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 *
9 * without fee, provided that the above copyright notice appears in all *
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 **************************************************************************/
18 #include <Riostream.h>
22 #include "AliESDtrack.h"
23 #include "AliTRDgeometry.h"
24 #include "AliTRDcluster.h"
25 #include "AliTRDtrack.h"
26 #include "AliTRDtracklet.h"
30 ///////////////////////////////////////////////////////////////////////////////
32 // Represents a reconstructed TRD track //
33 // Local TRD Kalman track //
35 ///////////////////////////////////////////////////////////////////////////////
37 AliTRDtrack::AliTRDtrack():
78 for (Int_t i=0; i<kNplane; i++) {
79 for (Int_t j=0; j<kNslice; j++) {
84 for (UInt_t i=0; i<kMAXCLUSTERSPERTRACK; i++) {
89 for (Int_t i=0; i<3; i++) fBudget[i] = 0;
92 //_____________________________________________________________________________
93 AliTRDtrack::AliTRDtrack(const AliTRDcluster *c, UInt_t index,
94 const Double_t xx[5], const Double_t cc[15],
95 Double_t xref, Double_t alpha) : AliKalmanTrack() {
96 //-----------------------------------------------------------------
97 // This is the main track constructor.
98 //-----------------------------------------------------------------
103 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
104 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
108 fY=xx[0]; fZ=xx[1]; fE=xx[2]; fT=xx[3]; fC=xx[4];
110 SaveLocalConvConst();
113 fCzy=cc[1]; fCzz=cc[2];
114 fCey=cc[3]; fCez=cc[4]; fCee=cc[5];
115 fCty=cc[6]; fCtz=cc[7]; fCte=cc[8]; fCtt=cc[9];
116 fCcy=cc[10]; fCcz=cc[11]; fCce=cc[12]; fCct=cc[13]; fCcc=cc[14];
119 SetNumberOfClusters(1);
124 for (Int_t i=0;i<kNplane;i++){
125 for (Int_t j=0; j<kNslice; j++) {
126 fdEdxPlane[i][j] = 0;
128 fTimBinPlane[i] = -1;
141 Double_t q = TMath::Abs(c->GetQ());
142 Double_t s = fX*fC - fE, t=fT;
143 if(s*s < 1) q *= TMath::Sqrt((1-s*s)/(1+t*t));
147 // initialisation [SR, GSI 18.02.2003] (i startd for 1)
148 for(UInt_t i=1; i<kMAXCLUSTERSPERTRACK; i++) {
151 fIndexBackup[i] = 0; //backup indexes MI
153 for (Int_t i=0;i<3;i++) { fBudget[i]=0;};
159 //_____________________________________________________________________________
160 AliTRDtrack::AliTRDtrack(const AliTRDtrack& t) : AliKalmanTrack(t)
166 SetLabel(t.GetLabel());
167 fSeedLab=t.GetSeedLabel();
169 SetChi2(t.GetChi2());
173 for (Int_t i=0;i<kNplane;i++){
174 for (Int_t j=0; j<kNslice; j++) {
175 fdEdxPlane[i][j] = t.fdEdxPlane[i][j];
177 fTimBinPlane[i] = t.fTimBinPlane[i];
178 fTracklets[i] = t.fTracklets[i];
183 fNRotate = t.fNRotate;
184 fStopped = t.fStopped;
186 fNExpected = t.fNExpected;
187 fNExpectedLast = t.fNExpectedLast;
190 fChi2Last = t.fChi2Last;
196 fY=t.fY; fZ=t.fZ; fE=t.fE; fT=t.fT; fC=t.fC;
199 fCzy=t.fCzy; fCzz=t.fCzz;
200 fCey=t.fCey; fCez=t.fCez; fCee=t.fCee;
201 fCty=t.fCty; fCtz=t.fCtz; fCte=t.fCte; fCtt=t.fCtt;
202 fCcy=t.fCcy; fCcz=t.fCcz; fCce=t.fCce; fCct=t.fCct; fCcc=t.fCcc;
204 Int_t n=t.GetNumberOfClusters();
205 SetNumberOfClusters(n);
206 for (Int_t i=0; i<n; i++) {
207 fIndex[i]=t.fIndex[i];
208 fIndexBackup[i]=t.fIndex[i]; // MI - backup indexes
212 // initialisation (i starts from n) [SR, GSI, 18.02.2003]
213 for(UInt_t i=n; i<kMAXCLUSTERSPERTRACK; i++) {
216 fIndexBackup[i] = 0; //MI backup indexes
218 for (Int_t i=0;i<6;i++){
219 fTracklets[i] = t.fTracklets[i];
221 for (Int_t i=0;i<3;i++) { fBudget[i]=t.fBudget[i];};
224 //_____________________________________________________________________________
225 AliTRDtrack::AliTRDtrack(const AliKalmanTrack& t, Double_t alpha)
229 // Constructor from AliTPCtrack or AliITStrack .
