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>
21 #include "AliESDtrack.h"
22 #include "AliTRDgeometry.h"
23 #include "AliTRDcluster.h"
24 #include "AliTRDtrack.h"
25 #include "AliTRDtracklet.h"
29 ///////////////////////////////////////////////////////////////////////////////
31 // Represents a reconstructed TRD track //
32 // Local TRD Kalman track //
34 ///////////////////////////////////////////////////////////////////////////////
36 //_____________________________________________________________________________
37 AliTRDtrack::AliTRDtrack(const AliTRDcluster *c, UInt_t index,
38 const Double_t xx[5], const Double_t cc[15],
39 Double_t xref, Double_t alpha) : AliKalmanTrack() {
40 //-----------------------------------------------------------------
41 // This is the main track constructor.
42 //-----------------------------------------------------------------
47 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
48 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
52 fY=xx[0]; fZ=xx[1]; fE=xx[2]; fT=xx[3]; fC=xx[4];
57 fCzy=cc[1]; fCzz=cc[2];
58 fCey=cc[3]; fCez=cc[4]; fCee=cc[5];
59 fCty=cc[6]; fCtz=cc[7]; fCte=cc[8]; fCtt=cc[9];
60 fCcy=cc[10]; fCcz=cc[11]; fCce=cc[12]; fCct=cc[13]; fCcc=cc[14];
63 SetNumberOfClusters(1);
68 for (Int_t i=0;i<kNplane;i++){
83 Double_t q = TMath::Abs(c->GetQ());
84 Double_t s = fX*fC - fE, t=fT;
85 if(s*s < 1) q *= TMath::Sqrt((1-s*s)/(1+t*t));
89 // initialisation [SR, GSI 18.02.2003] (i startd for 1)
90 for(UInt_t i=1; i<kMAXCLUSTERSPERTRACK; i++) {
93 fIndexBackup[i] = 0; //backup indexes MI
95 for (Int_t i=0;i<3;i++) { fBudget[i]=0;};
101 //_____________________________________________________________________________
102 AliTRDtrack::AliTRDtrack(const AliTRDtrack& t) : AliKalmanTrack(t)
108 SetLabel(t.GetLabel());
109 fSeedLab=t.GetSeedLabel();
111 SetChi2(t.GetChi2());
115 for (Int_t i=0;i<kNplane;i++){
116 fdEdxPlane[i] = t.fdEdxPlane[i];
117 fTimBinPlane[i] = t.fTimBinPlane[i];
118 fTracklets[i] = t.fTracklets[i];
123 fNRotate = t.fNRotate;
124 fStopped = t.fStopped;
126 fNExpected = t.fNExpected;
127 fNExpectedLast = t.fNExpectedLast;
130 fChi2Last = t.fChi2Last;
136 fY=t.fY; fZ=t.fZ; fE=t.fE; fT=t.fT; fC=t.fC;
139 fCzy=t.fCzy; fCzz=t.fCzz;
140 fCey=t.fCey; fCez=t.fCez; fCee=t.fCee;
141 fCty=t.fCty; fCtz=t.fCtz; fCte=t.fCte; fCtt=t.fCtt;
142 fCcy=t.fCcy; fCcz=t.fCcz; fCce=t.fCce; fCct=t.fCct; fCcc=t.fCcc;
144 Int_t n=t.GetNumberOfClusters();
145 SetNumberOfClusters(n);
146 for (Int_t i=0; i<n; i++) {
147 fIndex[i]=t.fIndex[i];
148 fIndexBackup[i]=t.fIndex[i]; // MI - backup indexes
152 // initialisation (i starts from n) [SR, GSI, 18.02.2003]
153 for(UInt_t i=n; i<kMAXCLUSTERSPERTRACK; i++) {
156 fIndexBackup[i] = 0; //MI backup indexes
158 for (Int_t i=0;i<6;i++){
159 fTracklets[i] = t.fTracklets[i];
161 for (Int_t i=0;i<3;i++) { fBudget[i]=t.fBudget[i];};
164 //_____________________________________________________________________________
165 AliTRDtrack::AliTRDtrack(const AliKalmanTrack& t, Double_t alpha)
169 // Constructor from AliTPCtrack or AliITStrack .
