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 Revision 1.20.2.1 2003/07/14 09:19:33 hristov
19 TOF included in the combined PID (Yu.Belikov)
21 Revision 1.20 2003/05/27 17:46:13 hristov
22 TRD PID included in the ESD schema (T.Kuhr)
24 Revision 1.19 2003/05/22 10:46:46 hristov
25 Using access methods instead of data members
27 Revision 1.18 2003/04/10 10:36:54 hristov
28 Code for unified TPC/TRD tracking (S.Radomski)
30 Revision 1.17 2003/02/19 09:02:28 hristov
31 Track time measurement (S.Radomski)
33 Revision 1.16 2003/02/10 14:06:10 cblume
34 Add tracking without tilted pads as option
36 Revision 1.15 2003/01/27 16:34:49 cblume
37 Update of tracking by Sergei and Chuncheng
39 Revision 1.14 2002/11/07 15:52:09 cblume
40 Update of tracking code for tilted pads
42 Revision 1.13 2002/10/22 15:53:08 alibrary
43 Introducing Riostream.h
45 Revision 1.12 2002/10/14 14:57:44 hristov
46 Merging the VirtualMC branch to the main development branch (HEAD)
48 Revision 1.8.10.2 2002/07/24 10:09:31 alibrary
51 RRevision 1.11 2002/06/13 12:09:58 hristov
54 Revision 1.10 2002/06/12 09:54:35 cblume
55 Update of tracking code provided by Sergei
57 Revision 1.8 2001/05/30 12:17:47 hristov
58 Loop variables declared once
60 Revision 1.7 2001/05/28 17:07:58 hristov
61 Last minute changes; ExB correction in AliTRDclusterizerV1; taking into account of material in G10 TEC frames and material between TEC planes (C.Blume,S.Sedykh)
63 Revision 1.4 2000/12/08 16:07:02 cblume
64 Update of the tracking by Sergei
66 Revision 1.3 2000/10/15 23:40:01 cblume
69 Revision 1.2 2000/10/06 16:49:46 cblume
72 Revision 1.1.2.1 2000/09/22 14:47:52 cblume
77 #include <Riostream.h>
80 #include "AliTRDgeometry.h"
81 #include "AliTRDcluster.h"
82 #include "AliTRDtrack.h"
83 #include "../TPC/AliTPCtrack.h"
84 #include "AliESDtrack.h"
90 //_____________________________________________________________________________
92 AliTRDtrack::AliTRDtrack(const AliTRDcluster *c, UInt_t index,
93 const Double_t xx[5], const Double_t cc[15],
94 Double_t xref, Double_t alpha) : AliKalmanTrack() {
95 //-----------------------------------------------------------------
96 // This is the main track constructor.
97 //-----------------------------------------------------------------
102 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
103 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
107 fY=xx[0]; fZ=xx[1]; fE=xx[2]; fT=xx[3]; fC=xx[4];
110 fCzy=cc[1]; fCzz=cc[2];
111 fCey=cc[3]; fCez=cc[4]; fCee=cc[5];
112 fCty=cc[6]; fCtz=cc[7]; fCte=cc[8]; fCtt=cc[9];
113 fCcy=cc[10]; fCcz=cc[11]; fCce=cc[12]; fCct=cc[13]; fCcc=cc[14];
116 SetNumberOfClusters(1);
124 Double_t q = TMath::Abs(c->GetQ());
125 Double_t s = fX*fC - fE, t=fT;
126 if(s*s < 1) q *= TMath::Sqrt((1-s*s)/(1+t*t));
130 // initialisation [SR, GSI 18.02.2003] (i startd for 1)
131 for(Int_t i=1; i<kMAX_CLUSTERS_PER_TRACK; i++) {
137 //_____________________________________________________________________________
138 AliTRDtrack::AliTRDtrack(const AliTRDtrack& t) : AliKalmanTrack(t) {
143 SetLabel(t.GetLabel());
144 fSeedLab=t.GetSeedLabel();
146 SetChi2(t.GetChi2());
151 fNRotate = t.fNRotate;
156 fY=t.fY; fZ=t.fZ; fE=t.fE; fT=t.fT; fC=t.fC;
159 fCzy=t.fCzy; fCzz=t.fCzz;
160 fCey=t.fCey; fCez=t.fCez; fCee=t.fCee;
161 fCty=t.fCty; fCtz=t.fCtz; fCte=t.fCte; fCtt=t.fCtt;
162 fCcy=t.fCcy; fCcz=t.fCcz; fCce=t.fCce; fCct=t.fCct; fCcc=t.fCcc;
164 Int_t n=t.GetNumberOfClusters();
165 SetNumberOfClusters(n);
166 for (Int_t i=0; i<n; i++) {
167 fIndex[i]=t.fIndex[i];
171 // initialisation (i starts from n) [SR, GSI, 18.02.2003]
172 for(Int_t i=n; i<kMAX_CLUSTERS_PER_TRACK; i++) {
178 //_____________________________________________________________________________
179 AliTRDtrack::AliTRDtrack(const AliKalmanTrack& t, Double_t alpha)
182 // Constructor from AliTPCtrack or AliITStrack .
