TRD/AliTRDclusterizerV1.cxx

   1
   2 /**************************************************************************
   3  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   4  *                                                                        *
   5  * Author: The ALICE Off-line Project.                                    *
   6  * Contributors are mentioned in the code where appropriate.              *
   7  *                                                                        *
   8  * Permission to use, copy, modify and distribute this software and its   *
   9  * documentation strictly for non-commercial purposes is hereby granted   *
  10  * without fee, provided that the above copyright notice appears in all   *
  11  * copies and that both the copyright notice and this permission notice   *
  12  * appear in the supporting documentation. The authors make no claims     *
  13  * about the suitability of this software for any purpose. It is          *
  14  * provided "as is" without express or implied warranty.                  *
  15  **************************************************************************/
  16
  17 /* $Id$ */
  18
  19 ///////////////////////////////////////////////////////////////////////////////
  20 //                                                                           //
  21 // TRD cluster finder for the slow simulator.
  22 //                                                                           //
  23 ///////////////////////////////////////////////////////////////////////////////
  24
  25 #include <TF1.h>
  26 #include <TTree.h>
  27 #include <TH1.h>
  28 #include <TFile.h>
  29
  30 #include "AliRun.h"
  31 #include "AliRunLoader.h"
  32 #include "AliLoader.h"
  33 #include "AliRawReader.h"
  34
  35 #include "AliTRDclusterizerV1.h"
  36 #include "AliTRDgeometry.h"
  37 #include "AliTRDdataArrayF.h"
  38 #include "AliTRDdataArrayI.h"
  39 #include "AliTRDdigitsManager.h"
  40 #include "AliTRDpadPlane.h"
  41 #include "AliTRDrawData.h"
  42 #include "AliTRDcalibDB.h"
  43 #include "AliTRDSimParam.h"
  44 #include "AliTRDRecParam.h"
  45 #include "AliTRDCommonParam.h"
  46 #include "AliTRDcluster.h"
  47
  48 ClassImp(AliTRDclusterizerV1)
  49
  50 //_____________________________________________________________________________
  51 AliTRDclusterizerV1::AliTRDclusterizerV1():AliTRDclusterizer()
  52 {
  53   //
  54   // AliTRDclusterizerV1 default constructor
  55   //
  56
  57   fDigitsManager = 0;
  58
  59 }
  60
  61 //_____________________________________________________________________________
  62 AliTRDclusterizerV1::AliTRDclusterizerV1(const Text_t* name, const Text_t* title)
  63                     :AliTRDclusterizer(name,title)
  64 {
  65   //
  66   // AliTRDclusterizerV1 default constructor
  67   //
  68
  69   fDigitsManager = new AliTRDdigitsManager();
  70   fDigitsManager->CreateArrays();
  71
  72 }
  73
  74 //_____________________________________________________________________________
  75 AliTRDclusterizerV1::AliTRDclusterizerV1(const AliTRDclusterizerV1 &c)
  76 :AliTRDclusterizer(c)
  77 {
  78   //
  79   // AliTRDclusterizerV1 copy constructor
  80   //
  81
  82   ((AliTRDclusterizerV1 &) c).Copy(*this);
  83
  84 }
  85
  86 //_____________________________________________________________________________
  87 AliTRDclusterizerV1::~AliTRDclusterizerV1()
  88 {
  89   //
  90   // AliTRDclusterizerV1 destructor
  91   //
  92
  93   if (fDigitsManager) {
  94     delete fDigitsManager;
  95     fDigitsManager = NULL;
  96   }
  97
  98 }
  99
 100 //_____________________________________________________________________________
 101 AliTRDclusterizerV1 &AliTRDclusterizerV1::operator=(const AliTRDclusterizerV1 &c)
 102 {
 103   //
 104   // Assignment operator
 105   //
 106
 107   if (this != &c) ((AliTRDclusterizerV1 &) c).Copy(*this);
 108   return *this;
 109
 110 }
 111
 112 //_____________________________________________________________________________