232 SetLabel(t.GetLabel());
234 SetMass(t.GetMass());
235 SetNumberOfClusters(0);
237 fdEdx=t.GetPIDsignal();
239 for (Int_t i=0;i<kNplane;i++){
240 for (Int_t j=0;j<kNslice;j++){
241 fdEdxPlane[i][j] = 0.0;
243 fTimBinPlane[i] = -1;
259 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
260 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
262 Double_t x, p[5]; t.GetExternalParameters(x,p);
268 fT=p[3]; x=GetLocalConvConst();
272 //Conversion of the covariance matrix
273 Double_t c[15]; t.GetExternalCovariance(c);
275 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
277 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
278 Double_t c32=fX*c[13] - c[8];
279 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
282 fCzy=c[1 ]; fCzz=c[2 ];
283 fCey=c20; fCez=c21; fCee=c22;
284 fCty=c[6 ]; fCtz=c[7 ]; fCte=c32; fCtt=c[9 ];
285 fCcy=c[10]; fCcz=c[11]; fCce=c42; fCct=c[13]; fCcc=c[14];
287 // Initialization [SR, GSI, 18.02.2003]
288 for(UInt_t i=0; i<kMAXCLUSTERSPERTRACK; i++) {
291 fIndexBackup[i] = 0; // MI backup indexes
294 for (Int_t i=0;i<3;i++) { fBudget[i]=0;};
297 //_____________________________________________________________________________
298 AliTRDtrack::AliTRDtrack(const AliESDtrack& t)
302 // Constructor from AliESDtrack
305 SetLabel(t.GetLabel());
307 SetMass(t.GetMass());
308 SetNumberOfClusters(t.GetTRDclusters(fIndex));
309 Int_t ncl = t.GetTRDclusters(fIndexBackup);
310 for (UInt_t i=ncl;i<kMAXCLUSTERSPERTRACK;i++) {
312 fIndex[i] = 0; //MI store indexes
314 fdEdx=t.GetTRDsignal();
316 for (Int_t i=0;i<kNplane;i++){
317 for (Int_t j=0;j<kNslice;j++){
318 fdEdxPlane[i][j] = t.GetTRDsignals(i,j);
320 fTimBinPlane[i] = t.GetTRDTimBin(i);
335 fAlpha = t.GetAlpha();
336 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
337 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
339 Double_t x, p[5]; t.GetExternalParameters(x,p);
340 //Conversion of the covariance matrix
341 Double_t c[15]; t.GetExternalCovariance(c);
342 if (t.GetStatus()&AliESDtrack::kTRDbackup){
343 t.GetOuterExternalParameters(fAlpha,x,p);
344 t.GetOuterExternalCovariance(c);
345 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
346 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
352 fZ=p[1]; SaveLocalConvConst();
353 fT=p[3]; x=GetLocalConvConst();
358 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
360 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
361 Double_t c32=fX*c[13] - c[8];
362 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
365 fCzy=c[1 ]; fCzz=c[2 ];
366 fCey=c20; fCez=c21; fCee=c22;
367 fCty=c[6 ]; fCtz=c[7 ]; fCte=c32; fCtt=c[9 ];
368 fCcy=c[10]; fCcz=c[11]; fCce=c42; fCct=c[13]; fCcc=c[14];
370 // Initialization [SR, GSI, 18.02.2003]
371 for(UInt_t i=0; i<kMAXCLUSTERSPERTRACK; i++) {
373 // fIndex[i] = 0; //MI store indexes
376 for (Int_t i=0;i<3;i++) { fBudget[i]=0;};
377 if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
379 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
380 SetIntegratedLength(t.GetIntegratedLength());
384 //____________________________________________________________________________
385 AliTRDtrack::~AliTRDtrack()
391 if (fBackupTrack) delete fBackupTrack;
396 //____________________________________________________________________________
397 AliTRDtrack &AliTRDtrack::operator=(const AliTRDtrack &t)
400 // Assignment operator
415 fAlpha = t.GetAlpha();
416 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
417 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
423 // //____________________________________________________________________________
424 // AliTRDtrack * AliTRDtrack::MakeTrack(const AliTrackReference *ref, Double_t mass)
427 // // Make dummy track from the track reference
428 // // negative mass means opposite charge
432 // for (Int_t i=0;i<15;i++) cc[i]=0;
433 // Double_t x = ref->X(), y = ref->Y(), z = ref->Z();
434 // Double_t alpha = TMath::ATan2(y,x);
435 // Double_t xr = TMath::Sqrt(x*x+y*y);
438 // xx[3] = ref->Pz()/ref->Pt();
440 // Float_t xyz[3]={x,y,z};
441 // Float_t convConst = 0;
442 // (AliKalmanTrack::GetFieldMap())->Field(xyz,b);
443 // convConst=1000/0.299792458/(1e-13 - b[2]);
444 // xx[4] = 1./(convConst*ref->Pt());
445 // if (mass<0) xx[4]*=-1.; // negative mass - negative direction
446 // Double_t lcos = (x*ref->Px()+y*ref->Py())/(xr*ref->Pt());
447 // Double_t lsin = TMath::Sin(TMath::ACos(lcos));
448 // if (mass<0) lsin*=-1.;
449 // xx[2] = xr*xx[4]-lsin;
451 // AliTRDtrack * track = new AliTRDtrack(&cl,100,xx,cc,xr,alpha);
452 // track->SetMass(TMath::Abs(mass));
453 // track->StartTimeIntegral();
457 //____________________________________________________________________________
458 Float_t AliTRDtrack::StatusForTOF()
461 // Defines the status of the TOF extrapolation
464 Float_t res = (0.2 + 0.8*(fN/(fNExpected+5.)))*(0.4+0.6*fTracklets[5].GetN()/20.);
465 res *= (0.25+0.8*40./(40.+fBudget[2]));
469 if (GetNumberOfClusters()<20) return 0; //
470 if (fN>110&&fChi2/(Float_t(fN))<3) return 3; //gold
471 if (fNLast>30&&fChi2Last/(Float_t(fNLast))<3) return 3; //gold
472 if (fNLast>20&&fChi2Last/(Float_t(fNLast))<2) return 3; //gold
473 if (fNLast/(fNExpectedLast+3.)>0.8 && fChi2Last/Float_t(fNLast)<5&&fNLast>20) return 2; //silber
474 if (fNLast>5 &&((fNLast+1.)/(fNExpectedLast+1.))>0.8&&fChi2Last/(fNLast-5.)<6) return 1;
480 //____________________________________________________________________________
481 void AliTRDtrack::GetExternalParameters(Double_t& xr, Double_t x[5]) const
484 // This function returns external TRD track representation
496 //_____________________________________________________________________________
497 void AliTRDtrack::GetExternalCovariance(Double_t cc[15]) const
500 // This function returns external representation of the covriance matrix.
