TRD/AliTRDtrackV1.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
   5  * Contributors are mentioned in the code where appropriate.              *
   6  *                                                                        *
   7  * Permission to use, copy, modify and distribute this software and its   *
   8  * documentation strictly for non-commercial purposes is hereby granted   *
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  10  * copies and that both the copyright notice and this permission notice   *
  11  * appear in the supporting documentation. The authors make no claims     *
  12  * about the suitability of this software for any purpose. It is          *
  13  * provided "as is" without express or implied warranty.                  *
  14  **************************************************************************/
  15
  16 /* $Id$ */
  17
  18 #include "AliESDtrack.h"
  19
  20 #include "AliTRDtrackV1.h"
  21 #include "AliTRDcluster.h"
  22 #include "AliTRDcalibDB.h"
  23 #include "AliTRDrecoParam.h"
  24
  25 ClassImp(AliTRDtrackV1)
  26
  27 ///////////////////////////////////////////////////////////////////////////////
  28 //                                                                           //
  29 //  Represents a reconstructed TRD track                                     //
  30 //  Local TRD Kalman track                                                   //
  31 //                                                                           //
  32 //  Authors:                                                                 //
  33 //    Alex Bercuci <A.Bercuci@gsi.de>                                        //
  34 //    Markus Fasel <M.Fasel@gsi.de>                                          //
  35 //                                                                           //
  36 ///////////////////////////////////////////////////////////////////////////////
  37
  38 //_______________________________________________________________
  39 AliTRDtrackV1::AliTRDtrackV1()
  40   :AliTRDtrack()
  41 {
  42   //
  43   // Default constructor
  44   //
  45
  46         for(int ip=0; ip<6; ip++){
  47                 fTrackletIndex[ip] = -1;
  48                 fTracklet[ip].Reset();
  49         }
  50 }
  51
  52 //_______________________________________________________________
  53 AliTRDtrackV1::AliTRDtrackV1(const AliESDtrack &t)
  54   :AliTRDtrack(t)
  55 {
  56   //
  57   // Constructor from AliESDtrack
  58   //
  59
  60         //AliInfo(Form("alpha %f", GetAlpha()));
  61         t.GetTRDtracklets(&fTrackletIndex[0]);
  62         for(int ip=0; ip<6; ip++) fTracklet[ip].Reset();
  63 }
  64
  65 //_______________________________________________________________
  66 AliTRDtrackV1::AliTRDtrackV1(const AliTRDtrackV1 &ref)
  67   :AliTRDtrack(ref)
  68 {
  69   //
  70   // Copy constructor
  71   //
  72
  73         for(int ip=0; ip<6; ip++){
  74                 fTrackletIndex[ip] = ref.fTrackletIndex[ip];
  75                 fTracklet[ip]      = ref.fTracklet[ip];
  76         }
  77 }
  78
  79 //_______________________________________________________________
  80 // AliTRDtrackV1::~AliTRDtrackV1()
  81 // {
  82 //
  83 // }
  84
  85 //_______________________________________________________________
  86 AliTRDtrackV1::AliTRDtrackV1(AliTRDseedV1 *trklts, const Double_t p[5], const Double_t cov[15]
  87              , Double_t x, Double_t alpha)
  88   :AliTRDtrack()
  89 {
  90   //
  91   // The stand alone tracking constructor
  92   // TEMPORARY !!!!!!!!!!!
