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