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 Float_t AliTRDtrack::StatusForTOF()
427 // Defines the status of the TOF extrapolation
430 Float_t res = (0.2 + 0.8*(fN/(fNExpected+5.)))*(0.4+0.6*fTracklets[5].GetN()/20.);
431 res *= (0.25+0.8*40./(40.+fBudget[2]));
435 if (GetNumberOfClusters()<20) return 0; //
436 if (fN>110&&fChi2/(Float_t(fN))<3) return 3; //gold
437 if (fNLast>30&&fChi2Last/(Float_t(fNLast))<3) return 3; //gold
438 if (fNLast>20&&fChi2Last/(Float_t(fNLast))<2) return 3; //gold
439 if (fNLast/(fNExpectedLast+3.)>0.8 && fChi2Last/Float_t(fNLast)<5&&fNLast>20) return 2; //silber
440 if (fNLast>5 &&((fNLast+1.)/(fNExpectedLast+1.))>0.8&&fChi2Last/(fNLast-5.)<6) return 1;
446 //_____________________________________________________________________________
447 void AliTRDtrack::GetExternalCovariance(Double_t cc[15]) const
450 // This function returns external representation of the covriance matrix.
453 Double_t a=GetLocalConvConst();
455 Double_t c22=fX*fX*fCcc-2*fX*fCce+fCee;
456 Double_t c32=fX*fCct-fCte;
457 Double_t c20=fX*fCcy-fCey, c21=fX*fCcz-fCez, c42=fX*fCcc-fCce;
460 cc[1 ]=fCzy; cc[2 ]=fCzz;
461 cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
462 cc[6 ]=fCty; cc[7 ]=fCtz; cc[8 ]=c32; cc[9 ]=fCtt;
463 cc[10]=fCcy*a; cc[11]=fCcz*a; cc[12]=c42*a; cc[13]=fCct*a; cc[14]=fCcc*a*a;
467 //_____________________________________________________________________________
468 void AliTRDtrack::GetCovariance(Double_t cc[15]) const
471 // Returns the track covariance matrix
475 cc[1]=fCzy; cc[2]=fCzz;
476 cc[3]=fCey; cc[4]=fCez; cc[5]=fCee;
477 cc[6]=fCcy; cc[7]=fCcz; cc[8]=fCce; cc[9]=fCcc;
478 cc[10]=fCty; cc[11]=fCtz; cc[12]=fCte; cc[13]=fCct; cc[14]=fCtt;
482 //_____________________________________________________________________________
483 Int_t AliTRDtrack::Compare(const TObject *o) const
486 // Compares tracks according to their Y2 or curvature
489 AliTRDtrack *t=(AliTRDtrack*)o;
490 // Double_t co=t->GetSigmaY2();
491 // Double_t c =GetSigmaY2();
493 Double_t co=TMath::Abs(t->GetC());
494 Double_t c =TMath::Abs(GetC());
497 else if (c<co) return -1;
502 //_____________________________________________________________________________
503 void AliTRDtrack::CookdEdx(Double_t low, Double_t up) {
504 //-----------------------------------------------------------------
505 // Calculates dE/dX within the "low" and "up" cuts.
