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                                                        //
  22 //                                                                           //
  23 ///////////////////////////////////////////////////////////////////////////////
  24
  25 #include <TF1.h>
  26 #include <TTree.h>
  27 #include <TH1.h>
  28 #include <TFile.h>
  29
  30 #include "AliRunLoader.h"
  31 #include "AliLoader.h"
  32 #include "AliRawReader.h"
  33 #include "AliLog.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 #include "Cal/AliTRDCalROC.h"
  49 #include "Cal/AliTRDCalDet.h"
  50
  51 ClassImp(AliTRDclusterizerV1)
  52
  53 //_____________________________________________________________________________
  54 AliTRDclusterizerV1::AliTRDclusterizerV1()
  55   :AliTRDclusterizer()
  56   ,fDigitsManager(NULL)
  57 {
  58   //
  59   // AliTRDclusterizerV1 default constructor
  60   //
  61
  62 }
  63
  64 //_____________________________________________________________________________
  65 AliTRDclusterizerV1::AliTRDclusterizerV1(const Text_t *name, const Text_t *title)
  66   :AliTRDclusterizer(name,title)
  67   ,fDigitsManager(new AliTRDdigitsManager())
  68 {
  69   //
  70   // AliTRDclusterizerV1 constructor
  71   //
  72
  73   fDigitsManager->CreateArrays();
  74
  75 }
  76
  77 //_____________________________________________________________________________
  78 AliTRDclusterizerV1::AliTRDclusterizerV1(const AliTRDclusterizerV1 &c)
  79   :AliTRDclusterizer(c)
  80   ,fDigitsManager(NULL)
  81 {
  82   //
  83   // AliTRDclusterizerV1 copy constructor
  84   //
  85
  86 }
  87
  88 //_____________________________________________________________________________
  89 AliTRDclusterizerV1::~AliTRDclusterizerV1()
  90 {
  91   //
  92   // AliTRDclusterizerV1 destructor
  93   //
  94
  95   if (fDigitsManager) {
  96     delete fDigitsManager;
  97     fDigitsManager = NULL;
  98   }
  99
 100 }
 101
 102 //_____________________________________________________________________________
 103 AliTRDclusterizerV1 &AliTRDclusterizerV1::operator=(const AliTRDclusterizerV1 &c)
 104 {
 105   //
 106   // Assignment operator
 107   //
 108
 109   if (this != &c) ((AliTRDclusterizerV1 &) c).Copy(*this);
 110   return *this;
 111
 112 }
 113
 114 //_____________________________________________________________________________
 115 void AliTRDclusterizerV1::Copy(TObject &c) const
 116 {
 117   //
 118   // Copy function
 119   //
 120
 121   ((AliTRDclusterizerV1 &) c).fDigitsManager = 0;
 122
 123   AliTRDclusterizer::Copy(c);
 124
 125 }
 126
 127 //_____________________________________________________________________________
 128 Bool_t AliTRDclusterizerV1::ReadDigits()
 129 {
 130   //
 131   // Reads the digits arrays from the input aliroot file
 132   //
 133
 134   if (!fRunLoader) {
 135     AliError("No run loader available");
 136     return kFALSE;
 137   }
 138
 139   AliLoader* loader = fRunLoader->GetLoader("TRDLoader");
 140   if (!loader->TreeD()) {
 141     loader->LoadDigits();
 142   }
 143
 144   // Read in the digit arrays
 145   return (fDigitsManager->ReadDigits(loader->TreeD()));
 146
 147 }
 148
 149 //_____________________________________________________________________________
 150 Bool_t AliTRDclusterizerV1::ReadDigits(AliRawReader *rawReader)
 151 {
 152   //
 153   // Reads the digits arrays from the ddl file
 154   //
 155
 156   AliTRDrawData raw;
 157   fDigitsManager = raw.Raw2Digits(rawReader);
 158
 159   return kTRUE;
 160
 161 }
 162
 163 //_____________________________________________________________________________
 164 Bool_t AliTRDclusterizerV1::MakeClusters()
 165 {
 166   //
 167   // Generates the cluster.
