1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
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 ITS track class
21 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
22 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
23 ///////////////////////////////////////////////////////////////////////////
26 #include "AliCluster.h"
27 #include "AliESDVertex.h"
28 #include "AliITSReconstructor.h"
29 #include "AliITStrackV2.h"
30 #include "AliTracker.h"
32 const Int_t AliITStrackV2::fgkWARN = 5;
34 ClassImp(AliITStrackV2)
37 //____________________________________________________________________________
38 AliITStrackV2::AliITStrackV2() : AliKalmanTrack(),
39 fCheckInvariant(kTRUE),
43 for(Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) {fIndex[i]=-1; fModule[i]=-1;}
44 for(Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;}
45 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
49 //____________________________________________________________________________
50 AliITStrackV2::AliITStrackV2(AliESDtrack& t,Bool_t c):
52 fCheckInvariant(kTRUE),
53 fdEdx(t.GetITSsignal()),
56 //------------------------------------------------------------------
57 // Conversion ESD track -> ITS track.
58 // If c==kTRUE, create the ITS track out of the constrained params.
59 //------------------------------------------------------------------
60 const AliExternalTrackParam *par=&t;
62 par=t.GetConstrainedParam();
63 if (!par) AliError("AliITStrackV2: conversion failed !\n");
65 Set(par->GetX(),par->GetAlpha(),par->GetParameter(),par->GetCovariance());
67 SetLabel(t.GetLabel());
69 SetNumberOfClusters(t.GetITSclusters(fIndex));
71 if (t.GetStatus()&AliESDtrack::kTIME) {
73 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
74 SetIntegratedLength(t.GetIntegratedLength());
77 for(Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;}
78 for(Int_t i=0; i<4; i++) fdEdxSample[i]=0;
81 //____________________________________________________________________________
82 void AliITStrackV2::ResetClusters() {
83 //------------------------------------------------------------------
84 // Reset the array of attached clusters.
85 //------------------------------------------------------------------
86 for (Int_t i=0; i<2*AliITSgeomTGeo::kNLayers; i++) fIndex[i]=-1;
87 for (Int_t i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=0;}
89 SetNumberOfClusters(0);
92 //____________________________________________________________________________
93 void AliITStrackV2::UpdateESDtrack(ULong_t flags) const {
94 // Update track params
95 fESDtrack->UpdateTrackParams(this,flags);
96 // copy the module indices
98 for(i=0;i<2*AliITSgeomTGeo::kNLayers;i++) {
99 // printf(" %d\n",GetModuleIndex(i));
100 fESDtrack->SetITSModuleIndex(i,GetModuleIndex(i));
102 // copy the map of shared clusters
103 if(flags==AliESDtrack::kITSin) {
104 UChar_t itsSharedMap=0;
105 for(i=0;i<AliITSgeomTGeo::kNLayers;i++) {
106 if(fSharedWeight[i]>0) {SETBIT(itsSharedMap,i);printf("UpdateESD: l %d\n",i);}
109 fESDtrack->SetITSSharedMap(itsSharedMap);
111 for(i=0;i<6;i++) if(fESDtrack->HasSharedPointOnITSLayer(i)) printf("shared on %d\n",i);
113 // copy the 4 dedx samples
114 Double_t sdedx[4]={0.,0.,0.,0.};
115 for(i=0; i<4; i++) sdedx[i]=fdEdxSample[i];
116 fESDtrack->SetITSdEdxSamples(sdedx);
119 //____________________________________________________________________________
120 AliITStrackV2::AliITStrackV2(const AliITStrackV2& t) :
122 fCheckInvariant(t.fCheckInvariant),
124 fESDtrack(t.fESDtrack)
126 //------------------------------------------------------------------
128 //------------------------------------------------------------------
130 for (i=0; i<4; i++) fdEdxSample[i]=t.fdEdxSample[i];
