1 /**************************************************************************
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4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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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12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //-----------------------------------------------------------------
19 // Implementation of the TPC track class
20 // This class is used by the AliTPCtracker class
21 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
22 //-----------------------------------------------------------------
24 #include <Riostream.h>
26 #include "AliTPCtrack.h"
27 #include "AliCluster.h"
28 #include "AliTracker.h"
29 #include "AliESDtrack.h"
30 #include "AliESDVertex.h"
31 #include "TTreeStream.h"
32 #include "AliTPCRecoParam.h"
33 #include "AliTPCReconstructor.h"
36 //_________________________________________________________________________
37 AliTPCtrack::AliTPCtrack():
51 //-------------------------------------------------
52 // default constructor
53 //-------------------------------------------------
54 for (Int_t i=0; i<kMaxRow;i++) fIndex[i]=-2;
55 for (Int_t i=0; i<4;i++) fPoints[i]=0.;
56 for (Int_t i=0; i<12;i++) fKinkPoint[i]=0.;
57 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=0;
58 for (Int_t i=0; i<3;i++) fV0Indexes[i]=0;
61 //_________________________________________________________________________
65 AliTPCtrack::AliTPCtrack(Double_t x, Double_t alpha, const Double_t p[5],
66 const Double_t cov[15], Int_t index) :
80 //-----------------------------------------------------------------
81 // This is the main track constructor.
82 //-----------------------------------------------------------------
83 Double_t cnv=1./(AliTracker::GetBz()*kB2C);
93 Double_t c22 = x*x*cov[14] - 2*x*cov[12] + cov[5];
94 Double_t c32 = x*cov[13] - cov[8];
95 Double_t c20 = x*cov[10] - cov[3],
96 c21 = x*cov[11] - cov[4], c42 = x*cov[14] - cov[12];
102 cov[6 ], cov[7 ], c32, cov[9 ],
103 cov[10]*cnv, cov[11]*cnv, c42*cnv, cov[13]*cnv, cov[14]*cnv*cnv
106 Double_t mostProbablePt=AliExternalTrackParam::GetMostProbablePt();
107 Double_t p0=TMath::Sign(1/mostProbablePt,pp[4]);
108 Double_t w0=cc[14]/(cc[14] + p0*p0), w1=p0*p0/(cc[14] + p0*p0);
109 pp[4] = w0*p0 + w1*pp[4];
110 cc[10]*=w1; cc[11]*=w1; cc[12]*=w1; cc[13]*=w1; cc[14]*=w1;
114 SetNumberOfClusters(1);
117 for (Int_t i=1; i<kMaxRow;i++) fIndex[i]=-2;
118 for (Int_t i=0; i<4;i++) fPoints[i]=0.;
119 for (Int_t i=0; i<12;i++) fKinkPoint[i]=0.;
120 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=0;
121 for (Int_t i=0; i<3;i++) fV0Indexes[i]=0;
124 //_____________________________________________________________________________
125 AliTPCtrack::AliTPCtrack(const AliESDtrack& t, TTreeSRedirector *pcstream) :
127 fdEdx(t.GetTPCsignal()),
139 //-----------------------------------------------------------------
140 // Conversion AliESDtrack -> AliTPCtrack.
141 //-----------------------------------------------------------------
142 const Double_t kmaxC[4]={10,10,0.1,0.1}; // cuts on the rms /fP0,fP1,fP2,fP3
143 SetNumberOfClusters(t.GetTPCclusters(fIndex));
144 SetLabel(t.GetLabel());
145 SetMass(t.GetMassForTracking());
146 for (Int_t i=0; i<4;i++) fPoints[i]=0.;
147 for (Int_t i=0; i<12;i++) fKinkPoint[i]=0.;
148 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=0;
149 for (Int_t i=0; i<3;i++) fV0Indexes[i]=0;
151 // choose parameters to start
153 const AliTPCRecoParam * recoParam = AliTPCReconstructor::GetRecoParam();
155 AliExternalTrackParam param(t);
157 const AliExternalTrackParam *tpcout=(t.GetFriendTrack())? ((AliESDfriendTrack*)(t.GetFriendTrack()))->GetTPCOut():0;
158 const AliExternalTrackParam *tpcin = t.GetInnerParam();
159 const AliExternalTrackParam *tpc=(tpcout)?tpcout:tpcin;