 168   //
 169
 170   Int_t row   = 0;
 171   Int_t col   = 0;
 172   Int_t time  = 0;
 173   Int_t icham = 0;
 174   Int_t iplan = 0;
 175   Int_t isect = 0;
 176   Int_t iPad  = 0;
 177
 178   AliTRDdataArrayI *digitsIn;
 179   AliTRDdataArrayI *tracksIn;
 180
 181   // Get the geometry
 182   AliTRDgeometry *geo            = AliTRDgeometry::GetGeometry(fRunLoader);
 183   if (!geo) {
 184     AliWarning("Loading default TRD geometry!");
 185     geo = new AliTRDgeometry();
 186   }
 187
 188   AliTRDcalibDB  *calibration    = AliTRDcalibDB::Instance();
 189   if (!calibration) {
 190     AliFatal("No AliTRDcalibDB instance available\n");
 191     return kFALSE;
 192   }
 193
 194   AliTRDSimParam *simParam       = AliTRDSimParam::Instance();
 195   if (!simParam) {
 196     AliError("No AliTRDSimParam instance available\n");
 197     return kFALSE;
 198   }
 199
 200   AliTRDRecParam *recParam       = AliTRDRecParam::Instance();
 201   if (!recParam) {
 202     AliError("No AliTRDRecParam instance available\n");
 203     return kFALSE;
 204   }
 205
 206   AliTRDCommonParam *commonParam = AliTRDCommonParam::Instance();
 207   if (!commonParam) {
 208     AliError("Could not get common parameters\n");
 209     return kFALSE;
 210   }
 211
 212   // ADC threshols
 213   Float_t ADCthreshold   = simParam->GetADCthreshold();
 214   // Threshold value for the maximum
 215   Float_t maxThresh      = recParam->GetClusMaxThresh();
 216   // Threshold value for the digit signal
 217   Float_t sigThresh      = recParam->GetClusSigThresh();
 218
 219   // Detector wise calibration object for t0
 220   const AliTRDCalDet *calT0Det = calibration->GetT0Det();
 221
 222   // Iteration limit for unfolding procedure
 223   const Float_t kEpsilon = 0.01;
 224   const Int_t   kNclus   = 3;
 225   const Int_t   kNsig    = 5;
 226   const Int_t   kNdict   = AliTRDdigitsManager::kNDict;
 227   const Int_t   kNtrack  = kNdict * kNclus;
 228
 229   Int_t    iType         = 0;
 230   Int_t    iUnfold       = 0;
 231   Double_t ratioLeft     = 1.0;
 232   Double_t ratioRight    = 1.0;
 233
 234   Int_t    iClusterROC   = 0;
 235
 236   Double_t padSignal[kNsig];
 237   Double_t clusterSignal[kNclus];
 238   Double_t clusterPads[kNclus];
 239
 240   Int_t    chamBeg    = 0;
 241   Int_t    chamEnd    = AliTRDgeometry::Ncham();
 242   Int_t    planBeg    = 0;
 243   Int_t    planEnd    = AliTRDgeometry::Nplan();
 244   Int_t    sectBeg    = 0;
 245   Int_t    sectEnd    = AliTRDgeometry::Nsect();
 246   Int_t    nTimeTotal = calibration->GetNumberOfTimeBins();
 247
 248   Int_t    dummy[9]   = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 249
 250   AliDebug(1,Form("Number of Time Bins = %d.\n",nTimeTotal));
 251
 252   // Start clustering in every chamber
 253   for (icham = chamBeg; icham < chamEnd; icham++) {
 254     for (iplan = planBeg; iplan < planEnd; iplan++) {
 255       for (isect = sectBeg; isect < sectEnd; isect++) {
 256
 257         Int_t idet = geo->GetDetector(iplan,icham,isect);
 258
 259         // Get the digits
 260         digitsIn = fDigitsManager->GetDigits(idet);
 261         // This is to take care of switched off super modules
 262         if (digitsIn->GetNtime() == 0) {
 263           continue;
 264         }
 265         digitsIn->Expand();
 266         AliTRDdataArrayI *tracksTmp = fDigitsManager->GetDictionary(idet,0);
 267         tracksTmp->Expand();
 268
 269         Int_t nRowMax = commonParam->GetRowMax(iplan,icham,isect);
 270         Int_t nColMax = commonParam->GetColMax(iplan);
 271
 272         AliTRDpadPlane *padPlane = commonParam->GetPadPlane(iplan,icham);
 273
 274         // Calibration object with pad wise values for t0
 275         AliTRDCalROC *calT0ROC      = calibration->GetT0ROC(idet);
 276         // Calibration value for chamber wise t0
 277         Float_t       calT0DetValue = calT0Det->GetValue(idet);
 278
 279         Int_t nClusters      = 0;
 280         Int_t nClusters2pad  = 0;
 281         Int_t nClusters3pad  = 0;
 282         Int_t nClusters4pad  = 0;
 283         Int_t nClusters5pad  = 0;
 284         Int_t nClustersLarge = 0;
 285
 286         // Apply the gain and the tail cancelation via digital filter
 287         AliTRDdataArrayF *digitsOut = new AliTRDdataArrayF(digitsIn->GetNrow()
 288                                                           ,digitsIn->GetNcol()
