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 #include "AliAlignObj.h"
  35
  36 #include "AliTRDclusterizerV1.h"
  37 #include "AliTRDgeometry.h"
  38 #include "AliTRDdataArrayF.h"
  39 #include "AliTRDdataArrayI.h"
  40 #include "AliTRDdigitsManager.h"
  41 #include "AliTRDpadPlane.h"
  42 #include "AliTRDrawData.h"
  43 #include "AliTRDcalibDB.h"
  44 #include "AliTRDSimParam.h"
  45 #include "AliTRDRecParam.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(TTree *digitsTree)
 151 {
 152   //
 153   // Reads the digits arrays from the input tree
 154   //
 155
 156   // Read in the digit arrays
 157   return (fDigitsManager->ReadDigits(digitsTree));
 158
 159 }
 160
 161 //_____________________________________________________________________________
 162 Bool_t AliTRDclusterizerV1::ReadDigits(AliRawReader *rawReader)
 163 {
 164   //
 165   // Reads the digits arrays from the ddl file
 166   //
 167
 168   AliTRDrawData raw;
 169   fDigitsManager = raw.Raw2Digits(rawReader);
 170
 171   return kTRUE;
 172
 173 }
 174
 175 //_____________________________________________________________________________
 176 Bool_t AliTRDclusterizerV1::MakeClusters()
 177 {
 178   //
 179   // Generates the cluster.
 180   //
 181
 182   Int_t row   = 0;
 183   Int_t col   = 0;
 184   Int_t time  = 0;
 185   Int_t icham = 0;
 186   Int_t iplan = 0;
 187   Int_t isect = 0;
 188   Int_t iPad  = 0;
 189
 190   AliTRDdataArrayI *digitsIn;
 191   AliTRDdataArrayI *tracksIn;
 192
 193   AliTRDgeometry geo;
 194
 195   AliTRDcalibDB  *calibration    = AliTRDcalibDB::Instance();
 196   if (!calibration) {
 197     AliFatal("No AliTRDcalibDB instance available\n");
 198     return kFALSE;
 199   }
 200
 201   AliTRDSimParam *simParam       = AliTRDSimParam::Instance();
 202   if (!simParam) {
 203     AliError("No AliTRDSimParam instance available\n");
 204     return kFALSE;
 205   }
 206
 207   AliTRDRecParam *recParam       = AliTRDRecParam::Instance();
 208   if (!recParam) {
 209     AliError("No AliTRDRecParam instance available\n");
 210     return kFALSE;
 211   }
 212
 213   // ADC thresholds
 214   Float_t ADCthreshold   = simParam->GetADCthreshold();
 215   // Threshold value for the maximum
 216   Float_t maxThresh      = recParam->GetClusMaxThresh();
 217   // Threshold value for the digit signal
 218   Float_t sigThresh      = recParam->GetClusSigThresh();
 219
 220   // Detector wise calibration object for t0
 221   const AliTRDCalDet *calT0Det         = calibration->GetT0Det();
 222   // Detector wise calibration object for the gain factors
 223   const AliTRDCalDet *calGainFactorDet = calibration->GetGainFactorDet();
 224
 225   // Iteration limit for unfolding procedure
 226   const Float_t kEpsilon = 0.01;
 227   const Int_t   kNclus   = 3;
 228   const Int_t   kNsig    = 5;
 229   const Int_t   kNdict   = AliTRDdigitsManager::kNDict;
 230   const Int_t   kNtrack  = kNdict * kNclus;
 231
 232   Int_t    iUnfold       = 0;
 233   Double_t ratioLeft     = 1.0;
 234   Double_t ratioRight    = 1.0;
 235
 236   Int_t    iClusterROC   = 0;
 237
 238   Double_t padSignal[kNsig];
 239   Double_t clusterSignal[kNclus];
 240   Double_t clusterPads[kNclus];
 241
 242   Int_t    chamBeg    = 0;
 243   Int_t    chamEnd    = AliTRDgeometry::Ncham();
 244   Int_t    planBeg    = 0;
 245   Int_t    planEnd    = AliTRDgeometry::Nplan();
 246   Int_t    sectBeg    = 0;
 247   Int_t    sectEnd    = AliTRDgeometry::Nsect();
 248   Int_t    nTimeTotal = calibration->GetNumberOfTimeBins();
 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         Int_t    ilayer  = AliGeomManager::kTRD1 + iplan;
 259         Int_t    imodule = icham + chamEnd * isect;