172 SetLabel(t.GetLabel());
174 SetMass(t.GetMass());
175 SetNumberOfClusters(0);
177 fdEdx=t.GetPIDsignal();
179 for (Int_t i=0;i<kNplane;i++){
181 fTimBinPlane[i] = -1;
197 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
198 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
200 Double_t x, p[5]; t.GetExternalParameters(x,p);
206 fT=p[3]; x=GetLocalConvConst();
210 //Conversion of the covariance matrix
211 Double_t c[15]; t.GetExternalCovariance(c);
213 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
215 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
216 Double_t c32=fX*c[13] - c[8];
217 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
220 fCzy=c[1 ]; fCzz=c[2 ];
221 fCey=c20; fCez=c21; fCee=c22;
222 fCty=c[6 ]; fCtz=c[7 ]; fCte=c32; fCtt=c[9 ];
223 fCcy=c[10]; fCcz=c[11]; fCce=c42; fCct=c[13]; fCcc=c[14];
225 // Initialization [SR, GSI, 18.02.2003]
226 for(UInt_t i=0; i<kMAXCLUSTERSPERTRACK; i++) {
229 fIndexBackup[i] = 0; // MI backup indexes
232 for (Int_t i=0;i<3;i++) { fBudget[i]=0;};
235 //_____________________________________________________________________________
236 AliTRDtrack::AliTRDtrack(const AliESDtrack& t)
240 // Constructor from AliESDtrack
243 SetLabel(t.GetLabel());
245 SetMass(t.GetMass());
246 SetNumberOfClusters(t.GetTRDclusters(fIndex));
247 Int_t ncl = t.GetTRDclusters(fIndexBackup);
248 for (UInt_t i=ncl;i<kMAXCLUSTERSPERTRACK;i++) {
250 fIndex[i] = 0; //MI store indexes
252 fdEdx=t.GetTRDsignal();
254 for (Int_t i=0;i<kNplane;i++){
255 fdEdxPlane[i] = t.GetTRDsignals(i);
256 fTimBinPlane[i] = t.GetTRDTimBin(i);
271 fAlpha = t.GetAlpha();
272 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
273 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
275 Double_t x, p[5]; t.GetExternalParameters(x,p);
276 //Conversion of the covariance matrix
277 Double_t c[15]; t.GetExternalCovariance(c);
278 if (t.GetStatus()&AliESDtrack::kTRDbackup){
279 t.GetOuterExternalParameters(fAlpha,x,p);
280 t.GetOuterExternalCovariance(c);
281 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
282 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
288 fZ=p[1]; SaveLocalConvConst();
289 fT=p[3]; x=GetLocalConvConst();
294 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
296 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
297 Double_t c32=fX*c[13] - c[8];
298 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
301 fCzy=c[1 ]; fCzz=c[2 ];
302 fCey=c20; fCez=c21; fCee=c22;
303 fCty=c[6 ]; fCtz=c[7 ]; fCte=c32; fCtt=c[9 ];
304 fCcy=c[10]; fCcz=c[11]; fCce=c42; fCct=c[13]; fCcc=c[14];
306 // Initialization [SR, GSI, 18.02.2003]
307 for(UInt_t i=0; i<kMAXCLUSTERSPERTRACK; i++) {
309 // fIndex[i] = 0; //MI store indexes
312 for (Int_t i=0;i<3;i++) { fBudget[i]=0;};
313 if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
315 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
316 SetIntegratedLength(t.GetIntegratedLength());
320 //____________________________________________________________________________
321 AliTRDtrack::~AliTRDtrack()
327 if (fBackupTrack) delete fBackupTrack;
332 //____________________________________________________________________________
333 AliTRDtrack &AliTRDtrack::operator=(const AliTRDtrack &t)
336 // Assignment operator
351 fAlpha = t.GetAlpha();
352 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
353 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
359 // //____________________________________________________________________________
360 // AliTRDtrack * AliTRDtrack::MakeTrack(const AliTrackReference *ref, Double_t mass)
363 // // Make dummy track from the track reference
364 // // negative mass means opposite charge
368 // for (Int_t i=0;i<15;i++) cc[i]=0;
369 // Double_t x = ref->X(), y = ref->Y(), z = ref->Z();
370 // Double_t alpha = TMath::ATan2(y,x);
371 // Double_t xr = TMath::Sqrt(x*x+y*y);
374 // xx[3] = ref->Pz()/ref->Pt();
376 // Float_t xyz[3]={x,y,z};
377 // Float_t convConst = 0;
378 // (AliKalmanTrack::GetFieldMap())->Field(xyz,b);
379 // convConst=1000/0.299792458/(1e-13 - b[2]);
380 // xx[4] = 1./(convConst*ref->Pt());
381 // if (mass<0) xx[4]*=-1.; // negative mass - negative direction
382 // Double_t lcos = (x*ref->Px()+y*ref->Py())/(xr*ref->Pt());
383 // Double_t lsin = TMath::Sin(TMath::ACos(lcos));
384 // if (mass<0) lsin*=-1.;
385 // xx[2] = xr*xx[4]-lsin;
387 // AliTRDtrack * track = new AliTRDtrack(&cl,100,xx,cc,xr,alpha);
388 // track->SetMass(TMath::Abs(mass));
389 // track->StartTimeIntegral();
393 //____________________________________________________________________________
394 Float_t AliTRDtrack::StatusForTOF()
397 // Defines the status of the TOF extrapolation
400 Float_t res = (0.2 + 0.8*(fN/(fNExpected+5.)))*(0.4+0.6*fTracklets[5].GetN()/20.);
401 res *= (0.25+0.8*40./(40.+fBudget[2]));
405 if (GetNumberOfClusters()<20) return 0; //
406 if (fN>110&&fChi2/(Float_t(fN))<3) return 3; //gold
407 if (fNLast>30&&fChi2Last/(Float_t(fNLast))<3) return 3; //gold
408 if (fNLast>20&&fChi2Last/(Float_t(fNLast))<2) return 3; //gold
409 if (fNLast/(fNExpectedLast+3.)>0.8 && fChi2Last/Float_t(fNLast)<5&&fNLast>20) return 2; //silber
410 if (fNLast>5 &&((fNLast+1.)/(fNExpectedLast+1.))>0.8&&fChi2Last/(fNLast-5.)<6) return 1;
416 //____________________________________________________________________________
417 void AliTRDtrack::GetExternalParameters(Double_t& xr, Double_t x[5]) const
420 // This function returns external TRD track representation
432 //_____________________________________________________________________________
433 void AliTRDtrack::GetExternalCovariance(Double_t cc[15]) const
436 // This function returns external representation of the covriance matrix.