 289                                                           ,digitsIn->GetNtime());
 290         Transform(digitsIn,digitsOut,idet,nRowMax,nColMax,nTimeTotal,ADCthreshold);
 291
 292         // Input digits are not needed any more
 293         digitsIn->Compress(1,0);
 294
 295         // Loop through the chamber and find the maxima
 296         for ( row = 0;  row <  nRowMax;    row++) {
 297           for ( col = 2;  col <  nColMax;    col++) {
 298             for (time = 0; time < nTimeTotal; time++) {
 299
 300               Float_t signalM = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time));
 301
 302               // Look for the maximum
 303               if (signalM >= maxThresh) {
 304
 305                 Float_t signalL = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time));
 306                 Float_t signalR = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 307
 308                 if ((TMath::Abs(signalL) <= signalM) &&
 309                     (TMath::Abs(signalR) <  signalM)) {
 310                   if ((TMath::Abs(signalL) >= sigThresh) ||
 311                       (TMath::Abs(signalR) >= sigThresh)) {
 312                     // Maximum found, mark the position by a negative signal
 313                     digitsOut->SetDataUnchecked(row,col-1,time,-signalM);
 314                   }
 315                 }
 316
 317               }
 318
 319             }
 320           }
 321         }
 322         tracksTmp->Compress(1,0);
 323
 324         // The index to the first cluster of a given ROC
 325         Int_t firstClusterROC = -1;
 326         // The number of cluster in a given ROC
 327         Int_t nClusterROC     =  0;
 328
 329         // Now check the maxima and calculate the cluster position
 330         for ( row = 0;  row <  nRowMax  ;  row++) {
 331           for (time = 0; time < nTimeTotal; time++) {
 332             for ( col = 1;  col <  nColMax-1;  col++) {
 333
 334               // Maximum found ?
 335               if (digitsOut->GetDataUnchecked(row,col,time) < 0.0) {
 336
 337                 for (iPad = 0; iPad < kNclus; iPad++) {
 338                   Int_t iPadCol = col - 1 + iPad;
 339                   clusterSignal[iPad] =
 340                     TMath::Abs(digitsOut->GetDataUnchecked(row,iPadCol,time));
 341                 }
 342
 343                 // Count the number of pads in the cluster
 344                 Int_t nPadCount = 0;
 345                 Int_t ii;
 346                 // Look to the left
 347                 ii = 0;
 348                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col-ii  ,time)) >= sigThresh) {
 349                   nPadCount++;
 350                   ii++;
 351                   if (col-ii   <        0) break;
 352                 }
 353                 // Look to the right
 354                 ii = 0;
 355                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col+ii+1,time)) >= sigThresh) {
 356                   nPadCount++;
 357                   ii++;
 358                   if (col+ii+1 >= nColMax) break;
 359                 }
 360                 nClusters++;
 361                 switch (nPadCount) {
 362                 case 2:
 363                   iType = 0;
 364                   nClusters2pad++;
 365                   break;
 366                 case 3:
 367                   iType = 1;
 368                   nClusters3pad++;
 369                   break;
 370                 case 4:
 371                   iType = 2;
 372                   nClusters4pad++;
 373                   break;
 374                 case 5:
 375                   iType = 3;
 376                   nClusters5pad++;
 377                   break;
 378                 default:
 379                   iType = 4;
 380                   nClustersLarge++;
 381                   break;
 382                 };
 383
 384                 // Look for 5 pad cluster with minimum in the middle
 385                 Bool_t fivePadCluster = kFALSE;
 386                 if (col < (nColMax - 3)) {
 387                   if (digitsOut->GetDataUnchecked(row,col+2,time) < 0) {
 388                     fivePadCluster = kTRUE;
 389                   }
 390                   if ((fivePadCluster) && (col < (nColMax - 5))) {