 260         UShort_t volid   = AliGeomManager::LayerToVolUID(ilayer,imodule);
 261
 262         // Get the digits
 263         digitsIn = fDigitsManager->GetDigits(idet);
 264         // This is to take care of switched off super modules
 265         if (digitsIn->GetNtime() == 0) {
 266           continue;
 267         }
 268         digitsIn->Expand();
 269         AliTRDdataArrayI *tracksTmp = fDigitsManager->GetDictionary(idet,0);
 270         tracksTmp->Expand();
 271
 272         Int_t nRowMax = geo.GetRowMax(iplan,icham,isect);
 273         Int_t nColMax = geo.GetColMax(iplan);
 274
 275         AliTRDpadPlane *padPlane = geo.GetPadPlane(iplan,icham);
 276
 277         // Calibration object with pad wise values for t0
 278         AliTRDCalROC *calT0ROC              = calibration->GetT0ROC(idet);
 279         // Calibration object with pad wise values for the gain factors
 280         AliTRDCalROC *calGainFactorROC      = calibration->GetGainFactorROC(idet);
 281         // Calibration value for chamber wise t0
 282         Float_t       calT0DetValue         = calT0Det->GetValue(idet);
 283         // Calibration value for chamber wise gain factor
 284         Float_t       calGainFactorDetValue = calGainFactorDet->GetValue(idet);
 285
 286         Int_t nClusters      = 0;
 287
 288         // Apply the gain and the tail cancelation via digital filter
 289         AliTRDdataArrayF *digitsOut = new AliTRDdataArrayF(digitsIn->GetNrow()
 290                                                           ,digitsIn->GetNcol()
 291                                                           ,digitsIn->GetNtime());
 292         Transform(digitsIn
 293                  ,digitsOut
 294                  ,nRowMax,nColMax,nTimeTotal
 295                  ,ADCthreshold
 296                  ,calGainFactorROC
 297                  ,calGainFactorDetValue);
 298
 299         // Input digits are not needed any more
 300         digitsIn->Compress(1,0);
 301
 302         // Loop through the chamber and find the maxima
 303         for ( row = 0;  row <  nRowMax;    row++) {
 304           for ( col = 2;  col <  nColMax;    col++) {
 305             for (time = 0; time < nTimeTotal; time++) {
 306
 307               Float_t signalM = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time));
 308
 309               // Look for the maximum
 310               if (signalM >= maxThresh) {
 311
 312                 Float_t signalL = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time));
 313                 Float_t signalR = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 314
 315                 if ((TMath::Abs(signalL) <= signalM) &&
 316                     (TMath::Abs(signalR) <  signalM)) {
 317                   if ((TMath::Abs(signalL) >= sigThresh) ||
 318                       (TMath::Abs(signalR) >= sigThresh)) {
 319                     // Maximum found, mark the position by a negative signal
 320                     digitsOut->SetDataUnchecked(row,col-1,time,-signalM);
 321                   }
 322                 }
 323
 324               }
 325
 326             }
 327           }
 328         }
 329         tracksTmp->Compress(1,0);
 330
 331         // The index to the first cluster of a given ROC
 332         Int_t firstClusterROC = -1;
 333         // The number of cluster in a given ROC
 334         Int_t nClusterROC     =  0;
 335
 336         // Now check the maxima and calculate the cluster position
 337         for ( row = 0;  row <  nRowMax  ;  row++) {
 338           for (time = 0; time < nTimeTotal; time++) {
 339             for ( col = 1;  col <  nColMax-1;  col++) {
 340
 341               // Maximum found ?