506 //-----------------------------------------------------------------
509 //Int_t nc=GetNumberOfClusters();
516 Float_t sorted[kMAXCLUSTERSPERTRACK];
517 for (i=0; i < nc; i++) {
520 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc);
522 //for (i=nl; i<=nu; i++) dedx += sorted[i];
524 for (i=0; i<nc; i++) dedx += sorted[i]; // ADDED by PS
525 if((nu-nl)) dedx /= (nu-nl); // ADDED by PS
529 // now real truncated mean
530 for (i=0; i < nc; i++) {
531 sorted[i]=TMath::Abs(fdQdl[i]);
533 Int_t * index = new Int_t[nc];
534 TMath::Sort(nc, sorted, index,kFALSE);
536 for (i=nl; i<=nu; i++) dedx += sorted[index[i]];
544 //_____________________________________________________________________________
545 Int_t AliTRDtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho)
547 // Propagates a track of particle with mass=pm to a reference plane
548 // defined by x=xk through media of density=rho and radiationLength=x0
550 if (xk == fX) return 1;
552 if (TMath::Abs(fC*xk - fE) >= 0.90000) {
553 // Int_t n=GetNumberOfClusters();
554 //if (n>4) cerr << n << " AliTRDtrack: Propagation failed, \tPt = "
555 // << GetPt() << "\t" << GetLabel() << "\t" << GetMass() << endl;
558 Double_t lcc=GetLocalConvConst();
560 // track Length measurement [SR, GSI, 17.02.2003]
561 Double_t oldX = fX, oldY = fY, oldZ = fZ;
563 Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fY, z1=fZ;
564 Double_t c1=fC*x1 - fE;
565 if((c1*c1) > 1) return 0;
566 Double_t r1=sqrt(1.- c1*c1);
567 Double_t c2=fC*x2 - fE;
568 if((c2*c2) > 1) return 0;
569 Double_t r2=sqrt(1.- c2*c2);
571 fY += dx*(c1+c2)/(r1+r2);
572 fZ += dx*(c1+c2)/(c1*r2 + c2*r1)*fT;
575 Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
576 Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
577 Double_t f04= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
578 Double_t cr=c1*r2+c2*r1;
579 Double_t f12=-dx*fT*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
580 Double_t f13= dx*cc/cr;
581 Double_t f14=dx*fT*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
584 Double_t b00=f02*fCey + f04*fCcy, b01=f12*fCey + f14*fCcy + f13*fCty;
585 Double_t b10=f02*fCez + f04*fCcz, b11=f12*fCez + f14*fCcz + f13*fCtz;
586 Double_t b20=f02*fCee + f04*fCce, b21=f12*fCee + f14*fCce + f13*fCte;
587 Double_t b30=f02*fCte + f04*fCct, b31=f12*fCte + f14*fCct + f13*fCtt;
588 Double_t b40=f02*fCce + f04*fCcc, b41=f12*fCce + f14*fCcc + f13*fCct;
591 Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a11=f12*b21+f14*b41+f13*b31;
593 //F*C*Ft = C + (a + b + bt)
595 fCzy += a01 + b01 + b10;
606 //Change of the magnetic field *************
607 SaveLocalConvConst();
609 fC*=lcc/GetLocalConvConst();
612 //Multiple scattering ******************
613 Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fY)*(y1-fY)+(z1-fZ)*(z1-fZ));
614 Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
615 Double_t beta2=p2/(p2 + GetMass()*GetMass());
616 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
618 Double_t ey=fC*fX - fE, ez=fT;
619 Double_t xz=fC*ez, zz1=ez*ez+1, xy=fE+ey;
621 fCee += (2*ey*ez*ez*fE+1-ey*ey+ez*ez+fE*fE*ez*ez)*theta2;
622 fCte += ez*zz1*xy*theta2;
623 fCtt += zz1*zz1*theta2;
624 fCce += xz*ez*xy*theta2;
625 fCct += xz*zz1*theta2;
626 fCcc += xz*xz*theta2;
628 Double_t dc22 = (1-ey*ey+xz*xz*fX*fX)*theta2;
629 Double_t dc32 = (xz*fX*zz1)*theta2;
630 Double_t dc33 = (zz1*zz1)*theta2;
631 Double_t dc42 = (xz*fX*xz)*theta2;
632 Double_t dc43 = (zz1*xz)*theta2;
633 Double_t dc44 = (xz*xz)*theta2;
641 //Energy losses************************
642 if((5940*beta2/(1-beta2+1e-10) - beta2) < 0) return 0;
644 Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2+1e-10)) - beta2)*d*rho;
645 Float_t budget = d* rho;
648 // suspicious part - think about it ?