  93   // to check :
  94   // 1. covariance matrix
  95   // 2. dQdl calculation
  96   //
  97
  98   Double_t cnv   = 1.0 / (GetBz() * kB2C);
  99
 100   Double_t pp[5] = { p[0]
 101                    , p[1]
 102                    , x*p[4] - p[2]
 103                    , p[3]
 104                    , p[4]*cnv      };
 105
 106   Double_t c22 = x*x*cov[14] - 2*x*cov[12] + cov[ 5];
 107   Double_t c32 =   x*cov[13] -     cov[ 8];
 108   Double_t c20 =   x*cov[10] -     cov[ 3];
 109   Double_t c21 =   x*cov[11] -     cov[ 4];
 110   Double_t c42 =   x*cov[14] -     cov[12];
 111
 112   Double_t cc[15] = { cov[ 0]
 113                     , cov[ 1],     cov[ 2]
 114                     , c20,         c21,         c22
 115                     , cov[ 6],     cov[ 7],     c32,     cov[ 9]
 116                     , cov[10]*cnv, cov[11]*cnv, c42*cnv, cov[13]*cnv, cov[14]*cnv*cnv };
 117
 118         Set(x,alpha,pp,cc);
 119   Double_t s = GetSnp();
 120   Double_t t = GetTgl();
 121
 122         Int_t ncl = 0, nclPlane; AliTRDcluster *c = 0x0;
 123         for(int iplane=0; iplane<6; iplane++){
 124                 fTrackletIndex[iplane] = -1;
 125                 fTracklet[iplane] = trklts[iplane];
 126                 nclPlane = 0;
 127                 for(int ic = 0; ic<AliTRDseed::knTimebins; ic++){
 128                         if(!fTracklet[iplane].IsUsable(ic)) continue;
 129                         if(!(c = fTracklet[iplane].GetClusters(ic))) continue;
 130
 131                         fIndex[ncl]      = fTracklet[iplane].GetIndexes(ic);
 132                         Double_t q = TMath::Abs(c->GetQ());
 133                         fClusters[ncl]   = c;
 134                         // temporary !!!
 135                         // This is not correctly. Has to be updated in the AliTRDtrackerV1::FollowBackProlonagation()
 136                         fdQdl[ncl]       = q * (s*s < 1.) ? TMath::Sqrt((1-s*s)/(1+t*t)) : 1.;
 137                         ncl++;
 138                         nclPlane++;
 139                 }
 140                 //printf("%d N clusters plane %d [%d %d].\n", iplane, nclPlane, fTracklet[iplane].GetN2(), trklts[iplane].GetN());
 141         }
 142         //printf("N clusters in AliTRDtrackV1 %d.\n", ncl);
 143         SetNumberOfClusters(/*ncl*/);
 144 }
 145
 146 //_______________________________________________________________
 147 Bool_t AliTRDtrackV1::CookLabel(Float_t wrong)
 148 {
 149         // set MC label for this tracklet
 150
 151   Int_t s[kMAXCLUSTERSPERTRACK][2];
 152   for (Int_t i = 0; i < kMAXCLUSTERSPERTRACK; i++) {
 153     s[i][0] = -1;
 154     s[i][1] =  0;
 155   }
 156
 157   Bool_t labelAdded;
 158         Int_t label;
 159         AliTRDcluster *c    = 0x0;
 160   for (Int_t ip = 0; ip < AliESDtrack::kNPlane; ip++) {
 161                 if(fTrackletIndex[ip] < 0) continue;
 162                 for (Int_t ic = 0; ic < AliTRDseed::knTimebins; ic++) {
 163                         if(!(c = fTracklet[ip].GetClusters(ic))) continue;
 164                         for (Int_t k = 0; k < 3; k++) {
 165                                 label      = c->GetLabel(k);
 166                                 labelAdded = kFALSE;
 167                                 Int_t j = 0;
 168                                 if (label >= 0) {
 169                                         while ((!labelAdded) && (j < kMAXCLUSTERSPERTRACK)) {
 170                                                 if ((s[j][0] == label) ||
 171                                                                 (s[j][1] ==     0)) {
 172                                                         s[j][0] = label;
 173                                                         s[j][1]++;
 174                                                         labelAdded = kTRUE;
 175                                                 }
 176                                                 j++;
 177                                         }
 178                                 }
 179                         }
 180                 }
 181         }
 182
 183   Int_t max = 0;
 184   label = -123456789;
 185   for (Int_t i = 0; i < kMAXCLUSTERSPERTRACK; i++) {
 186     if (s[i][1] <= max) continue;
 187                 max   = s[i][1];
 188                 label = s[i][0];
 189   }
 190
 191   if ((1. - Float_t(max)/GetNumberOfClusters()) > wrong) label = -label;
 192
 193   SetLabel(label);
 194
 195         return kTRUE;
 196 }
 197
 198 //_______________________________________________________________
 199 Bool_t AliTRDtrackV1::CookPID()
 200 {
 201   //
 202   // Cook the PID information
 203   //
 204
 205 // CookdEdx();  // truncated mean ... do we still need it ?