185 SetLabel(t.GetLabel());
187 SetMass(t.GetMass());
188 SetNumberOfClusters(0);
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);
212 //Conversion of the covariance matrix
213 Double_t c[15]; t.GetExternalCovariance(c);
215 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
217 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
218 Double_t c32=fX*c[13] - c[8];
219 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
222 fCzy=c[1 ]; fCzz=c[2 ];
223 fCey=c20; fCez=c21; fCee=c22;
224 fCty=c[6 ]; fCtz=c[7 ]; fCte=c32; fCtt=c[9 ];
225 fCcy=c[10]; fCcz=c[11]; fCce=c42; fCct=c[13]; fCcc=c[14];
227 // Initialization [SR, GSI, 18.02.2003]
228 for(Int_t i=0; i<kMAX_CLUSTERS_PER_TRACK; i++) {
233 //_____________________________________________________________________________
234 AliTRDtrack::AliTRDtrack(const AliESDtrack& t)
237 // Constructor from AliESDtrack
240 SetLabel(t.GetLabel());
242 SetMass(t.GetMass());
243 SetNumberOfClusters(0);
244 // WARNING: cluster indices are NOT copied !!!
252 fAlpha = t.GetAlpha();
253 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
254 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
256 Double_t x, p[5]; t.GetExternalParameters(x,p);
268 //Conversion of the covariance matrix
269 Double_t c[15]; t.GetExternalCovariance(c);
271 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
273 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
274 Double_t c32=fX*c[13] - c[8];
275 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
278 fCzy=c[1 ]; fCzz=c[2 ];
279 fCey=c20; fCez=c21; fCee=c22;
280 fCty=c[6 ]; fCtz=c[7 ]; fCte=c32; fCtt=c[9 ];
281 fCcy=c[10]; fCcz=c[11]; fCce=c42; fCct=c[13]; fCcc=c[14];
283 // Initialization [SR, GSI, 18.02.2003]
284 for(Int_t i=0; i<kMAX_CLUSTERS_PER_TRACK; i++) {
289 if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return;
291 Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times);
292 SetIntegratedLength(t.GetIntegratedLength());
295 //_____________________________________________________________________________
297 void AliTRDtrack::GetBarrelTrack(AliBarrelTrack *track) {
303 Double_t xr, vec[5], cov[15];
305 track->SetLabel(GetLabel());
306 track->SetX(fX, fAlpha);
307 track->SetNClusters(GetNumberOfClusters(), GetChi2());
308 track->SetNWrongClusters(fNWrong);
309 track->SetNRotate(fNRotate);
311 GetIntegratedTimes(times);
312 track->SetTime(times, GetIntegratedLength());
314 track->SetMass(GetMass());
315 track->SetdEdX(GetdEdx());
317 GetExternalParameters(xr, vec);
318 track->SetStateVector(vec);
320 GetExternalCovariance(cov);
321 track->SetCovarianceMatrix(cov);
323 //____________________________________________________________________________
324 void AliTRDtrack::GetExternalParameters(Double_t& xr, Double_t x[5]) const {
326 // This function returns external TRD track representation
336 //_____________________________________________________________________________
337 void AliTRDtrack::GetExternalCovariance(Double_t cc[15]) const {
339 // This function returns external representation of the covriance matrix.