649 Double_t kinE = TMath::Sqrt(p2);
650 if (dE>0.8*kinE) dE = 0.8*kinE; //
651 if (dE<0) dE = 0.0; // not valid region for Bethe bloch
657 fC*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE);
659 // Double_t sigmade = 0.1*dE*TMath::Sqrt(TMath::Sqrt(1+fT*fT)*90./(d+0.0001)); // 20 percent fluctuation - normalized to some length
660 Double_t sigmade = 0.07*TMath::Sqrt(TMath::Abs(dE)); // energy loss fluctuation
661 Double_t sigmac2 = sigmade*sigmade*fC*fC*(p2+GetMass()*GetMass())/(p2*p2);
663 fCee += fX*fX*sigmac2;
665 // track time measurement [SR, GSI 17.02.2002]
667 if (IsStartedTimeIntegral()) {
668 Double_t l2 = TMath::Sqrt((fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY) + (fZ-oldZ)*(fZ-oldZ));
669 if (TMath::Abs(l2*fC)>0.0001){
670 // make correction for curvature if neccesary
671 l2 = 0.5*TMath::Sqrt((fX-oldX)*(fX-oldX) + (fY-oldY)*(fY-oldY));
672 l2 = 2*TMath::ASin(l2*fC)/fC;
673 l2 = TMath::Sqrt(l2*l2+(fZ-oldZ)*(fZ-oldZ));
682 //_____________________________________________________________________________
683 Int_t AliTRDtrack::Update(const AliTRDcluster *c, Double_t chisq, UInt_t index
686 // Assignes found cluster to the track and updates track information
688 Bool_t fNoTilt = kTRUE;
689 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
690 // add angular effect to the error contribution - MI
691 Float_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
692 if (tangent2 < 0.90000){
693 tangent2 = tangent2/(1.-tangent2);
695 Float_t errang = tangent2*0.04; //
696 Float_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
698 Double_t r00=c->GetSigmaY2() +errang, r01=0., r11=c->GetSigmaZ2()*100.;
699 r00+=fCyy; r01+=fCzy; r11+=fCzz;
700 Double_t det=r00*r11 - r01*r01;
701 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
703 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
704 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
705 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
706 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
707 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
709 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
710 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
714 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
715 // Int_t n=GetNumberOfClusters();
716 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
719 fY += k00*dy + k01*dz;
720 fZ += k10*dy + k11*dz;
722 //fT += k30*dy + k31*dz;
726 Double_t xuFactor = 100.; // empirical factor set by C.Xu
727 // in the first tilt version
728 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
731 if (TMath::Abs(dz)>padlength/2.){
732 Float_t dy2 = c->GetY() - fY;
733 Float_t sign = (dz>0) ? -1.: 1.;
734 dy2+=h01*sign*padlength/2.;
741 r00=c->GetSigmaY2()+errang+add, r01=0., r11=c->GetSigmaZ2()*xuFactor;
742 r00+=(fCyy+2.0*h01*fCzy+h01*h01*fCzz);
743 r01+=(fCzy+h01*fCzz);
746 det=r00*r11 - r01*r01;
747 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
749 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
750 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
751 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
752 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
753 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
756 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
757 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
758 // Int_t n=GetNumberOfClusters();
759 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
762 fY += k00*dy + k01*dz;
763 fZ += k10*dy + k11*dz;
765 fT += k30*dy + k31*dz;
775 Double_t c01=fCzy, c02=fCey, c03=fCty, c04=fCcy;
776 Double_t c12=fCez, c13=fCtz, c14=fCcz;
779 fCyy-=k00*fCyy+k01*fCzy; fCzy-=k00*c01+k01*fCzz;
