49528},
       {1.18988, 1.19098, 1.19457, 1.20164, 1.21582, 1.27064,
        1.24937, 1.24044, 1.25275, 1.29004, 1.55137},
       {1.24592, 1.24706, 1.25087, 1.25773, 1.27188, 1.32670,
        1.30544, 1.29953, 1.30883, 1.34613, 1.60743},
       {1.30202, 1.30313, 1.30673, 1.31381, 1.32797, 1.38278,
        1.36151, 1.35167, 1.36490, 1.40221, 1.66306},
       {1.35809, 1.35921, 1.36282, 1.36986, 1.38403, 1.43888,
        1.41760, 1.41174, 1.42083, 1.45830, 1.71915},
       {1.41419, 1.41528, 1.41890, 1.42595, 1.44011, 1.49496,
        1.47368, 1.46769, 1.47706, 1.51436, 1.77523},
       {1.47131, 1.47141, 1.47494, 1.48850, 1.49620, 1.55137,
        1.52977, 1.51820, 1.53315, 1.57042, 1.83158},
       {1.52635, 1.52750, 1.53103, 1.53814, 1.55228, 1.60736,
        1.58503, 1.57986, 1.58920, 1.62649, 1.88767},
       {1.58418, 1.58355, 1.58711, 1.59526, 1.60833, 1.66316,
        1.63345, 1.63261, 1.64556, 1.68204, 1.94359},
       {1.64027, 1.63958, 1.64489, 1.65024, 1.66443, 1.71925,
        1.69794, 1.69201, 1.70143, 1.73865, 1.99968},
       {1.69450, 1.69566, 1.69940, 1.70697, 1.71841, 1.77819,
        1.75396, 1.74814, 1.75743, 1.79083, 2.05427},
       {1.75054, 1.75221, 1.75527, 1.76306, 1.77662, 1.83428,
        1.81006, 1.81173, 1.81345, 1.85076, 2.10289}};

