VZERO/AliVZERODigitizer.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
   5  * Contributors are mentioned in the code where appropriate.              *
   6  *                                                                        *
   7  * Permission to use, copy, modify and distribute this software and its   *
   8  * documentation strictly for non-commercial purposes is hereby granted   *
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  10  * copies and that both the copyright notice and this permission notice   *
  11  * appear in the supporting documentation. The authors make no claims     *
  12  * about the suitability of this software for any purpose. It is          *
  13  * provided "as is" without express or implied warranty.                  *
  14  **************************************************************************/
  15
  16 /* $Id$ */
  17
  18 ///_________________________________________________________________________
  19 ///
  20 /// This class constructs Digits out of Hits
  21 ///
  22 ///
  23
  24 // --- Standard library ---
  25
  26 // --- ROOT system ---
  27 #include <TMath.h>
  28 #include <TTree.h>
  29 #include <TMap.h>
  30 #include <TGeoManager.h>
  31 #include <TGeoPhysicalNode.h>
  32 #include <AliGeomManager.h>
  33 #include <TRandom.h>
  34 #include <TF1.h>
  35 #include <TH1F.h>
  36
  37 // --- AliRoot header files ---
  38 #include "AliRun.h"
  39 #include "AliVZERO.h"
  40 #include "AliVZEROhit.h"
  41 #include "AliRunLoader.h"
  42 #include "AliLoader.h"
  43 #include "AliGRPObject.h"
  44 #include "AliRunDigitizer.h"
  45 #include "AliCDBManager.h"
  46 #include "AliCDBStorage.h"
  47 #include "AliCDBEntry.h"
  48 #include "AliVZEROCalibData.h"
  49 #include "AliCTPTimeParams.h"
  50 #include "AliLHCClockPhase.h"
  51 #include "AliVZEROdigit.h"
  52 #include "AliVZERODigitizer.h"
  53 #include "AliVZEROSDigit.h"
  54
  55 ClassImp(AliVZERODigitizer)
  56
  57  AliVZERODigitizer::AliVZERODigitizer()
  58                    :AliDigitizer(),
  59                     fCalibData(GetCalibData()),
  60                     fPhotoCathodeEfficiency(0.18),
  61                     fNdigits(0),
  62                     fDigits(0),
  63                     fSignalShape(NULL),
  64                     fPMResponse(NULL),
  65                     fSinglePhESpectrum(NULL),
  66                     fEvenOrOdd(kFALSE),
  67                     fTask(kHits2Digits),
  68                     fVZERO(NULL)
  69 {
  70   // default constructor
  71   // Initialize OCDB and containers used in the digitization
  72
  73   Init();
  74 }
  75
  76 //____________________________________________________________________________
  77   AliVZERODigitizer::AliVZERODigitizer(AliVZERO *vzero, DigiTask_t task)
  78                     :AliDigitizer(),
  79                      fCalibData(GetCalibData()),
  80                      fPhotoCathodeEfficiency(0.18),
  81                      fNdigits(0),
  82                      fDigits(0),
  83                      fSignalShape(NULL),
  84                      fPMResponse(NULL),
  85                      fSinglePhESpectrum(NULL),
  86                      fEvenOrOdd(kFALSE),
  87                      fTask(task),
  88                      fVZERO(vzero)
  89 {
  90   // constructor