780 fCey-=k00*c02+k01*c12; fCty-=k00*c03+k01*c13;
781 fCcy-=k00*c04+k01*c14;
783 fCzz-=k10*c01+k11*fCzz;
784 fCez-=k10*c02+k11*c12; fCtz-=k10*c03+k11*c13;
785 fCcz-=k10*c04+k11*c14;
787 fCee-=k20*c02+k21*c12; fCte-=k20*c03+k21*c13;
788 fCce-=k20*c04+k21*c14;
790 fCtt-=k30*c03+k31*c13;
791 fCct-=k40*c03+k41*c13;
792 //fCct-=k30*c04+k31*c14; // symmetric formula MI
794 fCcc-=k40*c04+k41*c14;
796 Int_t n=GetNumberOfClusters();
798 SetNumberOfClusters(n+1);
800 SetChi2(GetChi2()+chisq);
801 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
807 //_____________________________________________________________________________
808 Int_t AliTRDtrack::UpdateMI(const AliTRDcluster *c, Double_t chisq, UInt_t index, Double_t h01,
811 // Assignes found cluster to the track and updates track information
813 Bool_t fNoTilt = kTRUE;
814 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
815 // add angular effect to the error contribution and make correction - MI
816 //AliTRDclusterCorrection *corrector = AliTRDclusterCorrection::GetCorrection();
818 Double_t tangent2 = (fC*fX-fE)*(fC*fX-fE);
819 if (tangent2 < 0.90000){
820 tangent2 = tangent2/(1.-tangent2);
822 Double_t tangent = TMath::Sqrt(tangent2);
823 if ((fC*fX-fE)<0) tangent*=-1;
824 // Double_t correction = 0*plane;
825 Double_t errang = tangent2*0.04; //
826 Double_t errsys =0.025*0.025*20; //systematic error part
828 if (c->GetNPads()==4) extend=2;
829 //if (c->GetNPads()==5) extend=3;
830 //if (c->GetNPads()==6) extend=3;
831 //if (c->GetQ()<15) return 1;
836 correction = corrector->GetCorrection(plane,c->GetLocalTimeBin(),tangent);
837 if (TMath::Abs(correction)>0){
839 errang = corrector->GetSigma(plane,c->GetLocalTimeBin(),tangent);
841 errang += tangent2*0.04;
846 // Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12.);
848 Double_t r00=(c->GetSigmaY2() +errang+errsys)*extend, r01=0., r11=c->GetSigmaZ2()*10000.;
849 r00+=fCyy; r01+=fCzy; r11+=fCzz;
850 Double_t det=r00*r11 - r01*r01;
851 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
853 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
854 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
855 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
856 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
857 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
859 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
860 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
864 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
865 // Int_t n=GetNumberOfClusters();
866 //if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
869 fY += k00*dy + k01*dz;
870 fZ += k10*dy + k11*dz;
872 //fT += k30*dy + k31*dz;
876 Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12);
878 Double_t xuFactor = 1000.; // empirical factor set by C.Xu
879 // in the first tilt version
880 dy=c->GetY() - fY; dz=c->GetZ() - fZ;
881 //dy=dy+h01*dz+correction;
883 Double_t tiltdz = dz;
884 if (TMath::Abs(tiltdz)>padlength/2.) {
885 tiltdz = TMath::Sign(padlength/2,dz);
891 if (TMath::Abs(dz)>padlength/2.){
892 //Double_t dy2 = c->GetY() - fY;
893 //Double_t sign = (dz>0) ? -1.: 1.;
894 //dy2-=h01*sign*padlength/2.;
898 Double_t s00 = (c->GetSigmaY2()+errang)*extend+errsys+add; // error pad
899 Double_t s11 = c->GetSigmaZ2()*xuFactor; // error pad-row
901 r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
902 r01 = fCzy + fCzz*h01;
904 det = r00*r11 - r01*r01;
906 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
909 k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
910 k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
911 k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
912 k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
