TRD/AliTRDgtuTMU.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
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  13  * provided "as is" without express or implied warranty.                  *
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  15
  16 /* $Id: AliTRDgtuTMU.cxx 28397 2008-09-02 09:33:00Z cblume $ */
  17
  18 ////////////////////////////////////////////////////////////////////////////
  19 //                                                                        //
  20 //  Track Matching Unit (TMU) simulation                                  //
  21 //                                                                        //
  22 //  Author: J. Klein (Jochen.Klein@cern.ch)                               //
  23 //                                                                        //
  24 ////////////////////////////////////////////////////////////////////////////
  25
  26 #include "TTree.h"
  27 #include "TList.h"
  28 #include "TVectorD.h"
  29 #include "TMath.h"
  30
  31 #include "AliESDEvent.h"
  32 #include "AliESDTrdTrack.h"
  33
  34 #include "AliLog.h"
  35 #include "AliTRDgeometry.h"
  36 #include "AliTRDpadPlane.h"
  37
  38 #include "AliTRDgtuParam.h"
  39 #include "AliTRDgtuTMU.h"
  40 #include "AliTRDtrackGTU.h"
  41
  42 ClassImp(AliTRDgtuTMU)
  43
  44 AliTRDgtuTMU::AliTRDgtuTMU(Int_t stack, Int_t sector) :
  45   TObject(),
  46   fTracklets(0x0),
  47   fTrackletsPostInput(0x0),
  48   fZChannelTracklets(0x0),
  49   fTracks(0x0),
  50   fGtuParam(0x0),
  51   fStack(-1),
  52   fSector(-1)
  53 {
  54   // constructor which initializes the position information of the TMU
  55
  56   fGtuParam = AliTRDgtuParam::Instance();
  57
  58   // store tracklets per link
  59   fTracklets = new TObjArray*[fGtuParam->GetNLinks()];
  60   for (Int_t iLink = 0; iLink < fGtuParam->GetNLinks(); iLink++) {
  61     fTracklets[iLink] = new TObjArray();
  62   }
  63
  64   // tracklets after input units per layer
  65   fTrackletsPostInput = new TObjArray*[fGtuParam->GetNLayers()];
  66   fZChannelTracklets = new TList*[fGtuParam->GetNLayers()];
  67   for (Int_t layer = 0;  layer <  fGtuParam->GetNLayers(); layer++) {
  68     fZChannelTracklets[layer] = new TList[fGtuParam->GetNZChannels()];
  69     fTrackletsPostInput[layer] = new TObjArray();
  70   }
  71
  72   fTracks = new TList*[fGtuParam->GetNZChannels()];
  73   for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
  74       fTracks[zch] = new TList[fGtuParam->GetNRefLayers()];
  75   }
  76
  77   if (stack > -1)
  78       SetStack(stack);
  79   if (sector > -1)
  80       SetSector(sector);
  81 }
  82
  83 AliTRDgtuTMU::~AliTRDgtuTMU()
  84 {
  85   // destructor
  86
  87   for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
  88     delete [] fTracks[zch];
  89   }
  90   delete [] fTracks;
  91   for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
  92     delete [] fZChannelTracklets[layer];
  93     //    delete [] fTrackletsPostInput[layer];
  94   }
  95   delete [] fZChannelTracklets;
  96   //  delete [] fTrackletsPostInput;
  97
  98   for (Int_t iLink = 0; iLink < fGtuParam->GetNLinks(); iLink++) {
  99     delete fTracklets[iLink];
 100   }
 101   delete [] fTracklets;
 102 }
 103
 104 Bool_t AliTRDgtuTMU::SetSector(Int_t sector)
 105 {
 106   // set the sector
 107
 108   if (sector > -1 && sector < fGtuParam->GetGeo()->Nsector() ) {
 109     fSector = sector;
 110     return kTRUE;
 111   }
 112
 113   AliError(Form("Invalid sector given: %i", sector));
 114   return kFALSE;
 115 }
 116
 117 Bool_t AliTRDgtuTMU::SetStack(Int_t stack)
 118 {
 119   // Set the stack (necessary for tracking)
 120
 121   if (stack > -1 && stack < fGtuParam->GetGeo()->Nstack() ) {
 122     fStack = stack;
 123     return kTRUE;
 124   }
 125
 126   AliError(Form("Invalid stack given: %i", stack));
 127   return kFALSE;
 128 }
 129
 130 Bool_t AliTRDgtuTMU::Reset()
 131 {
 132   // delete all tracks
 133
 134   for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
 135     for (Int_t reflayeridx = 0; reflayeridx < fGtuParam->GetNRefLayers(); reflayeridx++) {
 136       fTracks[zch][reflayeridx].Clear();
 137     }
 138   }
 139
 140   // delete all added tracklets
 141   for (Int_t iLink = 0; iLink < fGtuParam->GetNLinks(); iLink++) {
 142     fTracklets[iLink]->Clear();
 143   }
 144   for (Int_t layer = 0; layer < fGtuParam->GetNLinks()/2; layer++) {
 145     fTrackletsPostInput[layer]->Clear();
 146     for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++)
 147       fZChannelTracklets[layer][zch].Clear();
 148   }
 149
 150   fSector = -1;
 151   fStack = -1;
 152
 153   return kTRUE;
 154 }
 155
 156 Bool_t AliTRDgtuTMU::AddTracklet(AliTRDtrackletGTU *tracklet, Int_t link)
 157 {
 158   // add a tracklet on the given link
 159
 160   fTracklets[link]->Add(tracklet);
 161   return kTRUE;
 162 }
 163
 164
 165 Bool_t AliTRDgtuTMU::RunTMU(TList *ListOfTracks, AliESDEvent *esd)
 166 {
 167   // performs the analysis as in a TMU module of the GTU, i. e.
 168   // track matching
 169   // calculation of track parameteres (pt, deflection, ???)
