Finalise addition of EPEMGEN
[u/mrichter/AliRoot.git] / TRD / AliTRDtrack.cxx
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46d29e70 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
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 **************************************************************************/
15
16/*
17$Log$
a2cb5b3d 18Revision 1.12 2002/10/14 14:57:44 hristov
19Merging the VirtualMC branch to the main development branch (HEAD)
20
b9d0a01d 21Revision 1.8.10.2 2002/07/24 10:09:31 alibrary
22Updating VirtualMC
23
24Revision 1.11 2002/06/13 12:09:58 hristov
25Minor corrections
26
ca6c93d6 27Revision 1.10 2002/06/12 09:54:35 cblume
28Update of tracking code provided by Sergei
29
0a29d0f1 30Revision 1.8 2001/05/30 12:17:47 hristov
31Loop variables declared once
32
3ab6f951 33Revision 1.7 2001/05/28 17:07:58 hristov
34Last minute changes; ExB correction in AliTRDclusterizerV1; taking into account of material in G10 TEC frames and material between TEC planes (C.Blume,S.Sedykh)
35
2a941f4e 36Revision 1.4 2000/12/08 16:07:02 cblume
37Update of the tracking by Sergei
38
bbf92647 39Revision 1.3 2000/10/15 23:40:01 cblume
40Remove AliTRDconst
41
0e9c2ad5 42Revision 1.2 2000/10/06 16:49:46 cblume
43Made Getters const
44
46d29e70 45Revision 1.1.2.1 2000/09/22 14:47:52 cblume
46Add the tracking code
47
48*/
49
a2cb5b3d 50#include <Riostream.h>
5443e65e 51#include <TObject.h>
46d29e70 52
46d29e70 53#include "AliTRDgeometry.h"
54#include "AliTRDcluster.h"
55#include "AliTRDtrack.h"
5443e65e 56#include "../TPC/AliTPCtrack.h"
46d29e70 57
58ClassImp(AliTRDtrack)
59
60
61//_____________________________________________________________________________
62
a819a5f7 63AliTRDtrack::AliTRDtrack(const AliTRDcluster *c, UInt_t index,
5443e65e 64 const Double_t xx[5], const Double_t cc[15],
65 Double_t xref, Double_t alpha) : AliKalmanTrack() {
46d29e70 66 //-----------------------------------------------------------------
67 // This is the main track constructor.
68 //-----------------------------------------------------------------
5443e65e 69
70 fSeedLab = -1;
46d29e70 71
72 fAlpha=alpha;
5443e65e 73 if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi();
74 if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi();
75
46d29e70 76 fX=xref;
77
78 fY=xx[0]; fZ=xx[1]; fC=xx[2]; fE=xx[3]; fT=xx[4];
79
80 fCyy=cc[0];
81 fCzy=cc[1]; fCzz=cc[2];
82 fCcy=cc[3]; fCcz=cc[4]; fCcc=cc[5];
83 fCey=cc[6]; fCez=cc[7]; fCec=cc[8]; fCee=cc[9];
84 fCty=cc[10]; fCtz=cc[11]; fCtc=cc[12]; fCte=cc[13]; fCtt=cc[14];
85
5443e65e 86 fIndex[0]=index;
87 SetNumberOfClusters(1);
88
89 fdEdx=0.;
a2b90f83 90
5443e65e 91 Double_t q = TMath::Abs(c->GetQ());
a819a5f7 92 Double_t s = fX*fC - fE, t=fT;
5443e65e 93 if(s*s < 1) q *= TMath::Sqrt((1-s*s)/(1+t*t));
94
95 fdQdl[0] = q;
46d29e70 96}
97
98//_____________________________________________________________________________
5443e65e 99AliTRDtrack::AliTRDtrack(const AliTRDtrack& t) : AliKalmanTrack(t) {
46d29e70 100 //
101 // Copy constructor.