913 k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
916 cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
917 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
918 //Int_t n=GetNumberOfClusters();
919 // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
922 fY += k00*dy + k01*dz;
923 fZ += k10*dy + k11*dz;
925 fT += k30*dy + k31*dz;
938 Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
939 Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
940 Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
941 //Double_t oldte = fCte, oldce = fCce;
942 //Double_t oldct = fCct;
944 fCyy-=k00*oldyy+k01*oldzy;
945 fCzy-=k10*oldyy+k11*oldzy;
946 fCey-=k20*oldyy+k21*oldzy;
947 fCty-=k30*oldyy+k31*oldzy;
948 fCcy-=k40*oldyy+k41*oldzy;
950 fCzz-=k10*oldzy+k11*oldzz;
951 fCez-=k20*oldzy+k21*oldzz;
952 fCtz-=k30*oldzy+k31*oldzz;
953 fCcz-=k40*oldzy+k41*oldzz;
955 fCee-=k20*oldey+k21*oldez;
956 fCte-=k30*oldey+k31*oldez;
957 fCce-=k40*oldey+k41*oldez;
959 fCtt-=k30*oldty+k31*oldtz;
960 fCct-=k40*oldty+k41*oldtz;
962 fCcc-=k40*oldcy+k41*oldcz;
965 Int_t n=GetNumberOfClusters();
967 SetNumberOfClusters(n+1);
969 SetChi2(GetChi2()+chisq);
970 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
976 //_____________________________________________________________________________
977 Int_t AliTRDtrack::UpdateMI(const AliTRDtracklet &tracklet)
980 // Assignes found tracklet to the track and updates track information
983 Double_t r00=(tracklet.GetTrackletSigma2()), r01=0., r11= 10000.;
984 r00+=fCyy; r01+=fCzy; r11+=fCzz;
986 Double_t det=r00*r11 - r01*r01;
987 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
990 Double_t dy=tracklet.GetY() - fY, dz=tracklet.GetZ() - fZ;
993 Double_t s00 = tracklet.GetTrackletSigma2(); // error pad
994 Double_t s11 = 100000; // error pad-row
995 Float_t h01 = tracklet.GetTilt();
997 // r00 = fCyy + 2*fCzy*h01 + fCzz*h01*h01+s00;
998 r00 = fCyy + fCzz*h01*h01+s00;
999 // r01 = fCzy + fCzz*h01;
1002 det = r00*r11 - r01*r01;
1004 tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
1006 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
1007 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
1008 Double_t k20=fCey*r00+fCez*r01, k21=fCey*r01+fCez*r11;
1009 Double_t k30=fCty*r00+fCtz*r01, k31=fCty*r01+fCtz*r11;
1010 Double_t k40=fCcy*r00+fCcz*r01, k41=fCcy*r01+fCcz*r11;
1013 // k00=fCyy*r00+fCzy*(r01+h01*r00),k01=fCyy*r01+fCzy*(r11+h01*r01);
1014 // k10=fCzy*r00+fCzz*(r01+h01*r00),k11=fCzy*r01+fCzz*(r11+h01*r01);
1015 // k20=fCey*r00+fCez*(r01+h01*r00),k21=fCey*r01+fCez*(r11+h01*r01);
1016 // k30=fCty*r00+fCtz*(r01+h01*r00),k31=fCty*r01+fCtz*(r11+h01*r01);
1017 // k40=fCcy*r00+fCcz*(r01+h01*r00),k41=fCcy*r01+fCcz*(r11+h01*r01);
1019 //Update measurement
1020 Double_t cur=fC + k40*dy + k41*dz, eta=fE + k20*dy + k21*dz;
1021 // cur=fC + k40*dy + k41*dz; eta=fE + k20*dy + k21*dz;
1022 if (TMath::Abs(cur*fX-eta) >= 0.90000) {
1023 //Int_t n=GetNumberOfClusters();
1024 // if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
1034 fY += k00*dy + k01*dz;
1035 fZ += k10*dy + k11*dz;
1037 fT += k30*dy + k31*dz;
1044 Double_t oldyy = fCyy, oldzz = fCzz; //, oldee=fCee, oldcc =fCcc;
1045 Double_t oldzy = fCzy, oldey = fCey, oldty=fCty, oldcy =fCcy;
1046 Double_t oldez = fCez, oldtz = fCtz, oldcz=fCcz;
1047 //Double_t oldte = fCte, oldce = fCce;
1048 //Double_t oldct = fCct;
1050 fCyy-=k00*oldyy+k01*oldzy;
1051 fCzy-=k10*oldyy+k11*oldzy;
1052 fCey-=k20*oldyy+k21*oldzy;
1053 fCty-=k30*oldyy+k31*oldzy;
1054 fCcy-=k40*oldyy+k41*oldzy;
1056 fCzz-=k10*oldzy+k11*oldzz;
1057 fCez-=k20*oldzy+k21*oldzz;
1058 fCtz-=k30*oldzy+k31*oldzz;
1059 fCcz-=k40*oldzy+k41*oldzz;
1061 fCee-=k20*oldey+k21*oldez;
1062 fCte-=k30*oldey+k31*oldez;