503 Double_t a=GetLocalConvConst();
505 Double_t c22=fX*fX*fCcc-2*fX*fCce+fCee;
506 Double_t c32=fX*fCct-fCte;
507 Double_t c20=fX*fCcy-fCey, c21=fX*fCcz-fCez, c42=fX*fCcc-fCce;
510 cc[1 ]=fCzy; cc[2 ]=fCzz;
511 cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
512 cc[6 ]=fCty; cc[7 ]=fCtz; cc[8 ]=c32; cc[9 ]=fCtt;
513 cc[10]=fCcy*a; cc[11]=fCcz*a; cc[12]=c42*a; cc[13]=fCct*a; cc[14]=fCcc*a*a;
517 //_____________________________________________________________________________
518 void AliTRDtrack::GetCovariance(Double_t cc[15]) const
521 // Returns the track covariance matrix
525 cc[1]=fCzy; cc[2]=fCzz;
526 cc[3]=fCey; cc[4]=fCez; cc[5]=fCee;
527 cc[6]=fCcy; cc[7]=fCcz; cc[8]=fCce; cc[9]=fCcc;
528 cc[10]=fCty; cc[11]=fCtz; cc[12]=fCte; cc[13]=fCct; cc[14]=fCtt;
532 //_____________________________________________________________________________
533 Int_t AliTRDtrack::Compare(const TObject *o) const
536 // Compares tracks according to their Y2 or curvature
539 AliTRDtrack *t=(AliTRDtrack*)o;
540 // Double_t co=t->GetSigmaY2();
541 // Double_t c =GetSigmaY2();
543 Double_t co=TMath::Abs(t->GetC());
544 Double_t c =TMath::Abs(GetC());
547 else if (c<co) return -1;
552 //_____________________________________________________________________________
553 void AliTRDtrack::CookdEdx(Double_t low, Double_t up) {
554 //-----------------------------------------------------------------
555 // Calculates dE/dX within the "low" and "up" cuts.
556 //-----------------------------------------------------------------
559 //Int_t nc=GetNumberOfClusters();
566 Float_t sorted[kMAXCLUSTERSPERTRACK];
567 for (i=0; i < nc; i++) {
570 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc);
572 //for (i=nl; i<=nu; i++) dedx += sorted[i];
574 for (i=0; i<nc; i++) dedx += sorted[i]; // ADDED by PS
575 if((nu-nl)) dedx /= (nu-nl); // ADDED by PS
579 // now real truncated mean
580 for (i=0; i < nc; i++) {
581 sorted[i]=TMath::Abs(fdQdl[i]);
583 Int_t * index = new Int_t[nc];
584 TMath::Sort(nc, sorted, index,kFALSE);
586 for (i=nl; i<=nu; i++) dedx += sorted[index[i]];
594 //_____________________________________________________________________________
595 Int_t AliTRDtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho)
597 // Propagates a track of particle with mass=pm to a reference plane
598 // defined by x=xk through media of density=rho and radiationLength=x0
600 if (xk == fX) return 1;
602 if (TMath::Abs(fC*xk - fE) >= 0.90000) {
603 // Int_t n=GetNumberOfClusters();
604 //if (n>4) cerr << n << " AliTRDtrack: Propagation failed, \tPt = "
605 // << GetPt() << "\t" << GetLabel() << "\t" << GetMass() << endl;
608 Double_t lcc=GetLocalConvConst();
610 // track Length measurement [SR, GSI, 17.02.2003]
611 Double_t oldX = fX, oldY = fY, oldZ = fZ;
613 Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fY, z1=fZ;
614 Double_t c1=fC*x1 - fE;
615 if((c1*c1) > 1) return 0;
616 Double_t r1=sqrt(1.- c1*c1);
617 Double_t c2=fC*x2 - fE;
618 if((c2*c2) > 1) return 0;
619 Double_t r2=sqrt(1.- c2*c2);
621 fY += dx*(c1+c2)/(r1+r2);
622 fZ += dx*(c1+c2)/(c1*r2 + c2*r1)*fT;
625 Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
626 Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
627 Double_t f04= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
628 Double_t cr=c1*r2+c2*r1;
629 Double_t f12=-dx*fT*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
630 Double_t f13= dx*cc/cr;
631 Double_t f14=dx*fT*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
634 Double_t b00=f02*fCey + f04*fCcy, b01=f12*fCey + f14*fCcy + f13*fCty;
635 Double_t b10=f02*fCez + f04*fCcz, b11=f12*fCez + f14*fCcz + f13*fCtz;
636 Double_t b20=f02*fCee + f04*fCce, b21=f12*fCee + f14*fCce + f13*fCte;
637 Double_t b30=f02*fCte + f04*fCct, b31=f12*fCte + f14*fCct + f13*fCtt;
638 Double_t b40=f02*fCce + f04*fCcc, b41=f12*fCce + f14*fCcc + f13*fCct;
641 Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a11=f12*b21+f14*b41+f13*b31;
643 //F*C*Ft = C + (a + b + bt)
645 fCzy += a01 + b01 + b10;
656 //Change of the magnetic field *************
657 SaveLocalConvConst();
659 fC*=lcc/GetLocalConvConst();
662 //Multiple scattering ******************
663 Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fY)*(y1-fY)+(z1-fZ)*(z1-fZ));
664 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
665 Double_t beta2=p2/(p2 + GetMass()*GetMass());