102 //
103
5443e65e 104 SetLabel(t.GetLabel());
105 fSeedLab=t.GetSeedLabel();
46d29e70 106
5443e65e 107 SetChi2(t.GetChi2());
46d29e70 108 fdEdx=t.fdEdx;
109
110 fAlpha=t.fAlpha;
111 fX=t.fX;
112
113 fY=t.fY; fZ=t.fZ; fC=t.fC; fE=t.fE; fT=t.fT;
114
115 fCyy=t.fCyy;
116 fCzy=t.fCzy; fCzz=t.fCzz;
117 fCcy=t.fCcy; fCcz=t.fCcz; fCcc=t.fCcc;
118 fCey=t.fCey; fCez=t.fCez; fCec=t.fCec; fCee=t.fCee;
119 fCty=t.fCty; fCtz=t.fCtz; fCtc=t.fCtc; fCte=t.fCte; fCtt=t.fCtt;
120
5443e65e 121 Int_t n=t.GetNumberOfClusters();
122 SetNumberOfClusters(n);
123 for (Int_t i=0; i<n; i++) {
a819a5f7 124 fIndex[i]=t.fIndex[i];
125 fdQdl[i]=t.fdQdl[i];
126 }
5443e65e 127}
128
129//_____________________________________________________________________________
130AliTRDtrack::AliTRDtrack(const AliKalmanTrack& t, Double_t alpha) {
131 //
132 // Constructor from AliTPCtrack or AliITStrack .
133 //
134
135 SetLabel(t.GetLabel());
136 SetChi2(0.);
137 SetNumberOfClusters(0);
138
139 fdEdx=0;
140
141 fAlpha = alpha;
142 if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
143 else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
144
145 Double_t x, p[5]; t.GetExternalParameters(x,p);
146
147 fX=x;
148
149 x = GetConvConst();
150
151 fY=p[0]; fZ=p[1]; fC=p[4]/x;
152 fE=fX*fC-p[2]; fT=p[3];
153
154 //Conversion of the covariance matrix
155 Double_t c[15]; t.GetExternalCovariance(c);
156
157 c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x;
158
159 Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5];
160 Double_t c32=fX*c[13] - c[8];
161 Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12];
162
163 fCyy=c[0 ];
164 fCzy=c[1 ]; fCzz=c[2 ];
165 fCcy=c[10]; fCcz=c[11]; fCcc=c[14];
166 fCey=c20; fCez=c21; fCec=c42; fCee=c22;
167 fCty=c[6 ]; fCtz=c[7 ]; fCtc=c[13]; fCte=c32; fCtt=c[9 ];
168
169}
170
171//____________________________________________________________________________
172void AliTRDtrack::GetExternalParameters(Double_t& xr, Double_t x[5]) const {
173 //
174 // This function returns external TRD track representation
175 //
176 xr=fX;
177 x[0]=GetY();
178 x[1]=GetZ();
179 x[2]=GetSnp();
180 x[3]=GetTgl();
181 x[4]=fC*GetConvConst();
182}
183
184//_____________________________________________________________________________
185void AliTRDtrack::GetExternalCovariance(Double_t cc[15]) const {
186 //
187 // This function returns external representation of the covriance matrix.