 113 void AliTRDclusterizerV1::Copy(TObject &c) const
 114 {
 115   //
 116   // Copy function
 117   //
 118
 119   ((AliTRDclusterizerV1 &) c).fDigitsManager = 0;
 120
 121   AliTRDclusterizer::Copy(c);
 122
 123 }
 124
 125 //_____________________________________________________________________________
 126 Bool_t AliTRDclusterizerV1::ReadDigits()
 127 {
 128   //
 129   // Reads the digits arrays from the input aliroot file
 130   //
 131
 132   if (!fRunLoader) {
 133     printf("<AliTRDclusterizerV1::ReadDigits> ");
 134     printf("No input file open\n");
 135     return kFALSE;
 136   }
 137   AliLoader* loader = fRunLoader->GetLoader("TRDLoader");
 138   if (!loader->TreeD()) loader->LoadDigits();
 139
 140   // Read in the digit arrays
 141   return (fDigitsManager->ReadDigits(loader->TreeD()));
 142
 143 }
 144
 145 //_____________________________________________________________________________
 146 Bool_t AliTRDclusterizerV1::ReadDigits(AliRawReader* rawReader)
 147 {
 148   //
 149   // Reads the digits arrays from the ddl file
 150   //
 151
 152   AliTRDrawData raw;
 153
 154   fDigitsManager = raw.Raw2Digits(rawReader);
 155
 156   return kTRUE;
 157
 158 }
 159
 160 //_____________________________________________________________________________
 161 Bool_t AliTRDclusterizerV1::MakeClusters()
 162 {
 163   //
 164   // Generates the cluster.
 165   //
 166
 167   Int_t row, col, time;
 168
 169   /*
 170   if (fTRD->IsVersion() != 1) {
 171     printf("<AliTRDclusterizerV1::MakeCluster> ");
 172     printf("TRD must be version 1 (slow simulator).\n");
 173     return kFALSE;
 174   }
 175   */
 176
 177   // Get the geometry
 178   AliTRDgeometry *geo = AliTRDgeometry::GetGeometry(fRunLoader);
 179   AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
 180   if (!calibration)
 181   {
 182     printf("<AliTRDclusterizerV1::MakeCluster> ");
 183     printf("ERROR getting instance of AliTRDcalibDB");
 184     return kFALSE;
 185   }
 186
 187   AliTRDSimParam* simParam = AliTRDSimParam::Instance();
 188   if (!simParam)
 189   {
 190     printf("<AliTRDclusterizerV1::MakeCluster> ");
 191     printf("ERROR getting instance of AliTRDSimParam");
 192     return kFALSE;
 193   }
 194
 195   AliTRDRecParam* recParam = AliTRDRecParam::Instance();
 196   if (!recParam)
 197   {
 198     printf("<AliTRDclusterizerV1::MakeCluster> ");
 199     printf("ERROR getting instance of AliTRDRecParam");
 200     return kFALSE;
 201   }
 202
 203   AliTRDCommonParam* commonParam = AliTRDCommonParam::Instance();
 204   if (!commonParam)
 205   {
 206     printf("<AliTRDclusterizerV1::MakeDigits> ");
 207     printf("Could not get common params\n");
 208     return kFALSE;
 209   }
 210
 211   Float_t ADCthreshold = simParam->GetADCthreshold();
 212
 213   if (fVerbose > 0) {
 214     //printf("<AliTRDclusterizerV1::MakeCluster> ");
 215     //printf("OmegaTau = %f \n",omegaTau);
 216     printf("<AliTRDclusterizerV1::MakeCluster> ");
 217     printf("Start creating clusters.\n");
 218   }
 219
 220   AliTRDdataArrayI *digitsIn;
 221   AliTRDdataArrayI *track0;
 222   AliTRDdataArrayI *track1;
 223   AliTRDdataArrayI *track2;
 224
 225   // Threshold value for the maximum
 226   Float_t maxThresh = recParam->GetClusMaxThresh();
 227   // Threshold value for the digit signal
 228   Float_t sigThresh = recParam->GetClusSigThresh();
 229   // Iteration limit for unfolding procedure
 230   const Float_t kEpsilon = 0.01;
 231
 232   const Int_t   kNclus   = 3;
 233   const Int_t   kNsig    = 5;
 234   const Int_t   kNtrack  = 3 * kNclus;
 235
 236   Int_t    iType         = 0;
 237   Int_t    iUnfold       = 0;
 238   Double_t ratioLeft     = 1.0;
 239   Double_t ratioRight    = 1.0;
 240
 241   //
 242   Double_t padSignal[kNsig];
 243   Double_t clusterSignal[kNclus];
 244   Double_t clusterPads[kNclus];
 245   Int_t    clusterTracks[kNtrack];
 246
 247   Int_t    chamBeg = 0;