  // Garfield simulation at UD = -2100V; vd = 1.959cm/microsec, <driftfield> = 720V/cm
  Float_t time2100[ktimebin][kZbin] =
      {{0.09160, 0.09194, 0.09294, 0.09462, 0.09701, 0.10017,
        0.10424, 0.10974, 0.11823, 0.13988, 0.37762},
       {0.06585, 0.06619, 0.06731, 0.06916, 0.07174, 0.07509,
        0.07933, 0.08500, 0.09370, 0.11609, 0.35565},
       {0.03960, 0.04001, 0.04171, 0.04430, 0.04774, 0.05182,
        0.05668, 0.06294, 0.07291, 0.09896, 0.34676},
       {0.01109, 0.01280, 0.01716, 0.02279, 0.02876, 0.03474,
        0.04096, 0.04908, 0.06424, 0.10612, 0.36790},
       {0.01114, 0.01285, 0.01719, 0.02287, 0.02863, 0.03449,
        0.04073, 0.04964, 0.06759, 0.11446, 0.37162},
       {0.03922, 0.03977, 0.04146, 0.04386, 0.04711, 0.05109,
        0.05605, 0.06287, 0.07575, 0.10713, 0.36298},
       {0.06504, 0.06538, 0.06641, 0.06818, 0.07064, 0.07426,
        0.07852, 0.08483, 0.09581, 0.12363, 0.37424},
       {0.09103, 0.09129, 0.09186, 0.09291, 0.09476, 0.00000,
        0.10923, 0.11578, 0.12873, 0.16005, 0.41525},
       {0.12723, 0.12777, 0.12988, 0.13458, 0.14579, 0.20264,
        0.17421, 0.17078, 0.18132, 0.21708, 0.47699},
       {0.17508, 0.17601, 0.17897, 0.18487, 0.19698, 0.24881,
        0.22737, 0.22337, 0.23348, 0.27000, 0.53032},
       {0.22571, 0.22663, 0.22969, 0.23570, 0.24787, 0.29826,
        0.27871, 0.27462, 0.28471, 0.32122, 0.58166},
       {0.27664, 0.27759, 0.28067, 0.28669, 0.29891, 0.34898,
        0.32982, 0.32570, 0.33576, 0.37229, 0.63268},
       {0.32766, 0.32862, 0.33170, 0.33778, 0.34988, 0.39973,
        0.38088, 0.37675, 0.38680, 0.42333, 0.68159},
       {0.37872, 0.37966, 0.38275, 0.38875, 0.40093, 0.45073,
        0.43192, 0.42780, 0.43786, 0.47438, 0.73480},
       {0.42974, 0.43070, 0.43378, 0.43982, 0.45196, 0.50177,
        0.48297, 0.47884, 0.48889, 0.52544, 0.78581},
       {0.48081, 0.48175, 0.48482, 0.49084, 0.50302, 0.55290,
        0.53398, 0.52988, 0.53994, 0.57647, 0.83687},
       {0.53645, 0.53295, 0.53586, 0.54188, 0.55408, 0.60398,
        0.58504, 0.58092, 0.59100, 0.62768, 0.88773},
       {0.58345, 0.58409, 0.58690, 0.59292, 0.60510, 0.65562,
        0.63609, 0.63197, 0.64203, 0.67856, 0.93907},
       {0.63397, 0.63490, 0.63795, 0.64403, 0.65613, 0.70612,
        0.68714, 0.68301, 0.69294, 0.72955, 0.99000},
       {0.68496, 0.68592, 0.68899, 0.69504, 0.70733, 0.75708,
        0.73818, 0.73405, 0.74412, 0.78064, 1.04100},
       {0.73600, 0.73696, 0.74003, 0.74624, 0.75828, 0.80805,
        0.78904, 0.78512, 0.79517, 0.83152, 1.09205},
       {0.78709, 0.78801, 0.79108, 0.79709, 0.80931, 0.85906,
        0.84027, 0.83614, 0.84621, 0.88269, 1.14058},
       {0.83808, 0.83905, 0.84215, 0.84816, 0.86031, 0.91011,
        0.89139, 0.88718, 0.89725, 0.93377, 1.19413},
       {0.88916, 0.89010, 0.89320, 0.89920, 0.91136, 0.96117,
        0.94235, 0.93822, 0.94828, 0.98480, 1.24538},
       {0.94036, 0.94113, 0.94422, 0.95023, 0.96241, 1.01220,
        0.99310, 0.98927, 0.99933, 1.03585, 1.29629},
       {0.99139, 0.99220, 0.99525, 1.00127, 1.01344, 1.06324,
        1.04451, 1.04033, 1.04836, 1.08690, 1.34727},
       {1.04261, 1.04325, 1.04628, 1.05232, 1.06448, 1.12090,
        1.09546, 1.09136, 1.10142, 1.13795, 1.39831},
       {1.09331, 1.09429, 1.09742, 1.10336, 1.11557, 1.16547,
        1.14658, 1.13642, 1.15247, 1.18898, 1.44936},
       {1.14436, 1.14539, 1.14847, 1.15443, 1.16662, 1.21794,
        1.19763, 1.19329, 1.20349, 1.23956, 1.50043},
       {1.19533, 1.19651, 1.19943, 1.20548, 1.21666, 1.26753,
        1.24862, 1.24434, 1.25455, 1.29106, 1.55142},
       {1.24638, 1.24756, 1.25046, 1.25648, 1.26764, 1.31858,
        1.29967, 1.29538, 1.30499, 1.34211, 1.60250},
       {1.29747, 1.29847, 1.30175, 1.30753, 1.31869, 1.36969,
        1.35069, 1.34656, 1.35663, 1.39316, 1.64644},
       {1.35537, 1.34952, 1.35255, 1.35869, 1.36973, 1.41387,
        1.40173, 1.39761, 1.40768, 1.44396, 1.70238},
       {1.39956, 1.40056, 1.40380, 1.40961, 1.42178, 1.46492,
        1.45278, 1.45423, 1.45872, 1.49522, 1.75557},
       {1.45080, 1.45159, 1.45463, 1.46109, 1.47287, 1.52263,
        1.50382, 1.50050, 1.50977, 1.54502, 1.80670},
       {1.50165, 1.50264, 1.50570, 1.51214, 1.52233, 1.57370,
        1.55484, 1.55155, 1.56080, 1.59731, 1.85778},
       {1.55269, 1.55364, 1.55675, 1.56274, 1.57491, 1.62598,
        1.60590, 1.60259, 1.61185, 1.64836, 1.90883},
       {1.60368, 1.60469, 1.60779, 1.61373, 1.62596, 1.67738,
        1.65651, 1.65249, 1.66290, 1.69936, 1.95959}};