188 //
189 Double_t a=GetConvConst();
190
191 Double_t c22=fX*fX*fCcc-2*fX*fCec+fCee;
192 Double_t c32=fX*fCtc-fCte;
193 Double_t c20=fX*fCcy-fCey, c21=fX*fCcz-fCez, c42=fX*fCcc-fCec;
194
195 cc[0 ]=fCyy;
196 cc[1 ]=fCzy; cc[2 ]=fCzz;
197 cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22;
198 cc[6 ]=fCty; cc[7 ]=fCtz; cc[8 ]=c32; cc[9 ]=fCtt;
199 cc[10]=fCcy*a; cc[11]=fCcz*a; cc[12]=c42*a; cc[13]=fCtc*a; cc[14]=fCcc*a*a;
200}
201
46d29e70 202
203//_____________________________________________________________________________
204void AliTRDtrack::GetCovariance(Double_t cc[15]) const {
205 cc[0]=fCyy;
206 cc[1]=fCzy; cc[2]=fCzz;
207 cc[3]=fCcy; cc[4]=fCcz; cc[5]=fCcc;
208 cc[6]=fCey; cc[7]=fCez; cc[8]=fCec; cc[9]=fCee;
209 cc[10]=fCty; cc[11]=fCtz; cc[12]=fCtc; cc[13]=fCte; cc[14]=fCtt;
210}
211
212//_____________________________________________________________________________
2a941f4e 213Int_t AliTRDtrack::Compare(const TObject *o) const {
46d29e70 214
5443e65e 215// Compares tracks according to their Y2 or curvature
46d29e70 216
217 AliTRDtrack *t=(AliTRDtrack*)o;
218 // Double_t co=t->GetSigmaY2();
219 // Double_t c =GetSigmaY2();
220
221 Double_t co=TMath::Abs(t->GetC());
222 Double_t c =TMath::Abs(GetC());
223
224 if (c>co) return 1;
225 else if (c<co) return -1;
226 return 0;
227}
228
229//_____________________________________________________________________________
a819a5f7 230void AliTRDtrack::CookdEdx(Double_t low, Double_t up) {
231 //-----------------------------------------------------------------
232 // Calculates dE/dX within the "low" and "up" cuts.
233 //-----------------------------------------------------------------
5443e65e 234
a819a5f7 235 Int_t i;
5443e65e 236 Int_t nc=GetNumberOfClusters();
a819a5f7 237
5443e65e 238 Float_t sorted[kMAX_CLUSTERS_PER_TRACK];
239 for (i=0; i < nc; i++) {
240 sorted[i]=fdQdl[i];
241 }
a819a5f7 242
243 Int_t swap;
5443e65e 244
a819a5f7 245 do {
246 swap=0;
247 for (i=0; i<nc-1; i++) {
248 if (sorted[i]<=sorted[i+1]) continue;
249 Float_t tmp=sorted[i];
250 sorted[i]=sorted[i+1]; sorted[i+1]=tmp;
251 swap++;
252 }
253 } while (swap);
254
255 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc);
256 Float_t dedx=0;
257 for (i=nl; i<=nu; i++) dedx += sorted[i];
258 dedx /= (nu-nl+1);
5443e65e 259
a819a5f7 260 SetdEdx(dedx);
261}
262
263
264
265//_____________________________________________________________________________
46d29e70 266Int_t AliTRDtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho,Double_t pm)
267{
268 // Propagates a track of particle with mass=pm to a reference plane
269 // defined by x=xk through media of density=rho and radiationLength=x0
270
5443e65e 271
46d29e70 272 if (TMath::Abs(fC*xk - fE) >= 0.99999) {
5443e65e 273 Int_t n=GetNumberOfClusters();
274 if (n>4) cerr<<n<<" AliTRDtrack warning: Propagation failed !\n";
46d29e70 275 return 0;
276 }
277