1063 fCce-=k40*oldey+k41*oldez;
1065 fCtt-=k30*oldty+k31*oldtz;
1066 fCct-=k40*oldty+k41*oldtz;
1068 fCcc-=k40*oldcy+k41*oldcz;
1071 Int_t n=GetNumberOfClusters();
1073 SetNumberOfClusters(n+1);
1075 SetChi2(GetChi2()+chisq);
1076 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
1083 //_____________________________________________________________________________
1084 Int_t AliTRDtrack::Rotate(Double_t alpha, Bool_t absolute)
1086 // Rotates track parameters in R*phi plane
1087 // if absolute rotation alpha is in global system
1088 // otherwise alpha rotation is relative to the current rotation angle
1098 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
1099 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
1101 Double_t x1=fX, y1=fY;
1102 Double_t ca=cos(alpha), sa=sin(alpha);
1103 Double_t r1=fC*fX - fE;
1107 if((r1*r1) > 1) return 0;
1108 fE=fE*ca + (fC*y1 + sqrt(1.- r1*r1))*sa;
1110 Double_t r2=fC*fX - fE;
1111 if (TMath::Abs(r2) >= 0.90000) {
1112 Int_t n=GetNumberOfClusters();
1113 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !\n";
1117 if((r2*r2) > 1) return 0;
1118 Double_t y0=fY + sqrt(1.- r2*r2)/fC;
1119 if ((fY-y0)*fC >= 0.) {
1120 Int_t n=GetNumberOfClusters();
1121 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !!!\n";
1126 Double_t f00=ca-1, f24=(y1 - r1*x1/sqrt(1.- r1*r1))*sa,
1127 f20=fC*sa, f22=(ca + sa*r1/sqrt(1.- r1*r1))-1;
1130 Double_t b00=fCyy*f00, b02=fCyy*f20+fCcy*f24+fCey*f22;
1131 Double_t b10=fCzy*f00, b12=fCzy*f20+fCcz*f24+fCez*f22;
1132 Double_t b20=fCey*f00, b22=fCey*f20+fCce*f24+fCee*f22;
1133 Double_t b30=fCty*f00, b32=fCty*f20+fCct*f24+fCte*f22;
1134 Double_t b40=fCcy*f00, b42=fCcy*f20+fCcc*f24+fCce*f22;
1137 Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f24*b42+f22*b22;
1139 //F*C*Ft = C + (a + b + bt)
1140 fCyy += a00 + 2*b00;
1142 fCey += a02+b20+b02;
1147 fCee += a22 + 2*b22;
1154 //_____________________________________________________________________________
1155 Double_t AliTRDtrack::GetPredictedChi2(const AliTRDcluster *c, Double_t h01) const
1158 // Returns the track chi2
1161 Bool_t fNoTilt = kTRUE;
1162 if(TMath::Abs(h01) > 0.003) fNoTilt = kFALSE;
1163 Double_t chi2, dy, r00, r01, r11;
1167 r00=c->GetSigmaY2();
1171 Double_t padlength = TMath::Sqrt(c->GetSigmaZ2()*12);
1173 r00=c->GetSigmaY2(); r01=0.; r11=c->GetSigmaZ2();
1174 r00+=fCyy; r01+=fCzy; r11+=fCzz;
1176 Double_t det=r00*r11 - r01*r01;
1177 if (TMath::Abs(det) < 1.e-10) {
1178 Int_t n=GetNumberOfClusters();
1179 if (n>4) cerr<<n<<" AliTRDtrack warning: Singular matrix !\n";
1182 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
1183 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
1184 Double_t tiltdz = dz;
1185 if (TMath::Abs(tiltdz)>padlength/2.) {
1186 tiltdz = TMath::Sign(padlength/2,dz);
1191 chi2 = (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
1198 //_________________________________________________________________________
1199 void AliTRDtrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const
1201 // Returns reconstructed track momentum in the global system.
1203 Double_t pt=TMath::Abs(GetPt()); // GeV/c
1204 Double_t r=fC*fX-fE;
1207 if(r > 1) { py = pt; px = 0; }
1208 else if(r < -1) { py = -pt; px = 0; }
1210 y0=fY + sqrt(1.- r*r)/fC;
1211 px=-pt*(fY-y0)*fC; //cos(phi);
1212 py=-pt*(fE-fX*fC); //sin(phi);
1215 Double_t tmp=px*TMath::Cos(fAlpha) - py*TMath::Sin(fAlpha);
1216 py=px*TMath::Sin(fAlpha) + py*TMath::Cos(fAlpha);
1221 //_________________________________________________________________________
1222 void AliTRDtrack::GetGlobalXYZ(Double_t& x, Double_t& y, Double_t& z) const
1224 // Returns reconstructed track coordinates in the global system.
