HLT/global/AliHLTV0FinderComponent.cxx

   1 // $Id$
   2
   3 //**************************************************************************
   4 //* This file is property of and copyright by the ALICE HLT Project        *
   5 //* ALICE Experiment at CERN, All rights reserved.                         *
   6 //*                                                                        *
   7 //* Primary Authors: Timur Pocheptsov <Timur.Pocheptsov@cern.ch>           *
   8 //*                  for The ALICE HLT Project.                            *
   9 //*                                                                        *
  10 //* Permission to use, copy, modify and distribute this software and its   *
  11 //* documentation strictly for non-commercial purposes is hereby granted   *
  12 //* without fee, provided that the above copyright notice appears in all   *
  13 //* copies and that both the copyright notice and this permission notice   *
  14 //* appear in the supporting documentation. The authors make no claims     *
  15 //* about the suitability of this software for any purpose. It is          *
  16 //* provided "as is" without express or implied warranty.                  *
  17 //**************************************************************************
  18
  19 /// @file   AliHLTV0FinderComponent.cxx
  20 /// @author Timur Pocheptsov
  21 /// @date   2010-12-26
  22 /// @brief  V0 finder component
  23 ///
  24
  25 #include "TString.h"
  26
  27 #include "AliHLTDataTypes.h"
  28 #include "AliHLTV0FinderComponent.h"
  29
  30 ClassImp(AliHLTV0FinderComponent)
  31
  32 const double AliHLTV0FinderComponent::fgDaughterPrimDeviation = 2.5;
  33 const double AliHLTV0FinderComponent::fgPrimDeviation = 3.5;
  34 const double AliHLTV0FinderComponent::fgChi = 3.5;
  35 const double AliHLTV0FinderComponent::fgDecayLengthInSigmas = 3.;
  36
  37 //________________________________________________________________________
  38 AliHLTV0FinderComponent::AliHLTV0FinderComponent()
  39                   : fPrimaryVtx(),
  40                     fPrimaryTracks(),
  41                     fNPrimaryTracks(0),
  42                     fMinPrimID(0),
  43                     fMaxPrimID(0),
  44                     fDaughterPrimDeviation(fgDaughterPrimDeviation),
  45                     fPrimDeviation(fgPrimDeviation),
  46                     fChi(fgChi),
  47                     fDecayLengthInSigmas(fgDecayLengthInSigmas),
  48                     fPosPID(211),
  49                     fNegPID(211),
  50                     fV0s(),
  51                     fGammaFinder(false)
  52 {
  53   //Default ctor.
  54 }
  55
  56 //________________________________________________________________________
  57 const char* AliHLTV0FinderComponent::GetComponentID()
  58 {
  59   //Component's "name".
  60   return "V0Finder";
  61 }
  62
  63 //________________________________________________________________________
  64 void AliHLTV0FinderComponent::GetInputDataTypes(AliHLTComponentDataTypeList& list)
  65 {
  66   //Input to the primary vertex finder:
  67   //a)tracks from ESD object;
  68   //b)hlt tracks (ITS)
  69   //c)hlt tracks (TPC)
  70   //d)primary vertex (AliKFVertex)
  71   //e)indices of primary tracks.
  72   list.clear();
  73   //Input tracks.
  74   list.push_back(kAliHLTDataTypeESDObject);
  75   list.push_back(kAliHLTDataTypeTrack | kAliHLTDataOriginITS);
  76   list.push_back(kAliHLTDataTypeTrack | kAliHLTDataOriginTPC);
  77   //Input from primary finder:
  78   //Primary vertex.
  79   list.push_back(kAliHLTDataTypeKFVertex | kAliHLTDataOriginOut);
  80   //Primary tracks' indices.
  81   list.push_back(kAliHLTDataTypePrimaryFinder | kAliHLTDataOriginOut);
  82 }
  83
  84 //________________________________________________________________________
  85 AliHLTComponentDataType AliHLTV0FinderComponent::GetOutputDataType()
  86 {
  87   //Data type of output.
  88   return kAliHLTMultipleDataType;
  89 }
  90
  91 //________________________________________________________________________
  92 int AliHLTV0FinderComponent::GetOutputDataTypes(AliHLTComponentDataTypeList& tgtList)
  93 {
  94   //Output type for V0 finder.