278 Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fY, z1=fZ;
5443e65e 279 Double_t c1=fC*x1 - fE;
280 if((c1*c1) > 1) return 0;
281 Double_t r1=sqrt(1.- c1*c1);
282 Double_t c2=fC*x2 - fE;
283 if((c2*c2) > 1) return 0;
284 Double_t r2=sqrt(1.- c2*c2);
46d29e70 285
286 fY += dx*(c1+c2)/(r1+r2);
287 fZ += dx*(c1+c2)/(c1*r2 + c2*r1)*fT;
288
289 //f = F - 1
290 Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2;
291 Double_t f02= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr);
292 Double_t f03=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr);
293 Double_t cr=c1*r2+c2*r1;
294 Double_t f12= dx*fT*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr);
295 Double_t f13=-dx*fT*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr);
296 Double_t f14= dx*cc/cr;
297
298 //b = C*ft
299 Double_t b00=f02*fCcy + f03*fCey, b01=f12*fCcy + f13*fCey + f14*fCty;
300 Double_t b10=f02*fCcz + f03*fCez, b11=f12*fCcz + f13*fCez + f14*fCtz;
301 Double_t b20=f02*fCcc + f03*fCec, b21=f12*fCcc + f13*fCec + f14*fCtc;
302 Double_t b30=f02*fCec + f03*fCee, b31=f12*fCec + f13*fCee + f14*fCte;
303 Double_t b40=f02*fCtc + f03*fCte, b41=f12*fCtc + f13*fCte + f14*fCtt;
304
305 //a = f*b = f*C*ft
306 Double_t a00=f02*b20+f03*b30,a01=f02*b21+f03*b31,a11=f12*b21+f13*b31+f14*b41;
307
308 //F*C*Ft = C + (a + b + bt)
309 fCyy += a00 + 2*b00;
310 fCzy += a01 + b01 + b10;
311 fCcy += b20;
312 fCey += b30;
313 fCty += b40;
314 fCzz += a11 + 2*b11;
315 fCcz += b21;
316 fCez += b31;
317 fCtz += b41;
318
319 fX=x2;
320
321
322 //Multiple scattering ******************
323
324 Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fY)*(y1-fY)+(z1-fZ)*(z1-fZ));
325 Double_t p2=GetPt()*GetPt()*(1.+fT*fT);
5443e65e 326 p2 = TMath::Min(p2,1e+08); // to avoid division by (1-1) for stiff tracks
46d29e70 327 Double_t beta2=p2/(p2 + pm*pm);
328
329 Double_t ey=fC*fX - fE, ez=fT;
330 Double_t xz=fC*ez, zz1=ez*ez+1, xy=fE+ey;
331
332 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho;
333 fCcc += xz*xz*theta2;
334 fCec += xz*ez*xy*theta2;
335 fCtc += xz*zz1*theta2;
336 fCee += (2*ey*ez*ez*fE+1-ey*ey+ez*ez+fE*fE*ez*ez)*theta2;
337 fCte += ez*zz1*xy*theta2;
338 fCtt += zz1*zz1*theta2;
339
340
341 //Energy losses************************
5443e65e 342 if (x1 < x2) d=-d;
46d29e70 343 Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d*rho;
ca6c93d6 344 //PH SetLength(GetLength()+d);
5443e65e 345
346 cc = fC;
46d29e70 347 fC*=(1.- sqrt(p2+pm*pm)/p2*dE);
5443e65e 348 fE+=fX*(fC-cc);
46d29e70 349
350 return 1;
351
352}
353
46d29e70 354//_____________________________________________________________________________
5443e65e 355Int_t AliTRDtrack::Update(const AliTRDcluster *c, Double_t chisq, UInt_t index)
46d29e70 356{
357 // Assignes found cluster to the track and updates track information
358
a819a5f7 359 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
46d29e70 360 r00+=fCyy; r01+=fCzy; r11+=fCzz;