131 for (i=0; i<2*AliITSgeomTGeo::GetNLayers(); i++) {
132 fIndex[i]=t.fIndex[i];
133 fModule[i]=t.fModule[i];
135 for (i=0; i<AliITSgeomTGeo::kNLayers; i++) {fSharedWeight[i]=t.fSharedWeight[i];}
138 //_____________________________________________________________________________
139 Int_t AliITStrackV2::Compare(const TObject *o) const {
140 //-----------------------------------------------------------------
141 // This function compares tracks according to the their curvature
142 //-----------------------------------------------------------------
143 AliITStrackV2 *t=(AliITStrackV2*)o;
144 //Double_t co=OneOverPt();
145 //Double_t c =OneOverPt();
146 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2();
147 Double_t c =GetSigmaY2()*GetSigmaZ2();
149 else if (c<co) return -1;
153 //____________________________________________________________________________
155 AliITStrackV2::PropagateToVertex(const AliESDVertex *v,Double_t d,Double_t x0)
157 //------------------------------------------------------------------
158 //This function propagates a track to the minimal distance from the origin
159 //------------------------------------------------------------------
161 if (PropagateToDCA(v,bz,kVeryBig)) {
162 Double_t xOverX0,xTimesRho;
163 xOverX0 = d; xTimesRho = d*x0;
164 if (CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kTRUE;
169 //____________________________________________________________________________
170 Bool_t AliITStrackV2::
171 GetGlobalXYZat(Double_t xloc, Double_t &x, Double_t &y, Double_t &z) const {
172 //------------------------------------------------------------------
173 //This function returns a track position in the global system
174 //------------------------------------------------------------------
176 Bool_t rc=GetXYZAt(xloc, GetBz(), r);
177 x=r[0]; y=r[1]; z=r[2];
181 //_____________________________________________________________________________
182 Double_t AliITStrackV2::GetPredictedChi2(const AliCluster *c) const {
183 //-----------------------------------------------------------------
184 // This function calculates a predicted chi2 increment.
185 //-----------------------------------------------------------------
186 Double_t p[2]={c->GetY(), c->GetZ()};
187 Double_t cov[3]={c->GetSigmaY2(), 0., c->GetSigmaZ2()};
188 return AliExternalTrackParam::GetPredictedChi2(p,cov);
191 //____________________________________________________________________________
192 Bool_t AliITStrackV2::PropagateTo(Double_t xk, Double_t d, Double_t x0) {
193 //------------------------------------------------------------------
194 //This function propagates a track
195 //------------------------------------------------------------------
197 Double_t oldX=GetX(), oldY=GetY(), oldZ=GetZ();
199 //Double_t bz=GetBz();
200 //if (!AliExternalTrackParam::PropagateTo(xk,bz)) return kFALSE;
201 Double_t b[3]; GetBxByBz(b);
202 if (!AliExternalTrackParam::PropagateToBxByBz(xk,b)) return kFALSE;
203 Double_t xOverX0,xTimesRho;
204 xOverX0 = d; xTimesRho = d*x0;
205 if (!CorrectForMeanMaterial(xOverX0,xTimesRho,kTRUE)) return kFALSE;
207 Double_t x=GetX(), y=GetY(), z=GetZ();
208 if (IsStartedTimeIntegral() && x>oldX) {
209 Double_t l2 = (x-oldX)*(x-oldX) + (y-oldY)*(y-oldY) + (z-oldZ)*(z-oldZ);
210 AddTimeStep(TMath::Sqrt(l2));
216 //____________________________________________________________________________
217 Bool_t AliITStrackV2::PropagateToTGeo(Double_t xToGo, Int_t nstep, Double_t &xOverX0, Double_t &xTimesRho, Bool_t addTime) {
218 //-------------------------------------------------------------------
219 // Propagates the track to a reference plane x=xToGo in n steps.
220 // These n steps are only used to take into account the curvature.