439 Double_t a=GetLocalConvConst();
441 Double_t c22=fX*fX*fCcc-2*fX*fCce+fCee;
442 Double_t c32=fX*fCct-fCte;
443 Double_t c20=fX*fCcy-fCey, c21=fX*fCcz-fCez, c42=fX*fCcc-fCce;
446 cc[1 ]=fCzy; cc[2 ]=fCzz;
447 cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
448 cc[6 ]=fCty; cc[7 ]=fCtz; cc[8 ]=c32; cc[9 ]=fCtt;
449 cc[10]=fCcy*a; cc[11]=fCcz*a; cc[12]=c42*a; cc[13]=fCct*a; cc[14]=fCcc*a*a;
453 //_____________________________________________________________________________
454 void AliTRDtrack::GetCovariance(Double_t cc[15]) const
457 // Returns the track covariance matrix
461 cc[1]=fCzy; cc[2]=fCzz;
462 cc[3]=fCey; cc[4]=fCez; cc[5]=fCee;
463 cc[6]=fCcy; cc[7]=fCcz; cc[8]=fCce; cc[9]=fCcc;
464 cc[10]=fCty; cc[11]=fCtz; cc[12]=fCte; cc[13]=fCct; cc[14]=fCtt;
468 //_____________________________________________________________________________
469 Int_t AliTRDtrack::Compare(const TObject *o) const
472 // Compares tracks according to their Y2 or curvature
475 AliTRDtrack *t=(AliTRDtrack*)o;
476 // Double_t co=t->GetSigmaY2();
477 // Double_t c =GetSigmaY2();
479 Double_t co=TMath::Abs(t->GetC());
480 Double_t c =TMath::Abs(GetC());
483 else if (c<co) return -1;
488 //_____________________________________________________________________________
489 void AliTRDtrack::CookdEdx(Double_t low, Double_t up) {
490 //-----------------------------------------------------------------
491 // Calculates dE/dX within the "low" and "up" cuts.
492 //-----------------------------------------------------------------
495 //Int_t nc=GetNumberOfClusters();
502 Float_t sorted[kMAXCLUSTERSPERTRACK];
503 for (i=0; i < nc; i++) {
506 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc);
508 //for (i=nl; i<=nu; i++) dedx += sorted[i];
510 for (i=0; i<nc; i++) dedx += sorted[i]; // ADDED by PS
511 if((nu-nl)) dedx /= (nu-nl); // ADDED by PS
515 // now real truncated mean
516 for (i=0; i < nc; i++) {
517 sorted[i]=TMath::Abs(fdQdl[i]);
519 Int_t * index = new Int_t[nc];
520 TMath::Sort(nc, sorted, index,kFALSE);
522 for (i=nl; i<=nu; i++) dedx += sorted[index[i]];
530 //_____________________________________________________________________________
531 Int_t AliTRDtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho)
533 // Propagates a track of particle with mass=pm to a reference plane
534 // defined by x=xk through media of density=rho and radiationLength=x0
536 if (xk == fX) return 1;
538 if (TMath::Abs(fC*xk - fE) >= 0.90000) {
539 // Int_t n=GetNumberOfClusters();
540 //if (n>4) cerr << n << " AliTRDtrack: Propagation failed, \tPt = "
541 // << GetPt() << "\t" << GetLabel() << "\t" << GetMass() << endl;
544 Double_t lcc=GetLocalConvConst();
546 // track Length measurement [SR, GSI, 17.02.2003]
547 Double_t oldX = fX, oldY = fY, oldZ = fZ;
549 Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fY, z1=fZ;
550 Double_t c1=fC*x1 - fE;
551 if((c1*c1) > 1) return 0;
552 Double_t r1=sqrt(1.- c1*c1);
553 Double_t c2=fC*x2 - fE;
554 if((c2*c2) > 1) return 0;
555 Double_t r2=sqrt(1.- c2*c2);
557 fY += dx*(c1+c2)/(r1+r2);
558 fZ += dx*(c1+c2)/(c1*r2 + c2*r1)*fT;
561 Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
562 Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
563 Double_t f04= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
564 Double_t cr=c1*r2+c2*r1;
565 Double_t f12=-dx*fT*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
566 Double_t f13= dx*cc/cr;
567 Double_t f14=dx*fT*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
570 Double_t b00=f02*fCey + f04*fCcy, b01=f12*fCey + f14*fCcy + f13*fCty;
571 Double_t b10=f02*fCez + f04*fCcz, b11=f12*fCez + f14*fCcz + f13*fCtz;
572 Double_t b20=f02*fCee + f04*fCce, b21=f12*fCee + f14*fCce + f13*fCte;
573 Double_t b30=f02*fCte + f04*fCct, b31=f12*fCte + f14*fCct + f13*fCtt;
574 Double_t b40=f02*fCce + f04*fCcc, b41=f12*fCce + f14*fCcc + f13*fCct;
577 Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a11=f12*b21+f14*b41+f13*b31;
579 //F*C*Ft = C + (a + b + bt)
581 fCzy += a01 + b01 + b10;
592 //Change of the magnetic field *************
593 SaveLocalConvConst();
595 fC*=lcc/GetLocalConvConst();
598 //Multiple scattering ******************
599 Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fY)*(y1-fY)+(z1-fZ)*(z1-fZ));
600 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
601 Double_t beta2=p2/(p2 + GetMass()*GetMass());