1226 x = fX; y = fY; z = fZ;
1227 Double_t tmp=x*TMath::Cos(fAlpha) - y*TMath::Sin(fAlpha);
1228 y=x*TMath::Sin(fAlpha) + y*TMath::Cos(fAlpha);
1233 //_________________________________________________________________________
1234 void AliTRDtrack::ResetCovariance()
1237 // Resets covariance matrix
1242 fCey=0.; fCez=0.; fCee*=10.;
1243 fCty=0.; fCtz=0.; fCte=0.; fCtt*=10.;
1244 fCcy=0.; fCcz=0.; fCce=0.; fCct=0.; fCcc*=10.;
1248 //_____________________________________________________________________________
1249 void AliTRDtrack::ResetCovariance(Float_t mult)
1252 // Resets covariance matrix
1257 fCey*=0.; fCez*=0.; fCee*=mult;
1258 fCty*=0.; fCtz*=0.; fCte*=0.; fCtt*=1.;
1259 fCcy*=0.; fCcz*=0.; fCce*=0.; fCct*=0.; fCcc*=mult;
1263 //_____________________________________________________________________________
1264 void AliTRDtrack::MakeBackupTrack()
1267 // Creates a backup track
1270 if (fBackupTrack) delete fBackupTrack;
1271 fBackupTrack = new AliTRDtrack(*this);
1275 //_____________________________________________________________________________
1276 Int_t AliTRDtrack::GetProlongation(Double_t xk, Double_t &y, Double_t &z)
1279 // Find prolongation at given x
1280 // return 0 if not exist
1282 Double_t c1=fC*fX - fE;
1283 if (TMath::Abs(c1)>1.) return 0;
1284 Double_t r1=TMath::Sqrt(1.- c1*c1);
1285 Double_t c2=fC*xk - fE;
1286 if (TMath::Abs(c2)>1.) return 0;
1287 Double_t r2=TMath::Sqrt(1.- c2*c2);
1288 y =fY + (xk-fX)*(c1+c2)/(r1+r2);
1289 z =fZ + (xk-fX)*(c1+c2)/(c1*r2 + c2*r1)*fT;
1295 //_____________________________________________________________________________
1296 Int_t AliTRDtrack::PropagateToX(Double_t xr, Double_t step)
1299 // Propagate track to given x position
1300 // works inside of the 20 degree segmentation (local cooordinate frame for TRD , TPC, TOF)
1302 // material budget from geo manager
1304 Double_t xyz0[3], xyz1[3],y,z;
1305 const Double_t kAlphac = TMath::Pi()/9.;
1306 const Double_t kTalphac = TMath::Tan(kAlphac*0.5);
1307 // critical alpha - cross sector indication
1309 Double_t dir = (fX>xr) ? -1.:1.;
1311 for (Double_t x=fX+dir*step;dir*x<dir*xr;x+=dir*step){
1313 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1314 GetProlongation(x,y,z);
1315 xyz1[0] = x*TMath::Cos(fAlpha)+y*TMath::Sin(fAlpha);
1316 xyz1[1] = x*TMath::Sin(fAlpha)-y*TMath::Cos(fAlpha);
1319 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1321 if (param[0]>0&¶m[1]>0) PropagateTo(x,param[1],param[0]);
1322 if (fY>fX*kTalphac){
1325 if (fY<-fX*kTalphac){
1336 //_____________________________________________________________________________
1337 Int_t AliTRDtrack::PropagateToR(Double_t r,Double_t step)
1340 // propagate track to the radial position
1341 // rotation always connected to the last track position
1343 Double_t xyz0[3], xyz1[3],y,z;
1344 Double_t radius = TMath::Sqrt(fX*fX+fY*fY);
1345 Double_t dir = (radius>r) ? -1.:1.; // direction +-
1347 for (Double_t x=radius+dir*step;dir*x<dir*r;x+=dir*step){
1348 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1349 Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
1350 Rotate(alpha,kTRUE);
1351 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1352 GetProlongation(x,y,z);
1353 xyz1[0] = x*TMath::Cos(alpha)+y*TMath::Sin(alpha);