221 // The material is calculated with TGeo. (L.Gaudichet)
222 //-------------------------------------------------------------------
224 Double_t startx = GetX(), starty = GetY(), startz = GetZ();
225 Double_t sign = (startx<xToGo) ? -1.:1.;
226 Double_t step = (xToGo-startx)/TMath::Abs(nstep);
228 Double_t start[3], end[3], mparam[7];
229 //Double_t bz = GetBz();
230 Double_t b[3]; GetBxByBz(b);
235 for (Int_t i=0; i<nstep; i++) {
237 GetXYZ(start); //starting global position
239 if (!GetXYZAt(x, bz, end)) return kFALSE;
240 //if (!AliExternalTrackParam::PropagateTo(x, bz)) return kFALSE;
241 if (!AliExternalTrackParam::PropagateToBxByBz(x, b)) return kFALSE;
242 AliTracker::MeanMaterialBudget(start, end, mparam);
243 xTimesRho = sign*mparam[4]*mparam[0];
245 if (mparam[1]<900000) {
246 if (!AliExternalTrackParam::CorrectForMeanMaterial(xOverX0,
247 xTimesRho,GetMass())) return kFALSE;
248 } else { // this happens when MeanMaterialBudget cannot cross a boundary
253 if (addTime && IsStartedTimeIntegral() && GetX()>startx) {
254 Double_t l2 = ( (GetX()-startx)*(GetX()-startx) +
255 (GetY()-starty)*(GetY()-starty) +
256 (GetZ()-startz)*(GetZ()-startz) );
257 AddTimeStep(TMath::Sqrt(l2));
263 //____________________________________________________________________________
264 Bool_t AliITStrackV2::Update(const AliCluster* c, Double_t chi2, Int_t index)
266 //------------------------------------------------------------------
267 //This function updates track parameters
268 //------------------------------------------------------------------
269 Double_t p[2]={c->GetY(), c->GetZ()};
270 Double_t cov[3]={c->GetSigmaY2(), c->GetSigmaYZ(), c->GetSigmaZ2()};
272 if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
274 Int_t n=GetNumberOfClusters();
276 if (n>fgkWARN) AliWarning("Wrong invariant !");
280 if (chi2<0) return kTRUE;
282 // fill residuals for ITS+TPC tracks
284 if (fESDtrack->GetStatus()&AliESDtrack::kTPCin) {
285 AliTracker::FillResiduals(this,p,cov,c->GetVolumeId());
290 SetNumberOfClusters(n+1);
291 SetChi2(GetChi2()+chi2);
296 Bool_t AliITStrackV2::Invariant() const {
297 //------------------------------------------------------------------
298 // This function is for debugging purpose only
299 //------------------------------------------------------------------
300 if(!fCheckInvariant) return kTRUE;
302 Int_t n=GetNumberOfClusters();
304 // take into account the misalignment error
305 Float_t maxMisalErrY2=0,maxMisalErrZ2=0;
306 for (Int_t lay=0; lay<AliITSgeomTGeo::kNLayers; lay++) {
307 maxMisalErrY2 = TMath::Max(maxMisalErrY2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorY(lay,GetBz()));
308 maxMisalErrZ2 = TMath::Max(maxMisalErrZ2,AliITSReconstructor::GetRecoParam()->GetClusterMisalErrorZ(lay,GetBz()));
310 maxMisalErrY2 *= maxMisalErrY2;
311 maxMisalErrZ2 *= maxMisalErrZ2;
312 // this is because when we reset before refitting, we multiply the
314 maxMisalErrY2 *= 10.;
315 maxMisalErrZ2 *= 10.;
317 Double_t sP2=GetParameter()[2];
318 if (TMath::Abs(sP2) >= kAlmost1){
319 if (n>fgkWARN) Warning("Invariant","fP2=%f\n",sP2);
322 Double_t sC00=GetCovariance()[0];
323 if (sC00<=0 || sC00>(9.+maxMisalErrY2)) {
324 if (n>fgkWARN) Warning("Invariant","fC00=%f\n",sC00);
327 Double_t sC11=GetCovariance()[2];
328 if (sC11<=0 || sC11>(9.+maxMisalErrZ2)) {
329 if (n>fgkWARN) Warning("Invariant","fC11=%f\n",sC11);
332 Double_t sC22=GetCovariance()[5];
333 if (sC22<=0 || sC22>1.) {
334 if (n>fgkWARN) Warning("Invariant","fC22=%f\n",sC22);
337 Double_t sC33=GetCovariance()[9];
338 if (sC33<=0 || sC33>1.) {
339 if (n>fgkWARN) Warning("Invariant","fC33=%f\n",sC33);
342 Double_t sC44=GetCovariance()[14];
343 if (sC44<=0 /*|| sC44>6e-5*/) {
344 if (n>fgkWARN) Warning("Invariant","fC44=%f\n",sC44);