  95   tgtList.clear();
  96   //Indices of tracks, participating in V0s.
  97   tgtList.push_back(kAliHLTDataTypeV0Finder | kAliHLTDataOriginOut);
  98
  99   return tgtList.size();
 100 }
 101
 102 //________________________________________________________________________
 103 void AliHLTV0FinderComponent::GetOutputDataSize(unsigned long& constBase, double& inputMultiplier)
 104 {
 105   //These numbers are complete crap.
 106   constBase = 80000;
 107   inputMultiplier = 2.;
 108 }
 109
 110 //________________________________________________________________________
 111 AliHLTComponent* AliHLTV0FinderComponent::Spawn()
 112 {
 113   //Create primary vertex finder componet.
 114   return new AliHLTV0FinderComponent;
 115 }
 116
 117 //________________________________________________________________________
 118 int AliHLTV0FinderComponent::DoInit(int /*argc*/, const char** /*argv*/)
 119 {
 120   //1. Default parameters.
 121   fDaughterPrimDeviation = fgDaughterPrimDeviation;
 122   fPrimDeviation = fgPrimDeviation;
 123   fChi = fgChi;
 124   fDecayLengthInSigmas = fgDecayLengthInSigmas;
 125   fPosPID = 211;
 126   fNegPID = 211;
 127   fGammaFinder = false;
 128
 129   //Part with OCDB and command line arguments is commented
 130   //until OCDB is updated.
 131 /*
 132   //2. Parameters from OCDB.
 133   TString cdbPath("HLT/ConfigHLT/");
 134   cdbPath += GetComponentID();
 135
 136   int res = ConfigureFromCDBTObjString(cdbPath);
 137   if (res < 0)
 138     return res;
 139
 140   //3. "Command line" parameters.
 141   if (argc)
 142     res = ConfigureFromArgumentString(argc, argv);
 143
 144   return res;*/
 145   return 0;
 146 }
 147
 148 //________________________________________________________________________
 149 int AliHLTV0FinderComponent::ScanConfigurationArgument(int argc, const char** argv)
 150 {
 151   //Scan one argument and its parameters from the list
 152   //Return number of processed entries.
 153   //Possible arguments:
 154   //-daughterPrimDeviation num
 155   //-primDeviation num
 156   //-chi num
 157   //-decayLengthInSigmas num
 158   //-posPID int_num
 159   //-negPid int_num
 160   //-gammaFinder 0/1
 161
 162   AliHLTUtility::CmdLineParser parser;
 163   parser.Add("-daughterPrimDeviation", &fDaughterPrimDeviation);
 164   parser.Add("-primDeviation", &fPrimDeviation);
 165   parser.Add("-chi", &fChi);
 166   parser.Add("-decayLengthInSigmas", &fDecayLengthInSigmas);
 167   parser.Add("-posPID", &fPosPID);
 168   parser.Add("-negPID", &fNegPID);
 169   parser.Add("-gammaFinder", &fGammaFinder);
 170
 171   const int nParsed = parser.Parse(argc, argv, 0);
 172   if (nParsed < 0) {
 173     HLTError(parser.GetError().Data());
 174     return -EPROTO;
 175   }
 176
 177   return nParsed;
 178 }
 179
 180 //________________________________________________________________________
 181 int AliHLTV0FinderComponent::DoDeinit()
 182 {
 183   //Reset parameters to default.
 184   fDaughterPrimDeviation = fgDaughterPrimDeviation;
 185   fPrimDeviation = fgPrimDeviation;
 186   fChi = fgChi;
 187   fDecayLengthInSigmas = fgDecayLengthInSigmas;
 188   fPosPID = 211;
 189   fNegPID = 211;
 190   fGammaFinder = false;
 191
 192   return 0;
 193 }
 194
 195 //________________________________________________________________________
 196 int AliHLTV0FinderComponent::DoEvent(const AliHLTComponentEventData& /*evtData*/,
 197                             AliHLTComponentTriggerData& /*trigData*/)
 198 {
 199   //Find primary vertex.
 200   if (GetFirstInputBlock(kAliHLTDataTypeSOR) || GetFirstInputBlock(kAliHLTDataTypeEOR))
 201     return 0;
 202
 203   //Clean all previous track infos.