341 Double_t a=GetConvConst();
343 Double_t c22=fX*fX*fCcc-2*fX*fCce+fCee;
344 Double_t c32=fX*fCct-fCte;
345 Double_t c20=fX*fCcy-fCey, c21=fX*fCcz-fCez, c42=fX*fCcc-fCce;
348 cc[1 ]=fCzy; cc[2 ]=fCzz;
349 cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
350 cc[6 ]=fCty; cc[7 ]=fCtz; cc[8 ]=c32; cc[9 ]=fCtt;
351 cc[10]=fCcy*a; cc[11]=fCcz*a; cc[12]=c42*a; cc[13]=fCct*a; cc[14]=fCcc*a*a;
356 //_____________________________________________________________________________
357 void AliTRDtrack::GetCovariance(Double_t cc[15]) const {
360 cc[1]=fCzy; cc[2]=fCzz;
361 cc[3]=fCey; cc[4]=fCez; cc[5]=fCee;
362 cc[6]=fCcy; cc[7]=fCcz; cc[8]=fCce; cc[9]=fCcc;
363 cc[10]=fCty; cc[11]=fCtz; cc[12]=fCte; cc[13]=fCct; cc[14]=fCtt;
367 //_____________________________________________________________________________
368 Int_t AliTRDtrack::Compare(const TObject *o) const {
370 // Compares tracks according to their Y2 or curvature
372 AliTRDtrack *t=(AliTRDtrack*)o;
373 // Double_t co=t->GetSigmaY2();
374 // Double_t c =GetSigmaY2();
376 Double_t co=TMath::Abs(t->GetC());
377 Double_t c =TMath::Abs(GetC());
380 else if (c<co) return -1;
384 //_____________________________________________________________________________
385 void AliTRDtrack::CookdEdx(Double_t low, Double_t up) {
386 //-----------------------------------------------------------------
387 // Calculates dE/dX within the "low" and "up" cuts.
388 //-----------------------------------------------------------------
391 Int_t nc=GetNumberOfClusters();
393 Float_t sorted[kMAX_CLUSTERS_PER_TRACK];
394 for (i=0; i < nc; i++) {
402 for (i=0; i<nc-1; i++) {
403 if (sorted[i]<=sorted[i+1]) continue;
404 Float_t tmp=sorted[i];
405 sorted[i]=sorted[i+1]; sorted[i+1]=tmp;
410 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc);
412 for (i=nl; i<=nu; i++) dedx += sorted[i];
419 //_____________________________________________________________________________
420 Int_t AliTRDtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho)
422 // Propagates a track of particle with mass=pm to a reference plane
423 // defined by x=xk through media of density=rho and radiationLength=x0
425 if (xk == fX) return 1;
427 if (TMath::Abs(fC*xk - fE) >= 0.99999) {
428 Int_t n=GetNumberOfClusters();
429 if (n>4) cerr << n << " AliTRDtrack: Propagation failed, \tPt = "
430 << GetPt() << "\t" << GetLabel() << "\t" << GetMass() << endl;
434 // track Length measurement [SR, GSI, 17.02.2003]
435 Double_t oldX = fX, oldY = fY, oldZ = fZ;
437 Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fY, z1=fZ;
438 Double_t c1=fC*x1 - fE;
439 if((c1*c1) > 1) return 0;
440 Double_t r1=sqrt(1.- c1*c1);
441 Double_t c2=fC*x2 - fE;
442 if((c2*c2) > 1) return 0;
443 Double_t r2=sqrt(1.- c2*c2);
445 fY += dx*(c1+c2)/(r1+r2);
446 fZ += dx*(c1+c2)/(c1*r2 + c2*r1)*fT;
449 Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
450 Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
451 Double_t f04= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
452 Double_t cr=c1*r2+c2*r1;
453 Double_t f12=-dx*fT*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
454 Double_t f13= dx*cc/cr;
455 Double_t f14=dx*fT*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
458 Double_t b00=f02*fCey + f04*fCcy, b01=f12*fCey + f14*fCcy + f13*fCty;
459 Double_t b10=f02*fCez + f04*fCcz, b11=f12*fCez + f14*fCcz + f13*fCtz;
460 Double_t b20=f02*fCee + f04*fCce, b21=f12*fCee + f14*fCce + f13*fCte;
461 Double_t b30=f02*fCte + f04*fCct, b31=f12*fCte + f14*fCct + f13*fCtt;
462 Double_t b40=f02*fCce + f04*fCcc, b41=f12*fCce + f14*fCcc + f13*fCct;