 342               if (digitsOut->GetDataUnchecked(row,col,time) < 0.0) {
 343
 344                 for (iPad = 0; iPad < kNclus; iPad++) {
 345                   Int_t iPadCol = col - 1 + iPad;
 346                   clusterSignal[iPad] =
 347                     TMath::Abs(digitsOut->GetDataUnchecked(row,iPadCol,time));
 348                 }
 349
 350                 // Count the number of pads in the cluster
 351                 Int_t nPadCount = 0;
 352                 Int_t ii;
 353                 // Look to the left
 354                 ii = 0;
 355                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col-ii  ,time)) >= sigThresh) {
 356                   nPadCount++;
 357                   ii++;
 358                   if (col-ii   <        0) break;
 359                 }
 360                 // Look to the right
 361                 ii = 0;
 362                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col+ii+1,time)) >= sigThresh) {
 363                   nPadCount++;
 364                   ii++;
 365                   if (col+ii+1 >= nColMax) break;
 366                 }
 367                 nClusters++;
 368
 369                 // Look for 5 pad cluster with minimum in the middle
 370                 Bool_t fivePadCluster = kFALSE;
 371                 if (col < (nColMax - 3)) {
 372                   if (digitsOut->GetDataUnchecked(row,col+2,time) < 0) {
 373                     fivePadCluster = kTRUE;
 374                   }
 375                   if ((fivePadCluster) && (col < (nColMax - 5))) {
 376                     if (digitsOut->GetDataUnchecked(row,col+4,time) >= sigThresh) {
 377                       fivePadCluster = kFALSE;
 378                     }
 379                   }
 380                   if ((fivePadCluster) && (col >             1)) {
 381                     if (digitsOut->GetDataUnchecked(row,col-2,time) >= sigThresh) {
 382                       fivePadCluster = kFALSE;
 383                     }
 384                   }
 385                 }
 386
 387                 // 5 pad cluster
 388                 // Modify the signal of the overlapping pad for the left part
 389                 // of the cluster which remains from a previous unfolding
 390                 if (iUnfold) {
 391                   clusterSignal[0] *= ratioLeft;
 392                   iUnfold = 0;
 393                 }
 394
 395                 // Unfold the 5 pad cluster
 396                 if (fivePadCluster) {
 397                   for (iPad = 0; iPad < kNsig; iPad++) {
 398                     padSignal[iPad] = TMath::Abs(digitsOut->GetDataUnchecked(row
 399                                                                             ,col-1+iPad
 400                                                                             ,time));
 401                   }
 402                   // Unfold the two maxima and set the signal on
 403                   // the overlapping pad to the ratio
 404                   ratioRight        = Unfold(kEpsilon,iplan,padSignal);
 405                   ratioLeft         = 1.0 - ratioRight;
 406                   clusterSignal[2] *= ratioRight;
 407                   iUnfold = 1;
 408                 }
 409
 410                 Double_t clusterCharge = clusterSignal[0]
 411                                        + clusterSignal[1]
 412                                        + clusterSignal[2];
 413
 414                 // The position of the cluster
 415                 clusterPads[0] =  row + 0.5;
 416                 // Take the shift of the additional time bins into account
 417                 clusterPads[2] = time + 0.5;
 418
 419                 if (recParam->LUTOn()) {
 420                   // Calculate the position of the cluster by using the
 421                   // lookup table method
 422                   clusterPads[1] = recParam->LUTposition(iplan,clusterSignal[0]
 423                                                               ,clusterSignal[1]
 424                                                               ,clusterSignal[2]);
 425                 }
 426                 else {
 427                   // Calculate the position of the cluster by using the
 428                   // center of gravity method
 429                   for (Int_t i = 0; i < kNsig; i++) {
 430                     padSignal[i] = 0.0;
 431                   }
 432                   padSignal[2] = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time)); // Central pad
 433                   padSignal[1] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time)); // Left    pad
 434                   padSignal[3] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+1,time)); // Right   pad
 435                   if ((col >           2) &&
 436                       (TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time)) < padSignal[1])) {
 437                     padSignal[0] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 438                   }
 439                   if ((col < nColMax - 3) &&
 440                       (TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time)) < padSignal[3])) {
 441                     padSignal[4] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time));
 442                   }
 443                   clusterPads[1] = GetCOG(padSignal);
 444                 }
 445
 446                 Double_t q0 = clusterSignal[0];
 447                 Double_t q1 = clusterSignal[1];
 448                 Double_t q2 = clusterSignal[2];
 449                 Double_t clusterSigmaY2 = (q1 * (q0 + q2) + 4.0 * q0 * q2)
 450                                         / (clusterCharge*clusterCharge);
 451
 452                 //
 453                 // Calculate the position and the error
 454                 //
 455
 456                 // Correct for t0 (sum of chamber and pad wise values !!!)