  91   // Initialize OCDB and containers used in the digitization
  92
  93   Init();
  94 }
  95
  96 //____________________________________________________________________________
  97   AliVZERODigitizer::AliVZERODigitizer(AliRunDigitizer* manager)
  98                     :AliDigitizer(manager),
  99                      fCalibData(GetCalibData()),
 100                      fPhotoCathodeEfficiency(0.18),
 101                      fNdigits(0),
 102                      fDigits(0),
 103                      fSignalShape(NULL),
 104                      fPMResponse(NULL),
 105                      fSinglePhESpectrum(NULL),
 106                      fEvenOrOdd(kFALSE),
 107                      fTask(kHits2Digits),
 108                      fVZERO(NULL)
 109 {
 110   // constructor
 111   // Initialize OCDB and containers used in the digitization
 112
 113   Init();
 114 }
 115
 116 //____________________________________________________________________________
 117   AliVZERODigitizer::~AliVZERODigitizer()
 118 {
 119   // destructor
 120
 121   if (fDigits) {
 122     fDigits->Delete();
 123     delete fDigits;
 124     fDigits=0;
 125   }
 126
 127   if (fSignalShape) {
 128     delete fSignalShape;
 129     fSignalShape = NULL;
 130   }
 131   if (fPMResponse) {
 132     delete fPMResponse;
 133     fPMResponse = NULL;
 134   }
 135   if (fSinglePhESpectrum) {
 136     delete fSinglePhESpectrum;
 137     fSinglePhESpectrum = NULL;
 138   }
 139
 140   for(Int_t i = 0 ; i < 64; ++i) {
 141     if (fTime[i]) delete [] fTime[i];
 142   }
 143 }
 144
 145 //_____________________________________________________________________________
 146 Bool_t AliVZERODigitizer::Init()
 147 {
 148   // Initialises the digitizer
 149   // Initialize OCDB and containers used in the digitization
 150
 151   // check if the digitizer was already initialized
 152   if (fSignalShape) return kTRUE;
 153
 154   fSignalShape = new TF1("VZEROSignalShape",this,&AliVZERODigitizer::SignalShape,0,200,6,"AliVZERODigitizer","SignalShape");
 155   //  fSignalShape->SetParameters(0,1.57345e1,-4.25603e-1,2.9,6.40982,3.69339e-01);
 156   //  fSignalShape->SetParameters(1.34330e+00,1.13007e+02,-4.95705e-01,
 157   //                          3.68911e+00,1.01040e+00, 3.94675e-01);
 158   fSignalShape->SetParameters(-1.07335e+00,2.16002e+01,-1.26133e-01,
 159                               1.41619e+00,5.50334e-01,3.86111e-01);
 160   fPMResponse = new TF1("VZEROPMResponse",this,&AliVZERODigitizer::PMResponse,-kPMRespTime,2.*kPMRespTime,0,"AliVZERODigitizer","PMResponse");
 161   fSinglePhESpectrum = new TF1("VZEROSinglePhESpectrum",this,&AliVZERODigitizer::SinglePhESpectrum,0,20,0,"AliVZERODigitizer","SinglePhESpectrum");
 162
 163   // Now get the CTP L0->L1 delay
 164   AliCDBEntry *entry = AliCDBManager::Instance()->Get("GRP/CTP/CTPtiming");
 165   if (!entry) AliFatal("CTP timing parameters are not found in OCDB !");
 166   AliCTPTimeParams *ctpParams = (AliCTPTimeParams*)entry->GetObject();
 167   Float_t l1Delay = (Float_t)ctpParams->GetDelayL1L0()*25.0;
 168
 169   AliCDBEntry *entry1 = AliCDBManager::Instance()->Get("GRP/CTP/TimeAlign");
 170   if (!entry1) AliFatal("CTP time-alignment is not found in OCDB !");
 171   AliCTPTimeParams *ctpTimeAlign = (AliCTPTimeParams*)entry1->GetObject();
