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   // Get the geometry
 194   //AliTRDgeometry *geo            = AliTRDgeometry::GetGeometry(fRunLoader);
 195   //if (!geo) {
 196   //  AliWarning("Creating default TRD geometry!");
 197   //  geo = new AliTRDgeometry();
 198   //}
 199   AliTRDgeometry geo;
 200
 201   AliTRDcalibDB  *calibration    = AliTRDcalibDB::Instance();
 202   if (!calibration) {
 203     AliFatal("No AliTRDcalibDB instance available\n");
 204     return kFALSE;
 205   }
 206
 207   AliTRDSimParam *simParam       = AliTRDSimParam::Instance();
 208   if (!simParam) {
 209     AliError("No AliTRDSimParam instance available\n");
 210     return kFALSE;
 211   }
 212
 213   AliTRDRecParam *recParam       = AliTRDRecParam::Instance();
 214   if (!recParam) {
 215     AliError("No AliTRDRecParam instance available\n");
 216     return kFALSE;
 217   }
 218
 219   // ADC thresholds
 220   Float_t ADCthreshold   = simParam->GetADCthreshold();
 221   // Threshold value for the maximum
 222   Float_t maxThresh      = recParam->GetClusMaxThresh();
 223   // Threshold value for the digit signal
 224   Float_t sigThresh      = recParam->GetClusSigThresh();
 225
 226   // Detector wise calibration object for t0
 227   const AliTRDCalDet *calT0Det         = calibration->GetT0Det();
 228   // Detector wise calibration object for the gain factors
 229   const AliTRDCalDet *calGainFactorDet = calibration->GetGainFactorDet();
 230
 231   // Iteration limit for unfolding procedure
 232   const Float_t kEpsilon = 0.01;
 233   const Int_t   kNclus   = 3;
 234   const Int_t   kNsig    = 5;
 235   const Int_t   kNdict   = AliTRDdigitsManager::kNDict;
 236   const Int_t   kNtrack  = kNdict * kNclus;
 237
 238   Int_t    iType         = 0;
 239   Int_t    iUnfold       = 0;
 240   Double_t ratioLeft     = 1.0;
 241   Double_t ratioRight    = 1.0;
 242
 243   Int_t    iClusterROC   = 0;
 244
 245   Double_t padSignal[kNsig];
 246   Double_t clusterSignal[kNclus];
 247   Double_t clusterPads[kNclus];
 248
 249   Int_t    chamBeg    = 0;
 250   Int_t    chamEnd    = AliTRDgeometry::Ncham();
 251   Int_t    planBeg    = 0;
 252   Int_t    planEnd    = AliTRDgeometry::Nplan();
 253   Int_t    sectBeg    = 0;
 254   Int_t    sectEnd    = AliTRDgeometry::Nsect();
 255   Int_t    nTimeTotal = calibration->GetNumberOfTimeBins();
 256
 257   Int_t    dummy[9]   = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 258
 259   AliDebug(1,Form("Number of Time Bins = %d.\n",nTimeTotal));
 260
 261   // Start clustering in every chamber
 262   for (icham = chamBeg; icham < chamEnd; icham++) {
 263     for (iplan = planBeg; iplan < planEnd; iplan++) {
 264       for (isect = sectBeg; isect < sectEnd; isect++) {
 265
 266         Int_t    idet    = geo.GetDetector(iplan,icham,isect);
 267         Int_t    ilayer  = AliGeomManager::kTRD1 + iplan;
 268         Int_t    imodule = icham + chamEnd * isect;
 269         UShort_t volid   = AliGeomManager::LayerToVolUID(ilayer,imodule);
 270
 271         // Get the digits
 272         digitsIn = fDigitsManager->GetDigits(idet);
 273         // This is to take care of switched off super modules
 274         if (digitsIn->GetNtime() == 0) {
 275           continue;
 276         }
 277         digitsIn->Expand();
 278         AliTRDdataArrayI *tracksTmp = fDigitsManager->GetDictionary(idet,0);
 279         tracksTmp->Expand();
 280
 281         Int_t nRowMax = geo.GetRowMax(iplan,icham,isect);
 282         Int_t nColMax = geo.GetColMax(iplan);
 283
 284         AliTRDpadPlane *padPlane = geo.GetPadPlane(iplan,icham);
 285
 286         // Calibration object with pad wise values for t0
 287         AliTRDCalROC *calT0ROC              = calibration->GetT0ROC(idet);
 288         // Calibration object with pad wise values for the gain factors
 289         AliTRDCalROC *calGainFactorROC      = calibration->GetGainFactorROC(idet);
 290         // Calibration value for chamber wise t0
 291         Float_t       calT0DetValue         = calT0Det->GetValue(idet);
 292         // Calibration value for chamber wise gain factor
 293         Float_t       calGainFactorDetValue = calGainFactorDet->GetValue(idet);
 294
 295         Int_t nClusters      = 0;
 296         Int_t nClusters2pad  = 0;
 297         Int_t nClusters3pad  = 0;
 298         Int_t nClusters4pad  = 0;
 299         Int_t nClusters5pad  = 0;
 300         Int_t nClustersLarge = 0;
 301
 302         // Apply the gain and the tail cancelation via digital filter