 170
 171   if (fStack < 0 || fSector < 0) {
 172     AliError("No valid stack/sector set for this TMU! No tracking!");
 173     return kFALSE;
 174   }
 175
 176   // ----- Input units -----
 177   AliDebug(1,"--------- Running Input units ----------");
 178   for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
 179     if (!RunInputUnit(layer)) {
 180       AliError(Form("Input unit in layer %i failed", layer));
 181       return kFALSE;
 182     }
 183   }
 184
 185   // ----- Z-channel units -----
 186   AliDebug(1,"--------- Running Z-channel units ----------");
 187   for (Int_t layer = 0;  layer <  fGtuParam->GetNLayers(); layer++) {
 188     fZChannelTracklets[layer] = new TList[fGtuParam->GetNZChannels()];
 189     if (!RunZChannelUnit(layer)) {
 190       AliError(Form("Z-Channel unit in layer %i failed", layer));
 191       return kFALSE;
 192     }
 193   }
 194
 195   // ----- track finding -----
 196   AliDebug(1,"--------- Running tracking units ----------");
 197   for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
 198     if (!RunTrackFinder(zch, ListOfTracks)) {
 199       AliError(Form("Track Finder in z-channel %i failed", zch));
 200       return kFALSE;
 201     }
 202   }
 203
 204   // ----- Track Merging -----
 205   if (!RunTrackMerging(ListOfTracks)) {
 206     AliError("Track merging failed");
 207     return kFALSE;
 208   }
 209
 210   // ----- track reconstruction -----
 211   if (!RunTrackReconstruction(ListOfTracks)) {
 212     AliError("Track reconstruction failed");
 213     return kFALSE;
 214   }
 215
 216   // ----- label calculation and ESD storage -----
 217   TIter next(ListOfTracks);
 218   while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) next()) {
 219     trk->CookLabel();
 220     if (esd) {
 221       AliESDTrdTrack *trdtrack = trk->CreateTrdTrack();
 222       esd->AddTrdTrack(trdtrack);
 223       delete trdtrack;
 224     }
 225   }
 226
 227   return kTRUE;
 228 }
 229
 230 Bool_t AliTRDgtuTMU::RunInputUnit(Int_t layer)
 231 {
 232   // precalculations for the tracking and reconstruction
 233
 234   Int_t iTrkl0 = 0; // A-side tracklet
 235   Int_t iTrkl1 = 0; // B-side tracklet
 236
 237   while ((iTrkl0 < fTracklets[2*layer + 0]->GetEntriesFast()) || (iTrkl1 < fTracklets[2*layer + 1]->GetEntriesFast())) {
 238     if (iTrkl1 >= fTracklets[2*layer + 1]->GetEntriesFast()) {
 239       fTrackletsPostInput[layer]->AddLast(fTracklets[2*layer + 0]->At(iTrkl0));
 240       iTrkl0++;
 241     }
 242     else {
 243       if (iTrkl0 >= fTracklets[2*layer + 0]->GetEntriesFast()) {
 244         fTrackletsPostInput[layer]->AddLast(fTracklets[2*layer + 1]->At(iTrkl1));
 245         iTrkl1++;
 246       }
 247       else {
 248         if (((AliTRDtrackletGTU*) fTracklets[2*layer + 1]->At(iTrkl1))->GetZbin() <
 249             ((AliTRDtrackletGTU*) fTracklets[2*layer + 0]->At(iTrkl0))->GetZbin()) {
 250           fTrackletsPostInput[layer]->AddLast(fTracklets[2*layer + 1]->At(iTrkl1));
 251           iTrkl1++;
 252
 253         }
 254         else {
 255           fTrackletsPostInput[layer]->AddLast(fTracklets[2*layer + 0]->At(iTrkl0));
 256           iTrkl0++;
 257         }
 258       }
 259     }
 260   }
 261
 262   TIter next(fTrackletsPostInput[layer]);
 263
 264   while ( AliTRDtrackletGTU *trk = (AliTRDtrackletGTU*) next() ) {
 265     trk->SetIndex(fTrackletsPostInput[layer]->IndexOf(trk));
 266
 267     Int_t alpha = (trk->GetYbin() >> fGtuParam->GetBitExcessY()) * fGtuParam->GetCiAlpha(layer);
 268     alpha = ( 2 * trk->GetdY() - (alpha >> fGtuParam->GetBitExcessAlpha()) + 1 ) >> 1;
 269     // wrapping projected alpha as in hardware
 270     if ((alpha < -64) || (alpha > 63))
 271       AliError(Form("alpha out of range: %i", alpha));
 272     alpha = alpha & 0x7f;
 273     if (alpha & 0x40)
 274       trk->SetAlpha(0xffffffc0 | alpha);
 275     else
 276       trk->SetAlpha(alpha);
 277
 278     Int_t yproj = trk->GetdY() * (fGtuParam->GetCiYProj(layer));
 279     yproj = ( ( ( (yproj >> fGtuParam->GetBitExcessYProj()) + trk->GetYbin() ) >> 2) + 1) >> 1;
 280     trk->SetYProj(yproj);
 281
 282     trk->SetYPrime(trk->GetYbin() + fGtuParam->GetYt(fStack, layer, trk->GetZbin()));
 283
 284     AliDebug(10, Form("0x%08x: idx: %3i, z: %2i, y: %5i, dy: %3i, y': %5i, y_proj: %5i, alpha: %3i, pid: %3i, c: %5i, yt: %5i",
 285                       trk->GetTrackletWord(), trk->GetIndex(), trk->GetZbin(), trk->GetYbin(), trk->GetdY(), trk->GetYPrime(),
 286                       trk->GetYProj(), trk->GetAlpha(), trk->GetPID(),
 287                       fGtuParam->GetCiYProj(layer), fGtuParam->GetYt(fStack, layer, trk->GetZbin()) ));
 288   }
 289   return kTRUE;
 290 }
 291
 292 Bool_t AliTRDgtuTMU::RunZChannelUnit(Int_t layer)
 293 {
 294   // run the z-channel unit
 295
 296   TIter next(fTrackletsPostInput[layer]);
 297
 298   while (AliTRDtrackletGTU *trk = (AliTRDtrackletGTU*) next()) {
 299     for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
 300       if (fGtuParam->IsInZChannel(fStack, layer, zch, trk->GetZbin()) ) {
 301         trk->SetSubChannel(zch, fGtuParam->GetZSubchannel(fStack, layer, zch, trk->GetZbin()) );
 302
 303         TIter nexttrkl(&fZChannelTracklets[layer][zch], kIterBackward);
 304         AliTRDtrackletGTU *t = 0x0;
 305         while ((t = (AliTRDtrackletGTU*) nexttrkl.Next())) {
 306           if (t->GetSubChannel(zch) < trk->GetSubChannel(zch) ||
 307               ((t->GetSubChannel(zch) == trk->GetSubChannel(zch)) && (t->GetYProj() < trk->GetYProj())) ) {