 172   l1Delay += ((Float_t)ctpTimeAlign->GetDelayL1L0()*25.0);
 173
 174   AliCDBEntry *entry2 = AliCDBManager::Instance()->Get("VZERO/Calib/TimeDelays");
 175   if (!entry2) AliFatal("VZERO time delays are not found in OCDB !");
 176   TH1F *delays = (TH1F*)entry2->GetObject();
 177
 178   AliCDBEntry *entry3 = AliCDBManager::Instance()->Get("GRP/Calib/LHCClockPhase");
 179   if (!entry3) AliFatal("LHC clock-phase shift is not found in OCDB !");
 180   AliLHCClockPhase *phase = (AliLHCClockPhase*)entry3->GetObject();
 181
 182   for(Int_t i = 0 ; i < 64; ++i) {
 183
 184     for(Int_t j = 0; j < kNClocks; ++j) fAdc[i][j] = 0;
 185     fLeadingTime[i] = fTimeWidth[i] = 0;
 186
 187     fPmGain[i] = fCalibData->GetGain(i);
 188
 189     fAdcPedestal[i][0] = fCalibData->GetPedestal(i);
 190     fAdcSigma[i][0]    = fCalibData->GetSigma(i);
 191     fAdcPedestal[i][1] = fCalibData->GetPedestal(i+64);
 192     fAdcSigma[i][1]    = fCalibData->GetSigma(i+64);
 193
 194     Int_t board = AliVZEROCalibData::GetBoardNumber(i);
 195     fNBins[i] = TMath::Nint(((Float_t)(fCalibData->GetMatchWindow(board)+1)*25.0+
 196                              (Float_t)kMaxTDCWidth*fCalibData->GetWidthResolution(board))/
 197                             fCalibData->GetTimeResolution(board));
 198     fNBinsLT[i] = TMath::Nint(((Float_t)(fCalibData->GetMatchWindow(board)+1)*25.0)/
 199                               fCalibData->GetTimeResolution(board));
 200     fBinSize[i] = fCalibData->GetTimeResolution(board);
 201     fHptdcOffset[i] = (((Float_t)fCalibData->GetTriggerCountOffset(board)-
 202                         (Float_t)fCalibData->GetRollOver(board))*25.0+
 203                        fCalibData->GetTimeOffset(i)-
 204                        l1Delay-
 205                        phase->GetMeanPhase()+
 206                        delays->GetBinContent(i+1)+
 207                        kV0Offset);
 208
 209     fTime[i] = new Float_t[fNBins[i]];
 210     memset(fTime[i],0,fNBins[i]*sizeof(Float_t));
 211   }
 212
 213   return kTRUE;
 214 }
 215
 216 //____________________________________________________________________________
 217 void AliVZERODigitizer::Exec(Option_t* /*option*/)
 218 {
 219   // Creates digits from hits
 220   fNdigits = 0;
 221
 222   if (fVZERO && !fManager) {
 223     AliLoader *loader = fVZERO->GetLoader();
 224     if (!loader) {
 225       AliError("Can not get VZERO Loader via AliVZERO object!");
 226       return;
 227     }
 228     AliRunLoader* runLoader = AliRunLoader::Instance();
 229     for (Int_t iEvent = 0; iEvent < runLoader->GetNumberOfEvents(); ++iEvent) {
 230       runLoader->GetEvent(iEvent);
 231       if (fTask == kHits2Digits) {
 232         DigitizeHits();
 233         DigitizeSDigits();
 234         WriteDigits(loader);
 235       }
 236       else {
 237         DigitizeHits();
 238         WriteSDigits(loader);
 239       }
 240     }
 241   }
 242   else if (fManager) {
 243       ReadSDigits();
 244       DigitizeSDigits();
 245       AliRunLoader *currentLoader = AliRunLoader::GetRunLoader(fManager->GetOutputFolderName());
 246       AliLoader *loader = currentLoader->GetLoader("VZEROLoader");
 247       if (!loader) {
 248         AliError("Cannot get VZERO Loader via RunDigitizer!");
 249         return;
 250       }
 251       WriteDigits(loader);