  // Garfield simulation at UD = -2200V; vd = 2.134cm/microsec, <driftfield> = 753V/cm
  Float_t time2200[ktimebin][kZbin] =
      {{0.09162, 0.09194, 0.09292, 0.09460, 0.09702, 0.10014,
        0.10421, 0.10971, 0.11820, 0.13990, 0.37745},
       {0.06581, 0.06618, 0.06730, 0.06915, 0.07173, 0.07507,
        0.07931, 0.08497, 0.09368, 0.11609, 0.35560},
       {0.03947, 0.04001, 0.04167, 0.04429, 0.04772, 0.05183,
        0.05667, 0.06293, 0.07292, 0.09900, 0.34673},
       {0.01111, 0.01280, 0.01716, 0.02279, 0.02876, 0.03473,
        0.04091, 0.04907, 0.06426, 0.10620, 0.36766},
       {0.01113, 0.01285, 0.01719, 0.02276, 0.02863, 0.03452,
        0.04076, 0.04960, 0.06745, 0.11419, 0.37139},
       {0.03923, 0.03978, 0.04137, 0.04387, 0.04713, 0.05110,
        0.05605, 0.06284, 0.07551, 0.10677, 0.36210},
       {0.06505, 0.06540, 0.06644, 0.06820, 0.07069, 0.07401,
        0.07852, 0.08479, 0.09565, 0.12325, 0.37313},
       {0.09107, 0.09127, 0.09181, 0.09291, 0.09474, 0.00000,
        0.10883, 0.11528, 0.12789, 0.15865, 0.41313},
       {0.12559, 0.12622, 0.12800, 0.13206, 0.14166, 0.19331,
        0.16832, 0.16632, 0.17724, 0.21218, 0.47098},
       {0.16992, 0.17070, 0.17325, 0.17831, 0.18871, 0.23557,
        0.21690, 0.21451, 0.22514, 0.26082, 0.52034},
       {0.21640, 0.21722, 0.21987, 0.22500, 0.23540, 0.28097,
        0.26399, 0.26154, 0.27214, 0.30784, 0.56734},
       {0.26318, 0.26400, 0.26679, 0.27181, 0.28220, 0.32739,
        0.31090, 0.30842, 0.31902, 0.35474, 0.61415},
       {0.31001, 0.31085, 0.31348, 0.31866, 0.32903, 0.37412,
        0.35777, 0.35546, 0.36588, 0.40159, 0.66103},
       {0.35687, 0.35769, 0.36033, 0.36556, 0.37588, 0.42094,
        0.40523, 0.40214, 0.41273, 0.44841, 0.70785},
       {0.40372, 0.40457, 0.40723, 0.41234, 0.42273, 0.46778,
        0.45148, 0.44903, 0.45961, 0.49526, 0.75486},
       {0.45062, 0.45139, 0.45404, 0.45966, 0.46958, 0.51470,
        0.49833, 0.49584, 0.50644, 0.54211, 0.80160},
       {0.49742, 0.49825, 0.50088, 0.50605, 0.51644, 0.56148,
        0.54518, 0.54270, 0.55330, 0.58897, 0.84854},
       {0.54427, 0.54510, 0.54774, 0.55290, 0.56329, 0.60846,
        0.59203, 0.58955, 0.60014, 0.63578, 0.89528},
       {0.59119, 0.59199, 0.59471, 0.59975, 0.61014, 0.65533,
        0.63889, 0.63636, 0.64699, 0.68269, 0.94197},
       {0.63866, 0.63880, 0.64145, 0.64664, 0.65701, 0.70639,
        0.68574, 0.68325, 0.69385, 0.72949, 0.98900},
       {0.68483, 0.68566, 0.68831, 0.69347, 0.70386, 0.74890,
        0.73260, 0.73010, 0.74069, 0.77638, 1.03320},
       {0.73168, 0.73255, 0.73515, 0.74031, 0.75072, 0.79576,
        0.77117, 0.77501, 0.78755, 0.82318, 1.08006},
       {0.77854, 0.78310, 0.78200, 0.79525, 0.79756, 0.84281,
        0.81803, 0.82393, 0.83441, 0.87008, 1.12692},
       {0.82541, 0.82642, 0.82916, 0.83528, 0.84442, 0.89086,
        0.87315, 0.87079, 0.88125, 0.91694, 1.17648},
       {0.87226, 0.87308, 0.87602, 0.88086, 0.89128, 0.93772,
        0.92001, 0.91751, 0.92811, 0.95587, 1.22328},
       {0.91921, 0.91994, 0.92256, 0.92772, 0.94713, 0.98566,
        0.96690, 0.96436, 0.97495, 1.01064, 1.26882},
       {0.96790, 0.96679, 0.96941, 0.97463, 0.99399, 1.03001,
        1.01376, 1.01112, 1.02181, 1.05749, 1.31568},
       {1.01278, 1.01390, 1.01674, 1.02147, 1.03182, 1.07820,
        1.06056, 1.05798, 1.06867, 1.10433, 1.36390},
       {1.05964, 1.06076, 1.06331, 1.06833, 1.07870, 1.13297,
        1.10742, 1.10520, 1.11543, 1.15120, 1.41069},
       {1.10664, 1.10762, 1.10997, 1.11519, 1.12556, 1.17531,
        1.15427, 1.14620, 1.16229, 1.19805, 1.45758},
       {1.15352, 1.15421, 1.15683, 1.16218, 1.17242, 1.21910,
        1.20035, 1.19863, 1.20579, 1.24473, 1.50412},
       {1.20019, 1.20115, 1.20369, 1.20892, 1.21928, 1.26913,
        1.24721, 1.24549, 1.25605, 1.29159, 1.54920},
       {1.24707, 1.24846, 1.25052, 1.25602, 1.26608, 1.31558,
        1.29448, 1.29232, 1.30293, 1.33675, 1.59798},
       {1.29391, 1.29475, 1.29738, 1.30255, 1.31294, 1.36244,
        1.34167, 1.33918, 1.34979, 1.38229, 1.64496},
       {1.34078, 1.34304, 1.34424, 1.35565, 1.35980, 1.40930,
        1.38853, 1.38229, 1.39664, 1.42863, 1.69162},
       {1.38762, 1.38847, 1.39110, 1.39627, 1.40666, 1.45183,
        1.43539, 1.43289, 1.44348, 1.47549, 1.73876},
       {1.43524, 1.43533, 1.43796, 1.44310, 1.45371, 1.49305,
        1.48224, 1.47941, 1.49034, 1.52601, 1.78552},
       {1.48122, 1.48219, 1.48482, 1.48991, 1.50030, 1.53991,
        1.52898, 1.52653, 1.53653, 1.57282, 1.82386}};