 308             break;
 309           }
 310         }
 311         if (t)
 312           fZChannelTracklets[layer][zch].AddAfter(t, trk);
 313         else
 314           fZChannelTracklets[layer][zch].AddFirst(trk);
 315       }
 316     }
 317     AliDebug(10, Form("stack %d, layer %2d: 0x%08x Z(2..0)=%i/%i/%i",
 318                       fStack, layer, trk->GetTrackletWord(),
 319                       fGtuParam->IsInZChannel(fStack, layer, 2, trk->GetZbin()) ? trk->GetSubChannel(2) : -1,
 320                       fGtuParam->IsInZChannel(fStack, layer, 1, trk->GetZbin()) ? trk->GetSubChannel(1) : -1,
 321                       fGtuParam->IsInZChannel(fStack, layer, 0, trk->GetZbin()) ? trk->GetSubChannel(0) : -1
 322                       ));
 323   }
 324   return kTRUE;
 325 }
 326
 327 Bool_t AliTRDgtuTMU::RunTrackFinder(Int_t zch, TList* /* ListOfTracks */)
 328 {
 329   // run the track finding
 330
 331    Int_t        *notr = new Int_t[fGtuParam->GetNLayers()];
 332    Int_t        *ptrA = new Int_t[fGtuParam->GetNLayers()];
 333    Int_t        *ptrB = new Int_t[fGtuParam->GetNLayers()];
 334
 335    Bool_t       *bHitA     = new Bool_t[fGtuParam->GetNLayers()];
 336    Bool_t       *bHitB     = new Bool_t[fGtuParam->GetNLayers()];
 337    Bool_t       *bAligned  = new Bool_t[fGtuParam->GetNLayers()];
 338    Bool_t       *bAlignedA = new Bool_t[fGtuParam->GetNLayers()];
 339    Bool_t       *bAlignedB = new Bool_t[fGtuParam->GetNLayers()];
 340    Bool_t       *bDone     = new Bool_t[fGtuParam->GetNLayers()];
 341    Bool_t        ready;
 342
 343    Int_t        *inc      = new Int_t[fGtuParam->GetNLayers()];
 344    Int_t        *incprime = new Int_t[fGtuParam->GetNLayers()];
 345
 346 // ----- signals within current layer -----
 347    Int_t        yPlus;
 348    Int_t        yMinus;
 349    Int_t        ybPlus;
 350    Int_t        ybMinus;
 351    Int_t        alphaPlus;
 352    Int_t        alphaMinus;
 353    Int_t        nHits;
 354    Int_t        nUnc;
 355    Int_t        nWayBeyond;
 356
 357    AliTRDtrackletGTU    *trkRA  = 0x0;  // reference tracklet A
 358    AliTRDtrackletGTU    *trkRB  = 0x0;  // reference tracklet B
 359    AliTRDtrackletGTU    *trkA   = 0x0;  // tracklet A in current layer
 360    AliTRDtrackletGTU    *trkB   = 0x0;  // tracklet B in current layer
 361 /*
 362    AliTRDtrackletGTU    *trkEnd = new AliTRDtrackletGTU();
 363    for (Int_t i = 0; i < fGtuParam->GetNZChannels(); i++)
 364        trkEnd->SetSubChannel(i, 7);
 365    trkEnd->SetYProj(0);
 366    trkEnd->SetAlpha(0);
 367 */
 368
 369    for (Int_t refLayerIdx = 0; refLayerIdx < fGtuParam->GetNRefLayers(); refLayerIdx++) {
 370      Int_t reflayer = fGtuParam->GetRefLayer(refLayerIdx);
 371      AliDebug(5,Form("Tracking for z-channel: %i, reflayer: %i", zch, reflayer));
 372
 373      ready = kFALSE; // ready if all channels done
 374
 375 //      for (Int_t iLayer = 0; iLayer < fGtuParam->GetNLayers(); iLayer++) {
 376 //        for (Int_t iTrkl = 0; iTrkl < fZChannelTracklets[iLayer][zch].GetEntries(); iTrkl++) {
 377 //       printf("%4i/%4i(%i,%i) ",
 378 //              ((AliTRDtrackletGTU*) fZChannelTracklets[iLayer][zch].At(iTrkl))->GetYProj(),
 379 //              ((AliTRDtrackletGTU*) fZChannelTracklets[iLayer][zch].At(iTrkl))->GetAlpha(),
 380 //              ((AliTRDtrackletGTU*) fZChannelTracklets[iLayer][zch].At(iTrkl))->GetIndex(),
 381 //              ((AliTRDtrackletGTU*) fZChannelTracklets[iLayer][zch].At(iTrkl))->GetSubChannel(zch)
 382 //              );
 383 //        }
 384 //        printf("\n");
 385 //      }
 386
 387      for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
 388        notr[layer] = fZChannelTracklets[layer][zch].GetEntries();
 389        ptrA[layer] = 0; // notr[layer] > 0 ? 0 : -1;
 390        ptrB[layer] = 1; // notr[layer] > 1 ? 1 : -1;
 391
 392 // not necessary here
 393 //       bDone[layer] = (ptrB[layer] >= notr[layer] - 1); // trkB is last one
 394 //       bDone[layer] = (notr[layer] <= 0);
 395 //       ready = ready && bDone[layer];
 396
 397        if (reflayer == 1)
 398          AliDebug(5,Form("in layer: %i (zchannel = %i) there are: %i tracklets", layer, zch, notr[layer]));
 399      }
 400
 401      if (ptrA[reflayer] < 0 && ptrB[reflayer] < 0)
 402        continue;
 403
 404      while (!ready) {
 405        // ----- reference tracklets -----
 406        trkRA = 0x0;
 407        trkRB = 0x0;
 408        if (0 <= ptrA[reflayer] && ptrA[reflayer] < notr[reflayer])
 409          trkRA = (AliTRDtrackletGTU*) fZChannelTracklets[reflayer][zch].At(ptrA[reflayer]);
 410        else  {
 411          AliDebug(10,Form("No valid tracklet in the reference at ptr: %i! Nothing done!", ptrA[reflayer]));
 412          break;
 413        }
 414
 415        if (0 <= ptrB[reflayer] && ptrB[reflayer] < notr[reflayer])
 416          trkRB = (AliTRDtrackletGTU*) fZChannelTracklets[reflayer][zch].At(ptrB[reflayer]);
 417
 418        yPlus      = trkRA->GetYProj() + fGtuParam->GetDeltaY();
 419        yMinus     = trkRA->GetYProj() - fGtuParam->GetDeltaY();
 420        alphaPlus  = trkRA->GetAlpha() + fGtuParam->GetDeltaAlpha();
 421        alphaMinus = trkRA->GetAlpha() - fGtuParam->GetDeltaAlpha();
 422        if (trkRB) {
 423          ybPlus           = trkRB->GetYProj() + fGtuParam->GetDeltaY();
 424          ybMinus          = trkRB->GetYProj() - fGtuParam->GetDeltaY();
 425        }
 426        else { // irrelevant (should be, is it?)