 206
 207 // CookdEdxTimBin(seed->GetID());
 208
 209   // Sets the a priori probabilities
 210   for(int ispec=0; ispec<AliPID::kSPECIES; ispec++) {
 211     fPID[ispec] = 1.0 / AliPID::kSPECIES;
 212   }
 213
 214         // steer PID calculation @ tracklet level
 215         Double_t *prob = 0x0;
 216         fPIDquality = 0;
 217         for(int itrklt=0; itrklt<AliESDtrack::kNPlane; itrklt++){
 218     //for (Int_t iSlice = 0; iSlice < AliESDtrack::kNSlice; iSlice++) fdEdxPlane[itrklt][iSlice] = -1.;
 219
 220                 if(fTrackletIndex[itrklt]<0) continue;
 221                 if(!fTracklet[itrklt].IsOK()) continue;
 222                 if(!(prob = fTracklet[itrklt].GetProbability())) return kFALSE;
 223
 224                 Int_t nspec = 0; // quality check of tracklet dEdx
 225                 for(int ispec=0; ispec<AliPID::kSPECIES; ispec++){
 226                         if(prob[ispec] < 0.) continue;
 227                         fPID[ispec] *= prob[ispec];
 228                         nspec++;
 229                 }
 230                 if(!nspec) continue;
 231
 232                 fPIDquality++;
 233         }
 234
 235   // no tracklet found for PID calculations
 236   if(!fPIDquality) return kTRUE;
 237
 238         // slot for PID calculation @ track level
 239
 240
 241   // normalize probabilities
 242   Double_t probTotal = 0.0;
 243   for (Int_t is = 0; is < AliPID::kSPECIES; is++) probTotal += fPID[is];
 244
 245
 246   if (probTotal <= 0.0) {
 247     AliWarning("The total probability over all species <= 0. This may be caused by some error in the reference data.");
 248     return kFALSE;
 249   }
 250
 251   for (Int_t iSpecies = 0; iSpecies < AliPID::kSPECIES; iSpecies++) fPID[iSpecies] /= probTotal;
 252
 253   return kTRUE;
 254 }
 255
 256 //_______________________________________________________________
 257 Float_t AliTRDtrackV1::GetMomentum(Int_t plane) const
 258 {
 259   //
 260   // Get the momentum at a given plane
 261   //
 262
 263         return plane >=0 && plane < 6 && fTrackletIndex[plane] >= 0 ? fTracklet[plane].GetMomentum() : -1.;
 264 }
 265
 266 //_______________________________________________________________
 267 Double_t AliTRDtrackV1::GetPredictedChi2(const AliTRDseedV1 *trklt) const
 268 {
 269   //
 270   // Get the predicted chi2
 271   //
 272
 273   Double_t x      = trklt->GetX0();
 274   Double_t p[2]   = { trklt->GetYat(x)
 275                     , trklt->GetZat(x) };
 276   Double_t cov[3];
 277         trklt->GetCovAt(x, cov);
 278
 279   return AliExternalTrackParam::GetPredictedChi2(p, cov);
 280
 281 }
 282
 283 //_______________________________________________________________
 284 Bool_t AliTRDtrackV1::IsOwner() const
 285 {
 286   //
 287   // Check whether track owns the tracklets
 288   //
 289
 290         for (Int_t ip = 0; ip < AliESDtrack::kNPlane; ip++) {
 291                 if(fTrackletIndex[ip] < 0) continue;
 292                 if(!fTracklet[ip].IsOwner()) return kFALSE;
 293         }
 294         return kTRUE;
 295 }
 296
 297 //___________________________________________________________