 248   Int_t    chamEnd = AliTRDgeometry::Ncham();
 249   Int_t    planBeg = 0;
 250   Int_t    planEnd = AliTRDgeometry::Nplan();
 251   Int_t    sectBeg = 0;
 252   Int_t    sectEnd = AliTRDgeometry::Nsect();
 253
 254   Int_t    nTimeTotal  = calibration->GetNumberOfTimeBins();
 255
 256   if (fVerbose > 0) {
 257     printf("<AliTRDclusterizerV1::MakeCluster> ");
 258     printf("Number of Time Bins = %d.\n",nTimeTotal);
 259   }
 260
 261   // Start clustering in every chamber
 262   for (Int_t icham = chamBeg; icham < chamEnd; icham++) {
 263     for (Int_t iplan = planBeg; iplan < planEnd; iplan++) {
 264       for (Int_t isect = sectBeg; isect < sectEnd; isect++) {
 265
 266         Int_t idet    = geo->GetDetector(iplan,icham,isect);
 267
 268         Int_t nRowMax = commonParam->GetRowMax(iplan,icham,isect);
 269         Int_t nColMax = commonParam->GetColMax(iplan);
 270
 271         Int_t nClusters      = 0;
 272         Int_t nClusters2pad  = 0;
 273         Int_t nClusters3pad  = 0;
 274         Int_t nClusters4pad  = 0;
 275         Int_t nClusters5pad  = 0;
 276         Int_t nClustersLarge = 0;
 277
 278         if (fVerbose > 0) {
 279           printf("<AliTRDclusterizerV1::MakeCluster> ");
 280           printf("Analyzing chamber %d, plane %d, sector %d.\n"
 281                 ,icham,iplan,isect);
 282         }
 283
 284         AliTRDpadPlane *padPlane = commonParam->GetPadPlane(iplan,icham);
 285
 286         // Get the digits
 287         digitsIn = fDigitsManager->GetDigits(idet);
 288         digitsIn->Expand();
 289         AliTRDdataArrayF *digitsOut = new AliTRDdataArrayF(digitsIn->GetNrow(), digitsIn->GetNcol(), digitsIn->GetNtime());
 290
 291         Transform(digitsIn, digitsOut, idet, nRowMax, nColMax, nTimeTotal, ADCthreshold);
 292
 293         track0 = fDigitsManager->GetDictionary(idet,0);
 294         track0->Expand();
 295         track1 = fDigitsManager->GetDictionary(idet,1);
 296         track1->Expand();
 297         track2 = fDigitsManager->GetDictionary(idet,2);
 298         track2->Expand();
 299
 300         // Loop through the chamber and find the maxima
 301         for ( row = 0;  row <  nRowMax;    row++) {
 302           for ( col = 2;  col <  nColMax;    col++) {
 303             //for ( col = 4;  col <  nColMax-2;    col++) {
 304             for (time = 0; time < nTimeTotal; time++) {
 305
 306               Float_t signalL = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time));
 307               Float_t signalM = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time));
 308               Float_t signalR = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 309
 310 //            // Lonok for the maximum
 311 //               if (signalM >= maxThresh) {
 312 //                 if (((signalL >= sigThresh) &&
 313 //                      (signalL <  signalM))  ||
 314 //                     ((signalR >= sigThresh) &&
 315 //                      (signalR <  signalM))) {
 316 //                   // Maximum found, mark the position by a negative signal
 317 //                   digitsOut->SetDataUnchecked(row,col-1,time,-signalM);
 318 //              }
 319 //            }
 320               // Look for the maximum
 321               if (signalM >= maxThresh) {
 322                 if ( (TMath::Abs(signalL)<=signalM) && (TMath::Abs(signalR)<=signalM) &&
 323                      (TMath::Abs(signalL)+TMath::Abs(signalR))>sigThresh ) {
 324                   // Maximum found, mark the position by a negative signal
 325                   digitsOut->SetDataUnchecked(row,col-1,time,-signalM);
 326                 }
 327               }
 328             }
 329           }
 330         }
 331
 332         // Now check the maxima and calculate the cluster position
 333         for ( row = 0;  row <  nRowMax  ;  row++) {
 334           for (time = 0; time < nTimeTotal; time++) {
 335             for ( col = 1;  col <  nColMax-1;  col++) {
 336
 337               // Maximum found ?