602 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
604 Double_t ey=fC*fX - fE, ez=fT;
605 Double_t xz=fC*ez, zz1=ez*ez+1, xy=fE+ey;
607 fCee += (2*ey*ez*ez*fE+1-ey*ey+ez*ez+fE*fE*ez*ez)*theta2;
608 fCte += ez*zz1*xy*theta2;
609 fCtt += zz1*zz1*theta2;
610 fCce += xz*ez*xy*theta2;
611 fCct += xz*zz1*theta2;
612 fCcc += xz*xz*theta2;
614 Double_t dc22 = (1-ey*ey+xz*xz*fX*fX)*theta2;
615 Double_t dc32 = (xz*fX*zz1)*theta2;
616 Double_t dc33 = (zz1*zz1)*theta2;
617 Double_t dc42 = (xz*fX*xz)*theta2;
618 Double_t dc43 = (zz1*xz)*theta2;
619 Double_t dc44 = (xz*xz)*theta2;
627 //Energy losses************************
628 if((5940*beta2/(1-beta2+1e-10) - beta2) < 0) return 0;
630 Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2+1e-10)) - beta2)*d*rho;
631 Float_t budget = d* rho;
634 // suspicious part - think about it ?
635 Double_t kinE = TMath::Sqrt(p2);
636 if (dE>0.8*kinE) dE = 0.8*kinE; //
637 if (dE<0) dE = 0.0; // not valid region for Bethe bloch
643 fC*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE);
645 // Double_t sigmade = 0.1*dE*TMath::Sqrt(TMath::Sqrt(1+fT*fT)*90./(d+0.0001)); // 20 percent fluctuation - normalized to some length
646 Double_t sigmade = 0.07*TMath::Sqrt(TMath::Abs(dE)); // energy loss fluctuation
647 Double_t sigmac2 = sigmade*sigmade*fC*fC*(p2+GetMass()*GetMass())/(p2*p2);
649 fCee += fX*fX*sigmac2;
651 // track time measurement [SR, GSI 17.02.2002]
653 if (IsStartedTimeIntegral()) {
654 Double_t l2 = TMath::Sqrt((fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY) + (fZ-oldZ)*(fZ-oldZ));
655 if (TMath::Abs(l2*fC)>0.0001){
656 // make correction for curvature if neccesary
657 l2 = 0.5*TMath::Sqrt((fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY));
658 l2 = 2*TMath::ASin(l2*fC)/fC;
659 l2 = TMath::Sqrt(l2*l2+(fZ-oldZ)*(fZ-oldZ));
667 //_____________________________________________________________________________
668 Int_t AliTRDtrack::Update(const AliTRDcluster *c, Double_t chisq, UInt_t index
671 // Assignes found cluster to the track and updates track information
673 Bool_t fNoTilt = kTRUE;
674 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
675 // add angular effect to the error contribution - MI
676 Float_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
677 if (tangent2 < 0.90000){
678 tangent2 = tangent2/(1.-tangent2);
680 Float_t errang = tangent2*0.04; //
681 Float_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
683 Double_t r00=c->GetSigmaY2() +errang, r01=0., r11=c->GetSigmaZ2()*100.;
684 r00+=fCyy; r01+=fCzy; r11+=fCzz;
685 Double_t det=r00*r11 - r01*r01;
686 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
688 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
689 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
690 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
691 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
692 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
694 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
695 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
699 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
700 // Int_t n=GetNumberOfClusters();
701 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
704 fY += k00*dy + k01*dz;
705 fZ += k10*dy + k11*dz;
707 //fT += k30*dy + k31*dz;
711 Double_t xuFactor = 100.; // empirical factor set by C.Xu
712 // in the first tilt version
713 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
716 if (TMath::Abs(dz)>padlength/2.){
717 Float_t dy2 = c->GetY() - fY;
718 Float_t sign = (dz>0) ? -1.: 1.;
719 dy2+=h01*sign*padlength/2.;
726 r00=c->GetSigmaY2()+errang+add, r01=0., r11=c->GetSigmaZ2()*xuFactor;
727 r00+=(fCyy+2.0*h01*fCzy+h01*h01*fCzz);
728 r01+=(fCzy+h01*fCzz);
731 det=r00*r11 - r01*r01;
732 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
734 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
735 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
736 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
737 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
738 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
741 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
742 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
743 // Int_t n=GetNumberOfClusters();
744 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
747 fY += k00*dy + k01*dz;
748 fZ += k10*dy + k11*dz;