666 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
668 Double_t ey=fC*fX - fE, ez=fT;
669 Double_t xz=fC*ez, zz1=ez*ez+1, xy=fE+ey;
671 fCee += (2*ey*ez*ez*fE+1-ey*ey+ez*ez+fE*fE*ez*ez)*theta2;
672 fCte += ez*zz1*xy*theta2;
673 fCtt += zz1*zz1*theta2;
674 fCce += xz*ez*xy*theta2;
675 fCct += xz*zz1*theta2;
676 fCcc += xz*xz*theta2;
678 Double_t dc22 = (1-ey*ey+xz*xz*fX*fX)*theta2;
679 Double_t dc32 = (xz*fX*zz1)*theta2;
680 Double_t dc33 = (zz1*zz1)*theta2;
681 Double_t dc42 = (xz*fX*xz)*theta2;
682 Double_t dc43 = (zz1*xz)*theta2;
683 Double_t dc44 = (xz*xz)*theta2;
691 //Energy losses************************
692 if((5940*beta2/(1-beta2+1e-10) - beta2) < 0) return 0;
694 Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2+1e-10)) - beta2)*d*rho;
695 Float_t budget = d* rho;
698 // suspicious part - think about it ?
699 Double_t kinE = TMath::Sqrt(p2);
700 if (dE>0.8*kinE) dE = 0.8*kinE; //
701 if (dE<0) dE = 0.0; // not valid region for Bethe bloch
707 fC*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE);
709 // Double_t sigmade = 0.1*dE*TMath::Sqrt(TMath::Sqrt(1+fT*fT)*90./(d+0.0001)); // 20 percent fluctuation - normalized to some length
710 Double_t sigmade = 0.07*TMath::Sqrt(TMath::Abs(dE)); // energy loss fluctuation
711 Double_t sigmac2 = sigmade*sigmade*fC*fC*(p2+GetMass()*GetMass())/(p2*p2);
713 fCee += fX*fX*sigmac2;
715 // track time measurement [SR, GSI 17.02.2002]
717 if (IsStartedTimeIntegral()) {
718 Double_t l2 = TMath::Sqrt((fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY) + (fZ-oldZ)*(fZ-oldZ));
719 if (TMath::Abs(l2*fC)>0.0001){
720 // make correction for curvature if neccesary
721 l2 = 0.5*TMath::Sqrt((fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY));
722 l2 = 2*TMath::ASin(l2*fC)/fC;
723 l2 = TMath::Sqrt(l2*l2+(fZ-oldZ)*(fZ-oldZ));
732 //_____________________________________________________________________________
733 Int_t AliTRDtrack::Update(const AliTRDcluster *c, Double_t chisq, UInt_t index
736 // Assignes found cluster to the track and updates track information
738 Bool_t fNoTilt = kTRUE;
739 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
740 // add angular effect to the error contribution - MI
741 Float_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
742 if (tangent2 < 0.90000){
743 tangent2 = tangent2/(1.-tangent2);
745 Float_t errang = tangent2*0.04; //
746 Float_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
748 Double_t r00=c->GetSigmaY2() +errang, r01=0., r11=c->GetSigmaZ2()*100.;
749 r00+=fCyy; r01+=fCzy; r11+=fCzz;
750 Double_t det=r00*r11 - r01*r01;
751 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
753 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
754 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
755 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
756 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
757 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
759 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
760 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
764 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
765 // Int_t n=GetNumberOfClusters();
766 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
769 fY += k00*dy + k01*dz;
770 fZ += k10*dy + k11*dz;
772 //fT += k30*dy + k31*dz;
776 Double_t xuFactor = 100.; // empirical factor set by C.Xu
777 // in the first tilt version
778 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
781 if (TMath::Abs(dz)>padlength/2.){
782 Float_t dy2 = c->GetY() - fY;
783 Float_t sign = (dz>0) ? -1.: 1.;
784 dy2+=h01*sign*padlength/2.;
791 r00=c->GetSigmaY2()+errang+add, r01=0., r11=c->GetSigmaZ2()*xuFactor;
792 r00+=(fCyy+2.0*h01*fCzy+h01*h01*fCzz);
793 r01+=(fCzy+h01*fCzz);
796 det=r00*r11 - r01*r01;
797 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
799 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
800 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
801 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
802 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
803 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
806 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
807 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
808 // Int_t n=GetNumberOfClusters();
809 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
812 fY += k00*dy + k01*dz;
813 fZ += k10*dy + k11*dz;