  if (fTimeStructInfo.fTimeStruct1)  delete [] fTimeStructInfo.fTimeStruct1;
  fTimeStructInfo.fTimeStruct1  = new Float_t[ktimebin*kZbin];

  if (fTimeStructInfo.fTimeStruct2)  delete [] fTimeStructInfo.fTimeStruct2;
  fTimeStructInfo.fTimeStruct2  = new Float_t[ktimebin*kZbin];

  for (Int_t ctrt = 0; ctrt<ktimebin; ctrt++) {
    for (Int_t ctrz = 0; ctrz<kZbin; ctrz++) {
      if ( vdrift > fVDsmp[6] ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time2100[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time2200[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[6];
        fTimeStructInfo.fVDhi = fVDsmp[7];
      } else if ( vdrift > fVDsmp[5] ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time2000[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time2100[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[5];
        fTimeStructInfo.fVDhi = fVDsmp[6];
      } else if ( vdrift > fVDsmp[4] ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time1900[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time2000[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[4];
        fTimeStructInfo.fVDhi = fVDsmp[5];
      } else if ( vdrift > fVDsmp[3] ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time1800[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time1900[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[3];
        fTimeStructInfo.fVDhi = fVDsmp[4];
      } else if ( vdrift > fVDsmp[2] ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time1700[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time1800[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[2];
        fTimeStructInfo.fVDhi = fVDsmp[3];
      } else if ( vdrift > fVDsmp[1] ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time1600[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time1700[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[1];
        fTimeStructInfo.fVDhi = fVDsmp[2];
      } else if ( vdrift > (fVDsmp[0] - 1.e-5) ) {
        fTimeStructInfo.fTimeStruct1[ctrt+ctrz*ktimebin] = time1500[ctrt][ctrz];
        fTimeStructInfo.fTimeStruct2[ctrt+ctrz*ktimebin] = time1600[ctrt][ctrz];            
        fTimeStructInfo.fVDlo = fVDsmp[0];
        fTimeStructInfo.fVDhi = fVDsmp[1];
      }
    }
  }
}

//_____________________________________________________________________________
void AliTRDdigitizer::RecalcDiffusion(Float_t vdrift)
{
  if (vdrift == fDiffusionInfo.fLastVdrift)
    return;

  AliTRDSimParam*    simParam    = AliTRDSimParam::Instance();
  if (!simParam) {
    AliError("Could not get simulation parameters\n");
    return;
  }
  
  AliTRDCommonParam* commonParam = AliTRDCommonParam::Instance();
  if (!commonParam) {
    AliError("Could not get common parameters\n");
    return;
  }
  
  AliTRDcalibDB*     calibration = AliTRDcalibDB::Instance();
  if (!calibration) {
    AliError("Could not get calibration object\n");
    return;
  }
  
  Float_t field = commonParam->GetField();
  fDiffusionInfo.fLastVdrift = vdrift;
  