 298 void AliTRDtrackV1::SetNumberOfClusters()
 299 {
 300 // Calculate the number of clusters attached to this track
 301
 302         Int_t ncls = 0;
 303         for(int ip=0; ip<6; ip++){
 304                 if(fTrackletIndex[ip] >= 0) ncls += fTracklet[ip].GetN();
 305         }
 306         AliKalmanTrack::SetNumberOfClusters(ncls);
 307 }
 308
 309
 310 //_______________________________________________________________
 311 void AliTRDtrackV1::SetOwner(Bool_t own)
 312 {
 313   //
 314   // Toggle ownership of tracklets
 315   //
 316
 317         for (Int_t ip = 0; ip < AliESDtrack::kNPlane; ip++) {
 318                 if(fTrackletIndex[ip] < 0) continue;
 319                 //AliInfo(Form("p[%d] index[%d]", ip, fTrackletIndex[ip]));
 320                 fTracklet[ip].SetOwner(own);
 321         }
 322 }
 323
 324 //_______________________________________________________________
 325 void AliTRDtrackV1::SetTracklet(AliTRDseedV1 *trklt, Int_t plane, Int_t index)
 326 {
 327   //
 328   // Set the tracklets
 329   //
 330
 331         if(plane < 0 || plane >= AliESDtrack::kNPlane) return;
 332         fTracklet[plane]      = (*trklt);
 333         fTrackletIndex[plane] = index;
 334 }
 335
 336 //_______________________________________________________________
 337 Bool_t  AliTRDtrackV1::Update(AliTRDseedV1 *trklt, Double_t chisq)
 338 {
 339   //
 340   // Update track parameters
 341   //
 342
 343   Double_t x      = trklt->GetX0();
 344   Double_t p[2]   = { trklt->GetYat(x)
 345                     , trklt->GetZat(x) };
 346   Double_t cov[3];
 347         trklt->GetCovAt(x, cov);
 348
 349 //      Print();
 350 //      AliInfo(Form("cov[%f %f %f]", cov[0], cov[1], cov[2]));
 351
 352   if(!AliExternalTrackParam::Update(p, cov)) return kFALSE;
 353         //Print();
 354
 355   // Register info to track
 356 //   Int_t n      = GetNumberOfClusters();
 357 //   fIndex[n]    = index;
 358 //   fClusters[n] = c;
 359   SetNumberOfClusters(/*GetNumberOfClusters()+trklt->GetN()*/);
 360   SetChi2(GetChi2() + chisq);
 361
 362         // update tracklet
 363         trklt->SetMomentum(GetP());
 364         trklt->SetSnp(GetSnp());
 365         trklt->SetTgl(GetTgl());
 366         return kTRUE;
 367 }
 368
 369 //_______________________________________________________________
 370 void AliTRDtrackV1::UpdateESDtrack(AliESDtrack *track)
 371 {
 372   //
 373   // Update the ESD track
 374   //
 375
 376         // copy dEdx to ESD
 377         Float_t *dedx = 0x0;
 378         for (Int_t ip = 0; ip < AliESDtrack::kNPlane; ip++) {
 379                 if(fTrackletIndex[ip] < 0) continue;
 380                 fTracklet[ip].CookdEdx(AliESDtrack::kNSlice);
 381                 dedx = fTracklet[ip].GetdEdx();
 382                 for (Int_t js = 0; js < AliESDtrack::kNSlice; js++) track->SetTRDsignals(dedx[js], ip, js);
 383                 //track->SetTRDTimBin(fTimBinPlane[i], i);
 384         }
 385
 386         // copy PID to ESD
 387         track->SetTRDpid(fPID);
 388         track->SetTRDpidQuality(fPIDquality);
 389 }