815 fT += k30*dy + k31*dz;
825 Double_t c01=fCzy, c02=fCey, c03=fCty, c04=fCcy;
826 Double_t c12=fCez, c13=fCtz, c14=fCcz;
829 fCyy-=k00*fCyy+k01*fCzy; fCzy-=k00*c01+k01*fCzz;
830 fCey-=k00*c02+k01*c12; fCty-=k00*c03+k01*c13;
831 fCcy-=k00*c04+k01*c14;
833 fCzz-=k10*c01+k11*fCzz;
834 fCez-=k10*c02+k11*c12; fCtz-=k10*c03+k11*c13;
835 fCcz-=k10*c04+k11*c14;
837 fCee-=k20*c02+k21*c12; fCte-=k20*c03+k21*c13;
838 fCce-=k20*c04+k21*c14;
840 fCtt-=k30*c03+k31*c13;
841 fCct-=k40*c03+k41*c13;
842 //fCct-=k30*c04+k31*c14; // symmetric formula MI
844 fCcc-=k40*c04+k41*c14;
846 Int_t n=GetNumberOfClusters();
848 SetNumberOfClusters(n+1);
850 SetChi2(GetChi2()+chisq);
851 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
857 //_____________________________________________________________________________
858 Int_t AliTRDtrack::UpdateMI(const AliTRDcluster *c, Double_t chisq, UInt_t index, Double_t h01,
861 // Assignes found cluster to the track and updates track information
863 Bool_t fNoTilt = kTRUE;
864 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
865 // add angular effect to the error contribution and make correction - MI
866 //AliTRDclusterCorrection *corrector = AliTRDclusterCorrection::GetCorrection();
868 Double_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
869 if (tangent2 < 0.90000){
870 tangent2 = tangent2/(1.-tangent2);
872 Double_t tangent = TMath::Sqrt(tangent2);
873 if ((fC*fX-fE)<0) tangent*=-1;
874 // Double_t correction = 0*plane;
875 Double_t errang = tangent2*0.04; //
876 Double_t errsys =0.025*0.025*20; //systematic error part
878 if (c->GetNPads()==4) extend=2;
879 //if (c->GetNPads()==5) extend=3;
880 //if (c->GetNPads()==6) extend=3;
881 //if (c->GetQ()<15) return 1;
886 correction = corrector->GetCorrection(plane,c->GetLocalTimeBin(),tangent);
887 if (TMath::Abs(correction)>0){
889 errang = corrector->GetSigma(plane,c->GetLocalTimeBin(),tangent);
891 errang += tangent2*0.04;
896 // Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
898 Double_t r00=(c->GetSigmaY2() +errang+errsys)*extend, r01=0., r11=c->GetSigmaZ2()*10000.;
899 r00+=fCyy; r01+=fCzy; r11+=fCzz;
900 Double_t det=r00*r11 - r01*r01;
901 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
903 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
904 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
905 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
906 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
907 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
909 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
910 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
914 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
915 // Int_t n=GetNumberOfClusters();
916 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
919 fY += k00*dy + k01*dz;
920 fZ += k10*dy + k11*dz;
922 //fT += k30*dy + k31*dz;
926 Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12);
928 Double_t xuFactor = 1000.; // empirical factor set by C.Xu
929 // in the first tilt version
930 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
931 //dy=dy+h01*dz+correction;
933 Double_t tiltdz = dz;
934 if (TMath::Abs(tiltdz)>padlength/2.) {
935 tiltdz = TMath::Sign(padlength/2,dz);
941 if (TMath::Abs(dz)>padlength/2.){
942 //Double_t dy2 = c->GetY() - fY;
943 //Double_t sign = (dz>0) ? -1.: 1.;
944 //dy2-=h01*sign*padlength/2.;
948 Double_t s00 = (c->GetSigmaY2()+errang)*extend+errsys+add; // error pad
949 Double_t s11 = c->GetSigmaZ2()*xuFactor; // error pad-row
951 r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
952 r01 = fCzy + fCzz*h01;
954 det = r00*r11 - r01*r01;
956 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
959 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
960 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
961 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
962 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
963 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
966 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
967 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
968 //Int_t n=GetNumberOfClusters();
969 // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
972 fY += k00*dy + k01*dz;
973 fZ += k10*dy + k11*dz;
975 fT += k30*dy + k31*dz;
988 Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