361 Double_t det=r00*r11 - r01*r01;
362 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
363
364 Double_t k00=fCyy*r00+fCzy*r01, k01=fCyy*r01+fCzy*r11;
365 Double_t k10=fCzy*r00+fCzz*r01, k11=fCzy*r01+fCzz*r11;
366 Double_t k20=fCcy*r00+fCcz*r01, k21=fCcy*r01+fCcz*r11;
367 Double_t k30=fCey*r00+fCez*r01, k31=fCey*r01+fCez*r11;
368 Double_t k40=fCty*r00+fCtz*r01, k41=fCty*r01+fCtz*r11;
369
370 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
371 Double_t cur=fC + k20*dy + k21*dz, eta=fE + k30*dy + k31*dz;
372 if (TMath::Abs(cur*fX-eta) >= 0.99999) {
5443e65e 373 Int_t n=GetNumberOfClusters();
374 if (n>4) cerr<<n<<" AliTRDtrack warning: Filtering failed !\n";
375 return 0;
46d29e70 376 }
377
378 fY += k00*dy + k01*dz;
379 fZ += k10*dy + k11*dz;
380 fC = cur;
381 fE = eta;
382 fT += k40*dy + k41*dz;
383
384 Double_t c01=fCzy, c02=fCcy, c03=fCey, c04=fCty;
385 Double_t c12=fCcz, c13=fCez, c14=fCtz;
386
387 fCyy-=k00*fCyy+k01*fCzy; fCzy-=k00*c01+k01*fCzz;
388 fCcy-=k00*c02+k01*c12; fCey-=k00*c03+k01*c13;
389 fCty-=k00*c04+k01*c14;
390
391 fCzz-=k10*c01+k11*fCzz;
392 fCcz-=k10*c02+k11*c12; fCez-=k10*c03+k11*c13;
393 fCtz-=k10*c04+k11*c14;
394
395 fCcc-=k20*c02+k21*c12; fCec-=k20*c03+k21*c13;
396 fCtc-=k20*c04+k21*c14;
397
398 fCee-=k30*c03+k31*c13;
399 fCte-=k30*c04+k31*c14;
400
401 fCtt-=k40*c04+k41*c14;
402
5443e65e 403 Int_t n=GetNumberOfClusters();
404 fIndex[n]=index;
405 SetNumberOfClusters(n+1);
46d29e70 406
5443e65e 407 SetChi2(GetChi2()+chisq);
46d29e70 408 // cerr<<"in update: fIndex["<<fN<<"] = "<<index<<endl;
5443e65e 409
410 return 1;
46d29e70 411}
412
413//_____________________________________________________________________________
414Int_t AliTRDtrack::Rotate(Double_t alpha)
415{
416 // Rotates track parameters in R*phi plane
417
418 fAlpha += alpha;
419
420 Double_t x1=fX, y1=fY;
421 Double_t ca=cos(alpha), sa=sin(alpha);
422 Double_t r1=fC*fX - fE;
423
5443e65e 424 if (TMath::Abs(r1) >= 0.99999) {
425 Int_t n=GetNumberOfClusters();
426 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !\n";
427 return 0;
428 }
429
46d29e70 430 fX = x1*ca + y1*sa;
431 fY=-x1*sa + y1*ca;
432 fE=fE*ca + (fC*y1 + sqrt(1.- r1*r1))*sa;
433
434 Double_t r2=fC*fX - fE;
435 if (TMath::Abs(r2) >= 0.99999) {
5443e65e 436 Int_t n=GetNumberOfClusters();
437 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !\n";
46d29e70 438 return 0;
439 }
440
441 Double_t y0=fY + sqrt(1.- r2*r2)/fC;
442 if ((fY-y0)*fC >= 0.) {
5443e65e 443 Int_t n=GetNumberOfClusters();
444 if (n>4) cerr<<n<<" AliTRDtrack warning: Rotation failed !!!\n";
46d29e70 445 return 0;
446 }
447
448 //f = F - 1
449 Double_t f00=ca-1, f32=(y1 - r1*x1/sqrt(1.- r1*r1))*sa,
450 f30=fC*sa, f33=(ca + sa*r1/sqrt(1.- r1*r1))-1;
451
452 //b = C*ft
453 Double_t b00=fCyy*f00, b03=fCyy*f30+fCcy*f32+fCey*f33;
454 Double_t b10=fCzy*f00, b13=fCzy*f30+fCcz*f32+fCez*f33;
455 Double_t b20=fCcy*f00, b23=fCcy*f30+fCcc*f32+fCec*f33;