 252   }
 253   else {
 254     AliFatal("Invalid digitization task! Exiting!");
 255   }
 256 }
 257
 258 //____________________________________________________________________________
 259 void AliVZERODigitizer::AddDigit(Int_t pmnumber, Float_t time, Float_t width, Bool_t integrator, Short_t *chargeADC, Int_t *labels)
 260  {
 261
 262 // Adds Digit
 263
 264   TClonesArray &ldigits = *fDigits;
 265
 266   new(ldigits[fNdigits++]) AliVZEROdigit(pmnumber,time,width,integrator,chargeADC,labels);
 267
 268 }
 269 //____________________________________________________________________________
 270 void AliVZERODigitizer::AddSDigit(Int_t pmnumber, Int_t nbins, Float_t *charges, Int_t *labels)
 271  {
 272
 273 // Adds SDigit
 274
 275   TClonesArray &ldigits = *fDigits;
 276
 277   new(ldigits[fNdigits++]) AliVZEROSDigit(pmnumber,nbins,charges,labels);
 278
 279 }
 280 //____________________________________________________________________________
 281 void AliVZERODigitizer::ResetDigits()
 282 {
 283
 284 // Clears Digits
 285
 286   fNdigits = 0;
 287   if (fDigits) fDigits->Clear();
 288 }
 289
 290 //____________________________________________________________________________
 291 AliVZEROCalibData* AliVZERODigitizer::GetCalibData() const
 292
 293 {
 294   AliCDBManager *man = AliCDBManager::Instance();
 295
 296   AliCDBEntry *entry=0;
 297
 298   entry = man->Get("VZERO/Calib/Data");
 299
 300 //   if(!entry){
 301 //     AliWarning("Load of calibration data from default storage failed!");
 302 //     AliWarning("Calibration data will be loaded from local storage ($ALICE_ROOT)");
 303 //     Int_t runNumber = man->GetRun();
 304 //     entry = man->GetStorage("local://$ALICE_ROOT/OCDB")
 305 //       ->Get("VZERO/Calib/Data",runNumber);
 306 //
 307 //   }
 308
 309   // Retrieval of data in directory VZERO/Calib/Data:
 310
 311
 312   AliVZEROCalibData *calibdata = 0;
 313
 314   if (entry) calibdata = (AliVZEROCalibData*) entry->GetObject();
 315   if (!calibdata)  AliFatal("No calibration data from calibration database !");
 316
 317   return calibdata;
 318
 319 }
 320
 321 double AliVZERODigitizer::SignalShape(double *x, double *par)
 322 {
 323   // this function simulates the time
 324   // of arrival of the photons at the
 325   // photocathode
 326   Double_t xx = x[0];
 327   if (xx <= par[0]) return 0;
 328   Double_t a = 1./TMath::Power((xx-par[0])/par[1],1./par[2]);
 329   if (xx <= par[3]) return a;
 330   Double_t b = 1./TMath::Power((xx-par[3])/par[4],1./par[5]);
 331   Double_t f = a*b/(a+b);
 332   AliDebug(100,Form("x=%f func=%f",xx,f));
 333   return f;
 334 }
 335
 336 double AliVZERODigitizer::PMResponse(double *x, double * /* par */)
 337 {
 338   // this function describes the
 339   // PM time response to a single
 340   // photoelectron
 341   Double_t xx = x[0]+kPMRespTime;
 342   return xx*xx*TMath::Exp(-xx*xx/(kPMRespTime*kPMRespTime));
 343 }
 344
 345 double AliVZERODigitizer::SinglePhESpectrum(double *x, double * /* par */)
 346 {
 347   // this function describes the
 348   // PM amplitude response to a single
 349   // photoelectron
 350   Double_t xx = x[0];
 351   if (xx < 0) return 0;
 352   return (TMath::Poisson(xx,kPMNbOfSecElec)+kPMTransparency*TMath::Poisson(xx,1.0));
 353 }
 354