 338               if (digitsOut->GetDataUnchecked(row,col,time) < 0) {
 339
 340                 Int_t iPad;
 341                 for (iPad = 0; iPad < kNclus; iPad++) {
 342                   Int_t iPadCol = col - 1 + iPad;
 343                   clusterSignal[iPad]     = TMath::Abs(digitsOut->GetDataUnchecked(row
 344                                                                                ,iPadCol
 345                                                                                ,time));
 346                   clusterTracks[3*iPad  ] = track0->GetDataUnchecked(row,iPadCol,time) - 1;
 347                   clusterTracks[3*iPad+1] = track1->GetDataUnchecked(row,iPadCol,time) - 1;
 348                   clusterTracks[3*iPad+2] = track2->GetDataUnchecked(row,iPadCol,time) - 1;
 349                 }
 350
 351                 // Count the number of pads in the cluster
 352                 Int_t nPadCount = 0;
 353                 Int_t ii        = 0;
 354                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col-ii  ,time))
 355                                                                   >= sigThresh) {
 356                   nPadCount++;
 357                   ii++;
 358                   if (col-ii   <        0) break;
 359                 }
 360                 ii = 0;
 361                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col+ii+1,time))
 362                                                                   >= sigThresh) {
 363                   nPadCount++;
 364                   ii++;
 365                   if (col+ii+1 >= nColMax) break;
 366                 }
 367
 368                 nClusters++;
 369                 switch (nPadCount) {
 370                 case 2:
 371                   iType = 0;
 372                   nClusters2pad++;
 373                   break;
 374                 case 3:
 375                   iType = 1;
 376                   nClusters3pad++;
 377                   break;
 378                 case 4:
 379                   iType = 2;
 380                   nClusters4pad++;
 381                   break;
 382                 case 5:
 383                   iType = 3;
 384                   nClusters5pad++;
 385                   break;
 386                 default:
 387                   iType = 4;
 388                   nClustersLarge++;
 389                   break;
 390                 };
 391
 392                  // Look for 5 pad cluster with minimum in the middle
 393                 Bool_t fivePadCluster = kFALSE;
 394                 if (col < nColMax-3) {
 395                   if (digitsOut->GetDataUnchecked(row,col+2,time) < 0) {
 396                     fivePadCluster = kTRUE;
 397                   }
 398                   if ((fivePadCluster) && (col < nColMax-5)) {
 399                     if (digitsOut->GetDataUnchecked(row,col+4,time) >= sigThresh) {
 400                       fivePadCluster = kFALSE;
 401                     }
 402                   }
 403                   if ((fivePadCluster) && (col >         1)) {
 404                     if (digitsOut->GetDataUnchecked(row,col-2,time) >= sigThresh) {
 405                       fivePadCluster = kFALSE;
 406                     }
 407                   }
 408                 }
 409
 410                 // 5 pad cluster
 411                 // Modify the signal of the overlapping pad for the left part
 412                 // of the cluster which remains from a previous unfolding
 413                 if (iUnfold) {
 414                   clusterSignal[0] *= ratioLeft;
 415                   iType   = 5;
 416                   iUnfold = 0;
 417                 }
 418
 419                 // Unfold the 5 pad cluster
 420                 if (fivePadCluster) {
 421                   for (iPad = 0; iPad < kNsig; iPad++) {
 422                     padSignal[iPad] = TMath::Abs(digitsOut->GetDataUnchecked(row
 423                                                                              ,col-1+iPad
 424                                                                              ,time));
 425                   }
 426                   // Unfold the two maxima and set the signal on
 427                   // the overlapping pad to the ratio
 428                   ratioRight        = Unfold(kEpsilon,iplan,padSignal);
 429                   ratioLeft         = 1.0 - ratioRight;
 430                   clusterSignal[2] *= ratioRight;
 431                   iType   = 5;
 432                   iUnfold = 1;
 433                 }
 434
 435                 Double_t clusterCharge = clusterSignal[0]
 436                                        + clusterSignal[1]
 437                                        + clusterSignal[2];
 438
 439                 // The position of the cluster
 440                 clusterPads[0] = row + 0.5;
 441                 // Take the shift of the additional time bins into account