 427          ybPlus           = trkRA->GetYProj() + fGtuParam->GetDeltaY();
 428          ybMinus          = trkRA->GetYProj() - fGtuParam->GetDeltaY();
 429        }
 430
 431        nHits      = 0;
 432        nUnc       = 0;
 433        nWayBeyond = 0;
 434
 435        for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
 436          bHitA[layer] = bHitB[layer] = bAligned[layer] = kFALSE;
 437          inc[layer] = incprime[layer] = 0;
 438
 439          if (layer == reflayer) {
 440            bHitA[layer] = kTRUE;
 441            bAligned[layer] = kTRUE;
 442            nHits++;
 443            continue;
 444          }
 445
 446          trkA = 0x0;
 447          trkB = 0x0;
 448          if (0 <= ptrA[layer] && ptrA[layer] < notr[layer])
 449            trkA = (AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrA[layer]);
 450          if (0 <= ptrB[layer] && ptrB[layer] < notr[layer])
 451            trkB = (AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrB[layer]);
 452
 453          bAlignedA[layer] = kFALSE;
 454          bAlignedB[layer] = kFALSE;
 455
 456          if (trkA) {
 457            bHitA[layer] = ( !(trkA->GetSubChannel(zch) < trkRA->GetSubChannel(zch) || (trkA->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkA->GetYProj() < yMinus) ) &&
 458                             !(trkA->GetSubChannel(zch) > trkRA->GetSubChannel(zch) || (trkA->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkA->GetYProj() > yPlus)  ) &&
 459                             !(trkA->GetAlpha() < alphaMinus) &&
 460                             !(trkA->GetAlpha() > alphaPlus) );
 461            bAlignedA[layer] = !(trkA->GetSubChannel(zch) < trkRA->GetSubChannel(zch) || (trkA->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkA->GetYProj() < yMinus) );
 462          }
 463          else {
 464            bHitA[layer] = 0;
 465            bAlignedA[layer] = kTRUE;
 466          }
 467
 468          if (trkB) {
 469            bHitB[layer] = ( !(trkB->GetSubChannel(zch) < trkRA->GetSubChannel(zch) || (trkB->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkB->GetYProj() < yMinus) ) &&
 470                             !(trkB->GetSubChannel(zch) > trkRA->GetSubChannel(zch) || (trkB->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkB->GetYProj() > yPlus) ) &&
 471                             !(trkB->GetAlpha() < alphaMinus) &&
 472                             !(trkB->GetAlpha() > alphaPlus) );
 473            bAlignedB[layer] = (trkB->GetSubChannel(zch) > trkRA->GetSubChannel(zch) || (trkB->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkB->GetYProj() > yPlus) );
 474          }
 475          else {
 476            bHitB[layer] = 0;
 477            bAlignedB[layer] = kTRUE;
 478          }
 479
 480          bAligned[layer] = bAlignedA[layer] || bAlignedB[layer]; //???
 481 //       bAligned[layer] = bAlignedA[layer]; //???
 482
 483          if (bAligned[layer] && (bHitA[layer] || bHitB[layer]) )
 484            nHits++;
 485          else if (!bAligned[layer] )
 486            nUnc++;
 487          if (trkRB) {
 488            if (trkA) {
 489              if ((trkA->GetSubChannel(zch) > trkRB->GetSubChannel(zch)) || (trkA->GetSubChannel(zch) == trkRB->GetSubChannel(zch) && trkA->GetYProj() > ybPlus) )
 490                nWayBeyond++;
 491            }
 492            else
 493              nWayBeyond++;
 494          }
 495
 496          //  pre-calculation for the layer shifting (alignment w. r. t. trkRB)
 497          if (trkA) {
 498              if(trkRB) {
 499                  if ((trkA->GetSubChannel(zch) < trkRB->GetSubChannel(zch)) || (trkA->GetSubChannel(zch) == trkRB->GetSubChannel(zch) && trkA->GetYProj() < ybMinus )) // could trkA be aligned for trkRB
 500                      incprime[layer] = 1;
 501                  else
 502                      incprime[layer] = 0;
 503              }
 504              else
 505                  incprime[layer] = 1;
 506
 507              if (trkB) {
 508                  if (trkRB) {
 509                      if ((trkB->GetSubChannel(zch) < trkRB->GetSubChannel(zch)) || (trkB->GetSubChannel(zch) == trkRB->GetSubChannel(zch) && trkB->GetYProj() < ybMinus )) // could trkB be aligned for trkRB
 510                          incprime[layer] = 2;
 511                  }
 512                  else
 513                      incprime[layer] = 2;
 514              }
 515          }
 516        } // end of loop over layers
 517
 518        AliDebug(5,Form("logic calculation finished, Nhits: %i %s",
 519                        nHits, (nHits >= 4) ? "-> track found" : ""));
 520
 521        if (nHits >= 4) {
 522          // ----- track registration -----
 523          AliTRDtrackGTU *track = new AliTRDtrackGTU();
 524          track->SetSector(fSector);
 525          track->SetStack(fStack);
 526          for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++ ) {
 527            if (bHitA[layer] || layer == reflayer)
 528              track->AddTracklet((AliTRDtrackletGTU* ) fZChannelTracklets[layer][zch].At(ptrA[layer]), layer );
 529            else if (bHitB[layer])
 530              track->AddTracklet((AliTRDtrackletGTU* ) fZChannelTracklets[layer][zch].At(ptrB[layer]), layer );
 531          }
 532
 533          Bool_t registerTrack = kTRUE;
 534          for (Int_t layerIdx = refLayerIdx-1; layerIdx >= 0; layerIdx--) {
 535            if (track->IsTrackletInLayer(fGtuParam->GetRefLayer(layerIdx))) {
 536              if ((track->GetTracklet(fGtuParam->GetRefLayer(layerIdx)))->GetSubChannel(zch) > 0) {
 537                AliDebug(1,"Not registered");
 538                  registerTrack = kFALSE;
 539              }
 540            }
 541          }
 542          if (registerTrack) {
 543              track->SetZChannel(zch);
 544              track->SetRefLayerIdx(refLayerIdx);
 545              fTracks[zch][refLayerIdx].Add(track);
 546          }
 547        }
 548
 549        if ( (nUnc != 0) && (nUnc + nHits >= 4) ) // could this position of the reference layer give some track //??? special check in case of hit?