 355 Int_t AliVZERODigitizer::Cell2Pmt(Int_t cell) const
 356 {
 357   // The method maps the scintillator
 358   // indexes to the PM ones
 359   if (cell < 0 || cell >= 80) {
 360     AliError(Form("Wrong VZERO cell index %d",cell));
 361     return -1;
 362   }
 363   if (cell < 16) return cell;
 364   if (cell < 48) return 8 + cell/2;
 365   return cell - 16;
 366 }
 367
 368 void AliVZERODigitizer::DigitizeHits()
 369 {
 370   // Digitize the hits to the level of
 371   // SDigits (fTime arrays)
 372
 373   for(Int_t i = 0 ; i < 64; ++i) {
 374     memset(fTime[i],0,fNBins[i]*sizeof(Float_t));
 375     fLabels[i][0] = fLabels[i][1] = fLabels[i][2] = -1;
 376   }
 377   Float_t integral = fPMResponse->Integral(-kPMRespTime,2.*kPMRespTime);
 378   Float_t meansPhE = fSinglePhESpectrum->Mean(0,20);
 379
 380      AliLoader* loader = fVZERO->GetLoader();
 381      if (!loader) {
 382        AliError("Can not get VZERO Loader!");
 383        return;
 384      }
 385      loader->LoadHits();
 386      TTree* treeH = loader->TreeH();
 387      if (!treeH) {
 388        AliError("Cannot get TreeH!");
 389        return;
 390      }
 391      TClonesArray* hits = fVZERO->Hits();
 392
 393      //     Float_t lightYieldCorr[64] = {0.00707,0.00517,0.00520,0.00537,0.00735,0.00537,0.00733,0.00605,0.00778,0.00749,0.00701,0.00755,0.00732,0.00617,0.00669,0.00525,0.00752,0.00820,0.00797,0.01107,0.01080,0.00889,0.00880,0.01712,0.00866,0.00701,0.00811,0.00602,0.00879,0.00821,0.00861,0.01433,0.00061,0.00032,0.00099,0.00061,0.00034,0.00046,0.00031,0.00122,0.00155,0.00091,0.00032,0.00096,0.00120,0.00067,0.00113,0.00060,0.00158,0.00136,0.00340,0.00066,0.00076,0.00119,0.00129,0.00147,0.00137,0.00117,0.00088,0.00164,0.00128,0.00081,0.00121,0.00250};
 394      Float_t lightYieldCorr[64] = {0.01173,0.00874,0.00878,0.00886,0.01151,0.00925,0.01167,0.00983,0.01181,0.01243,0.01115,0.01220,0.01228,0.01053,0.01021,0.00930,0.01270,0.01411,0.01316,0.01894,0.01923,0.01860,0.01738,0.00305,0.01584,0.01251,0.01344,0.00310,0.01302,0.01266,0.01407,0.00338,0.00089,0.00100,0.00130,0.00081,0.00052,0.01230,0.00059,0.02452,0.02980,0.00137,0.01421,0.00116,0.00141,0.00092,0.02480,0.00096,0.00182,0.00174,0.00218,0.00106,0.00116,0.00160,0.00162,0.03097,0.00194,0.00171,0.00132,0.00239,0.00173,0.00118,0.00163,0.00262};
 395 //  Now makes Digits from hits
 396      Int_t nTracks = (Int_t) treeH->GetEntries();
 397      for (Int_t iTrack = 0; iTrack < nTracks; iTrack++) {
 398          fVZERO->ResetHits();
 399          treeH->GetEvent(iTrack);
 400          Int_t nHits = hits->GetEntriesFast();
 401          for (Int_t iHit = 0; iHit < nHits; iHit++) {
 402            AliVZEROhit* hit = (AliVZEROhit *)hits->UncheckedAt(iHit);
 403            Int_t nPhot = hit->Nphot();
 404            Int_t cell  = hit->Cell();
 405            Int_t pmt = Cell2Pmt(cell);
 406            Int_t trackLabel = hit->GetTrack();
 407            for(Int_t l = 0; l < 3; ++l) {
 408              if (fLabels[pmt][l] < 0) {
 409                fLabels[pmt][l] = trackLabel;
 410                break;
 411              }
 412            }
 413            Float_t dt_scintillator = gRandom->Gaus(0,kIntTimeRes);
 414            Float_t t = dt_scintillator + 1e9*hit->Tof();
 415            if (pmt < 32) t += kV0CDelayCables;
 416            t += fHptdcOffset[pmt];