160 Bool_t isBackProp = tpcout==0; // is this backpropagation?
161 if (!tpc) tpc=¶m;
163 Bool_t isOK = (recoParam->GetUseOuterDetectors() && t.IsOn(AliESDtrack::kTRDrefit)) || isBackProp;
164 if (param.GetCovariance()[0]>kmaxC[0]*kmaxC[0] ||
165 param.GetCovariance()[2]>kmaxC[1]*kmaxC[1] ||
166 param.GetCovariance()[5]>kmaxC[2]*kmaxC[2] ||
167 param.GetCovariance()[9]>kmaxC[3]*kmaxC[3]) isOK=kFALSE;
169 if (isOK) isOK &= param.Rotate(tpc->GetAlpha()); // using external seed
170 Double_t oldX=param.GetX(), oldY=param.GetY(), oldZ=param.GetZ();
176 else { // using external seed
177 // param.Rotate(tpc->GetAlpha()); // not needed
178 if (!AliTracker::PropagateTrackToBxByBz(¶m,tpc->GetX(),GetMass(),2.,kFALSE) ||
179 param.GetCovariance()[0]>kmaxC[0]*kmaxC[0] ||
180 param.GetCovariance()[2]>kmaxC[1]*kmaxC[1] ||
181 param.GetCovariance()[5]>kmaxC[2]*kmaxC[2] ||
182 param.GetCovariance()[9]>kmaxC[3]*kmaxC[3]) isOK=kFALSE;
185 Double_t chi2= param.GetPredictedChi2(tpc);
187 if (chi2>recoParam->GetMaxChi2TPCITS()) isOK=kFALSE; // protection against outliers in the ITS
189 else if (chi2>recoParam->GetMaxChi2TPCTRD()) isOK=kFALSE; // protection against outliers in the TRD
198 param.ResetCovariance(4.); // reset covariance if start from backup param
203 AliExternalTrackParam dummy;
204 AliExternalTrackParam *ptpc=(AliExternalTrackParam *)tpc;
205 // if (!ptpc) ptpc=&dummy;
206 AliESDtrack *esd= (AliESDtrack *)&t;
207 (*pcstream)<<"trackP"<<
208 "reject="<<reject<< // flag - rejection of current esd track parameters
209 "esd.="<<esd<< // original esd track
210 "tr.="<<¶m<< // starting track parameters
211 "out.="<<ptpc<< // backup tpc parameters
215 Set(param.GetX(),param.GetAlpha(),param.GetParameter(),param.GetCovariance());
217 if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
219 Double_t times[AliPID::kSPECIESC];
220 t.GetIntegratedTimes(times,AliPID::kSPECIESC);
221 SetIntegratedTimes(times);
222 SetIntegratedLength(t.GetIntegratedLength());
225 Double_t dX=GetX()-oldX, dY=GetY()-oldY, dZ=GetZ()-oldZ;
226 Double_t d=TMath::Sqrt(dX*dX + dY*dY + dZ*dZ);
231 //_____________________________________________________________________________
232 AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) :
236 fNFoundable(t.fNFoundable),
237 fBConstrain(t.fBConstrain),
238 fLastPoint(t.fLastPoint),
239 fFirstPoint(t.fFirstPoint),
240 fRemoval(t.fRemoval),
241 fTrackType(t.fTrackType),
243 fNShared(t.fNShared),
244 fReference(t.fReference)
247 //-----------------------------------------------------------------
248 // This is a track copy constructor.