465 Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a11=f12*b21+f14*b41+f13*b31;
467 //F*C*Ft = C + (a + b + bt)
469 fCzy += a01 + b01 + b10;
480 //Multiple scattering ******************
481 Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fY)*(y1-fY)+(z1-fZ)*(z1-fZ));
482 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
483 Double_t beta2=p2/(p2 + GetMass()*GetMass());
484 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
486 Double_t ey=fC*fX - fE, ez=fT;
487 Double_t xz=fC*ez, zz1=ez*ez+1, xy=fE+ey;
489 fCee += (2*ey*ez*ez*fE+1-ey*ey+ez*ez+fE*fE*ez*ez)*theta2;
490 fCte += ez*zz1*xy*theta2;
491 fCtt += zz1*zz1*theta2;
492 fCce += xz*ez*xy*theta2;
493 fCct += xz*zz1*theta2;
494 fCcc += xz*xz*theta2;
496 //Energy losses************************
497 if((5940*beta2/(1-beta2+1e-10) - beta2) < 0) return 0;
499 Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2+1e-10)) - beta2)*d*rho;
502 fC*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE);
505 // track time measurement [SR, GSI 17.02.2002]
506 if (IsStartedTimeIntegral()) {
507 Double_t l2 = (fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY) + (fZ-oldZ)*(fZ-oldZ);
508 AddTimeStep(TMath::Sqrt(l2));
515 //_____________________________________________________________________________
516 Int_t AliTRDtrack::Update(const AliTRDcluster *c, Double_t chisq, UInt_t index, Double_t h01)
518 // Assignes found cluster to the track and updates track information
520 Bool_t fNoTilt = kTRUE;
521 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
523 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
524 r00+=fCyy; r01+=fCzy; r11+=fCzz;
525 Double_t det=r00*r11 - r01*r01;
526 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
528 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
529 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
530 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
531 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
532 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
534 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
535 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
537 Double_t c01=fCzy, c02=fCey, c03=fCty, c04=fCcy;
538 Double_t c12=fCez, c13=fCtz, c14=fCcz;
541 if (TMath::Abs(cur*fX-eta) >= 0.99999) {
542 Int_t n=GetNumberOfClusters();
543 if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
546 fY += k00*dy + k01*dz;
547 fZ += k10*dy + k11*dz;
549 //fT += k30*dy + k31*dz;
553 Double_t xu_factor = 100.; // empirical factor set by C.Xu
554 // in the first tilt version
555 r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2()*xu_factor;
556 r00+=(fCyy+2.0*h01*fCzy+h01*h01*fCzz);
557 r01+=(fCzy+h01*fCzz);
558 det=r00*r11 - r01*r01;
559 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
561 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
562 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
563 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
564 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
565 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
567 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
570 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
571 if (TMath::Abs(cur*fX-eta) >= 0.99999) {
572 Int_t n=GetNumberOfClusters();
573 if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
576 fY += k00*dy + k01*dz;
577 fZ += k10*dy + k11*dz;
579 //fT += k30*dy + k31*dz;
589 fCyy-=k00*fCyy+k01*fCzy; fCzy-=k00*c01+k01*fCzz;
590 fCey-=k00*c02+k01*c12; fCty-=k00*c03+k01*c13;
591 fCcy-=k00*c04+k01*c14;
593 fCzz-=k10*c01+k11*fCzz;
594 fCez-=k10*c02+k11*c12; fCtz-=k10*c03+k11*c13;
595 fCcz-=k10*c04+k11*c14;