 550           inc[reflayer] = 0;
 551        else if (nWayBeyond > 2) // no track possible for both reference tracklets
 552          inc[reflayer] = 2;
 553        else
 554          inc[reflayer] = 1;
 555
 556        if (inc[reflayer] != 0) // reflayer is shifted
 557          for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
 558            if (layer == reflayer)
 559              continue;
 560            inc[layer] = incprime[layer];
 561          }
 562        else { // reflayer is not shifted
 563          for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
 564            if (layer == reflayer || notr[layer] == 0)
 565              continue;
 566            inc[layer] = 0;
 567            trkA = 0x0;
 568            trkB = 0x0;
 569            if (0 <= ptrA[layer] && ptrA[layer] < notr[layer])
 570              trkA = (AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrA[layer]);
 571
 572            if (0 <= ptrB[layer] && ptrB[layer] < notr[layer])
 573              trkB = (AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrB[layer]);
 574
 575            if (trkA) {
 576              if ( !(trkA->GetSubChannel(zch) < trkRA->GetSubChannel(zch) || (trkA->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkA->GetYProj() < yMinus) ) &&
 577                   !(trkA->GetSubChannel(zch) > trkRA->GetSubChannel(zch) || (trkA->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkA->GetYProj() > yPlus ) ) )  // trkA could hit trkRA
 578              // if ( !(trkA->GetSubChannel(zch) < trkRA->GetSubChannel(zch) || (trkA->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkA->GetYProj() < yMinus) ) )
 579                    inc[layer] = 0;
 580                else if (trkB) {
 581                    if ( trkB->GetSubChannel(zch) < trkRA->GetSubChannel(zch) || (trkB->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkB->GetYProj() < yMinus) )
 582                        inc[layer] = 2;
 583                    else if ( !(trkB->GetSubChannel(zch) > trkRA->GetSubChannel(zch) || (trkB->GetSubChannel(zch) == trkRA->GetSubChannel(zch) && trkB->GetYProj() > yPlus) ) )
 584                        inc[layer] = 1;
 585                    else
 586                        inc[layer] = incprime[layer];
 587                }
 588                else
 589                    inc[layer] = incprime[layer];
 590            }
 591          }
 592        }
 593
 594        ready = kTRUE;
 595        for (Int_t layer = fGtuParam->GetNLayers()-1; layer >= 0; layer--) {
 596
 597          bDone[layer] = ptrB[layer] < 0 || ptrB[layer] >= notr[layer];
 598          ready = ready && bDone[layer];
 599
 600          if (inc[layer] != 0 && ptrA[layer] >= notr[layer])
 601            AliError(Form("Invalid increment: %i at ptrA: %i, notr: %i", inc[layer], ptrA[layer], notr[layer]));
 602
 603 //       AliInfo(Form("Shifting layer: %i, notr: %i, ptrA: %i, ptrB: %i, inc: %i", layer, notr[layer], ptrA[layer], ptrB[layer], inc[layer]));
 604          AliDebug(10,Form("    Layer: %i   %2i(%2i, %2i, %4i, %3i)%s%s   %2i(%2i, %2i, %4i, %3i)%s%s   +%i   %s  (no: %i)",
 605                           layer,
 606                           ptrA[layer],
 607                           (0 <= ptrA[layer] && ptrA[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrA[layer]))->GetIndex() : -1,
 608                           (0 <= ptrA[layer] && ptrA[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrA[layer]))->GetSubChannel(zch) : -1,
 609                           (0 <= ptrA[layer] && ptrA[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrA[layer]))->GetYProj() : -1,
 610                           (0 <= ptrA[layer] && ptrA[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrA[layer]))->GetAlpha() : -1,
 611                           bHitA[layer] ? "*" : " ", bAlignedA[layer] ? "+" : " ",
 612                           ptrB[layer],
 613                           (0 <= ptrB[layer] && ptrB[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrB[layer]))->GetIndex() : -1,
 614                           (0 <= ptrB[layer] && ptrB[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrB[layer]))->GetSubChannel(zch) : -1,
 615                           (0 <= ptrB[layer] && ptrB[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrB[layer]))->GetYProj() : -1,
 616                           (0 <= ptrB[layer] && ptrB[layer] < notr[layer]) ? ((AliTRDtrackletGTU*) fZChannelTracklets[layer][zch].At(ptrB[layer]))->GetAlpha() : -1,
 617                           bHitB[layer] ? "*" : " ", bAlignedB[layer] ? "+" : " ",
 618                           inc[layer], bDone[layer] ? "done" : "    ", notr[layer]));
 619          ptrA[layer] += inc[layer];
 620          ptrB[layer] += inc[layer];
 621        }
 622
 623      } // end of while
 624    } // end of loop over reflayer
 625
 626    delete [] bHitA;
 627    delete [] bHitB;
 628    delete [] bAligned;
 629    delete [] bDone;
 630    delete [] inc;
 631    delete [] incprime;
 632    delete [] bAlignedA;
 633    delete [] bAlignedB;
 634    delete [] notr;
 635    delete [] ptrA;
 636    delete [] ptrB;
 637
 638    return kTRUE;
 639 }
 640
 641 Bool_t AliTRDgtuTMU::RunTrackMerging(TList* ListOfTracks)
 642 {
 643     TList **tracksRefMerged = new TList*[fGtuParam->GetNZChannels()];
 644     TList **tracksRefUnique = new TList*[fGtuParam->GetNZChannels()];
 645
 646     for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
 647         tracksRefMerged[zch] = new TList;
 648         tracksRefUnique[zch] = new TList;
 649     }
 650
 651     TList *tracksZMergedStage0 = new TList;
 652     TList *tracksZUniqueStage0 = new TList;
 653
 654     TList **tracksZSplitted = new TList*[2];
 655     for (Int_t i = 0; i < 2; i++)
 656         tracksZSplitted[i] = new TList;
 657
 658     TList *tracksZMergedStage1 = new TList;
 659
 660     AliTRDtrackGTU **trkInRefLayer = new AliTRDtrackGTU*[fGtuParam->GetNRefLayers()];
 661
 662     // Bool_t done = kFALSE;
 663     Int_t minIdx = 0;
 664     AliTRDtrackGTU *trkStage0 = 0x0;
 665
 666     for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
 667         // ----- Merging and Unification in Reflayers (seed_merger) -----
 668         do {
 669           // done = kTRUE;
 670             trkStage0 = 0x0;
 671             for (Int_t refLayerIdx = 0; refLayerIdx < fGtuParam->GetNRefLayers(); refLayerIdx++) {
 672                 trkInRefLayer[refLayerIdx] = (AliTRDtrackGTU*) fTracks[zch][refLayerIdx].First();
 673                 if (trkInRefLayer[refLayerIdx] == 0) {