1354 xyz1[1] = x*TMath::Sin(alpha)-y*TMath::Cos(alpha);
1357 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1358 if (param[1]<=0) param[1] =100000000;
1359 PropagateTo(x,param[1],param[0]);
1361 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1362 Double_t alpha = TMath::ATan2(xyz0[1],xyz0[0]);
1363 Rotate(alpha,kTRUE);
1364 GetGlobalXYZ(xyz0[0],xyz0[1],xyz0[2]);
1365 GetProlongation(r,y,z);
1366 xyz1[0] = r*TMath::Cos(alpha)+y*TMath::Sin(alpha);
1367 xyz1[1] = r*TMath::Sin(alpha)-y*TMath::Cos(alpha);
1370 AliKalmanTrack::MeanMaterialBudget(xyz0,xyz1,param);
1372 if (param[1]<=0) param[1] =100000000;
1373 PropagateTo(r,param[1],param[0]);
1379 //_____________________________________________________________________________
1380 Int_t AliTRDtrack::GetSector() const
1383 // Return the current sector
1386 return Int_t(TVector2::Phi_0_2pi(fAlpha)
1387 / AliTRDgeometry::GetAlpha())
1388 % AliTRDgeometry::kNsect;
1392 //_____________________________________________________________________________
1393 Double_t AliTRDtrack::Get1Pt() const
1395 //--------------------------------------------------------------
1396 // Returns the inverse Pt (1/GeV/c)
1397 // (or 1/"most probable pt", if the field is too weak)
1398 //--------------------------------------------------------------
1399 if (TMath::Abs(GetLocalConvConst()) > kVeryBigConvConst)
1400 return 1./kMostProbableMomentum/TMath::Sqrt(1.+ GetTgl()*GetTgl());
1401 return (TMath::Sign(1e-9,fC) + fC)*GetLocalConvConst();
1404 //_____________________________________________________________________________
1405 Double_t AliTRDtrack::GetP() const
1408 // Returns the total momentum
1411 return TMath::Abs(GetPt())*sqrt(1.+GetTgl()*GetTgl());
1415 //_____________________________________________________________________________
1416 Double_t AliTRDtrack::GetYat(Double_t xk) const
1419 // This function calculates the Y-coordinate of a track at
1420 // the plane x = xk.
1421 // Needed for matching with the TOF (I.Belikov)
1424 Double_t c1 = fC*fX - fE;
1425 Double_t r1 = TMath::Sqrt(1.0 - c1*c1);
1426 Double_t c2 = fC*xk - fE;
1427 Double_t r2 = TMath::Sqrt(1.0- c2*c2);
1428 return fY + (xk-fX)*(c1+c2)/(r1+r2);
1432 //_____________________________________________________________________________
1433 void AliTRDtrack::SetSampledEdx(Float_t q, Int_t i)
1436 // The sampled energy loss
1439 Double_t s = GetSnp();
1440 Double_t t = GetTgl();
1441 q *= TMath::Sqrt((1-s*s)/(1+t*t));
1446 //_____________________________________________________________________________
1447 void AliTRDtrack::SetSampledEdx(Float_t q)
1450 // The sampled energy loss
1453 Double_t s = GetSnp();
1454 Double_t t = GetTgl();
1455 q*= TMath::Sqrt((1-s*s)/(1+t*t));
1461 //_____________________________________________________________________________
1462 void AliTRDtrack::GetXYZ(Float_t r[3]) const
1465 //---------------------------------------------------------------------
1466 // Returns the position of the track in the global coord. system
1467 //---------------------------------------------------------------------
1469 Double_t cs = TMath::Cos(fAlpha);
1470 Double_t sn = TMath::Sin(fAlpha);
1471 r[0] = fX*cs - fY*sn;
1472 r[1] = fX*sn + fY*cs;