249 //-----------------------------------------------------------------
250 Set(t.GetX(),t.GetAlpha(),t.GetParameter(),t.GetCovariance());
252 for (Int_t i=0; i<kMaxRow; i++) fIndex[i]=t.fIndex[i];
253 for (Int_t i=0; i<4;i++) fPoints[i]=t.fPoints[i];
254 for (Int_t i=0; i<12;i++) fKinkPoint[i]=t.fKinkPoint[i];
255 for (Int_t i=0; i<3;i++) fKinkIndexes[i]=t.fKinkIndexes[i];
256 for (Int_t i=0; i<3;i++) fV0Indexes[i]=t.fV0Indexes[i];
259 AliTPCtrack& AliTPCtrack::operator=(const AliTPCtrack& o){
261 AliKalmanTrack::operator=(o);
263 for(Int_t i = 0;i<kMaxRow;++i)fIndex[i] = o.fIndex[i];
264 for(Int_t i = 0;i<4;++i)fPoints[i] = o.fPoints[i];
266 fNFoundable = o.fNFoundable;
267 fBConstrain = o.fBConstrain;
268 fLastPoint = o.fLastPoint;
269 fFirstPoint = o.fFirstPoint;
270 fTrackType = o.fTrackType;
272 fNShared = o.fNShared;
273 fReference = o.fReference;
274 for(Int_t i = 0;i<12;++i) fKinkPoint[i] = o.fKinkPoint[i];
276 for(Int_t i = 0;i<3;++i){
277 fKinkIndexes[i] = o.fKinkIndexes[i];
278 fV0Indexes[i] = o.fV0Indexes[i];
286 //_____________________________________________________________________________
287 Int_t AliTPCtrack::Compare(const TObject *o) const {
288 //-----------------------------------------------------------------
289 // This function compares tracks according to the their curvature
290 //-----------------------------------------------------------------
291 AliTPCtrack *t=(AliTPCtrack*)o;
292 //Double_t co=t->OneOverPt();
293 //Double_t c = OneOverPt();
294 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
295 Double_t c =GetSigmaY2()*GetSigmaZ2();
297 else if (c<co) return -1;
301 Double_t AliTPCtrack::GetPredictedChi2(const AliCluster *c) const {
302 //-----------------------------------------------------------------
303 // This function calculates a predicted chi2 increment.
304 //-----------------------------------------------------------------
305 Double_t p[2]={c->GetY(), c->GetZ()};
306 Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
307 return AliExternalTrackParam::GetPredictedChi2(p,cov);
310 //_____________________________________________________________________________
311 Bool_t AliTPCtrack::PropagateTo(Double_t xk,Double_t rho,Double_t x0) {
312 //-----------------------------------------------------------------
313 // This function propagates a track to a reference plane x=xk.
314 // rho - density of the crossed matrial (g/cm^3)
315 // x0 - radiation length of the crossed material (g/cm^2)
316 //-----------------------------------------------------------------
320 if (!GetZAt(xk, bz,zat)) return kFALSE;
321 if (TMath::Abs(zat)>250.){
322 // Don't propagate track outside of the fiducial volume - material budget not proper one
324 //AliWarning("Propagate outside of fiducial volume");
328 Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
329 //if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
330 Double_t b[3]; GetBxByBz(b);
331 if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) return kFALSE;
333 Double_t d = TMath::Sqrt((GetX()-oldX)*(GetX()-oldX) +
334 (GetY()-oldY)*(GetY()-oldY) +
335 (GetZ()-oldZ)*(GetZ()-oldZ));
336 if (IsStartedTimeIntegral() && GetX()>oldX) AddTimeStep(d);
338 if (oldX < xk) d = -d;
339 if (!AliExternalTrackParam::CorrectForMeanMaterial(d*rho/x0,d*rho,GetMass(),
340 kFALSE,AliExternalTrackParam::BetheBlochGas)) return kFALSE;