 417            Int_t nPhE;
 418            Float_t prob = lightYieldCorr[pmt]*fPhotoCathodeEfficiency; // Optical losses included!
 419            if (nPhot > 100)
 420              nPhE = (Int_t)gRandom->Gaus(prob*Float_t(nPhot)+0.5,
 421                                          sqrt(Float_t(nPhot)*prob*(1.-prob)));
 422            else
 423              nPhE = gRandom->Binomial(nPhot,prob);
 424            Float_t charge = TMath::Qe()*fPmGain[pmt]*fBinSize[pmt]/integral;
 425            for (Int_t iPhE = 0; iPhE < nPhE; ++iPhE) {
 426              Float_t tPhE = t + fSignalShape->GetRandom(0,fBinSize[pmt]*Float_t(fNBins[pmt]));
 427              Float_t gainVar = fSinglePhESpectrum->GetRandom(0,20)/meansPhE;
 428              Int_t firstBin = TMath::Max(0,(Int_t)((tPhE-kPMRespTime)/fBinSize[pmt]));
 429              Int_t lastBin = TMath::Min(fNBins[pmt]-1,(Int_t)((tPhE+2.*kPMRespTime)/fBinSize[pmt]));
 430              for(Int_t iBin = firstBin; iBin <= lastBin; ++iBin) {
 431                Float_t tempT = fBinSize[pmt]*(0.5+iBin)-tPhE;
 432                fTime[pmt][iBin] += gainVar*charge*fPMResponse->Eval(tempT);
 433              }
 434            }         // ph.e. loop
 435          }           // hit loop
 436      }               // track loop
 437      loader->UnloadHits();
 438 }
 439
 440
 441 void AliVZERODigitizer::DigitizeSDigits()
 442 {
 443   // Digitize the fTime arrays (SDigits) to the level of
 444   // Digits (fAdc arrays)
 445   for(Int_t i = 0 ; i < 64; ++i) {
 446     for(Int_t j = 0; j < kNClocks; ++j) fAdc[i][j] = 0;
 447     fLeadingTime[i] = fTimeWidth[i] = 0;
 448   }
 449
 450   Float_t maximum = 0.9*fSignalShape->GetMaximum(0,200); // Not exact, one needs to do this on the convoluted
 451   Float_t integral2 = fSignalShape->Integral(0,200); // function. Anyway the effect is small <10% on the 2.5 ADC thr
 452   for (Int_t ipmt = 0; ipmt < 64; ++ipmt) {
 453     Float_t thr = fCalibData->GetDiscriThr(ipmt)*kChargePerADC*maximum*fBinSize[ipmt]/integral2;
 454     Bool_t ltFound = kFALSE, ttFound = kFALSE;
 455     for (Int_t iBin = 0; iBin < fNBins[ipmt]; ++iBin) {
 456       Float_t t = fBinSize[ipmt]*Float_t(iBin);
 457       if (fTime[ipmt][iBin] > thr) {
 458         if (!ltFound && (iBin < fNBinsLT[ipmt])) {
 459           ltFound = kTRUE;
 460           fLeadingTime[ipmt] = t;
 461         }
 462       }
 463       else {
 464         if (ltFound) {
 465           if (!ttFound) {
 466             ttFound = kTRUE;
 467             fTimeWidth[ipmt] = t - fLeadingTime[ipmt];
 468           }
 469         }
 470       }
 471       Float_t tadc = t - kClockOffset - fCalibData->GetTimeOffset(ipmt);
 472       Int_t clock = kNClocks/2 - Int_t(tadc/25.0);
 473       if (clock >= 0 && clock < kNClocks)
 474         fAdc[ipmt][clock] += fTime[ipmt][iBin]/kChargePerADC;
 475     }
 476     Int_t board = AliVZEROCalibData::GetBoardNumber(ipmt);
 477     if (ltFound && ttFound) {
 478       fTimeWidth[ipmt] = fCalibData->GetWidthResolution(board)*