 303         AliTRDdataArrayF *digitsOut = new AliTRDdataArrayF(digitsIn->GetNrow()
 304                                                           ,digitsIn->GetNcol()
 305                                                           ,digitsIn->GetNtime());
 306         Transform(digitsIn
 307                  ,digitsOut
 308                  ,nRowMax,nColMax,nTimeTotal
 309                  ,ADCthreshold
 310                  ,calGainFactorROC
 311                  ,calGainFactorDetValue);
 312
 313         // Input digits are not needed any more
 314         digitsIn->Compress(1,0);
 315
 316         // Loop through the chamber and find the maxima
 317         for ( row = 0;  row <  nRowMax;    row++) {
 318           for ( col = 2;  col <  nColMax;    col++) {
 319             for (time = 0; time < nTimeTotal; time++) {
 320
 321               Float_t signalM = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time));
 322
 323               // Look for the maximum
 324               if (signalM >= maxThresh) {
 325
 326                 Float_t signalL = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time));
 327                 Float_t signalR = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 328
 329                 if ((TMath::Abs(signalL) <= signalM) &&
 330                     (TMath::Abs(signalR) <  signalM)) {
 331                   if ((TMath::Abs(signalL) >= sigThresh) ||
 332                       (TMath::Abs(signalR) >= sigThresh)) {
 333                     // Maximum found, mark the position by a negative signal
 334                     digitsOut->SetDataUnchecked(row,col-1,time,-signalM);
 335                   }
 336                 }
 337
 338               }
 339
 340             }
 341           }
 342         }
 343         tracksTmp->Compress(1,0);
 344
 345         // The index to the first cluster of a given ROC
 346         Int_t firstClusterROC = -1;
 347         // The number of cluster in a given ROC
 348         Int_t nClusterROC     =  0;
 349
 350         // Now check the maxima and calculate the cluster position
 351         for ( row = 0;  row <  nRowMax  ;  row++) {
 352           for (time = 0; time < nTimeTotal; time++) {
 353             for ( col = 1;  col <  nColMax-1;  col++) {
 354
 355               // Maximum found ?
 356               if (digitsOut->GetDataUnchecked(row,col,time) < 0.0) {
 357
 358                 for (iPad = 0; iPad < kNclus; iPad++) {
 359                   Int_t iPadCol = col - 1 + iPad;
 360                   clusterSignal[iPad] =
 361                     TMath::Abs(digitsOut->GetDataUnchecked(row,iPadCol,time));
 362                 }
 363
 364                 // Count the number of pads in the cluster
 365                 Int_t nPadCount = 0;
 366                 Int_t ii;
 367                 // Look to the left
 368                 ii = 0;
 369                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col-ii  ,time)) >= sigThresh) {
 370                   nPadCount++;
 371                   ii++;
 372                   if (col-ii   <        0) break;
 373                 }
 374                 // Look to the right
 375                 ii = 0;
 376                 while (TMath::Abs(digitsOut->GetDataUnchecked(row,col+ii+1,time)) >= sigThresh) {
 377                   nPadCount++;
 378                   ii++;
 379                   if (col+ii+1 >= nColMax) break;
 380                 }
 381                 nClusters++;
 382                 switch (nPadCount) {
 383                 case 2:
 384                   iType = 0;
 385                   nClusters2pad++;
 386                   break;
 387                 case 3:
 388                   iType = 1;
 389                   nClusters3pad++;
 390                   break;
 391                 case 4:
 392                   iType = 2;
 393                   nClusters4pad++;
 394                   break;
 395                 case 5:
 396                   iType = 3;
 397                   nClusters5pad++;
 398                   break;
 399                 default:
 400                   iType = 4;
 401                   nClustersLarge++;
 402                   break;
 403                 };
 404
 405                 // Look for 5 pad cluster with minimum in the middle
 406                 Bool_t fivePadCluster = kFALSE;
 407                 if (col < (nColMax - 3)) {
 408                   if (digitsOut->GetDataUnchecked(row,col+2,time) < 0) {
 409                     fivePadCluster = kTRUE;