351 //____________________________________________________________________________
352 Bool_t AliITStrackV2::Propagate(Double_t alp,Double_t xk) {
353 //------------------------------------------------------------------
354 //This function propagates a track
355 //------------------------------------------------------------------
356 //Double_t bz=GetBz();
357 //if (!AliExternalTrackParam::Propagate(alp,xk,bz)) return kFALSE;
358 Double_t b[3]; GetBxByBz(b);
359 if (!AliExternalTrackParam::PropagateBxByBz(alp,xk,b)) return kFALSE;
362 Int_t n=GetNumberOfClusters();
363 if (n>fgkWARN) AliWarning("Wrong invariant !");
370 Bool_t AliITStrackV2::MeanBudgetToPrimVertex(Double_t xyz[3], Double_t step, Double_t &d) const {
372 //-------------------------------------------------------------------
373 // Get the mean material budget between the actual point and the
374 // primary vertex. (L.Gaudichet)
375 //-------------------------------------------------------------------
377 Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
378 Double_t vertexX = xyz[0]*cs + xyz[1]*sn;
380 Int_t nstep = Int_t((GetX()-vertexX)/step);
381 if (nstep<1) nstep = 1;
382 step = (GetX()-vertexX)/nstep;
384 // Double_t mparam[7], densMean=0, radLength=0, length=0;
386 Double_t p1[3], p2[3], x = GetX(), bz = GetBz();
391 for (Int_t i=0; i<nstep; i++) {
393 if (!GetXYZAt(x, bz, p2)) return kFALSE;
394 AliTracker::MeanMaterialBudget(p1, p2, mparam);
395 if (mparam[1]>900000) return kFALSE;
406 Bool_t AliITStrackV2::Improve(Double_t x0,Double_t xyz[3],Double_t ers[3]) {
407 //------------------------------------------------------------------
408 //This function improves angular track parameters
409 //------------------------------------------------------------------
410 //Store the initail track parameters
413 Double_t alpha = GetAlpha();
414 Double_t par[] = {GetY(),GetZ(),GetSnp(),GetTgl(),GetSigned1Pt()};
434 Double_t cs=TMath::Cos(GetAlpha()), sn=TMath::Sin(GetAlpha());
435 Double_t xv = xyz[0]*cs + xyz[1]*sn; // vertex
436 Double_t yv =-xyz[0]*sn + xyz[1]*cs; // in the
437 Double_t zv = xyz[2]; // local frame
439 Double_t dx = x - xv, dy = par[0] - yv, dz = par[1] - zv;
440 Double_t r2=dx*dx + dy*dy;
441 Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt());
442 Double_t beta2=p2/(p2 + GetMass()*GetMass());
443 x0*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
444 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*x0;
445 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*x0*9.36*2.33;
447 Double_t cnv=GetBz()*kB2C;
449 Double_t dummy = 4/r2 - GetC()*GetC();
450 if (dummy < 0) return kFALSE;
451 Double_t parp = 0.5*(GetC()*dx + dy*TMath::Sqrt(dummy));
452 Double_t sigma2p = theta2*(1.-GetSnp())*(1.+GetSnp())*(1. + GetTgl()*GetTgl());
453 Double_t ovSqr2 = 1./TMath::Sqrt(r2);
454 Double_t tfact = ovSqr2*(1.-dy*ovSqr2)*(1.+dy*ovSqr2);
455 sigma2p += cov[0]*tfact*tfact;
456 sigma2p += ers[1]*ers[1]/r2;
457 sigma2p += 0.25*cov[14]*cnv*cnv*dx*dx;
458 Double_t eps2p=sigma2p/(cov[5] + sigma2p);
459 par[0] += cov[3]/(cov[5] + sigma2p)*(parp - GetSnp());
460 par[2] = eps2p*GetSnp() + (1 - eps2p)*parp;
465 Double_t parl=0.5*GetC()*dz/TMath::ASin(0.5*GetC()*TMath::Sqrt(r2));
466 Double_t sigma2l=theta2;
467 sigma2l += cov[2]/r2 + cov[0]*dy*dy*dz*dz/(r2*r2*r2);
468 sigma2l += ers[2]*ers[2]/r2;
469 Double_t eps2l = sigma2l/(cov[9] + sigma2l);
470 par[1] += cov[7 ]/(cov[9] + sigma2l)*(parl - par[3]);
471 par[4] += cov[13]/(cov[9] + sigma2l)*(parl - par[3]);
472 par[3] = eps2l*par[3] + (1-eps2l)*parl;
478 Set(x,alpha,par,cov);
480 if (!Invariant()) return kFALSE;
485 void AliITStrackV2::CookdEdx(Double_t low, Double_t up) {
486 //-----------------------------------------------------------------
487 // This function calculates dE/dX within the "low" and "up" cuts.