750 fT += k30*dy + k31*dz;
760 Double_t c01=fCzy, c02=fCey, c03=fCty, c04=fCcy;
761 Double_t c12=fCez, c13=fCtz, c14=fCcz;
764 fCyy-=k00*fCyy+k01*fCzy; fCzy-=k00*c01+k01*fCzz;
765 fCey-=k00*c02+k01*c12; fCty-=k00*c03+k01*c13;
766 fCcy-=k00*c04+k01*c14;
768 fCzz-=k10*c01+k11*fCzz;
769 fCez-=k10*c02+k11*c12; fCtz-=k10*c03+k11*c13;
770 fCcz-=k10*c04+k11*c14;
772 fCee-=k20*c02+k21*c12; fCte-=k20*c03+k21*c13;
773 fCce-=k20*c04+k21*c14;
775 fCtt-=k30*c03+k31*c13;
776 fCct-=k40*c03+k41*c13;
777 //fCct-=k30*c04+k31*c14; // symmetric formula MI
779 fCcc-=k40*c04+k41*c14;
781 Int_t n=GetNumberOfClusters();
783 SetNumberOfClusters(n+1);
785 SetChi2(GetChi2()+chisq);
786 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
792 //_____________________________________________________________________________
793 Int_t AliTRDtrack::UpdateMI(const AliTRDcluster *c, Double_t chisq, UInt_t index, Double_t h01,
796 // Assignes found cluster to the track and updates track information
798 Bool_t fNoTilt = kTRUE;
799 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
800 // add angular effect to the error contribution and make correction - MI
801 //AliTRDclusterCorrection *corrector = AliTRDclusterCorrection::GetCorrection();
803 Double_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
804 if (tangent2 < 0.90000){
805 tangent2 = tangent2/(1.-tangent2);
807 Double_t tangent = TMath::Sqrt(tangent2);
808 if ((fC*fX-fE)<0) tangent*=-1;
809 // Double_t correction = 0*plane;
810 Double_t errang = tangent2*0.04; //
811 Double_t errsys =0.025*0.025*20; //systematic error part
813 if (c->GetNPads()==4) extend=2;
814 //if (c->GetNPads()==5) extend=3;
815 //if (c->GetNPads()==6) extend=3;
816 //if (c->GetQ()<15) return 1;
821 correction = corrector->GetCorrection(plane,c->GetLocalTimeBin(),tangent);
822 if (TMath::Abs(correction)>0){
824 errang = corrector->GetSigma(plane,c->GetLocalTimeBin(),tangent);
826 errang += tangent2*0.04;
831 // Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
833 Double_t r00=(c->GetSigmaY2() +errang+errsys)*extend, r01=0., r11=c->GetSigmaZ2()*10000.;
834 r00+=fCyy; r01+=fCzy; r11+=fCzz;
835 Double_t det=r00*r11 - r01*r01;
836 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
838 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
839 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
840 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
841 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
842 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
844 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
845 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
849 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
850 // Int_t n=GetNumberOfClusters();
851 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
854 fY += k00*dy + k01*dz;
855 fZ += k10*dy + k11*dz;
857 //fT += k30*dy + k31*dz;
861 Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12);
863 Double_t xuFactor = 1000.; // empirical factor set by C.Xu
864 // in the first tilt version
865 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
866 //dy=dy+h01*dz+correction;
868 Double_t tiltdz = dz;
869 if (TMath::Abs(tiltdz)>padlength/2.) {
870 tiltdz = TMath::Sign(padlength/2,dz);
876 if (TMath::Abs(dz)>padlength/2.){
877 //Double_t dy2 = c->GetY() - fY;
878 //Double_t sign = (dz>0) ? -1.: 1.;
879 //dy2-=h01*sign*padlength/2.;
883 Double_t s00 = (c->GetSigmaY2()+errang)*extend+errsys+add; // error pad
884 Double_t s11 = c->GetSigmaZ2()*xuFactor; // error pad-row
886 r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
887 r01 = fCzy + fCzz*h01;
889 det = r00*r11 - r01*r01;
891 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
894 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
895 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
896 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
897 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
898 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
901 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
902 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
903 //Int_t n=GetNumberOfClusters();
904 // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
907 fY += k00*dy + k01*dz;
908 fZ += k10*dy + k11*dz;
910 fT += k30*dy + k31*dz;
923 Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