 457                 Float_t  calT0ROCValue  = calT0ROC->GetValue(col,row);
 458                 Char_t   clusterTimeBin = ((Char_t) TMath::Nint(time - (calT0DetValue + calT0ROCValue)));
 459                 Double_t colSize        = padPlane->GetColSize(col);
 460                 Double_t rowSize        = padPlane->GetRowSize(row);
 461
 462                 Float_t clusterPos[3];
 463                 clusterPos[0] = padPlane->GetColPos(col) - (clusterPads[1] + 0.5) * colSize;
 464                 clusterPos[1] = padPlane->GetRowPos(row) - 0.5                    * rowSize;
 465                 clusterPos[2] = CalcXposFromTimebin(clusterPads[2],idet,col,row);
 466                 Float_t clusterSig[2];
 467                 clusterSig[0] = (clusterSigmaY2 + 1.0/12.0) * colSize*colSize;
 468                 clusterSig[1] = rowSize * rowSize / 12.0;
 469
 470                 // Store the amplitudes of the pads in the cluster for later analysis
 471                 Short_t signals[7] = { 0, 0, 0, 0, 0, 0, 0 };
 472                 for (Int_t jPad = col-3; jPad <= col+3; jPad++) {
 473                   if ((jPad <          0) ||
 474                       (jPad >= nColMax-1)) {
 475                     continue;
 476                   }
 477                   signals[jPad-col+3] = TMath::Nint(TMath::Abs(digitsOut->GetDataUnchecked(row,jPad,time)));
 478                 }
 479
 480                 // Add the cluster to the output array
 481                 // The track indices will be stored later
 482                 AliTRDcluster *cluster = new AliTRDcluster(idet
 483                                                           ,clusterCharge
 484                                                           ,clusterPos
 485                                                           ,clusterSig
 486                                                           ,0x0
 487                                                           ,((Char_t) nPadCount)
 488                                                           ,signals
 489                                                           ,((UChar_t) col)
 490                                                           ,clusterTimeBin
 491                                                           ,clusterPads[1]
 492                                                           ,volid);
 493                 // Temporarily store the row, column and time bin of the center pad
 494                 // Used to later on assign the track indices
 495                 cluster->SetLabel( row,0);
 496                 cluster->SetLabel( col,1);
 497                 cluster->SetLabel(time,2);
 498                 RecPoints()->Add(cluster);
 499
 500                 // Store the index of the first cluster in the current ROC
 501                 if (firstClusterROC < 0) {
 502                   firstClusterROC = RecPoints()->GetEntriesFast() - 1;
 503                 }
 504                 // Count the number of cluster in the current ROC
 505                 nClusterROC++;
 506
 507               } // if: Maximum found ?
 508
 509             } // loop: pad columns
 510           } // loop: time bins
 511         } // loop: pad rows
 512
 513         delete digitsOut;
 514
 515         //
 516         // Add the track indices to the found clusters
 517         //
 518
 519         // Temporary array to collect the track indices
 520         Int_t *idxTracks = new Int_t[kNtrack*nClusterROC];
 521
 522         // Loop through the dictionary arrays one-by-one
 523         // to keep memory consumption low
 524         for (Int_t iDict = 0; iDict < kNdict; iDict++) {
 525
 526           tracksIn = fDigitsManager->GetDictionary(idet,iDict);
 527           tracksIn->Expand();
 528
 529           // Loop though the clusters found in this ROC
 530           for (iClusterROC = 0; iClusterROC < nClusterROC; iClusterROC++) {
 531
 532             AliTRDcluster *cluster = (AliTRDcluster *)
 533                                      RecPoints()->UncheckedAt(firstClusterROC+iClusterROC);
 534             row  = cluster->GetLabel(0);
 535             col  = cluster->GetLabel(1);
 536             time = cluster->GetLabel(2);