 674                     continue;
 675                 }
 676                 else if (trkStage0 == 0x0 ) {
 677                     trkStage0 = trkInRefLayer[refLayerIdx];
 678                     minIdx = refLayerIdx;
 679                     // done = kFALSE;
 680                 }
 681                 else if ( (trkInRefLayer[refLayerIdx]->GetZSubChannel() < trkStage0->GetZSubChannel()) ||
 682                           ((trkInRefLayer[refLayerIdx]->GetZSubChannel() == trkStage0->GetZSubChannel()) &&
 683                            ((trkInRefLayer[refLayerIdx]->GetYapprox() >> 3) < (trkStage0->GetYapprox() >> 3)) ) ) {
 684                     minIdx = refLayerIdx;
 685                     trkStage0 = trkInRefLayer[refLayerIdx];
 686                     // done = kFALSE;
 687                 }
 688             }
 689             if (!trkStage0)
 690               break;
 691             tracksRefMerged[zch]->Add(trkStage0);
 692             fTracks[zch][minIdx].RemoveFirst();
 693         } while (trkStage0 != 0);
 694
 695         Uniquifier(tracksRefMerged[zch], tracksRefUnique[zch]);
 696
 697         AliDebug(2, Form("zchannel %i", zch));
 698         TIter trackRefMerged(tracksRefMerged[zch]);
 699         while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) trackRefMerged())
 700           AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, z_idx=%i",
 701                            AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 702                            trk->GetTrackletIndex(5),
 703                            trk->GetTrackletIndex(4),
 704                            trk->GetTrackletIndex(3),
 705                            trk->GetTrackletIndex(2),
 706                            trk->GetTrackletIndex(1),
 707                            trk->GetTrackletIndex(0),
 708                            trk->GetYapprox() >> 3,
 709                            trk->GetZSubChannel()));
 710         AliDebug(2, "uniquified:");
 711         TIter trackRefUnique(tracksRefUnique[zch]);
 712         while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) trackRefUnique())
 713           AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, z_idx=%i",
 714                            AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 715                            trk->GetTrackletIndex(5),
 716                            trk->GetTrackletIndex(4),
 717                            trk->GetTrackletIndex(3),
 718                            trk->GetTrackletIndex(2),
 719                            trk->GetTrackletIndex(1),
 720                            trk->GetTrackletIndex(0),
 721                            trk->GetYapprox() >> 3,
 722                            trk->GetZSubChannel()));
 723     }
 724
 725 // ----- Merging in zchannels - 1st stage -----
 726
 727     if (AliTRDgtuParam::GetUseGTUmerge()) {
 728       Int_t notEmpty;
 729       do {
 730         Bool_t lowerThan[3] = { kFALSE, kFALSE, kFALSE };
 731         AliTRDtrackGTU *trk[3] = { 0x0, 0x0, 0x0 };
 732         for (Int_t iChannel = 0; iChannel < fGtuParam->GetNZChannels(); ++iChannel)
 733           trk[iChannel] = (AliTRDtrackGTU*) tracksRefUnique[iChannel]->First();
 734
 735         for (Int_t iChannel = 0; iChannel < fGtuParam->GetNZChannels(); ++iChannel) {
 736           AliTRDtrackGTU *trk1 = trk[iChannel];
 737           AliTRDtrackGTU *trk2 = trk[(iChannel + 1) % 3];
 738           if (trk1 && trk2) {
 739             Int_t sortnum1 = (trk1->GetZChannel() + 3 * trk1->GetZSubChannel()) / 2 - 1;
 740             Int_t sortnum2 = (trk2->GetZChannel() + 3 * trk2->GetZSubChannel()) / 2 - 1;
 741             AliDebug(5, Form("comparing tracks %i - %i: %i - %i",
 742                              trk1->GetZChannel(), trk2->GetZChannel(),
 743                              sortnum1, sortnum2));
 744             if ( (sortnum1 < sortnum2) ||
 745                  ((sortnum1 == sortnum2) &&
 746                   ((trk1->GetYapprox() >> 3) < (trk2->GetYapprox() >> 3)) ) ) {
 747               lowerThan[iChannel] = kTRUE;
 748             }
 749           }
 750         }
 751
 752         notEmpty = (trk[2] ? (1 << 2) : 0) |
 753           (trk[1] ? (1 << 1) : 0) |
 754           (trk[0] ? (1 << 0) : 0);
 755         Int_t pop = -1;
 756
 757         switch (notEmpty) {
 758           // one track only
 759         case 0x1:
 760           pop = 0;
 761           break;
 762         case 0x2:
 763           pop = 1;
 764           break;
 765         case 0x4:
 766           pop = 2;
 767           break;
 768
 769           // two tracks
 770         case 0x3:
 771           if (lowerThan[0])
 772             pop = 0;
 773           else
 774             pop = 1;
 775           break;
 776         case 0x5:
 777           if (lowerThan[2])
 778             pop = 2;
 779           else
 780             pop = 0;
 781           break;
 782         case 0x6:
 783           if (lowerThan[1])
 784             pop = 1;
 785           else
 786             pop = 2;
 787           break;
 788
 789           // three tracks
 790         case 0x7:
 791           if (lowerThan[0]) {
 792             if (lowerThan[2])
 793               pop = 2;
 794             else
 795               pop = 0;
 796           } else {
 797             if (lowerThan[1])
 798               pop = 1;
 799             else
 800               pop = 2;
 801           }
 802           break;
 803
 804           // no tracks
 805         default:
 806           // nop
 807           ;
 808         }
 809
 810         if (pop > -1) {
 811           tracksZMergedStage0->Add(trk[pop]);
 812           tracksRefUnique[pop]->RemoveFirst();
 813         }
 814       } while (notEmpty);
 815     }
 816     else {
 817       // there is still a difference between this implementation and
 818       // the hardware algorithm, only for expert use
 819
 820       do {
 821         // done = kTRUE;
 822         trkStage0 = 0x0;
 823         // compare tracks from all adjacent zchannels
 824         // (including comparison of channels 2 and 0)
 825         for (Int_t i = fGtuParam->GetNZChannels() - 1; i > -1; i--) {
 826           Int_t zch = i % 3;
 827           AliTRDtrackGTU *trk = (AliTRDtrackGTU*) tracksRefUnique[zch]->First();
 828           if (trk == 0) {
 829             continue;
 830           }
 831           else if (trkStage0 == 0x0 ) {
 832             trkStage0 = trk;
 833             minIdx = zch;
 834             // done = kFALSE;