 442                 clusterPads[2] = time + 0.5;
 443
 444
 445                 if (recParam->LUTOn()) {
 446                   // Calculate the position of the cluster by using the
 447                   // lookup table method
 448                   clusterPads[1] = recParam->LUTposition(iplan,clusterSignal[0]
 449                                                          ,clusterSignal[1]
 450                                                          ,clusterSignal[2]);
 451                 }
 452                 else {
 453                   // Calculate the position of the cluster by using the
 454                   // center of gravity method
 455                   for (Int_t i=0;i<5;i++) padSignal[i]=0;
 456                   padSignal[2] = TMath::Abs(digitsOut->GetDataUnchecked(row,col,time));   // central  pad
 457                   padSignal[1] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time)); // left     pad
 458                   padSignal[3] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+1,time)); // right    pad
 459                   if (col>2 &&TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time)<padSignal[1])){
 460                     padSignal[0] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 461                   }
 462                   if (col<nColMax-3 &&TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time)<padSignal[3])){
 463                     padSignal[4] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time));
 464                   }
 465                   clusterPads[1] =  GetCOG(padSignal);
 466
 467                 }
 468
 469                 Double_t q0 = clusterSignal[0];
 470                 Double_t q1 = clusterSignal[1];
 471                 Double_t q2 = clusterSignal[2];
 472                 Double_t clusterSigmaY2 = (q1*(q0+q2)+4*q0*q2) /
 473                                           (clusterCharge*clusterCharge);
 474
 475
 476
 477                 // Calculate the position and the error
 478
 479                 // correct for t0
 480                 Int_t clusterTimeBin = TMath::Nint(time - calibration->GetT0(idet, col, row));
 481
 482                 Double_t colSize = padPlane->GetColSize(col);
 483                 Double_t rowSize = padPlane->GetRowSize(row);
 484                 Double_t clusterPos[3];
 485                 clusterPos[0] = padPlane->GetColPos(col) - (clusterPads[1]+0.5)*colSize;  // MI change
 486                 clusterPos[1] = padPlane->GetRowPos(row) - 0.5*rowSize; //MI change
 487                 clusterPos[2] = CalcXposFromTimebin(clusterPads[2], idet, col, row);
 488                 Double_t clusterSig[2];
 489                 clusterSig[0] = (clusterSigmaY2 + 1./12.) * colSize*colSize;
 490                 clusterSig[1] = rowSize * rowSize / 12.;
 491
 492
 493                 // Add the cluster to the output array
 494                 AliTRDcluster * cluster = AddCluster(clusterPos
 495                           ,clusterTimeBin
 496                           ,idet
 497                           ,clusterCharge
 498                           ,clusterTracks
 499                           ,clusterSig
 500                           ,iType,clusterPads[1]);
 501                 //
 502                 //
 503                 Short_t signals[7]={0,0,0,0,0,0,0};
 504                 for (Int_t jPad = col-3;jPad<=col+3;jPad++){
 505                   if (jPad<0 ||jPad>=nColMax-1) continue;
 506                   signals[jPad-col+3] = TMath::Nint(TMath::Abs(digitsOut->GetDataUnchecked(row,jPad,time)));
 507                 }
 508                 cluster->SetSignals(signals);
 509               }
 510             }
 511           }
 512         }
 513
 514         delete digitsOut;
 515
 516         // Compress the arrays
 517         track0->Compress(1,0);
 518         track1->Compress(1,0);
 519         track2->Compress(1,0);
 520
 521         // Write the cluster and reset the array
 522         WriteClusters(idet);
 523         ResetRecPoints();
 524       }
 525     }
 526   }
 527
 528   if (fVerbose > 0) {
 529     printf("<AliTRDclusterizerV1::MakeCluster> ");
 530     printf("Done.\n");
 531   }
 532
 533   //delete digitsIn;
 534
 535   return kTRUE;
 536
 537 }
 538
 539 //_____________________________________________________________________________
 540 Double_t AliTRDclusterizerV1::GetCOG(Double_t signal[5])
 541 {
 542   //
 543   // get COG position
 544   // used for clusters with more than 3 pads - where LUT not applicable
 545   Double_t sum = signal[0]+signal[1]+signal[2]+signal[3]+signal[4];
 546   Double_t res = (0.0*(-signal[0]+signal[4])+(-signal[1]+signal[3]))/sum;
 547   return res;
 548 }
 549
 550 //_____________________________________________________________________________
 551 Double_t AliTRDclusterizerV1::Unfold(Double_t eps, Int_t plane, Double_t* padSignal)
 552 {
 553   //
 554   // Method to unfold neighbouring maxima.