 537
 538             for (iPad = 0; iPad < kNclus; iPad++) {
 539               Int_t iPadCol = col - 1 + iPad;
 540               Int_t index   = tracksIn->GetDataUnchecked(row,iPadCol,time) - 1;
 541               idxTracks[3*iPad+iDict + iClusterROC*kNtrack] = index;
 542             }
 543
 544           }
 545
 546           // Compress the arrays
 547           tracksIn->Compress(1,0);
 548
 549         }
 550
 551         // Copy the track indices into the cluster
 552         // Loop though the clusters found in this ROC
 553         for (iClusterROC = 0; iClusterROC < nClusterROC; iClusterROC++) {
 554
 555           AliTRDcluster *cluster = (AliTRDcluster *)
 556                                    RecPoints()->UncheckedAt(firstClusterROC+iClusterROC);
 557           cluster->SetLabel(-9999,0);
 558           cluster->SetLabel(-9999,1);
 559           cluster->SetLabel(-9999,2);
 560
 561           cluster->AddTrackIndex(&idxTracks[iClusterROC*kNtrack]);
 562
 563         }
 564
 565         delete [] idxTracks;
 566
 567         // Write the cluster and reset the array
 568         WriteClusters(idet);
 569         ResetRecPoints();
 570
 571       } // loop: Sectors
 572     } // loop: Planes
 573   } // loop: Chambers
 574
 575   return kTRUE;
 576
 577 }
 578
 579 //_____________________________________________________________________________
 580 Double_t AliTRDclusterizerV1::GetCOG(Double_t signal[5])
 581 {
 582   //
 583   // Get COG position
 584   // Used for clusters with more than 3 pads - where LUT not applicable
 585   //
 586
 587   Double_t sum = signal[0]
 588                + signal[1]
 589                + signal[2]
 590                + signal[3]
 591                + signal[4];
 592
 593   Double_t res = (0.0 * (-signal[0] + signal[4])
 594                       + (-signal[1] + signal[3])) / sum;
 595
 596   return res;
 597
 598 }
 599
 600 //_____________________________________________________________________________
 601 Double_t AliTRDclusterizerV1::Unfold(Double_t eps, Int_t plane, Double_t *padSignal)
 602 {
 603   //
 604   // Method to unfold neighbouring maxima.
 605   // The charge ratio on the overlapping pad is calculated
 606   // until there is no more change within the range given by eps.
 607   // The resulting ratio is then returned to the calling method.
 608   //
 609
 610   AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
 611   if (!calibration) {
 612     AliError("No AliTRDcalibDB instance available\n");
 613     return kFALSE;
 614   }
 615
 616   Int_t   irc                = 0;
 617   Int_t   itStep             = 0;                 // Count iteration steps
 618
 619   Double_t ratio             = 0.5;               // Start value for ratio
 620   Double_t prevRatio         = 0.0;               // Store previous ratio
 621
 622   Double_t newLeftSignal[3]  = { 0.0, 0.0, 0.0 }; // Array to store left cluster signal
 623   Double_t newRightSignal[3] = { 0.0, 0.0, 0.0 }; // Array to store right cluster signal
 624   Double_t newSignal[3]      = { 0.0, 0.0, 0.0 };
 625
 626   // Start the iteration
 627   while ((TMath::Abs(prevRatio - ratio) > eps) && (itStep < 10)) {
 628
 629     itStep++;
 630     prevRatio = ratio;
 631
 632     // Cluster position according to charge ratio
 633     Double_t maxLeft  = (ratio*padSignal[2] - padSignal[0])
 634                       / (padSignal[0] + padSignal[1] + ratio*padSignal[2]);
 635     Double_t maxRight = (padSignal[4] - (1-ratio)*padSignal[2])
 636                       / ((1.0 - ratio)*padSignal[2] + padSignal[3] + padSignal[4]);
 637
 638     // Set cluster charge ratio
 639     irc = calibration->PadResponse(1.0,maxLeft ,plane,newSignal);
 640     Double_t ampLeft  = padSignal[1] / newSignal[1];
 641     irc = calibration->PadResponse(1.0,maxRight,plane,newSignal);
 642     Double_t ampRight = padSignal[3] / newSignal[1];
 643
 644     // Apply pad response to parameters
 645     irc = calibration->PadResponse(ampLeft ,maxLeft ,plane,newLeftSignal );
 646     irc = calibration->PadResponse(ampRight,maxRight,plane,newRightSignal);
 647
 648     // Calculate new overlapping ratio