 204   fTrackInfos.clear();
 205   fPrimaryTracks.clear();
 206
 207   //Initialize KF package.
 208   AliKFParticle::SetField(GetBz());
 209
 210   if (!ReadPrimaryVertex())
 211     return 0;
 212
 213   if (!ReadTracks())
 214     return 0;
 215
 216   FindV0s();
 217
 218   return DoOutput();
 219 }
 220
 221 //________________________________________________________________________
 222 bool AliHLTV0FinderComponent::ReadPrimaryVertex()
 223 {
 224   //Primary finder produces primary vertex (AliKFVertex) and
 225   //indices for primary tracks.
 226   //1. Try to extract primary vertex.
 227   const TObject* obj = GetFirstInputObject(kAliHLTDataTypeKFVertex | kAliHLTDataOriginOut);
 228   const AliKFVertex* kfVtx = dynamic_cast<const AliKFVertex*>(obj);
 229
 230   if (!kfVtx) {
 231     HLTError("V0 finder requires KF vertex (primary vertex) as input");
 232     return false;
 233   }
 234
 235   //2. Try to read primary track indices.
 236   const AliHLTComponentBlockData* p = GetFirstInputBlock(kAliHLTDataTypePrimaryFinder
 237                                                           | kAliHLTDataOriginOut);
 238   if (!p || !p->fSize || !p->fPtr) {
 239     HLTError("Array of primary track indices expected");
 240     return false;
 241   }
 242
 243   //Data block from primary finder
 244   const PrimaryFinderBlock* blk = static_cast<PrimaryFinderBlock*>(p->fPtr);
 245   //Track ids must be positive integers.
 246   if (blk->fMinPrimID < 0 || blk->fMaxPrimID < 0) {
 247     HLTError("Got negative track ID from primary finder, internal HLT error");
 248     return false;
 249   }
 250
 251   //3. Got correct data, modify the component's state.
 252   //KF vertex.
 253   fPrimaryVtx = *kfVtx;
 254   //Primary tracks.
 255   fNPrimaryTracks = blk->fNPrimaryTracks;
 256   fMinPrimID = blk->fMinPrimID;
 257   fMaxPrimID = blk->fMaxPrimID;
 258
 259   fPrimaryTracks.assign(fMaxPrimID + 1, 0);
 260   for (int i = 0; i < fNPrimaryTracks; ++i)
 261     fPrimaryTracks[blk->fPrimTrackIds[i]] = 1;
 262
 263   return true;
 264 }
 265
 266 //________________________________________________________________________
 267 bool AliHLTV0FinderComponent::ReadTracks()
 268 {
 269   //The logic, how vertex finder reads input tracks,
 270   //is taken from the original global vertexer.
 271   //First, try to read tracks from ESD event.
 272   ReadESDTracks();
 273   if (fTrackInfos.size()) {
 274     FindPrimaryDeviations();
 275     return true;
 276   }
 277
 278   //No good esd tracks, try:
 279   ReadHLTTracks(kAliHLTDataTypeTrack | kAliHLTDataOriginITS);
 280   if (fTrackInfos.size()) {
 281     FindPrimaryDeviations();
 282     return true;
 283   }
 284
 285   //If no good its tracks, try:
 286   ReadHLTTracks(kAliHLTDataTypeTrack | kAliHLTDataOriginTPC);
 287   if (fTrackInfos.size()) {
 288     FindPrimaryDeviations();
 289     return true;
 290   }
 291
 292   HLTError("No input tracks found for V0 finder");
 293
 294   return false;
 295 }
 296
 297 //________________________________________________________________________
 298 void AliHLTV0FinderComponent::FindPrimaryDeviations()
 299 {
 300   //Quite a tricky part.