 391                     if (digitsOut->GetDataUnchecked(row,col+4,time) >= sigThresh) {
 392                       fivePadCluster = kFALSE;
 393                     }
 394                   }
 395                   if ((fivePadCluster) && (col >             1)) {
 396                     if (digitsOut->GetDataUnchecked(row,col-2,time) >= sigThresh) {
 397                       fivePadCluster = kFALSE;
 398                     }
 399                   }
 400                 }
 401
 402                 // 5 pad cluster
 403                 // Modify the signal of the overlapping pad for the left part
 404                 // of the cluster which remains from a previous unfolding
 405                 if (iUnfold) {
 406                   clusterSignal[0] *= ratioLeft;
 407                   iType   = 5;
 408                   iUnfold = 0;
 409                 }
 410
 411                 // Unfold the 5 pad cluster
 412                 if (fivePadCluster) {
 413                   for (iPad = 0; iPad < kNsig; iPad++) {
 414                     padSignal[iPad] = TMath::Abs(digitsOut->GetDataUnchecked(row
 415                                                                             ,col-1+iPad
 416                                                                             ,time));
 417                   }
 418                   // Unfold the two maxima and set the signal on
 419                   // the overlapping pad to the ratio
 420                   ratioRight        = Unfold(kEpsilon,iplan,padSignal);
 421                   ratioLeft         = 1.0 - ratioRight;
 422                   clusterSignal[2] *= ratioRight;
 423                   iType   = 5;
 424                   iUnfold = 1;
 425                 }
 426
 427                 Double_t clusterCharge = clusterSignal[0]
 428                                        + clusterSignal[1]
 429                                        + clusterSignal[2];
 430
 431                 // The position of the cluster
 432                 clusterPads[0] =  row + 0.5;
 433                 // Take the shift of the additional time bins into account
 434                 clusterPads[2] = time + 0.5;
 435
 436                 if (recParam->LUTOn()) {
 437                   // Calculate the position of the cluster by using the
 438                   // lookup table method
 439                   clusterPads[1] = recParam->LUTposition(iplan,clusterSignal[0]
 440                                                               ,clusterSignal[1]
 441                                                               ,clusterSignal[2]);
 442                 }
 443                 else {
 444                   // Calculate the position of the cluster by using the
 445                   // center of gravity method
 446                   for (Int_t i = 0; i < kNsig; i++) {
 447                     padSignal[i] = 0.0;
 448                   }
 449                   padSignal[2] = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time)); // Central pad
 450                   padSignal[1] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time)); // Left    pad
 451                   padSignal[3] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+1,time)); // Right   pad
 452                   if ((col >           2) &&
 453                       (TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time)) < padSignal[1])) {
 454                     padSignal[0] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 455                   }
 456                   if ((col < nColMax - 3) &&
 457                       (TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time)) < padSignal[3])) {
 458                     padSignal[4] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time));
 459                   }
 460                   clusterPads[1] = GetCOG(padSignal);
 461                 }
 462
 463                 Double_t q0 = clusterSignal[0];
 464                 Double_t q1 = clusterSignal[1];
 465                 Double_t q2 = clusterSignal[2];
 466                 Double_t clusterSigmaY2 = (q1 * (q0 + q2) + 4.0 * q0 * q2)
 467                                         / (clusterCharge*clusterCharge);
 468
 469                 //
 470                 // Calculate the position and the error
 471                 //
 472
 473                 // Correct for t0 (sum of chamber and pad wise values !!!)