488 // Origin: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
489 // Updated: F. Prino 8-June-2009
490 //-----------------------------------------------------------------
491 // The cluster order is: SDD-1, SDD-2, SSD-1, SSD-2
495 for (Int_t il=0; il<4; il++) { // count good (>0) dE/dx values
496 if(fdEdxSample[il]>0.){
497 dedx[nc]= fdEdxSample[il];
506 Int_t swap; // sort in ascending order
509 for (Int_t i=0; i<nc-1; i++) {
510 if (dedx[i]<=dedx[i+1]) continue;
519 Double_t nl=low*nc, nu =up*nc;
521 Float_t sumweight =0;
522 for (Int_t i=0; i<nc; i++) {
524 if (i<nl+0.1) weight = TMath::Max(1.-(nl-i),0.);
525 if (i>nu-1) weight = TMath::Max(nu-i,0.);
526 sumamp+= dedx[i]*weight;
529 SetdEdx(sumamp/sumweight);
532 //____________________________________________________________________________
533 Bool_t AliITStrackV2::
534 GetPhiZat(Double_t r, Double_t &phi, Double_t &z) const {
535 //------------------------------------------------------------------
536 // This function returns the global cylindrical (phi,z) of the track
537 // position estimated at the radius r.
538 // The track curvature is neglected.
539 //------------------------------------------------------------------
540 Double_t d=GetD(0.,0.);
541 if (TMath::Abs(d) > r) {
542 if (r>1e-1) return kFALSE;
546 Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
547 if (TMath::Abs(d) > rcurr) return kFALSE;
548 Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
549 Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
552 phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
554 phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
557 // return a phi in [0,2pi[
558 if (phi<0.) phi+=2.*TMath::Pi();
559 else if (phi>=2.*TMath::Pi()) phi-=2.*TMath::Pi();
560 z=GetZ()+GetTgl()*(TMath::Sqrt((r-d)*(r+d))-TMath::Sqrt((rcurr-d)*(rcurr+d)));
563 //____________________________________________________________________________
564 Bool_t AliITStrackV2::
565 GetLocalXat(Double_t r,Double_t &xloc) const {
566 //------------------------------------------------------------------
567 // This function returns the local x of the track
568 // position estimated at the radius r.
569 // The track curvature is neglected.
570 //------------------------------------------------------------------
571 Double_t d=GetD(0.,0.);
572 if (TMath::Abs(d) > r) {
573 if (r>1e-1) return kFALSE;
577 Double_t rcurr=TMath::Sqrt(GetX()*GetX() + GetY()*GetY());
578 Double_t globXYZcurr[3]; GetXYZ(globXYZcurr);
579 Double_t phicurr=TMath::ATan2(globXYZcurr[1],globXYZcurr[0]);
582 phi=phicurr+TMath::ASin(d/r)-TMath::ASin(d/rcurr);
584 phi=phicurr+TMath::ASin(d/r)+TMath::ASin(d/rcurr)-TMath::Pi();
587 xloc=r*(TMath::Cos(phi)*TMath::Cos(GetAlpha())
588 +TMath::Sin(phi)*TMath::Sin(GetAlpha()));