 835           }
 836           else {
 837             Int_t sortnum1 = (trk->GetZChannel() + 3 * trk->GetZSubChannel()) / 2 - 1;
 838             Int_t sortnum2 = (trkStage0->GetZChannel() + 3 * trkStage0->GetZSubChannel()) / 2 - 1;
 839             AliDebug(5, Form("comparing tracks %i - %i: %i - %i",
 840                              trk->GetZChannel(), trkStage0->GetZChannel(),
 841                              sortnum1, sortnum2));
 842             if ( (sortnum1 < sortnum2) ||
 843                  ((sortnum1 == sortnum2) &&
 844                   ((trk->GetYapprox() >> 3) < (trkStage0->GetYapprox() >> 3)) ) ) {
 845               minIdx = zch;
 846               trkStage0 = trk;
 847               // done = kFALSE;
 848             }
 849           }
 850         }
 851
 852         if (!trkStage0)
 853           break;
 854         tracksZMergedStage0->Add(trkStage0);
 855         tracksRefUnique[minIdx]->RemoveFirst();
 856       } while (trkStage0 != 0);
 857     }
 858
 859     Uniquifier(tracksZMergedStage0, tracksZUniqueStage0);
 860
 861     AliDebug(2, "stage 0:");
 862     TIter trackZMergedStage0(tracksZMergedStage0);
 863     while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) trackZMergedStage0())
 864       AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, zch=%i idx=%i",
 865                        AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 866                        trk->GetTrackletIndex(5),
 867                        trk->GetTrackletIndex(4),
 868                        trk->GetTrackletIndex(3),
 869                        trk->GetTrackletIndex(2),
 870                        trk->GetTrackletIndex(1),
 871                        trk->GetTrackletIndex(0),
 872                        trk->GetYapprox() >> 3,
 873                        trk->GetZChannel(),
 874                        trk->GetZSubChannel()));
 875
 876     AliDebug(2, "uniquified:");
 877     TIter trackZUniqueStage0(tracksZUniqueStage0);
 878     while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) trackZUniqueStage0())
 879       AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, zch=%i idx=%i",
 880                        AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 881                        trk->GetTrackletIndex(5),
 882                        trk->GetTrackletIndex(4),
 883                        trk->GetTrackletIndex(3),
 884                        trk->GetTrackletIndex(2),
 885                        trk->GetTrackletIndex(1),
 886                        trk->GetTrackletIndex(0),
 887                        trk->GetYapprox() >> 3,
 888                        trk->GetZChannel(),
 889                        trk->GetZSubChannel()));
 890
 891 // ----- Splitting in z -----
 892
 893     TIter next(tracksZUniqueStage0);
 894     while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) next()) {
 895         tracksZSplitted[(trk->GetZChannel() + 3 * (trk->GetZSubChannel() - 1)) % 2]->Add(trk);
 896     }
 897
 898     for (Int_t i = 0; i < 2; i++) {
 899       AliDebug(2, Form("split %i:", i));
 900       TIter trackZSplit(tracksZSplitted[i]);
 901       while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) trackZSplit())
 902         AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, zch=%i idx=%i",
 903                          AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 904                          trk->GetTrackletIndex(5),
 905                          trk->GetTrackletIndex(4),
 906                          trk->GetTrackletIndex(3),
 907                          trk->GetTrackletIndex(2),
 908                          trk->GetTrackletIndex(1),
 909                          trk->GetTrackletIndex(0),
 910                          trk->GetYapprox() >> 3,
 911                          trk->GetZChannel(),
 912                          trk->GetZSubChannel()));
 913     }
 914
 915 // ----- Merging in zchanels - 2nd stage -----
 916
 917     do {
 918       // done = kTRUE;
 919         trkStage0 = 0x0;
 920         for (Int_t i = 1; i >= 0; i--) {
 921             AliTRDtrackGTU *trk = (AliTRDtrackGTU*) tracksZSplitted[i]->First();
 922             if (trk == 0) {
 923                 continue;
 924             }
 925             else if (trkStage0 == 0x0 ) {
 926                 trkStage0 = trk;
 927                 minIdx = i;
 928                 // done = kFALSE;
 929             }
 930             else if (  (((trk->GetZChannel() + 3 * (trk->GetZSubChannel() - 1)) / 2) <  ((trkStage0->GetZChannel() + 3 * (trkStage0->GetZSubChannel() - 1)) / 2)) ||
 931                       ((((trk->GetZChannel() + 3 * (trk->GetZSubChannel() - 1)) / 2) == ((trkStage0->GetZChannel() + 3 * (trkStage0->GetZSubChannel() - 1)) / 2)) &&
 932                        ((trk->GetYapprox() >> 3) < (trkStage0->GetYapprox() >> 3)) ) ) {
 933                 minIdx = i;
 934                 trkStage0 = trk;
 935                 // done = kFALSE;
 936             }
 937         }
 938
 939         if (!trkStage0)
 940           break;
 941         tracksZMergedStage1->Add(trkStage0);
 942         tracksZSplitted[minIdx]->RemoveFirst();
 943     } while (trkStage0 != 0);
 944
 945     Uniquifier(tracksZMergedStage1, ListOfTracks);
 946
 947     AliDebug(2, "merged:");
 948     TIter trackZMergedStage1(tracksZMergedStage1);
 949     while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) trackZMergedStage1())
 950       AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, zch=%i idx=%i",
 951                        AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 952                        trk->GetTrackletIndex(5),
 953                        trk->GetTrackletIndex(4),
 954                        trk->GetTrackletIndex(3),
 955                        trk->GetTrackletIndex(2),
 956                        trk->GetTrackletIndex(1),
 957                        trk->GetTrackletIndex(0),
 958                        trk->GetYapprox() >> 3,
 959                        trk->GetZChannel(),
 960                        trk->GetZSubChannel()));
 961
 962     AliDebug(2, "uniquified:");
 963     TIter track(ListOfTracks);
 964     while (AliTRDtrackGTU *trk = (AliTRDtrackGTU*) track())
 965       AliDebug(2, Form("track ref layer %i : %i %i %i %i %i %i, y=%i, zch=%i idx=%i",
 966                        AliTRDgtuParam::GetRefLayer(trk->GetRefLayerIdx()),
 967                        trk->GetTrackletIndex(5),
 968                        trk->GetTrackletIndex(4),
 969                        trk->GetTrackletIndex(3),