 474                 Float_t  calT0ROCValue  = calT0ROC->GetValue(col,row);
 475                 Int_t    clusterTimeBin = TMath::Nint(time - (calT0DetValue + calT0ROCValue));
 476                 Double_t colSize        = padPlane->GetColSize(col);
 477                 Double_t rowSize        = padPlane->GetRowSize(row);
 478
 479                 Double_t clusterPos[3];
 480                 clusterPos[0] = padPlane->GetColPos(col) - (clusterPads[1] + 0.5) * colSize;
 481                 clusterPos[1] = padPlane->GetRowPos(row) - 0.5                    * rowSize;
 482                 clusterPos[2] = CalcXposFromTimebin(clusterPads[2],idet,col,row);
 483                 Double_t clusterSig[2];
 484                 clusterSig[0] = (clusterSigmaY2 + 1.0/12.0) * colSize*colSize;
 485                 clusterSig[1] = rowSize * rowSize / 12.0;
 486
 487                 // Add the cluster to the output array
 488                 // The track indices will be stored later
 489                 AliTRDcluster *cluster = AddCluster(clusterPos
 490                                                    ,clusterTimeBin
 491                                                    ,idet
 492                                                    ,clusterCharge
 493                                                    ,dummy
 494                                                    ,clusterSig
 495                                                    ,iType
 496                                                    ,clusterPads[1]);
 497
 498                 // Store the amplitudes of the pads in the cluster for later analysis
 499                 Short_t signals[7] = { 0, 0, 0, 0, 0, 0, 0 };
 500                 for (Int_t jPad = col-3; jPad <= col+3; jPad++) {
 501                   if ((jPad <          0) ||
 502                       (jPad >= nColMax-1)) {
 503                     continue;
 504                   }
 505                   signals[jPad-col+3] = TMath::Nint(TMath::Abs(digitsOut->GetDataUnchecked(row,jPad,time)));
 506                 }
 507                 cluster->SetSignals(signals);
 508
 509                 // Temporarily store the row, column and time bin of the center pad
 510                 // Used to later on assign the track indices
 511                 cluster->SetLabel( row,0);
 512                 cluster->SetLabel( col,1);
 513                 cluster->SetLabel(time,2);
 514
 515                 // Store the index of the first cluster in the current ROC
 516                 if (firstClusterROC < 0) {
 517                   firstClusterROC = RecPoints()->GetEntriesFast() - 1;
 518                 }
 519                 // Count the number of cluster in the current ROC
 520                 nClusterROC++;
 521
 522               } // if: Maximum found ?
 523
 524             } // loop: pad columns
 525           } // loop: time bins
 526         } // loop: pad rows
 527
 528         delete digitsOut;
 529
 530         //
 531         // Add the track indices to the found clusters
 532         //
 533
 534         // Temporary array to collect the track indices
 535         Int_t *idxTracks = new Int_t[kNtrack*nClusterROC];
 536
 537         // Loop through the dictionary arrays one-by-one
 538         // to keep memory consumption low
 539         for (Int_t iDict = 0; iDict < kNdict; iDict++) {
 540
 541           tracksIn = fDigitsManager->GetDictionary(idet,iDict);
 542           tracksIn->Expand();
 543
 544           // Loop though the clusters found in this ROC
 545           for (iClusterROC = 0; iClusterROC < nClusterROC; iClusterROC++) {
 546
 547             AliTRDcluster *cluster = (AliTRDcluster *)
 548                                      RecPoints()->UncheckedAt(firstClusterROC+iClusterROC);
 549             row  = cluster->GetLabel(0);
 550             col  = cluster->GetLabel(1);
 551             time = cluster->GetLabel(2);
 552
 553             for (iPad = 0; iPad < kNclus; iPad++) {
 554               Int_t iPadCol = col - 1 + iPad;
 555               Int_t index   = tracksIn->GetDataUnchecked(row,iPadCol,time) - 1;
 556               idxTracks[3*iPad+iDict + iClusterROC*kNtrack] = index;
 557             }
 558
 559           }
 560
 561           // Compress the arrays
 562           tracksIn->Compress(1,0);
 563
 564         }
 565
 566         // Copy the track indices into the cluster
 567         // Loop though the clusters found in this ROC
 568         for (iClusterROC = 0; iClusterROC < nClusterROC; iClusterROC++) {
 569
 570           AliTRDcluster *cluster = (AliTRDcluster *)
 571                                    RecPoints()->UncheckedAt(firstClusterROC+iClusterROC);
 572           cluster->SetLabel(-9999,0);
 573           cluster->SetLabel(-9999,1);
 574           cluster->SetLabel(-9999,2);
 575
 576           cluster->AddTrackIndex(&idxTracks[iClusterROC*kNtrack]);
 577
 578         }
 579
 580         delete [] idxTracks;
 581
 582         // Write the cluster and reset the array
 583         WriteClusters(idet);
 584         ResetRecPoints();
 585
 586       } // loop: Sectors
 587     } // loop: Planes
 588   } // loop: Chambers
 589
 590   return kTRUE;
 591
 592 }
 593
 594 //_____________________________________________________________________________
 595 Double_t AliTRDclusterizerV1::GetCOG(Double_t signal[5])
 596 {
 597   //
 598   // Get COG position
 599   // Used for clusters with more than 3 pads - where LUT not applicable
 600   //
 601
 602   Double_t sum = signal[0]
 603                + signal[1]
 604                + signal[2]
 605                + signal[3]
 606                + signal[4];
 607
 608   Double_t res = (0.0 * (-signal[0] + signal[4])
 609                       + (-signal[1] + signal[3])) / sum;
 610
 611   return res;
 612
 613 }
 614
 615 //_____________________________________________________________________________
 616 Double_t AliTRDclusterizerV1::Unfold(Double_t eps, Int_t plane, Double_t *padSignal)
 617 {
 618   //
 619   // Method to unfold neighbouring maxima.