 410                   }
 411                   if ((fivePadCluster) && (col < (nColMax - 5))) {
 412                     if (digitsOut->GetDataUnchecked(row,col+4,time) >= sigThresh) {
 413                       fivePadCluster = kFALSE;
 414                     }
 415                   }
 416                   if ((fivePadCluster) && (col >             1)) {
 417                     if (digitsOut->GetDataUnchecked(row,col-2,time) >= sigThresh) {
 418                       fivePadCluster = kFALSE;
 419                     }
 420                   }
 421                 }
 422
 423                 // 5 pad cluster
 424                 // Modify the signal of the overlapping pad for the left part
 425                 // of the cluster which remains from a previous unfolding
 426                 if (iUnfold) {
 427                   clusterSignal[0] *= ratioLeft;
 428                   iType   = 5;
 429                   iUnfold = 0;
 430                 }
 431
 432                 // Unfold the 5 pad cluster
 433                 if (fivePadCluster) {
 434                   for (iPad = 0; iPad < kNsig; iPad++) {
 435                     padSignal[iPad] = TMath::Abs(digitsOut->GetDataUnchecked(row
 436                                                                             ,col-1+iPad
 437                                                                             ,time));
 438                   }
 439                   // Unfold the two maxima and set the signal on
 440                   // the overlapping pad to the ratio
 441                   ratioRight        = Unfold(kEpsilon,iplan,padSignal);
 442                   ratioLeft         = 1.0 - ratioRight;
 443                   clusterSignal[2] *= ratioRight;
 444                   iType   = 5;
 445                   iUnfold = 1;
 446                 }
 447
 448                 Double_t clusterCharge = clusterSignal[0]
 449                                        + clusterSignal[1]
 450                                        + clusterSignal[2];
 451
 452                 // The position of the cluster
 453                 clusterPads[0] =  row + 0.5;
 454                 // Take the shift of the additional time bins into account
 455                 clusterPads[2] = time + 0.5;
 456
 457                 if (recParam->LUTOn()) {
 458                   // Calculate the position of the cluster by using the
 459                   // lookup table method
 460                   clusterPads[1] = recParam->LUTposition(iplan,clusterSignal[0]
 461                                                               ,clusterSignal[1]
 462                                                               ,clusterSignal[2]);
 463                 }
 464                 else {
 465                   // Calculate the position of the cluster by using the
 466                   // center of gravity method
 467                   for (Int_t i = 0; i < kNsig; i++) {
 468                     padSignal[i] = 0.0;
 469                   }
 470                   padSignal[2] = TMath::Abs(digitsOut->GetDataUnchecked(row,col  ,time)); // Central pad
 471                   padSignal[1] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-1,time)); // Left    pad
 472                   padSignal[3] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+1,time)); // Right   pad
 473                   if ((col >           2) &&
 474                       (TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time)) < padSignal[1])) {
 475                     padSignal[0] = TMath::Abs(digitsOut->GetDataUnchecked(row,col-2,time));
 476                   }
 477                   if ((col < nColMax - 3) &&
 478                       (TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time)) < padSignal[3])) {
 479                     padSignal[4] = TMath::Abs(digitsOut->GetDataUnchecked(row,col+2,time));
 480                   }
 481                   clusterPads[1] = GetCOG(padSignal);
 482                 }
 483
 484                 Double_t q0 = clusterSignal[0];
 485                 Double_t q1 = clusterSignal[1];
 486                 Double_t q2 = clusterSignal[2];
 487                 Double_t clusterSigmaY2 = (q1 * (q0 + q2) + 4.0 * q0 * q2)
 488                                         / (clusterCharge*clusterCharge);
 489
 490                 //
 491                 // Calculate the position and the error
 492                 //
 493
 494                 // Correct for t0 (sum of chamber and pad wise values !!!)