 301   for (VectorSize_t i = 0; i < fTrackInfos.size(); ++i) {
 302     AliHLTTrackInfo& info = fTrackInfos[i];
 303     if (IsPrimaryTrack(info.fID)) {
 304       info.fPrimUsed = true;
 305       //The way primary deviation is computed in primary finder:
 306       if (fNPrimaryTracks <= 20) {
 307         AliKFVertex tmp(fPrimaryVtx - info.fParticle);
 308         info.fPrimDeviation = info.fParticle.GetDeviationFromVertex(tmp);
 309       } else
 310         info.fPrimDeviation = info.fParticle.GetDeviationFromVertex(fPrimaryVtx);
 311     } else {
 312       info.fPrimUsed = false;
 313       info.fPrimDeviation = info.fParticle.GetDeviationFromVertex(fPrimaryVtx);
 314     }
 315   }
 316 }
 317
 318 //________________________________________________________________________
 319 bool AliHLTV0FinderComponent::IsPrimaryTrack(int id)const
 320 {
 321   if (id < fMinPrimID || id > fMaxPrimID)
 322     return false;
 323
 324   return fPrimaryTracks[id];
 325 }
 326
 327 //________________________________________________________________________
 328 void AliHLTV0FinderComponent::FindV0s()
 329 {
 330   //Here's the core.
 331   if (fPrimaryVtx.GetNContributors() < 3)
 332     return;
 333
 334   fV0s.clear();
 335   fV0s.push_back(0); //Number of v0s.
 336
 337   for (int iTr = 0, ei = fTrackInfos.size(); iTr < ei; ++iTr) {
 338     AliHLTTrackInfo& info = fTrackInfos[iTr];
 339     if (info.fParticle.GetQ() > 0)
 340       continue;
 341     if (info.fPrimDeviation < fDaughterPrimDeviation)
 342       continue;
 343
 344     for (int jTr = 0; jTr < ei; ++jTr) {
 345       AliHLTTrackInfo& jnfo = fTrackInfos[jTr];
 346       if (jnfo.fParticle.GetQ() < 0)
 347         continue;
 348       if (jnfo.fPrimDeviation < fDaughterPrimDeviation)
 349         continue;
 350
 351       //Check if the particles fit
 352       if (info.fParticle.GetDeviationFromParticle(jnfo.fParticle) > fChi)
 353         continue;
 354
 355       //Construct V0 mother
 356       AliKFParticle v0(info.fParticle, jnfo.fParticle /*, bGammaFinder*/);
 357       //Check V0 Chi^2
 358       if (v0.GetChi2() < 0. || v0.GetChi2() > fChi * fChi * v0.GetNDF())
 359         continue;
 360
 361       //Subtruct daughters from primary vertex
 362       AliKFVertex primVtxCopy(fPrimaryVtx);
 363
 364       if (info.fPrimUsed) {
 365         if (primVtxCopy.GetNContributors() <= 2)
 366           continue;
 367         primVtxCopy -= info.fParticle;
 368       }
 369
 370       if (jnfo.fPrimUsed) {
 371         if (primVtxCopy.GetNContributors() <= 2)
 372           continue;
 373         primVtxCopy -= jnfo.fParticle;
 374       }
 375
 376       //Check v0 Chi^2 deviation from primary vertex
 377       if (v0.GetDeviationFromVertex(primVtxCopy) > fPrimDeviation)
 378         continue;
 379       //Add V0 to primary vertex to improve the primary vertex resolution
 380       primVtxCopy += v0;
 381       //Set production vertex for V0
 382       v0.SetProductionVertex(primVtxCopy);
 383       //Get V0 decay length with estimated error
 384       double length = 0., sigmaLength = 0.;
 385       if (v0.GetDecayLength(length, sigmaLength))
 386         continue;
 387       //Reject V0 if it decays too close[sigma] to the primary vertex
 388       if (length  < fDecayLengthInSigmas * sigmaLength)
 389         continue;
 390       //Keep v0
 391       fV0s.push_back(info.fID);
 392       fV0s.push_back(jnfo.fID);
 393
 394       fV0s[0] += 1;
 395     }
 396   }
 397 }
 398
 399 //________________________________________________________________________
 400 int AliHLTV0FinderComponent::DoOutput()
 401 {
 402   //Save V0s' track pairs' indices.
 403   if (!fV0s.size() || !fV0s[0]) {
 404     HLTInfo("No v0s were found");
 405     return 0;
 406   }
 407
 408   //Indices of primary tracks.
 409   return PushBack(&fV0s[0], fV0s.size() * sizeof(int),
 410                   kAliHLTDataTypeV0Finder | kAliHLTDataOriginOut);
 411 }