 479         Float_t(Int_t(fTimeWidth[ipmt]/fCalibData->GetWidthResolution(board)));
 480       if (fTimeWidth[ipmt] < Float_t(kMinTDCWidth)*fCalibData->GetWidthResolution(board))
 481         fTimeWidth[ipmt] = Float_t(kMinTDCWidth)*fCalibData->GetWidthResolution(board);
 482       if (fTimeWidth[ipmt] > Float_t(kMaxTDCWidth)*fCalibData->GetWidthResolution(board))
 483         fTimeWidth[ipmt] = Float_t(kMaxTDCWidth)*fCalibData->GetWidthResolution(board);
 484     }
 485   }
 486
 487   fEvenOrOdd = gRandom->Integer(2);
 488   for (Int_t j=0; j<64; ++j){
 489     for (Int_t iClock = 0; iClock < kNClocks; ++iClock) {
 490       Int_t integrator = (iClock + fEvenOrOdd) % 2;
 491       fAdc[j][iClock]  += gRandom->Gaus(fAdcPedestal[j][integrator], fAdcSigma[j][integrator]);
 492     }
 493   }
 494
 495 }
 496
 497 void AliVZERODigitizer::WriteDigits(AliLoader *loader)
 498 {
 499   // Take fAdc arrays filled by the previous
 500   // method and produce and add digits to the digit Tree
 501
 502   loader->LoadDigits("UPDATE");
 503
 504   if (!loader->TreeD()) loader->MakeTree("D");
 505   loader->MakeDigitsContainer();
 506   TTree* treeD  = loader->TreeD();
 507   DigitsArray();
 508   treeD->Branch("VZERODigit", &fDigits);
 509
 510   Short_t *chargeADC = new Short_t[kNClocks];
 511   for (Int_t i=0; i<64; i++) {
 512     for (Int_t j = 0; j < kNClocks; ++j) {
 513       Int_t tempadc = Int_t(fAdc[i][j]);
 514       if (tempadc > 1023) tempadc = 1023;
 515       chargeADC[j] = tempadc;
 516     }
 517     AddDigit(i, fLeadingTime[i], fTimeWidth[i], Bool_t((10+fEvenOrOdd)%2), chargeADC, fLabels[i]);
 518   }
 519   delete [] chargeADC;
 520
 521   treeD->Fill();
 522   loader->WriteDigits("OVERWRITE");
 523   loader->UnloadDigits();
 524   ResetDigits();
 525 }
 526
 527 void AliVZERODigitizer::WriteSDigits(AliLoader *loader)
 528 {
 529   // Take fTime arrays filled by the previous
 530   // method and produce and add sdigits to the sdigit Tree
 531
 532   loader->LoadSDigits("UPDATE");
 533
 534   if (!loader->TreeS()) loader->MakeTree("S");
 535   loader->MakeSDigitsContainer();
 536   TTree* treeS  = loader->TreeS();
 537   SDigitsArray();
 538   treeS->Branch("VZEROSDigit", &fDigits);
 539
 540   for (Int_t ipmt = 0; ipmt < 64; ++ipmt) {
 541     AddSDigit(ipmt,fNBins[ipmt],fTime[ipmt],fLabels[ipmt]);
 542   }
 543
 544   treeS->Fill();
 545   loader->WriteSDigits("OVERWRITE");
 546   loader->UnloadSDigits();
 547   ResetDigits();
 548 }
 549
 550 void AliVZERODigitizer::ReadSDigits()
 551 {
 552   // Read SDigits which are then to precessed
 553   // in the following method
 554   for(Int_t i = 0 ; i < 64; ++i) {
 555     memset(fTime[i],0,fNBins[i]*sizeof(Float_t));
 556     fLabels[i][0] = fLabels[i][1] = fLabels[i][2] = -1;
 557   }
 558
 559   // Loop over input files
 560   Int_t nFiles= fManager->GetNinputs();
 561   for (Int_t inputFile = 0; inputFile < nFiles; inputFile++) {
 562     // Get the current loader
 563     AliRunLoader* currentLoader =