989 Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
990 Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
991 //Double_t oldte = fCte, oldce = fCce;
992 //Double_t oldct = fCct;
994 fCyy-=k00*oldyy+k01*oldzy;
995 fCzy-=k10*oldyy+k11*oldzy;
996 fCey-=k20*oldyy+k21*oldzy;
997 fCty-=k30*oldyy+k31*oldzy;
998 fCcy-=k40*oldyy+k41*oldzy;
1000 fCzz-=k10*oldzy+k11*oldzz;
1001 fCez-=k20*oldzy+k21*oldzz;
1002 fCtz-=k30*oldzy+k31*oldzz;
1003 fCcz-=k40*oldzy+k41*oldzz;
1005 fCee-=k20*oldey+k21*oldez;
1006 fCte-=k30*oldey+k31*oldez;
1007 fCce-=k40*oldey+k41*oldez;
1009 fCtt-=k30*oldty+k31*oldtz;
1010 fCct-=k40*oldty+k41*oldtz;
1012 fCcc-=k40*oldcy+k41*oldcz;
1015 Int_t n=GetNumberOfClusters();
1017 SetNumberOfClusters(n+1);
1019 SetChi2(GetChi2()+chisq);
1020 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
1026 //_____________________________________________________________________________
1027 Int_t AliTRDtrack::UpdateMI(const AliTRDtracklet &tracklet)
1030 // Assignes found tracklet to the track and updates track information
1033 Double_t r00=(tracklet.GetTrackletSigma2()), r01=0., r11= 10000.;
1034 r00+=fCyy; r01+=fCzy; r11+=fCzz;
1036 Double_t det=r00*r11 - r01*r01;
1037 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
1040 Double_t dy=tracklet.GetY() - fY, dz=tracklet.GetZ() - fZ;
1043 Double_t s00 = tracklet.GetTrackletSigma2(); // error pad
1044 Double_t s11 = 100000; // error pad-row
1045 Float_t h01 = tracklet.GetTilt();
1047 // r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
1048 r00 = fCyy + fCzz*h01*h01+s00;
1049 // r01 = fCzy + fCzz*h01;
1052 det = r00*r11 - r01*r01;
1054 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
1056 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
1057 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
1058 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
1059 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
1060 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
1063 // k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
1064 // k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
1065 // k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
1066 // k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
1067 // k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
1069 //Update measurement
1070 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
1071 // cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
1072 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
1073 //Int_t n=GetNumberOfClusters();
1074 // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
1084 fY += k00*dy + k01*dz;
1085 fZ += k10*dy + k11*dz;
1087 fT += k30*dy + k31*dz;
1094 Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
1095 Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
1096 Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
1097 //Double_t oldte = fCte, oldce = fCce;
1098 //Double_t oldct = fCct;
1100 fCyy-=k00*oldyy+k01*oldzy;
1101 fCzy-=k10*oldyy+k11*oldzy;
1102 fCey-=k20*oldyy+k21*oldzy;
1103 fCty-=k30*oldyy+k31*oldzy;
1104 fCcy-=k40*oldyy+k41*oldzy;
1106 fCzz-=k10*oldzy+k11*oldzz;
1107 fCez-=k20*oldzy+k21*oldzz;
1108 fCtz-=k30*oldzy+k31*oldzz;
1109 fCcz-=k40*oldzy+k41*oldzz;
1111 fCee-=k20*oldey+k21*oldez;
1112 fCte-=k30*oldey+k31*oldez;
1113 fCce-=k40*oldey+k41*oldez;
1115 fCtt-=k30*oldty+k31*oldtz;
1116 fCct-=k40*oldty+k41*oldtz;
1118 fCcc-=k40*oldcy+k41*oldcz;
1121 Int_t n=GetNumberOfClusters();
1123 SetNumberOfClusters(n+1);
1125 SetChi2(GetChi2()+chisq);
1126 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
1133 //_____________________________________________________________________________
1134 Int_t AliTRDtrack::Rotate(Double_t alpha, Bool_t absolute)
1136 // Rotates track parameters in R*phi plane
1137 // if absolute rotation alpha is in global system
1138 // otherwise alpha rotation is relative to the current rotation angle
1148 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
1149 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
1151 Double_t x1=fX, y1=fY;
1152 Double_t ca=cos(alpha), sa=sin(alpha);
1153 Double_t r1=fC*fX - fE;
1157 if((r1*r1) > 1) return 0;
1158 fE=fE*ca + (fC*y1 + sqrt(1.- r1*r1))*sa;
1160 Double_t r2=fC*fX - fE;
1161 if (TMath::Abs(r2) >= 0.90000) {
1162 Int_t n=GetNumberOfClusters();
1163 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !\n";
1167 if((r2*r2) > 1) return 0;