597 fCee-=k20*c02+k21*c12; fCte-=k20*c03+k21*c13;
598 fCce-=k20*c04+k21*c14;
600 fCtt-=k30*c03+k31*c13;
601 fCct-=k40*c03+k41*c13;
603 fCcc-=k40*c04+k41*c14;
605 Int_t n=GetNumberOfClusters();
607 SetNumberOfClusters(n+1);
609 SetChi2(GetChi2()+chisq);
610 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
616 //_____________________________________________________________________________
617 Int_t AliTRDtrack::Rotate(Double_t alpha)
619 // Rotates track parameters in R*phi plane
624 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
625 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
627 Double_t x1=fX, y1=fY;
628 Double_t ca=cos(alpha), sa=sin(alpha);
629 Double_t r1=fC*fX - fE;
633 if((r1*r1) > 1) return 0;
634 fE=fE*ca + (fC*y1 + sqrt(1.- r1*r1))*sa;
636 Double_t r2=fC*fX - fE;
637 if (TMath::Abs(r2) >= 0.99999) {
638 Int_t n=GetNumberOfClusters();
639 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !\n";
643 if((r2*r2) > 1) return 0;
644 Double_t y0=fY + sqrt(1.- r2*r2)/fC;
645 if ((fY-y0)*fC >= 0.) {
646 Int_t n=GetNumberOfClusters();
647 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !!!\n";
652 Double_t f00=ca-1, f24=(y1 - r1*x1/sqrt(1.- r1*r1))*sa,
653 f20=fC*sa, f22=(ca + sa*r1/sqrt(1.- r1*r1))-1;
656 Double_t b00=fCyy*f00, b02=fCyy*f20+fCcy*f24+fCey*f22;
657 Double_t b10=fCzy*f00, b12=fCzy*f20+fCcz*f24+fCez*f22;
658 Double_t b20=fCey*f00, b22=fCey*f20+fCce*f24+fCee*f22;
659 Double_t b30=fCty*f00, b32=fCty*f20+fCct*f24+fCte*f22;
660 Double_t b40=fCcy*f00, b42=fCcy*f20+fCcc*f24+fCce*f22;
663 Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f24*b42+f22*b22;
665 //F*C*Ft = C + (a + b + bt)
680 //_____________________________________________________________________________
681 Double_t AliTRDtrack::GetPredictedChi2(const AliTRDcluster *c, Double_t h01) const
684 Bool_t fNoTilt = kTRUE;
685 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
686 Double_t chi2, dy, r00, r01, r11;
694 r00=c->GetSigmaY2(); r01=0.; r11=c->GetSigmaZ2();
695 r00+=fCyy; r01+=fCzy; r11+=fCzz;
697 Double_t det=r00*r11 - r01*r01;
698 if (TMath::Abs(det) < 1.e-10) {
699 Int_t n=GetNumberOfClusters();
700 if (n>4) cerr<<n<<" AliTRDtrack warning: Singular matrix !\n";
703 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
704 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
707 chi2 = (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
713 //_________________________________________________________________________
714 void AliTRDtrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const
716 // Returns reconstructed track momentum in the global system.
718 Double_t pt=TMath::Abs(GetPt()); // GeV/c
722 if(r > 1) { py = pt; px = 0; }
723 else if(r < -1) { py = -pt; px = 0; }
725 y0=fY + sqrt(1.- r*r)/fC;
726 px=-pt*(fY-y0)*fC; //cos(phi);
727 py=-pt*(fE-fX*fC); //sin(phi);
730 Double_t tmp=px*TMath::Cos(fAlpha) - py*TMath::Sin(fAlpha);
731 py=px*TMath::Sin(fAlpha) + py*TMath::Cos(fAlpha);
736 //_________________________________________________________________________
737 void AliTRDtrack::GetGlobalXYZ(Double_t& x, Double_t& y, Double_t& z) const
739 // Returns reconstructed track coordinates in the global system.
741 x = fX; y = fY; z = fZ;
742 Double_t tmp=x*TMath::Cos(fAlpha) - y*TMath::Sin(fAlpha);
743 y=x*TMath::Sin(fAlpha) + y*TMath::Cos(fAlpha);
748 //_________________________________________________________________________
749 void AliTRDtrack::ResetCovariance() {
751 // Resets covariance matrix
756 fCey=0.; fCez=0.; fCee*=10.;
757 fCty=0.; fCtz=0.; fCte=0.; fCtt*=10.;
758 fCcy=0.; fCcz=0.; fCce=0.; fCct=0.; fCcc*=10.;