924 Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
925 Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
926 //Double_t oldte = fCte, oldce = fCce;
927 //Double_t oldct = fCct;
929 fCyy-=k00*oldyy+k01*oldzy;
930 fCzy-=k10*oldyy+k11*oldzy;
931 fCey-=k20*oldyy+k21*oldzy;
932 fCty-=k30*oldyy+k31*oldzy;
933 fCcy-=k40*oldyy+k41*oldzy;
935 fCzz-=k10*oldzy+k11*oldzz;
936 fCez-=k20*oldzy+k21*oldzz;
937 fCtz-=k30*oldzy+k31*oldzz;
938 fCcz-=k40*oldzy+k41*oldzz;
940 fCee-=k20*oldey+k21*oldez;
941 fCte-=k30*oldey+k31*oldez;
942 fCce-=k40*oldey+k41*oldez;
944 fCtt-=k30*oldty+k31*oldtz;
945 fCct-=k40*oldty+k41*oldtz;
947 fCcc-=k40*oldcy+k41*oldcz;
950 Int_t n=GetNumberOfClusters();
952 SetNumberOfClusters(n+1);
954 SetChi2(GetChi2()+chisq);
955 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
961 //_____________________________________________________________________________
962 Int_t AliTRDtrack::UpdateMI(const AliTRDtracklet &tracklet)
965 // Assignes found tracklet to the track and updates track information
968 Double_t r00=(tracklet.GetTrackletSigma2()), r01=0., r11= 10000.;
969 r00+=fCyy; r01+=fCzy; r11+=fCzz;
971 Double_t det=r00*r11 - r01*r01;
972 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
975 Double_t dy=tracklet.GetY() - fY, dz=tracklet.GetZ() - fZ;
978 Double_t s00 = tracklet.GetTrackletSigma2(); // error pad
979 Double_t s11 = 100000; // error pad-row
980 Float_t h01 = tracklet.GetTilt();
982 // r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
983 r00 = fCyy + fCzz*h01*h01+s00;
984 // r01 = fCzy + fCzz*h01;
987 det = r00*r11 - r01*r01;
989 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
991 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
992 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
993 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
994 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
995 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
998 // k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
999 // k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
1000 // k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
1001 // k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
1002 // k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
1004 //Update measurement
1005 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
1006 // cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
1007 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
1008 //Int_t n=GetNumberOfClusters();
1009 // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
1019 fY += k00*dy + k01*dz;
1020 fZ += k10*dy + k11*dz;
1022 fT += k30*dy + k31*dz;
1029 Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
1030 Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
1031 Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
1032 //Double_t oldte = fCte, oldce = fCce;
1033 //Double_t oldct = fCct;
1035 fCyy-=k00*oldyy+k01*oldzy;
1036 fCzy-=k10*oldyy+k11*oldzy;
1037 fCey-=k20*oldyy+k21*oldzy;
1038 fCty-=k30*oldyy+k31*oldzy;
1039 fCcy-=k40*oldyy+k41*oldzy;
1041 fCzz-=k10*oldzy+k11*oldzz;
1042 fCez-=k20*oldzy+k21*oldzz;
1043 fCtz-=k30*oldzy+k31*oldzz;
1044 fCcz-=k40*oldzy+k41*oldzz;
1046 fCee-=k20*oldey+k21*oldez;
1047 fCte-=k30*oldey+k31*oldez;
1048 fCce-=k40*oldey+k41*oldez;
1050 fCtt-=k30*oldty+k31*oldtz;
1051 fCct-=k40*oldty+k41*oldtz;
1053 fCcc-=k40*oldcy+k41*oldcz;
1056 Int_t n=GetNumberOfClusters();
1058 SetNumberOfClusters(n+1);
1060 SetChi2(GetChi2()+chisq);
1061 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
1068 //_____________________________________________________________________________
1069 Int_t AliTRDtrack::Rotate(Double_t alpha, Bool_t absolute)
1071 // Rotates track parameters in R*phi plane
1072 // if absolute rotation alpha is in global system
1073 // otherwise alpha rotation is relative to the current rotation angle
1083 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
1084 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
1086 Double_t x1=fX, y1=fY;
1087 Double_t ca=cos(alpha), sa=sin(alpha);
1088 Double_t r1=fC*fX - fE;
1092 if((r1*r1) > 1) return 0;
1093 fE=fE*ca + (fC*y1 + sqrt(1.- r1*r1))*sa;
1095 Double_t r2=fC*fX - fE;
1096 if (TMath::Abs(r2) >= 0.90000) {
1097 Int_t n=GetNumberOfClusters();
1098 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !\n";
1102 if((r2*r2) > 1) return 0;
1103 Double_t y0=fY + sqrt(1.- r2*r2)/fC;