  // DiffusionL
  {
    const Int_t kNb = 5;
    Float_t p0[kNb] = {  0.007440,  0.007493,  0.007513,  0.007672,  0.007831 };
    Float_t p1[kNb] = {  0.019252,  0.018912,  0.018636,  0.018012,  0.017343 };
    Float_t p2[kNb] = { -0.005042, -0.004926, -0.004867, -0.004650, -0.004424 };
    Float_t p3[kNb] = {  0.000195,  0.000189,  0.000195,  0.000182,  0.000169 };

    Int_t ib = ((Int_t) (10 * (field - 0.15)));
    ib       = TMath::Max(  0,ib);
    ib       = TMath::Min(kNb,ib);

    fDiffusionInfo.fDiffusionL = p0[ib] 
                               + p1[ib] * vdrift
                               + p2[ib] * vdrift*vdrift
                               + p3[ib] * vdrift*vdrift*vdrift;
  }
  
  // DiffusionT
  {
    const Int_t kNb = 5;
    Float_t p0[kNb] = {  0.009550,  0.009599,  0.009674,  0.009757,  0.009850 };
    Float_t p1[kNb] = {  0.006667,  0.006539,  0.006359,  0.006153,  0.005925 };
    Float_t p2[kNb] = { -0.000853, -0.000798, -0.000721, -0.000635, -0.000541 };
    Float_t p3[kNb] = {  0.000131,  0.000122,  0.000111,  0.000098,  0.000085 };

    Int_t ib = ((Int_t) (10 * (field - 0.15)));
    ib       = TMath::Max(  0,ib);
    ib       = TMath::Min(kNb,ib);

    fDiffusionInfo.fDiffusionT = p0[ib] 
                               + p1[ib] * vdrift
                               + p2[ib] * vdrift*vdrift
                               + p3[ib] * vdrift*vdrift*vdrift;
  }    

  // OmegaTau
  fDiffusionInfo.fOmegaTau = calibration->GetOmegaTau(vdrift);
  
  // Lorentzfactor
  {
    if (commonParam->ExBOn()) {
      fDiffusionInfo.fLorentzFactor = 1.0 / (1.0 + fDiffusionInfo.fOmegaTau*fDiffusionInfo.fOmegaTau);
    }
    else {
      fDiffusionInfo.fLorentzFactor = 1.0;
    }
  }

}
  
//_____________________________________________________________________________
Float_t AliTRDdigitizer::GetDiffusionL(Float_t vdrift)
{
  //
  // Returns the longitudinal diffusion coefficient for a given drift 
  // velocity <vd> and a B-field <b> for Xe/CO2 (15%).
  // The values are according to a GARFIELD simulation.
  //

  RecalcDiffusion(vdrift);
  return fDiffusionInfo.fDiffusionL;

}

//_____________________________________________________________________________
Float_t AliTRDdigitizer::GetDiffusionT(Float_t vdrift)
{
  //
  // Returns the transverse diffusion coefficient for a given drift 
  // velocity <vd> and a B-field <b> for Xe/CO2 (15%).
  // The values are according to a GARFIELD simulation.
  //

  RecalcDiffusion(vdrift);
  return fDiffusionInfo.fDiffusionT;

}

//_____________________________________________________________________________
Int_t AliTRDdigitizer::Diffusion(Float_t vdrift, Double_t driftlength, Double_t *xyz)
{
  //
  // Applies the diffusion smearing to the position of a single electron
  //
  
  RecalcDiffusion(vdrift);

  Float_t driftSqrt = TMath::Sqrt(driftlength);
  Float_t sigmaT    = driftSqrt * fDiffusionInfo.fDiffusionT;
  Float_t sigmaL    = driftSqrt * fDiffusionInfo.fDiffusionL;
  xyz[0] = gRandom->Gaus(xyz[0], sigmaL * GetLorentzFactor(vdrift));
  xyz[1] = gRandom->Gaus(xyz[1], sigmaT * GetLorentzFactor(vdrift));
  xyz[2] = gRandom->Gaus(xyz[2], sigmaT);

  return 1;

}

//_____________________________________________________________________________
Float_t AliTRDdigitizer::GetLorentzFactor(Float_t vd)
{
  //
  // Returns the recalculated Lorentz factor
  //

  RecalcDiffusion(vd);
  return fDiffusionInfo.fLorentzFactor;

}
  
//_____________________________________________________________________________
Int_t AliTRDdigitizer::ExB(Float_t vdrift, Double_t driftlength, Double_t *xyz)
{
  //
  // Applies E x B effects to the position of a single electron
  //
  
  RecalcDiffusion(vdrift);
  
  xyz[0] = xyz[0];
  xyz[1] = xyz[1] + fDiffusionInfo.fOmegaTau * driftlength;
  xyz[2] = xyz[2];

  return 1;

}