 495                 Float_t  calT0ROCValue  = calT0ROC->GetValue(col,row);
 496                 Int_t    clusterTimeBin = TMath::Nint(time - (calT0DetValue + calT0ROCValue));
 497                 Double_t colSize        = padPlane->GetColSize(col);
 498                 Double_t rowSize        = padPlane->GetRowSize(row);
 499
 500                 Double_t clusterPos[3];
 501                 clusterPos[0] = padPlane->GetColPos(col) - (clusterPads[1] + 0.5) * colSize;
 502                 clusterPos[1] = padPlane->GetRowPos(row) - 0.5                    * rowSize;
 503                 clusterPos[2] = CalcXposFromTimebin(clusterPads[2],idet,col,row);
 504                 Double_t clusterSig[2];
 505                 clusterSig[0] = (clusterSigmaY2 + 1.0/12.0) * colSize*colSize;
 506                 clusterSig[1] = rowSize * rowSize / 12.0;
 507
 508                 // Add the cluster to the output array
 509                 // The track indices will be stored later
 510                 AliTRDcluster *cluster = AddCluster(clusterPos
 511                                                    ,clusterTimeBin
 512                                                    ,idet
 513                                                    ,clusterCharge
 514                                                    ,dummy
 515                                                    ,clusterSig
 516                                                    ,iType
 517                                                    ,col
 518                                                    ,volid
 519                                                    ,clusterPads[1]);
 520
 521                 // Store the amplitudes of the pads in the cluster for later analysis
 522                 Short_t signals[7] = { 0, 0, 0, 0, 0, 0, 0 };
 523                 for (Int_t jPad = col-3; jPad <= col+3; jPad++) {
 524                   if ((jPad <          0) ||
 525                       (jPad >= nColMax-1)) {
 526                     continue;
 527                   }
 528                   signals[jPad-col+3] = TMath::Nint(TMath::Abs(digitsOut->GetDataUnchecked(row,jPad,time)));
 529                 }
 530                 cluster->SetSignals(signals);
 531
 532                 // Temporarily store the row, column and time bin of the center pad
 533                 // Used to later on assign the track indices
 534                 cluster->SetLabel( row,0);
 535                 cluster->SetLabel( col,1);
 536                 cluster->SetLabel(time,2);
 537
 538                 // Store the index of the first cluster in the current ROC
 539                 if (firstClusterROC < 0) {
 540                   firstClusterROC = RecPoints()->GetEntriesFast() - 1;
 541                 }
 542                 // Count the number of cluster in the current ROC
 543                 nClusterROC++;
 544
 545               } // if: Maximum found ?
 546
 547             } // loop: pad columns
 548           } // loop: time bins
 549         } // loop: pad rows
 550
 551         delete digitsOut;
 552
 553         //
 554         // Add the track indices to the found clusters
 555         //
 556
 557         // Temporary array to collect the track indices
 558         Int_t *idxTracks = new Int_t[kNtrack*nClusterROC];
 559
 560         // Loop through the dictionary arrays one-by-one
 561         // to keep memory consumption low
 562         for (Int_t iDict = 0; iDict < kNdict; iDict++) {
 563
 564           tracksIn = fDigitsManager->GetDictionary(idet,iDict);
 565           tracksIn->Expand();
 566
 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             row  = cluster->GetLabel(0);
 573             col  = cluster->GetLabel(1);
 574             time = cluster->GetLabel(2);
 575
 576             for (iPad = 0; iPad < kNclus; iPad++) {
 577               Int_t iPadCol = col - 1 + iPad;
 578               Int_t index   = tracksIn->GetDataUnchecked(row,iPadCol,time) - 1;
 579               idxTracks[3*iPad+iDict + iClusterROC*kNtrack] = index;