1104 if ((fY-y0)*fC >= 0.) {
1105 Int_t n=GetNumberOfClusters();
1106 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !!!\n";
1111 Double_t f00=ca-1, f24=(y1 - r1*x1/sqrt(1.- r1*r1))*sa,
1112 f20=fC*sa, f22=(ca + sa*r1/sqrt(1.- r1*r1))-1;
1115 Double_t b00=fCyy*f00, b02=fCyy*f20+fCcy*f24+fCey*f22;
1116 Double_t b10=fCzy*f00, b12=fCzy*f20+fCcz*f24+fCez*f22;
1117 Double_t b20=fCey*f00, b22=fCey*f20+fCce*f24+fCee*f22;
1118 Double_t b30=fCty*f00, b32=fCty*f20+fCct*f24+fCte*f22;
1119 Double_t b40=fCcy*f00, b42=fCcy*f20+fCcc*f24+fCce*f22;
1122 Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f24*b42+f22*b22;
1124 //F*C*Ft = C + (a + b + bt)
1125 fCyy += a00 + 2*b00;
1127 fCey += a02+b20+b02;
1132 fCee += a22 + 2*b22;
1139 //_____________________________________________________________________________
1140 Double_t AliTRDtrack::GetPredictedChi2(const AliTRDcluster *c, Double_t h01) const
1143 // Returns the track chi2
1146 Bool_t fNoTilt = kTRUE;
1147 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
1148 Double_t chi2, dy, r00, r01, r11;
1152 r00=c->GetSigmaY2();
1156 Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12);
1158 r00=c->GetSigmaY2(); r01=0.; r11=c->GetSigmaZ2();
1159 r00+=fCyy; r01+=fCzy; r11+=fCzz;
1161 Double_t det=r00*r11 - r01*r01;
1162 if (TMath::Abs(det) < 1.e-10) {
1163 Int_t n=GetNumberOfClusters();
1164 if (n>4) cerr<<n<<" AliTRDtrack warning: Singular matrix !\n";
1167 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
1168 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
1169 Double_t tiltdz = dz;
1170 if (TMath::Abs(tiltdz)>padlength/2.) {
1171 tiltdz = TMath::Sign(padlength/2,dz);
1176 chi2 = (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
1183 //_________________________________________________________________________
1184 void AliTRDtrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const
1186 // Returns reconstructed track momentum in the global system.
1188 Double_t pt=TMath::Abs(GetPt()); // GeV/c
1189 Double_t r=fC*fX-fE;
1192 if(r > 1) { py = pt; px = 0; }
1193 else if(r < -1) { py = -pt; px = 0; }
1195 y0=fY + sqrt(1.- r*r)/fC;
1196 px=-pt*(fY-y0)*fC; //cos(phi);
1197 py=-pt*(fE-fX*fC); //sin(phi);
1200 Double_t tmp=px*TMath::Cos(fAlpha) - py*TMath::Sin(fAlpha);
1201 py=px*TMath::Sin(fAlpha) + py*TMath::Cos(fAlpha);
1206 //_________________________________________________________________________
1207 void AliTRDtrack::GetGlobalXYZ(Double_t& x, Double_t& y, Double_t& z) const
1209 // Returns reconstructed track coordinates in the global system.
1211 x = fX; y = fY; z = fZ;
1212 Double_t tmp=x*TMath::Cos(fAlpha) - y*TMath::Sin(fAlpha);
1213 y=x*TMath::Sin(fAlpha) + y*TMath::Cos(fAlpha);
1218 //_________________________________________________________________________
1219 void AliTRDtrack::ResetCovariance()
1222 // Resets covariance matrix
1227 fCey=0.; fCez=0.; fCee*=10.;
1228 fCty=0.; fCtz=0.; fCte=0.; fCtt*=10.;
1229 fCcy=0.; fCcz=0.; fCce=0.; fCct=0.; fCcc*=10.;
1233 //_____________________________________________________________________________
1234 void AliTRDtrack::ResetCovariance(Float_t mult)
1237 // Resets covariance matrix
1242 fCey*=0.; fCez*=0.; fCee*=mult;
1243 fCty*=0.; fCtz*=0.; fCte*=0.; fCtt*=1.;
1244 fCcy*=0.; fCcz*=0.; fCce*=0.; fCct*=0.; fCcc*=mult;
1248 //_____________________________________________________________________________
1249 void AliTRDtrack::MakeBackupTrack()
1252 // Creates a backup track
1255 if (fBackupTrack) delete fBackupTrack;
1256 fBackupTrack = new AliTRDtrack(*this);
1260 //_____________________________________________________________________________
1261 Int_t AliTRDtrack::GetProlongation(Double_t xk, Double_t &y, Double_t &z)
1264 // Find prolongation at given x
1265 // return 0 if not exist
1267 Double_t c1=fC*fX - fE;
1268 if (TMath::Abs(c1)>1.) return 0;
1269 Double_t r1=TMath::Sqrt(1.- c1*c1);
1270 Double_t c2=fC*xk - fE;
1271 if (TMath::Abs(c2)>1.) return 0;
1272 Double_t r2=TMath::Sqrt(1.- c2*c2);
1273 y =fY + (xk-fX)*(c1+c2)/(r1+r2);
1274 z =fZ + (xk-fX)*(c1+c2)/(c1*r2 + c2*r1)*fT;
1280 //_____________________________________________________________________________
1281 Int_t AliTRDtrack::PropagateToX(Double_t xr, Double_t step)
1284 // Propagate track to given x position
1285 // works inside of the 20 degree segmentation (local cooordinate frame for TRD , TPC, TOF)