 649     ratio = TMath::Min((Double_t)1.0,newLeftSignal[2] /
 650                                     (newLeftSignal[2] + newRightSignal[0]));
 651
 652   }
 653
 654   return ratio;
 655
 656 }
 657
 658 //_____________________________________________________________________________
 659 void AliTRDclusterizerV1::Transform(AliTRDdataArrayI *digitsIn
 660                                   , AliTRDdataArrayF *digitsOut
 661                                   , Int_t nRowMax, Int_t nColMax, Int_t nTimeTotal
 662                                   , Float_t ADCthreshold
 663                                   , AliTRDCalROC *calGainFactorROC
 664                                   , Float_t calGainFactorDetValue)
 665 {
 666   //
 667   // Apply gain factor
 668   // Apply tail cancelation: Transform digitsIn to digitsOut
 669   //
 670
 671   Int_t iRow  = 0;
 672   Int_t iCol  = 0;
 673   Int_t iTime = 0;
 674
 675   AliTRDRecParam *recParam = AliTRDRecParam::Instance();
 676   if (!recParam) {
 677     AliError("No AliTRDRecParam instance available\n");
 678     return;
 679   }
 680
 681   Double_t *inADC  = new Double_t[nTimeTotal];  // ADC data before tail cancellation
 682   Double_t *outADC = new Double_t[nTimeTotal];  // ADC data after tail cancellation
 683
 684   for (iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
 685     for (iCol  = 0; iCol  <  nColMax;   iCol++ ) {
 686
 687       Float_t  calGainFactorROCValue = calGainFactorROC->GetValue(iCol,iRow);
 688       Double_t gain                  = calGainFactorDetValue
 689                                      * calGainFactorROCValue;
 690
 691       for (iTime = 0; iTime < nTimeTotal; iTime++) {
 692
 693         //
 694         // Add gain
 695         //
 696         inADC[iTime]   = digitsIn->GetDataUnchecked(iRow,iCol,iTime);
 697         inADC[iTime]  /= gain;
 698         outADC[iTime]  = inADC[iTime];
 699
 700       }
 701
 702       // Apply the tail cancelation via the digital filter
 703       if (recParam->TCOn()) {
 704         DeConvExp(inADC,outADC,nTimeTotal,recParam->GetTCnexp());
 705       }
 706
 707       for (iTime = 0; iTime < nTimeTotal; iTime++) {
 708
 709         // Store the amplitude of the digit if above threshold
 710         if (outADC[iTime] > ADCthreshold) {
 711           digitsOut->SetDataUnchecked(iRow,iCol,iTime,outADC[iTime]);
 712         }
 713
 714       }
 715
 716     }
 717   }
 718
 719   delete [] inADC;
 720   delete [] outADC;
 721
 722   return;
 723
 724 }
 725
 726 //_____________________________________________________________________________
 727 void AliTRDclusterizerV1::DeConvExp(Double_t *source, Double_t *target
 728                                   , Int_t n, Int_t nexp)
 729 {
 730   //
 731   // Tail cancellation by deconvolution for PASA v4 TRF
 732   //
 733
 734   Double_t rates[2];
 735   Double_t coefficients[2];
 736
 737   // Initialization (coefficient = alpha, rates = lambda)
 738   Double_t R1 = 1.0;
 739   Double_t R2 = 1.0;
 740   Double_t C1 = 0.5;
 741   Double_t C2 = 0.5;
 742
 743   if (nexp == 1) {   // 1 Exponentials
 744     R1 = 1.156;
 745     R2 = 0.130;
 746     C1 = 0.066;
 747     C2 = 0.000;
 748   }
 749   if (nexp == 2) {   // 2 Exponentials
 750     R1 = 1.156;
 751     R2 = 0.130;
 752     C1 = 0.114;
 753     C2 = 0.624;
 754   }
 755
 756   coefficients[0] = C1;
 757   coefficients[1] = C2;
 758
 759   Double_t Dt = 0.1;
 760
 761   rates[0] = TMath::Exp(-Dt/(R1));
 762   rates[1] = TMath::Exp(-Dt/(R2));
 763
 764   Int_t i = 0;
 765   Int_t k = 0;
 766
 767   Double_t reminder[2];
 768   Double_t correction;
 769   Double_t result;
 770
 771   // Attention: computation order is important
 772   correction = 0.0;
 773   for (k = 0; k < nexp; k++) {
 774     reminder[k] = 0.0;
 775   }
 776   for (i = 0; i < n; i++) {
 777     result    = (source[i] - correction);    // No rescaling
 778     target[i] = result;
 779
 780     for (k = 0; k < nexp; k++) {
 781       reminder[k] = rates[k] * (reminder[k] + coefficients[k] * result);
 782     }
 783     correction = 0.0;
 784     for (k = 0; k < nexp; k++) {
 785       correction += reminder[k];
 786     }
 787   }
 788
 789 }