 564       AliRunLoader::GetRunLoader(fManager->GetInputFolderName(inputFile));
 565
 566     AliLoader *loader = currentLoader->GetLoader("VZEROLoader");
 567     loader->LoadSDigits("READ");
 568
 569     // Get the tree of summable digits
 570     TTree* sdigitsTree = loader->TreeS();
 571     if (!sdigitsTree)  {
 572       AliError("No sdigit tree from manager");
 573       continue;
 574     }
 575
 576     // Get the branch
 577     TBranch* sdigitsBranch = sdigitsTree->GetBranch("VZEROSDigit");
 578     if (!sdigitsBranch) {
 579       AliError("Failed to get sdigit branch");
 580       return;
 581     }
 582
 583     // Set the branch address
 584     TClonesArray *sdigitsArray = NULL;
 585     sdigitsBranch->SetAddress(&sdigitsArray);
 586
 587     // Sum contributions from the sdigits
 588     // Get number of entries in the tree
 589     Int_t nentries  = Int_t(sdigitsBranch->GetEntries());
 590     for (Int_t entry = 0; entry < nentries; ++entry)  {
 591       sdigitsBranch->GetEntry(entry);
 592       // Get the number of sdigits
 593       Int_t nsdigits = sdigitsArray->GetEntries();
 594       for (Int_t sdigit = 0; sdigit < nsdigits; sdigit++) {
 595         AliVZEROSDigit* sDigit = static_cast<AliVZEROSDigit*>(sdigitsArray->UncheckedAt(sdigit));
 596         Int_t pmNumber = sDigit->PMNumber();
 597         Int_t nbins = sDigit->GetNBins();
 598         if (nbins != fNBins[pmNumber]) {
 599           AliError(Form("Incompatible number of bins between digitizer (%d) and sdigit (%d) for PM %d! Skipping sdigit!",
 600                         fNBins[pmNumber],nbins,pmNumber));
 601           continue;
 602         }
 603         // Sum the charges
 604         Float_t *charges = sDigit->GetCharges();
 605         for(Int_t iBin = 0; iBin < nbins; ++iBin) fTime[pmNumber][iBin] += charges[iBin];
 606         // and the labels
 607         Int_t *labels = sDigit->GetTracks();
 608         Int_t j = 0;
 609         for(Int_t i = 0; i < 3; ++i) {
 610           if (fLabels[pmNumber][i] < 0) {
 611             if (labels[j] < 0) break;
 612             fLabels[pmNumber][i] = labels[j];
 613             j++;
 614           }
 615         }
 616       }
 617     }
 618     loader->UnloadSDigits();
 619   }
 620 }
 621
 622 //____________________________________________________________________
 623 TClonesArray*
 624 AliVZERODigitizer::DigitsArray()
 625 {
 626   // Initialize digit array if not already and
 627   // return pointer to it.
 628   if (!fDigits) {
 629     fDigits = new TClonesArray("AliVZEROdigit", 64);
 630     fNdigits = 0;
 631   }
 632   return fDigits;
 633 }
 634
 635 //____________________________________________________________________
 636 TClonesArray*
 637 AliVZERODigitizer::SDigitsArray()
 638 {
 639   // Initialize sdigit array if not already and
 640   // return pointer to it.
 641   if (!fDigits) {
 642     fDigits = new TClonesArray("AliVZEROSDigit", 64);
 643     fNdigits = 0;
 644   }
 645   return fDigits;
 646 }