 620   // The charge ratio on the overlapping pad is calculated
 621   // until there is no more change within the range given by eps.
 622   // The resulting ratio is then returned to the calling method.
 623   //
 624
 625   AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
 626   if (!calibration) {
 627     AliError("No AliTRDcalibDB instance available\n");
 628     return kFALSE;
 629   }
 630
 631   Int_t   irc                = 0;
 632   Int_t   itStep             = 0;                 // Count iteration steps
 633
 634   Double_t ratio             = 0.5;               // Start value for ratio
 635   Double_t prevRatio         = 0.0;               // Store previous ratio
 636
 637   Double_t newLeftSignal[3]  = { 0.0, 0.0, 0.0 }; // Array to store left cluster signal
 638   Double_t newRightSignal[3] = { 0.0, 0.0, 0.0 }; // Array to store right cluster signal
 639   Double_t newSignal[3]      = { 0.0, 0.0, 0.0 };
 640
 641   // Start the iteration
 642   while ((TMath::Abs(prevRatio - ratio) > eps) && (itStep < 10)) {
 643
 644     itStep++;
 645     prevRatio = ratio;
 646
 647     // Cluster position according to charge ratio
 648     Double_t maxLeft  = (ratio*padSignal[2] - padSignal[0])
 649                       / (padSignal[0] + padSignal[1] + ratio*padSignal[2]);
 650     Double_t maxRight = (padSignal[4] - (1-ratio)*padSignal[2])
 651                       / ((1.0 - ratio)*padSignal[2] + padSignal[3] + padSignal[4]);
 652
 653     // Set cluster charge ratio
 654     irc = calibration->PadResponse(1.0,maxLeft ,plane,newSignal);
 655     Double_t ampLeft  = padSignal[1] / newSignal[1];
 656     irc = calibration->PadResponse(1.0,maxRight,plane,newSignal);
 657     Double_t ampRight = padSignal[3] / newSignal[1];
 658
 659     // Apply pad response to parameters
 660     irc = calibration->PadResponse(ampLeft ,maxLeft ,plane,newLeftSignal );
 661     irc = calibration->PadResponse(ampRight,maxRight,plane,newRightSignal);
 662
 663     // Calculate new overlapping ratio
 664     ratio = TMath::Min((Double_t)1.0,newLeftSignal[2] /
 665                                     (newLeftSignal[2] + newRightSignal[0]));
 666
 667   }
 668
 669   return ratio;
 670
 671 }
 672
 673 //_____________________________________________________________________________
 674 void AliTRDclusterizerV1::Transform(AliTRDdataArrayI *digitsIn
 675                                   , AliTRDdataArrayF *digitsOut
 676                                   , Int_t idet, Int_t nRowMax
 677                                   , Int_t nColMax, Int_t nTimeTotal
 678                                   , Float_t ADCthreshold)
 679 {
 680   //
 681   // Apply gain factor
 682   // Apply tail cancelation: Transform digitsIn to digitsOut
 683   //
 684
 685   Int_t iRow  = 0;
 686   Int_t iCol  = 0;
 687   Int_t iTime = 0;
 688
 689   AliTRDRecParam *recParam = AliTRDRecParam::Instance();
 690   if (!recParam) {
 691     AliError("No AliTRDRecParam instance available\n");
 692     return;
 693   }
 694   AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
 695   if (!calibration) {
 696     AliError("No AliTRDcalibDB instance available\n");
 697     return;
 698   }
 699
 700   Double_t *inADC  = new Double_t[nTimeTotal];  // ADC data before tail cancellation
 701   Double_t *outADC = new Double_t[nTimeTotal];  // ADC data after tail cancellation
 702
 703   AliDebug(1,Form("Tail cancellation (nExp = %d) for detector %d.\n"