1168 Double_t y0=fY + sqrt(1.- r2*r2)/fC;
1169 if ((fY-y0)*fC >= 0.) {
1170 Int_t n=GetNumberOfClusters();
1171 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !!!\n";
1176 Double_t f00=ca-1, f24=(y1 - r1*x1/sqrt(1.- r1*r1))*sa,
1177 f20=fC*sa, f22=(ca + sa*r1/sqrt(1.- r1*r1))-1;
1180 Double_t b00=fCyy*f00, b02=fCyy*f20+fCcy*f24+fCey*f22;
1181 Double_t b10=fCzy*f00, b12=fCzy*f20+fCcz*f24+fCez*f22;
1182 Double_t b20=fCey*f00, b22=fCey*f20+fCce*f24+fCee*f22;
1183 Double_t b30=fCty*f00, b32=fCty*f20+fCct*f24+fCte*f22;
1184 Double_t b40=fCcy*f00, b42=fCcy*f20+fCcc*f24+fCce*f22;
1187 Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f24*b42+f22*b22;
1189 //F*C*Ft = C + (a + b + bt)
1190 fCyy += a00 + 2*b00;
1192 fCey += a02+b20+b02;
1197 fCee += a22 + 2*b22;
1204 //_____________________________________________________________________________
1205 Double_t AliTRDtrack::GetPredictedChi2(const AliTRDcluster *c, Double_t h01) const
1208 // Returns the track chi2
1211 Bool_t fNoTilt = kTRUE;
1212 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
1213 Double_t chi2, dy, r00, r01, r11;
1217 r00=c->GetSigmaY2();
1221 Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12);
1223 r00=c->GetSigmaY2(); r01=0.; r11=c->GetSigmaZ2();
1224 r00+=fCyy; r01+=fCzy; r11+=fCzz;
1226 Double_t det=r00*r11 - r01*r01;
1227 if (TMath::Abs(det) < 1.e-10) {
1228 Int_t n=GetNumberOfClusters();
1229 if (n>4) cerr<<n<<" AliTRDtrack warning: Singular matrix !\n";
1232 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
1233 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
1234 Double_t tiltdz = dz;
1235 if (TMath::Abs(tiltdz)>padlength/2.) {
1236 tiltdz = TMath::Sign(padlength/2,dz);
1241 chi2 = (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
1248 //_________________________________________________________________________
1249 void AliTRDtrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const
1251 // Returns reconstructed track momentum in the global system.
1253 Double_t pt=TMath::Abs(GetPt()); // GeV/c
1254 Double_t r=fC*fX-fE;
1257 if(r > 1) { py = pt; px = 0; }
1258 else if(r < -1) { py = -pt; px = 0; }
1260 y0=fY + sqrt(1.- r*r)/fC;
1261 px=-pt*(fY-y0)*fC; //cos(phi);
1262 py=-pt*(fE-fX*fC); //sin(phi);
1265 Double_t tmp=px*TMath::Cos(fAlpha) - py*TMath::Sin(fAlpha);
1266 py=px*TMath::Sin(fAlpha) + py*TMath::Cos(fAlpha);
1271 //_________________________________________________________________________
1272 void AliTRDtrack::GetGlobalXYZ(Double_t& x, Double_t& y, Double_t& z) const
1274 // Returns reconstructed track coordinates in the global system.
1276 x = fX; y = fY; z = fZ;
1277 Double_t tmp=x*TMath::Cos(fAlpha) - y*TMath::Sin(fAlpha);
1278 y=x*TMath::Sin(fAlpha) + y*TMath::Cos(fAlpha);
1283 //_________________________________________________________________________
1284 void AliTRDtrack::ResetCovariance()
1287 // Resets covariance matrix
1292 fCey=0.; fCez=0.; fCee*=10.;
1293 fCty=0.; fCtz=0.; fCte=0.; fCtt*=10.;
1294 fCcy=0.; fCcz=0.; fCce=0.; fCct=0.; fCcc*=10.;
1298 //_____________________________________________________________________________
1299 void AliTRDtrack::ResetCovariance(Float_t mult)
1302 // Resets covariance matrix
1307 fCey*=0.; fCez*=0.; fCee*=mult;
1308 fCty*=0.; fCtz*=0.; fCte*=0.; fCtt*=1.;
1309 fCcy*=0.; fCcz*=0.; fCce*=0.; fCct*=0.; fCcc*=mult;
1313 //_____________________________________________________________________________
1314 void AliTRDtrack::MakeBackupTrack()
1317 // Creates a backup track
1320 if (fBackupTrack) delete fBackupTrack;
1321 fBackupTrack = new AliTRDtrack(*this);
1325 //_____________________________________________________________________________
1326 Int_t AliTRDtrack::GetProlongation(Double_t xk, Double_t &y, Double_t &z)
1329 // Find prolongation at given x
1330 // return 0 if not exist
1332 Double_t c1=fC*fX - fE;
1333 if (TMath::Abs(c1)>1.) return 0;
1334 Double_t r1=TMath::Sqrt(1.- c1*c1);
1335 Double_t c2=fC*xk - fE;
1336 if (TMath::Abs(c2)>1.) return 0;
1337 Double_t r2=TMath::Sqrt(1.- c2*c2);
1338 y =fY + (xk-fX)*(c1+c2)/(r1+r2);
1339 z =fZ + (xk-fX)*(c1+c2)/(c1*r2 + c2*r1)*fT;
1345 //_____________________________________________________________________________
1346 Int_t AliTRDtrack::PropagateToX(Double_t xr, Double_t step)
1349 // Propagate track to given x position