1287 // material budget from geo manager
1289 Double_t xyz0[3], xyz1[3],y,z;
1290 const Double_t kAlphac = TMath::Pi()/9.;
1291 const Double_t kTalphac = TMath::Tan(kAlphac*0.5);
1292 // critical alpha - cross sector indication
1294 Double_t dir = (fX>xr) ? -1.:1.;
1296 for (Double_t x=fX+dir*step;dir*x<dir*xr;x+=dir*step){
1298 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1299 GetProlongation(x,y,z);
1300 xyz1[0] = x*TMath::Cos(fAlpha)+y*TMath::Sin(fAlpha);
1301 xyz1[1] = x*TMath::Sin(fAlpha)-y*TMath::Cos(fAlpha);
1304 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1306 if (param[0]>0&¶m[1]>0) PropagateTo(x,param[1],param[0]);
1307 if (fY>fX*kTalphac){
1310 if (fY<-fX*kTalphac){
1321 //_____________________________________________________________________________
1322 Int_t AliTRDtrack::PropagateToR(Double_t r,Double_t step)
1325 // propagate track to the radial position
1326 // rotation always connected to the last track position
1328 Double_t xyz0[3], xyz1[3],y,z;
1329 Double_t radius = TMath::Sqrt(fX*fX+fY*fY);
1330 Double_t dir = (radius>r) ? -1.:1.; // direction +-
1332 for (Double_t x=radius+dir*step;dir*x<dir*r;x+=dir*step){
1333 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1334 Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
1335 Rotate(alpha,kTRUE);
1336 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1337 GetProlongation(x,y,z);
1338 xyz1[0] = x*TMath::Cos(alpha)+y*TMath::Sin(alpha);
1339 xyz1[1] = x*TMath::Sin(alpha)-y*TMath::Cos(alpha);
1342 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1343 if (param[1]<=0) param[1] =100000000;
1344 PropagateTo(x,param[1],param[0]);
1346 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1347 Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
1348 Rotate(alpha,kTRUE);
1349 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1350 GetProlongation(r,y,z);
1351 xyz1[0] = r*TMath::Cos(alpha)+y*TMath::Sin(alpha);
1352 xyz1[1] = r*TMath::Sin(alpha)-y*TMath::Cos(alpha);
1355 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1357 if (param[1]<=0) param[1] =100000000;
1358 PropagateTo(r,param[1],param[0]);
1364 //_____________________________________________________________________________
1365 inline Int_t AliTRDtrack::GetSector() const
1368 // Return the current sector
1371 return Int_t(TVector2::Phi_0_2pi(fAlpha)
1372 / AliTRDgeometry::GetAlpha())
1373 % AliTRDgeometry::kNsect;
1377 //_____________________________________________________________________________
1378 inline Double_t AliTRDtrack::Get1Pt() const
1384 return (TMath::Sign(1e-9,fC) + fC)*GetLocalConvConst();
1388 //_____________________________________________________________________________
1389 inline Double_t AliTRDtrack::GetP() const
1392 // Returns the total momentum
1395 return TMath::Abs(GetPt())*sqrt(1.+GetTgl()*GetTgl());
1399 //_____________________________________________________________________________
1400 inline Double_t AliTRDtrack::GetYat(Double_t xk) const
1403 // This function calculates the Y-coordinate of a track at
1404 // the plane x = xk.
1405 // Needed for matching with the TOF (I.Belikov)
1408 Double_t c1 = fC*fX - fE;
1409 Double_t r1 = TMath::Sqrt(1.0 - c1*c1);
1410 Double_t c2 = fC*xk - fE;
1411 Double_t r2 = TMath::Sqrt(1.0- c2*c2);
1412 return fY + (xk-fX)*(c1+c2)/(r1+r2);
1416 //_____________________________________________________________________________
1417 inline void AliTRDtrack::SetSampledEdx(Float_t q, Int_t i)
1420 // The sampled energy loss
1423 Double_t s = GetSnp();
1424 Double_t t = GetTgl();
1425 q *= TMath::Sqrt((1-s*s)/(1+t*t));
1430 //_____________________________________________________________________________
1431 inline void AliTRDtrack::SetSampledEdx(Float_t q)
1434 // The sampled energy loss
1437 Double_t s = GetSnp();
1438 Double_t t = GetTgl();
1439 q*= TMath::Sqrt((1-s*s)/(1+t*t));
1445 //_____________________________________________________________________________
1446 inline void AliTRDtrack::GetXYZ(Float_t r[3]) const
1449 //---------------------------------------------------------------------
1450 // Returns the position of the track in the global coord. system
1451 //---------------------------------------------------------------------
1453 Double_t cs = TMath::Cos(fAlpha);
1454 Double_t sn = TMath::Sin(fAlpha);
1455 r[0] = fX*cs - fY*sn;
1456 r[1] = fX*sn + fY*cs;