 555   // The charge ratio on the overlapping pad is calculated
 556   // until there is no more change within the range given by eps.
 557   // The resulting ratio is then returned to the calling method.
 558   //
 559
 560   AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
 561   if (!calibration)
 562   {
 563     printf("<AliTRDclusterizerMI::Unfold> ");
 564     printf("ERROR getting instance of AliTRDcalibDB");
 565     return kFALSE;
 566   }
 567
 568   Int_t   irc                = 0;
 569   Int_t   itStep             = 0;      // Count iteration steps
 570
 571   Double_t ratio             = 0.5;    // Start value for ratio
 572   Double_t prevRatio         = 0;      // Store previous ratio
 573
 574   Double_t newLeftSignal[3]  = {0};    // Array to store left cluster signal
 575   Double_t newRightSignal[3] = {0};    // Array to store right cluster signal
 576   Double_t newSignal[3]      = {0};
 577
 578   // Start the iteration
 579   while ((TMath::Abs(prevRatio - ratio) > eps) && (itStep < 10)) {
 580
 581     itStep++;
 582     prevRatio = ratio;
 583
 584     // Cluster position according to charge ratio
 585     Double_t maxLeft  = (ratio*padSignal[2] - padSignal[0])
 586                       / (padSignal[0] + padSignal[1] + ratio*padSignal[2]);
 587     Double_t maxRight = (padSignal[4] - (1-ratio)*padSignal[2])
 588                       / ((1-ratio)*padSignal[2] + padSignal[3] + padSignal[4]);
 589
 590     // Set cluster charge ratio
 591     irc = calibration->PadResponse(1.0,maxLeft ,plane,newSignal);
 592     Double_t ampLeft  = padSignal[1] / newSignal[1];
 593     irc = calibration->PadResponse(1.0,maxRight,plane,newSignal);
 594     Double_t ampRight = padSignal[3] / newSignal[1];
 595
 596     // Apply pad response to parameters
 597     irc = calibration->PadResponse(ampLeft ,maxLeft ,plane,newLeftSignal );
 598     irc = calibration->PadResponse(ampRight,maxRight,plane,newRightSignal);
 599
 600     // Calculate new overlapping ratio
 601     ratio = TMath::Min((Double_t)1.0,newLeftSignal[2] /
 602                           (newLeftSignal[2] + newRightSignal[0]));
 603
 604   }
 605
 606   return ratio;
 607
 608 }
 609
 610 //_____________________________________________________________________________
 611 void AliTRDclusterizerV1::Transform(AliTRDdataArrayI* digitsIn,
 612                                     AliTRDdataArrayF* digitsOut,
 613                                     Int_t idet, Int_t nRowMax,
 614                                     Int_t nColMax, Int_t nTimeTotal,
 615                                     Float_t ADCthreshold)
 616 {
 617
 618   //
 619   // Apply gain factor
 620   // Apply tail cancellation: Transform digitsIn to digitsOut
 621   //
 622
 623
 624   AliTRDRecParam* recParam = AliTRDRecParam::Instance();
 625   if (!recParam)
 626   {
 627     printf("<AliTRDclusterizerV1::Transform> ");
 628     printf("ERROR getting instance of AliTRDRecParam");
 629     return;
 630   }
 631   AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
 632
 633   Double_t *inADC  = new Double_t[nTimeTotal];  // adc data before tail cancellation
 634   Double_t *outADC = new Double_t[nTimeTotal];  // adc data after tail cancellation