456 Double_t b30=fCey*f00, b33=fCey*f30+fCec*f32+fCee*f33;
457 Double_t b40=fCty*f00, b43=fCty*f30+fCtc*f32+fCte*f33;
458
459 //a = f*b = f*C*ft
460 Double_t a00=f00*b00, a03=f00*b03, a33=f30*b03+f32*b23+f33*b33;
461
462 // *** Double_t dy2=fCyy;
463
464 //F*C*Ft = C + (a + b + bt)
465 fCyy += a00 + 2*b00;
466 fCzy += b10;
467 fCcy += b20;
468 fCey += a03+b30+b03;
469 fCty += b40;
470 fCez += b13;
471 fCec += b23;
472 fCee += a33 + 2*b33;
473 fCte += b43;
474
475 // *** fCyy+=dy2*sa*sa*r1*r1/(1.- r1*r1);
476 // *** fCzz+=d2y*sa*sa*fT*fT/(1.- r1*r1);
477
478 return 1;
479}
480
481
46d29e70 482//_____________________________________________________________________________
483Double_t AliTRDtrack::GetPredictedChi2(const AliTRDcluster *c) const
484{
a819a5f7 485 /*
486 Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2();
46d29e70 487 r00+=fCyy; r01+=fCzy; r11+=fCzz;
488
489 Double_t det=r00*r11 - r01*r01;
490 if (TMath::Abs(det) < 1.e-10) {
491 if (fN>4) cerr<<fN<<" AliTRDtrack warning: Singular matrix !\n";
492 return 1e10;
493 }
494 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
495
496 Double_t dy=c->GetY() - fY, dz=c->GetZ() - fZ;
497
498 return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
a819a5f7 499 */
500
501 Double_t dy=c->GetY() - fY;
502 Double_t r00=c->GetSigmaY2();
503
504 return (dy*dy)/r00;
505
46d29e70 506}
507
508
509//_________________________________________________________________________
510void AliTRDtrack::GetPxPyPz(Double_t& px, Double_t& py, Double_t& pz) const
511{
512 // Returns reconstructed track momentum in the global system.
513
514 Double_t pt=TMath::Abs(GetPt()); // GeV/c
515 Double_t r=fC*fX-fE;
5443e65e 516
517 Double_t y0;
518 if(r > 1) { py = pt; px = 0; }
519 else if(r < -1) { py = -pt; px = 0; }
520 else {
521 y0=fY + sqrt(1.- r*r)/fC;
522 px=-pt*(fY-y0)*fC; //cos(phi);
523 py=-pt*(fE-fX*fC); //sin(phi);
524 }
46d29e70 525 pz=pt*fT;
526 Double_t tmp=px*TMath::Cos(fAlpha) - py*TMath::Sin(fAlpha);
527 py=px*TMath::Sin(fAlpha) + py*TMath::Cos(fAlpha);
528 px=tmp;
529
530}
531
5443e65e 532//_________________________________________________________________________
533void AliTRDtrack::GetGlobalXYZ(Double_t& x, Double_t& y, Double_t& z) const
46d29e70 534{
5443e65e 535 // Returns reconstructed track coordinates in the global system.
536
537 x = fX; y = fY; z = fZ;
538 Double_t tmp=x*TMath::Cos(fAlpha) - y*TMath::Sin(fAlpha);
539 y=x*TMath::Sin(fAlpha) + y*TMath::Cos(fAlpha);
540 x=tmp;
541
542}
3ab6f951 543
5443e65e 544//_________________________________________________________________________
545void AliTRDtrack::ResetCovariance() {
546 //
547 // Resets covariance matrix
548 //
46d29e70 549
5443e65e 550 fCyy*=10.;
551 fCzy=0.; fCzz*=10.;
552 fCcy=0.; fCcz=0.; fCcc*=10.;
553 fCey=0.; fCez=0.; fCec=0.; fCee*=10.;
554 fCty=0.; fCtz=0.; fCtc=0.; fCte=0.; fCtt*=10.;
46d29e70 555
5443e65e 556}