 580             }
 581
 582           }
 583
 584           // Compress the arrays
 585           tracksIn->Compress(1,0);
 586
 587         }
 588
 589         // Copy the track indices into the cluster
 590         // Loop though the clusters found in this ROC
 591         for (iClusterROC = 0; iClusterROC < nClusterROC; iClusterROC++) {
 592
 593           AliTRDcluster *cluster = (AliTRDcluster *)
 594                                    RecPoints()->UncheckedAt(firstClusterROC+iClusterROC);
 595           cluster->SetLabel(-9999,0);
 596           cluster->SetLabel(-9999,1);
 597           cluster->SetLabel(-9999,2);
 598
 599           cluster->AddTrackIndex(&idxTracks[iClusterROC*kNtrack]);
 600
 601         }
 602
 603         delete [] idxTracks;
 604
 605         // Write the cluster and reset the array
 606         WriteClusters(idet);
 607         ResetRecPoints();
 608
 609       } // loop: Sectors
 610     } // loop: Planes
 611   } // loop: Chambers
 612
 613   return kTRUE;
 614
 615 }
 616
 617 //_____________________________________________________________________________
 618 Double_t AliTRDclusterizerV1::GetCOG(Double_t signal[5])
 619 {
 620   //
 621   // Get COG position
 622   // Used for clusters with more than 3 pads - where LUT not applicable
 623   //
 624
 625   Double_t sum = signal[0]
 626                + signal[1]
 627                + signal[2]
 628                + signal[3]
 629                + signal[4];
 630
 631   Double_t res = (0.0 * (-signal[0] + signal[4])
 632                       + (-signal[1] + signal[3])) / sum;
 633
 634   return res;
 635
 636 }
 637
 638 //_____________________________________________________________________________
 639 Double_t AliTRDclusterizerV1::Unfold(Double_t eps, Int_t plane, Double_t *padSignal)
 640 {
 641   //
 642   // Method to unfold neighbouring maxima.
 643   // The charge ratio on the overlapping pad is calculated
 644   // until there is no more change within the range given by eps.
 645   // The resulting ratio is then returned to the calling method.
 646   //
 647
 648   AliTRDcalibDB *calibration = AliTRDcalibDB::Instance();
 649   if (!calibration) {
 650     AliError("No AliTRDcalibDB instance available\n");
 651     return kFALSE;
 652   }
 653
 654   Int_t   irc                = 0;
 655   Int_t   itStep             = 0;                 // Count iteration steps
 656
 657   Double_t ratio             = 0.5;               // Start value for ratio
 658   Double_t prevRatio         = 0.0;               // Store previous ratio
 659
 660   Double_t newLeftSignal[3]  = { 0.0, 0.0, 0.0 }; // Array to store left cluster signal
 661   Double_t newRightSignal[3] = { 0.0, 0.0, 0.0 }; // Array to store right cluster signal
 662   Double_t newSignal[3]      = { 0.0, 0.0, 0.0 };
 663
 664   // Start the iteration
 665   while ((TMath::Abs(prevRatio - ratio) > eps) && (itStep < 10)) {
 666
 667     itStep++;
 668     prevRatio = ratio;
 669
 670     // Cluster position according to charge ratio
 671     Double_t maxLeft  = (ratio*padSignal[2] - padSignal[0])
 672                       / (padSignal[0] + padSignal[1] + ratio*padSignal[2]);
 673     Double_t maxRight = (padSignal[4] - (1-ratio)*padSignal[2])
 674                       / ((1.0 - ratio)*padSignal[2] + padSignal[3] + padSignal[4]);
 675
 676     // Set cluster charge ratio
 677     irc = calibration->PadResponse(1.0,maxLeft ,plane,newSignal);
 678     Double_t ampLeft  = padSignal[1] / newSignal[1];
 679     irc = calibration->PadResponse(1.0,maxRight,plane,newSignal);
 680     Double_t ampRight = padSignal[3] / newSignal[1];
 681
 682     // Apply pad response to parameters
 683     irc = calibration->PadResponse(ampLeft ,maxLeft ,plane,newLeftSignal );
 684     irc = calibration->PadResponse(ampRight,maxRight,plane,newRightSignal);
 685
 686     // Calculate new overlapping ratio
 687     ratio = TMath::Min((Double_t)1.0,newLeftSignal[2] /
 688                                     (newLeftSignal[2] + newRightSignal[0]));
 689