 704                  ,recParam->GetTCnexp(),idet));
 705
 706   // Calibration object with chamber wise values for the gain factor
 707   const AliTRDCalDet *calGainFactorDet      = calibration->GetGainFactorDet();
 708   // Calibration object with pad wise values for the gain factor
 709   AliTRDCalROC       *calGainFactorROC      = calibration->GetGainFactorROC(idet);
 710   // Calibration value for chamber wise gain factors
 711   Float_t             calGainFactorDetValue = calGainFactorDet->GetValue(idet);
 712
 713   for (iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
 714     for (iCol  = 0; iCol  <  nColMax;   iCol++ ) {
 715
 716       Float_t  calGainFactorROCValue = calGainFactorROC->GetValue(iCol,iRow);
 717       Double_t gain                  = calGainFactorDetValue
 718                                      * calGainFactorROCValue;
 719
 720       for (iTime = 0; iTime < nTimeTotal; iTime++) {
 721
 722         //
 723         // Add gain
 724         //
 725         inADC[iTime]   = digitsIn->GetDataUnchecked(iRow,iCol,iTime);
 726         inADC[iTime]  /= gain;
 727         outADC[iTime]  = inADC[iTime];
 728
 729       }
 730
 731       // Apply the tail cancelation via the digital filter
 732       if (recParam->TCOn()) {
 733         DeConvExp(inADC,outADC,nTimeTotal,recParam->GetTCnexp());
 734       }
 735
 736       for (iTime = 0; iTime < nTimeTotal; iTime++) {
 737
 738         // Store the amplitude of the digit if above threshold
 739         if (outADC[iTime] > ADCthreshold) {
 740           digitsOut->SetDataUnchecked(iRow,iCol,iTime,outADC[iTime]);
 741         }
 742
 743       }
 744
 745     }
 746   }
 747
 748   delete [] inADC;
 749   delete [] outADC;
 750
 751   return;
 752
 753 }
 754
 755 //_____________________________________________________________________________
 756 void AliTRDclusterizerV1::DeConvExp(Double_t *source, Double_t *target
 757                                   , Int_t n, Int_t nexp)
 758 {
 759   //
 760   // Tail cancellation by deconvolution for PASA v4 TRF
 761   //
 762
 763   Double_t rates[2];
 764   Double_t coefficients[2];
 765
 766   // Initialization (coefficient = alpha, rates = lambda)
 767   Double_t R1 = 1.0;
 768   Double_t R2 = 1.0;
 769   Double_t C1 = 0.5;
 770   Double_t C2 = 0.5;
 771
 772   if (nexp == 1) {   // 1 Exponentials
 773     R1 = 1.156;
 774     R2 = 0.130;
 775     C1 = 0.066;
 776     C2 = 0.000;
 777   }
 778   if (nexp == 2) {   // 2 Exponentials
 779     R1 = 1.156;
 780     R2 = 0.130;
 781     C1 = 0.114;
 782     C2 = 0.624;
 783   }
 784
 785   coefficients[0] = C1;
 786   coefficients[1] = C2;
 787
 788   Double_t Dt = 0.1;
 789
 790   rates[0] = TMath::Exp(-Dt/(R1));
 791   rates[1] = TMath::Exp(-Dt/(R2));
 792
 793   Int_t i = 0;
 794   Int_t k = 0;
 795
 796   Double_t reminder[2];
 797   Double_t correction;
 798   Double_t result;
 799
 800   // Attention: computation order is important
 801   correction = 0.0;
 802   for (k = 0; k < nexp; k++) {
 803     reminder[k] = 0.0;
 804   }
 805   for (i = 0; i < n; i++) {
 806     result    = (source[i] - correction);    // No rescaling
 807     target[i] = result;
 808
 809     for (k = 0; k < nexp; k++) {
 810       reminder[k] = rates[k] * (reminder[k] + coefficients[k] * result);
 811     }
 812     correction = 0.0;
 813     for (k = 0; k < nexp; k++) {
 814       correction += reminder[k];
 815     }
 816   }
 817
 818 }