1350 // works inside of the 20 degree segmentation (local cooordinate frame for TRD , TPC, TOF)
1352 // material budget from geo manager
1354 Double_t xyz0[3], xyz1[3],y,z;
1355 const Double_t kAlphac = TMath::Pi()/9.;
1356 const Double_t kTalphac = TMath::Tan(kAlphac*0.5);
1357 // critical alpha - cross sector indication
1359 Double_t dir = (fX>xr) ? -1.:1.;
1361 for (Double_t x=fX+dir*step;dir*x<dir*xr;x+=dir*step){
1363 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1364 GetProlongation(x,y,z);
1365 xyz1[0] = x*TMath::Cos(fAlpha)+y*TMath::Sin(fAlpha);
1366 xyz1[1] = x*TMath::Sin(fAlpha)-y*TMath::Cos(fAlpha);
1369 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1371 if (param[0]>0&¶m[1]>0) PropagateTo(x,param[1],param[0]);
1372 if (fY>fX*kTalphac){
1375 if (fY<-fX*kTalphac){
1386 //_____________________________________________________________________________
1387 Int_t AliTRDtrack::PropagateToR(Double_t r,Double_t step)
1390 // propagate track to the radial position
1391 // rotation always connected to the last track position
1393 Double_t xyz0[3], xyz1[3],y,z;
1394 Double_t radius = TMath::Sqrt(fX*fX+fY*fY);
1395 Double_t dir = (radius>r) ? -1.:1.; // direction +-
1397 for (Double_t x=radius+dir*step;dir*x<dir*r;x+=dir*step){
1398 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1399 Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
1400 Rotate(alpha,kTRUE);
1401 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1402 GetProlongation(x,y,z);
1403 xyz1[0] = x*TMath::Cos(alpha)+y*TMath::Sin(alpha);
1404 xyz1[1] = x*TMath::Sin(alpha)-y*TMath::Cos(alpha);
1407 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1408 if (param[1]<=0) param[1] =100000000;
1409 PropagateTo(x,param[1],param[0]);
1411 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1412 Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
1413 Rotate(alpha,kTRUE);
1414 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1415 GetProlongation(r,y,z);
1416 xyz1[0] = r*TMath::Cos(alpha)+y*TMath::Sin(alpha);
1417 xyz1[1] = r*TMath::Sin(alpha)-y*TMath::Cos(alpha);
1420 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1422 if (param[1]<=0) param[1] =100000000;
1423 PropagateTo(r,param[1],param[0]);
1429 //_____________________________________________________________________________
1430 Int_t AliTRDtrack::GetSector() const
1433 // Return the current sector
1436 return Int_t(TVector2::Phi_0_2pi(fAlpha)
1437 / AliTRDgeometry::GetAlpha())
1438 % AliTRDgeometry::kNsect;
1442 //_____________________________________________________________________________
1443 Double_t AliTRDtrack::Get1Pt() const
1449 return (TMath::Sign(1e-9,fC) + fC)*GetLocalConvConst();
1453 //_____________________________________________________________________________
1454 Double_t AliTRDtrack::GetP() const
1457 // Returns the total momentum
1460 return TMath::Abs(GetPt())*sqrt(1.+GetTgl()*GetTgl());
1464 //_____________________________________________________________________________
1465 Double_t AliTRDtrack::GetYat(Double_t xk) const
1468 // This function calculates the Y-coordinate of a track at
1469 // the plane x = xk.
1470 // Needed for matching with the TOF (I.Belikov)
1473 Double_t c1 = fC*fX - fE;
1474 Double_t r1 = TMath::Sqrt(1.0 - c1*c1);
1475 Double_t c2 = fC*xk - fE;
1476 Double_t r2 = TMath::Sqrt(1.0- c2*c2);
1477 return fY + (xk-fX)*(c1+c2)/(r1+r2);
1481 //_____________________________________________________________________________
1482 void AliTRDtrack::SetSampledEdx(Float_t q, Int_t i)
1485 // The sampled energy loss
1488 Double_t s = GetSnp();
1489 Double_t t = GetTgl();
1490 q *= TMath::Sqrt((1-s*s)/(1+t*t));
1495 //_____________________________________________________________________________
1496 void AliTRDtrack::SetSampledEdx(Float_t q)
1499 // The sampled energy loss
1502 Double_t s = GetSnp();
1503 Double_t t = GetTgl();
1504 q*= TMath::Sqrt((1-s*s)/(1+t*t));
1510 //_____________________________________________________________________________
1511 void AliTRDtrack::GetXYZ(Float_t r[3]) const
1514 //---------------------------------------------------------------------
1515 // Returns the position of the track in the global coord. system
1516 //---------------------------------------------------------------------
1518 Double_t cs = TMath::Cos(fAlpha);
1519 Double_t sn = TMath::Sin(fAlpha);
1520 r[0] = fX*cs - fY*sn;
1521 r[1] = fX*sn + fY*cs;