 690   }
 691
 692   return ratio;
 693
 694 }
 695
 696 //_____________________________________________________________________________
 697 void AliTRDclusterizerV1::Transform(AliTRDdataArrayI *digitsIn
 698                                   , AliTRDdataArrayF *digitsOut
 699                                   , Int_t nRowMax, Int_t nColMax, Int_t nTimeTotal
 700                                   , Float_t ADCthreshold
 701                                   , AliTRDCalROC *calGainFactorROC
 702                                   , Float_t calGainFactorDetValue)
 703 {
 704   //
 705   // Apply gain factor
 706   // Apply tail cancelation: Transform digitsIn to digitsOut
 707   //
 708
 709   Int_t iRow  = 0;
 710   Int_t iCol  = 0;
 711   Int_t iTime = 0;
 712
 713   AliTRDRecParam *recParam = AliTRDRecParam::Instance();
 714   if (!recParam) {
 715     AliError("No AliTRDRecParam instance available\n");
 716     return;
 717   }
 718
 719   Double_t *inADC  = new Double_t[nTimeTotal];  // ADC data before tail cancellation
 720   Double_t *outADC = new Double_t[nTimeTotal];  // ADC data after tail cancellation
 721
 722   for (iRow  = 0; iRow  <  nRowMax;   iRow++ ) {
 723     for (iCol  = 0; iCol  <  nColMax;   iCol++ ) {
 724
 725       Float_t  calGainFactorROCValue = calGainFactorROC->GetValue(iCol,iRow);
 726       Double_t gain                  = calGainFactorDetValue
 727                                      * calGainFactorROCValue;
 728
 729       for (iTime = 0; iTime < nTimeTotal; iTime++) {
 730
 731         //
 732         // Add gain
 733         //
 734         inADC[iTime]   = digitsIn->GetDataUnchecked(iRow,iCol,iTime);
 735         inADC[iTime]  /= gain;
 736         outADC[iTime]  = inADC[iTime];
 737
 738       }
 739
 740       // Apply the tail cancelation via the digital filter
 741       if (recParam->TCOn()) {
 742         DeConvExp(inADC,outADC,nTimeTotal,recParam->GetTCnexp());
 743       }
 744
 745       for (iTime = 0; iTime < nTimeTotal; iTime++) {
 746
 747         // Store the amplitude of the digit if above threshold
 748         if (outADC[iTime] > ADCthreshold) {
 749           digitsOut->SetDataUnchecked(iRow,iCol,iTime,outADC[iTime]);
 750         }
 751
 752       }
 753
 754     }
 755   }
 756
 757   delete [] inADC;
 758   delete [] outADC;
 759
 760   return;
 761
 762 }
 763
 764 //_____________________________________________________________________________
 765 void AliTRDclusterizerV1::DeConvExp(Double_t *source, Double_t *target
 766                                   , Int_t n, Int_t nexp)
 767 {
 768   //
 769   // Tail cancellation by deconvolution for PASA v4 TRF
 770   //
 771
 772   Double_t rates[2];
 773   Double_t coefficients[2];
 774
 775   // Initialization (coefficient = alpha, rates = lambda)
 776   Double_t R1 = 1.0;
 777   Double_t R2 = 1.0;
 778   Double_t C1 = 0.5;
 779   Double_t C2 = 0.5;
 780
 781   if (nexp == 1) {   // 1 Exponentials
 782     R1 = 1.156;
 783     R2 = 0.130;
 784     C1 = 0.066;
 785     C2 = 0.000;
 786   }
 787   if (nexp == 2) {   // 2 Exponentials
 788     R1 = 1.156;
 789     R2 = 0.130;
 790     C1 = 0.114;
 791     C2 = 0.624;
 792   }
 793
 794   coefficients[0] = C1;
 795   coefficients[1] = C2;
 796
 797   Double_t Dt = 0.1;
 798
 799   rates[0] = TMath::Exp(-Dt/(R1));
 800   rates[1] = TMath::Exp(-Dt/(R2));
 801
 802   Int_t i = 0;
 803   Int_t k = 0;
 804
 805   Double_t reminder[2];
 806   Double_t correction;
 807   Double_t result;
 808
 809   // Attention: computation order is important
 810   correction = 0.0;
 811   for (k = 0; k < nexp; k++) {
 812     reminder[k] = 0.0;
 813   }
 814   for (i = 0; i < n; i++) {
 815     result    = (source[i] - correction);    // No rescaling
 816     target[i] = result;
 817
 818     for (k = 0; k < nexp; k++) {
 819       reminder[k] = rates[k] * (reminder[k] + coefficients[k] * result);
 820     }
 821     correction = 0.0;
 822     for (k = 0; k < nexp; k++) {
 823       correction += reminder[k];
 824     }
 825   }
 826
 827 }