 970                        trk->GetTrackletIndex(2),
 971                        trk->GetTrackletIndex(1),
 972                        trk->GetTrackletIndex(0),
 973                        trk->GetYapprox() >> 3,
 974                        trk->GetZChannel(),
 975                        trk->GetZSubChannel()));
 976
 977     // cleaning up
 978     for (Int_t zch = 0; zch < fGtuParam->GetNZChannels(); zch++) {
 979       delete tracksRefMerged[zch];
 980       delete tracksRefUnique[zch];
 981     }
 982     delete [] tracksRefMerged;
 983     delete [] tracksRefUnique;
 984
 985
 986     delete tracksZMergedStage0;
 987     delete tracksZUniqueStage0;
 988
 989     for (Int_t i = 0; i < 2; i++)
 990       delete tracksZSplitted[i];
 991     delete [] tracksZSplitted;
 992
 993     delete tracksZMergedStage1;
 994
 995     delete [] trkInRefLayer;
 996
 997     return kTRUE;
 998 }
 999
1000 Bool_t AliTRDgtuTMU::RunTrackReconstruction(TList* ListOfTracks)
1001 {
1002   // run the track reconstruction for all tracks in the list
1003
1004   TIter next(ListOfTracks);
1005   while (AliTRDtrackGTU *track = (AliTRDtrackGTU*) next()) {
1006     CalculateTrackParams(track);
1007     CalculatePID(track);
1008     AliDebug(1, Form("track with pid = %i", track->GetPID()));
1009   }
1010   return kTRUE;
1011 }
1012
1013 Bool_t AliTRDgtuTMU::CalculatePID(AliTRDtrackGTU *track)
1014 {
1015   // calculate PID for the given track
1016   if (!track) {
1017     AliError("No track to calculate!");
1018     return kFALSE;
1019   }
1020
1021   if (AliTRDgtuParam::GetUseGTUconst()) {
1022     // averaging as in GTU
1023     AliDebug(1, "using GTU constants for PID calculation");
1024     ULong64_t coeff;
1025
1026     // selection of coefficient for averaging
1027     switch(track->GetTrackletMask()){
1028     case 0x3f:
1029       // 6 tracklets
1030       coeff=0x5558; // approx. 1/6
1031       break;
1032
1033     case 0x3e:
1034     case 0x3d:
1035     case 0x3b:
1036     case 0x37:
1037     case 0x2f:
1038     case 0x1f:
1039       // 5 tracklets
1040       coeff=0x6666; // approx. 1/5
1041       break;
1042
1043     default:
1044       // 4 tracklets
1045       coeff=0x8000; // = 0.25
1046     }
1047     coeff &= 0x1ffff; // 17-bit constant
1048
1049     ULong64_t sum = 0;
1050     Int_t i = 0;
1051     for (Int_t iLayer = 0; iLayer < fGtuParam->GetNLayers(); iLayer++) {
1052       if ((track->GetTrackletMask() >> iLayer) & 1) {
1053         sum += track->GetTracklet(iLayer)->GetPID();
1054         ++i;
1055       }
1056     }
1057
1058     Float_t av = 1./i * sum;
1059     sum = sum & 0x7ff;
1060     ULong64_t prod   = (sum * coeff) & 0xfffffffffull;
1061     ULong64_t prodFinal = ((prod >> 17) + ((prod >> 16) & 1)) & 0xff;
1062
1063     if (TMath::Abs((prodFinal & 0xff) - av) > 0.5)
1064       AliError(Form("problem with PID averaging (hw <-> ar): %3lli <-> %4.1f", prodFinal & 0xff, av));
1065     track->SetPID(prodFinal & 0xff);
1066
1067     return kTRUE;
1068   }
1069   else {
1070
1071     // simple averaging
1072     Int_t nTracklets = 0;
1073     Int_t pidSum = 0;
1074     for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
1075       if (!track->IsTrackletInLayer(layer)) {
1076         continue;
1077       }
1078       AliTRDtrackletGTU *trk = track->GetTracklet(layer);
1079       pidSum += trk->GetPID();
1080       nTracklets++;
1081     }
1082
1083     if (nTracklets>0)
1084       track->SetPID(pidSum/nTracklets);
1085     else
1086       AliError("Track without contributing tracklets, no PID assigned");
1087
1088     return kTRUE;
1089   }
1090 }
1091
1092 Bool_t AliTRDgtuTMU::CalculateTrackParams(AliTRDtrackGTU *track)
1093 {
1094   // calculate the track parameters
1095
1096   if (!track) {
1097     AliError("No track to calculate!");
1098     return kFALSE;
1099   }
1100
1101   Int_t a = 0;
1102   Float_t b = 0;
1103   Float_t c = 0;
1104   Float_t x1;
1105   Float_t x2;
1106
1107   AliDebug(5,Form("There are %i tracklets in this track.", track->GetNTracklets()));
1108
1109   for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
1110     if (!track->IsTrackletInLayer(layer)) {
1111       continue;
1112     }
1113     AliTRDtrackletGTU *trk = track->GetTracklet(layer);
1114     if (!trk) {
1115       AliError(Form("Could not get tracklet in layer %i\n", layer));
1116       continue;
1117     }
1118     AliDebug(10,Form("  layer %i trk yprime: %6i, aki: %6i", layer, trk->GetYPrime(),
1119                      fGtuParam->GetAki(track->GetTrackletMask(), layer)));
1120     a += (((fGtuParam->GetAki(track->GetTrackletMask(), layer) * trk->GetYPrime()) >> 7) + 1) >> 1;
1121     b += fGtuParam->GetBki(track->GetTrackletMask(), layer) * trk->GetYPrime() * fGtuParam->GetBinWidthY();
1122     c += fGtuParam->GetCki(track->GetTrackletMask(), layer) * trk->GetYPrime() * fGtuParam->GetBinWidthY();
1123   }
1124   if (a < 0)
1125       a += 3;
1126   a = a >> 2;
1127
1128   track->SetFitParams(a << 2, b, c);
1129
1130   fGtuParam->GetIntersectionPoints(track->GetTrackletMask(), x1, x2);
1131
1132   AliDebug(5,Form("  Track parameters: a16 = %i, a18 = %i, b = %f, c = %f, x1 = %f, x2 = %f, pt = %f (trkl mask: %i)",
1133                   a, a << 2, b, c, x1, x2, track->GetPt(), track->GetTrackletMask()));
1134
1135   return kTRUE;
1136 }
1137
1138
1139 Bool_t AliTRDgtuTMU::Uniquifier(const TList *inlist, TList *outlist)
1140 {
1141   // remove multiple occurences of the same track
1142
1143     TIter next(inlist);
1144     AliTRDtrackGTU *trkStage0 = 0x0;
1145     AliTRDtrackGTU *trkStage1 = 0x0;
1146
1147     do {
1148         trkStage0 = (AliTRDtrackGTU*) next();
1149
1150         Bool_t tracksEqual = kFALSE;
1151         if (trkStage0 != 0 && trkStage1 != 0) {
1152             for (Int_t layer = 0; layer < fGtuParam->GetNLayers(); layer++) {
1153                 if (trkStage0->GetTrackletIndex(layer) != -1 && trkStage0->GetTrackletIndex(layer) == trkStage1->GetTrackletIndex(layer)) {
1154                     tracksEqual = kTRUE;
1155                     break;
1156                 }
1157             }
1158         }
1159
1160         if (tracksEqual) {
1161             if (trkStage0->GetNTracklets() >= trkStage1->GetNTracklets())
1162                 trkStage1 = trkStage0;
1163         }
1164         else {
1165             if (trkStage1 != 0x0)
1166                 outlist->Add(trkStage1);
1167             trkStage1 = trkStage0;
1168         }
1169
1170     } while (trkStage1 != 0x0);
1171     return kTRUE;
1172 }