 635
 636   if (fVerbose > 0) {
 637     printf("<AliTRDclusterizerV1::Transform> ");
 638     printf("Tail cancellation (nExp = %d) for detector %d.\n",
 639            recParam->GetTCnexp(),idet);
 640   }
 641
 642   for (Int_t iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
 643     for (Int_t iCol  = 0; iCol  <  nColMax;   iCol++ ) {
 644       for (Int_t iTime = 0; iTime < nTimeTotal; iTime++) {
 645         //
 646         // add gain
 647         //
 648         Double_t gain = calibration->GetGainFactor(idet, iCol, iRow);
 649         if (gain==0) {
 650           AliError("Not a valid gain\n");
 651         }
 652         inADC[iTime]  = digitsIn->GetDataUnchecked(iRow, iCol, iTime);
 653
 654         inADC[iTime] /= gain;
 655         outADC[iTime] = inADC[iTime];
 656       }
 657
 658       // Apply the tail cancelation via the digital filter
 659       if (recParam->TCOn())
 660       {
 661         DeConvExp(inADC,outADC,nTimeTotal,recParam->GetTCnexp());
 662       }
 663
 664       for (Int_t iTime = 0; iTime < nTimeTotal; iTime++) {
 665         // Store the amplitude of the digit if above threshold
 666         if (outADC[iTime] > ADCthreshold) {
 667           if (fVerbose > 1)
 668           {
 669             printf("  iRow = %d, iCol = %d, iTime = %d, adc = %f\n"
 670                    ,iRow,iCol,iTime,outADC[iTime]);
 671           }
 672           digitsOut->SetDataUnchecked(iRow,iCol,iTime,outADC[iTime]);
 673         }
 674
 675       }
 676
 677     }
 678
 679   }
 680
 681   delete [] inADC;
 682   delete [] outADC;
 683
 684   return;
 685
 686 }
 687
 688
 689 //_____________________________________________________________________________
 690 void AliTRDclusterizerV1::DeConvExp(Double_t *source, Double_t *target,
 691                                     Int_t n, Int_t nexp)
 692 {
 693   //
 694   // Tail Cancellation by Deconvolution for PASA v4 TRF
 695   //
 696
 697   Double_t rates[2];
 698   Double_t coefficients[2];
 699
 700   // initialize (coefficient = alpha, rates = lambda)
 701
 702   Double_t R1 = 1.0;
 703   Double_t R2 = 1.0;
 704   Double_t C1 = 0.5;
 705   Double_t C2 = 0.5;
 706
 707   if (nexp == 1) {   // 1 Exponentials
 708     R1 = 1.156;
 709     R2 = 0.130;
 710     C1 = 0.066;
 711     C2 = 0.000;
 712   }
 713   if (nexp == 2) {   // 2 Exponentials
 714     R1 = 1.156;
 715     R2 = 0.130;
 716     C1 = 0.114;
 717     C2 = 0.624;
 718   }
 719
 720   coefficients[0] = C1;
 721   coefficients[1] = C2;
 722
 723   Double_t Dt = 0.100;
 724
 725   rates[0] = TMath::Exp(-Dt/(R1));
 726   rates[1] = TMath::Exp(-Dt/(R2));
 727
 728   Int_t i, k;
 729   Double_t reminder[2];
 730   Double_t correction, result;
 731
 732   /* attention: computation order is important */
 733   correction=0.0;
 734
 735   for ( k=0; k<nexp; k++ ) reminder[k]=0.0;
 736
 737   for ( i=0; i<n; i++ ) {
 738     result = ( source[i] - correction );    // no rescaling
 739     target[i] = result;
 740
 741     for ( k=0; k<nexp; k++ ) reminder[k] = rates[k] *
 742                                ( reminder[k] + coefficients[k] * result);
 743     correction=0.0;
 744     for ( k=0; k<nexp; k++ ) correction += reminder[k];
 745   }
 746
 747 }