345 //_____________________________________________________________________________
347 AliTPCtrack::PropagateToVertex(const AliESDVertex *v,Double_t rho,Double_t x0)
349 //-----------------------------------------------------------------
350 // This function propagates tracks to the vertex
351 // rho - density of the crossed matrial (g/cm3)
352 // x0 - radiation length of the crossed material (g/cm2)
353 //-----------------------------------------------------------------
354 Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
356 //Double_t bz=GetBz();
357 //if (!PropagateToDCA(v,bz,kVeryBig)) return kFALSE;
358 Double_t b[3]; GetBxByBz(b);
359 if (!PropagateToDCABxByBz(v,b,kVeryBig)) return kFALSE;
361 Double_t d = TMath::Sqrt((GetX()-oldX)*(GetX()-oldX) +
362 (GetY()-oldY)*(GetY()-oldY) +
363 (GetZ()-oldZ)*(GetZ()-oldZ));
365 if (oldX < GetX()) d = -d;
366 if (!AliExternalTrackParam::CorrectForMeanMaterial(d*rho/x0,d*rho,GetMass(),
367 kFALSE,AliExternalTrackParam::BetheBlochGas)) return kFALSE;
372 //_____________________________________________________________________________
373 Bool_t AliTPCtrack::Update(const AliCluster *c, Double_t chisq, Int_t index) {
374 //-----------------------------------------------------------------
375 // This function associates a cluster with this track.
376 //-----------------------------------------------------------------
377 Double_t p[2]={c->GetY(), c->GetZ()};
378 Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
380 if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
382 AliTracker::FillResiduals(this,p,cov,c->GetVolumeId());
384 Int_t n=GetNumberOfClusters();
386 SetNumberOfClusters(n+1);
387 SetChi2(GetChi2()+chisq);
392 ////////////////////////////////////////////////////////////////////////
395 Float_t AliTPCtrack::Density(Int_t row0, Int_t row1)
398 // calculate cluster density
401 //if (row0<fFirstPoint) row0 = fFirstPoint;
402 if (row1>fLastPoint) row1 = fLastPoint;
405 for (Int_t i=row0;i<=row1;i++){
406 // Int_t index = fClusterIndex[i];
407 Int_t index = fIndex[i];
408 if (index!=-1) good++;
409 if (index>0) found++;
412 if (good>0) density = Float_t(found)/Float_t(good);
417 Float_t AliTPCtrack::Density2(Int_t row0, Int_t row1)
420 // calculate cluster density
424 for (Int_t i=row0;i<=row1;i++){
425 Int_t index = fIndex[i];
426 if (index!=-1) good++;
427 if (index>0) found++;
430 if (good>0) density = Float_t(found)/Float_t(good);
434 void AliTPCtrack::UpdatePoints()
436 //--------------------------------------------------
437 //calculates first ,amx dens and last points
438 //--------------------------------------------------
439 Float_t density[160];
440 for (Int_t i=0;i<160;i++) density[i]=-1.;
448 for (Int_t i=0;i<160;i++){
449 Int_t last = i-range;
450 if (nall<range) nall++;
452 if (fIndex[last]>0&& (fIndex[last]&0x8000)==0) ngood--;
453 if (fIndex[last]==-1) undeff--;
455 if (fIndex[i]>0&& (fIndex[i]&0x8000)==0) ngood++;
456 if (fIndex[i]==-1) undeff++;
457 if (nall==range &&undeff<range/2) density[i-range/2] = Float_t(ngood)/Float_t(nall-undeff);
461 for (Int_t i=0;i<160;i++){
462 if (density[i]<0) continue;
463 if (density[i]>maxdens){
470 fPoints[3] = maxdens;
471 fPoints[1] = indexmax;
474 for (Int_t i=indexmax;i<160;i++){
475 if (density[i]<0) continue;
476 if (density[i]<maxdens/2.) {
483 for (Int_t i=indexmax;i>0;i--){
484 if (density[i]<0) continue;
485 if (density[i]<maxdens/2.) {