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87594435 | 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 | ||
acd84897 | 16 | /* $Id$ */ |
fb17acd4 | 17 | |
87594435 | 18 | //------------------------------------------------------------------------- |
19 | // Implementation of the AliKalmanTrack class | |
066782e8 | 20 | // that is the base for AliTPCtrack, AliITStrackV2 and AliTRDtrack |
87594435 | 21 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch |
22 | //------------------------------------------------------------------------- | |
7d0f8548 | 23 | #include "AliTracker.h" |
87594435 | 24 | #include "AliKalmanTrack.h" |
4557b520 | 25 | #include "TGeoManager.h" |
87594435 | 26 | |
27 | ClassImp(AliKalmanTrack) | |
28 | ||
e2afb3b6 | 29 | //_______________________________________________________________________ |
30 | AliKalmanTrack::AliKalmanTrack(): | |
31 | fLab(-3141593), | |
68b8060b | 32 | fFakeRatio(0), |
e2afb3b6 | 33 | fChi2(0), |
304864ab | 34 | fMass(AliPID::ParticleMass(AliPID::kPion)), |
90e48c0c | 35 | fN(0), |
c84a5e9e | 36 | fLocalConvConst(0), |
90e48c0c | 37 | fStartTimeIntegral(kFALSE), |
38 | fIntegratedLength(0) | |
e2afb3b6 | 39 | { |
116cbefd | 40 | // |
41 | // Default constructor | |
42 | // | |
7d0f8548 | 43 | if (AliTracker::GetFieldMap()==0) { |
f37d970d | 44 | AliFatal("The magnetic field has not been set!"); |
7d0f8548 | 45 | } |
c84a5e9e | 46 | |
7d0f8548 | 47 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; |
e2afb3b6 | 48 | } |
49 | ||
50 | //_______________________________________________________________________ | |
51 | AliKalmanTrack::AliKalmanTrack(const AliKalmanTrack &t): | |
52 | TObject(t), | |
53 | fLab(t.fLab), | |
babd135a | 54 | fFakeRatio(t.fFakeRatio), |
e2afb3b6 | 55 | fChi2(t.fChi2), |
56 | fMass(t.fMass), | |
90e48c0c | 57 | fN(t.fN), |
c84a5e9e | 58 | fLocalConvConst(t.fLocalConvConst), |
90e48c0c | 59 | fStartTimeIntegral(t.fStartTimeIntegral), |
60 | fIntegratedLength(t.fIntegratedLength) | |
e2afb3b6 | 61 | { |
116cbefd | 62 | // |
63 | // Copy constructor | |
64 | // | |
7d0f8548 | 65 | if (AliTracker::GetFieldMap()==0) { |
f37d970d | 66 | AliFatal("The magnetic field has not been set!"); |
8de97894 | 67 | } |
74f9526e | 68 | |
c84a5e9e | 69 | for (Int_t i=0; i<AliPID::kSPECIES; i++) |
70 | fIntegratedTime[i] = t.fIntegratedTime[i]; | |
74f9526e | 71 | } |
c5507f6d | 72 | |
74f9526e | 73 | //_______________________________________________________________________ |
74 | void AliKalmanTrack::StartTimeIntegral() | |
75 | { | |
49a7a79a | 76 | // Sylwester Radomski, GSI |
77 | // S.Radomski@gsi.de | |
74f9526e | 78 | // |
79 | // Start time integration | |
80 | // To be called at Vertex by ITS tracker | |
81 | // | |
82 | ||
83 | //if (fStartTimeIntegral) | |
f37d970d | 84 | // AliWarning("Reseting Recorded Time."); |
74f9526e | 85 | |
86 | fStartTimeIntegral = kTRUE; | |
304864ab | 87 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; |
74f9526e | 88 | fIntegratedLength = 0; |
89 | } | |
7d0f8548 | 90 | |
74f9526e | 91 | //_______________________________________________________________________ |
92 | void AliKalmanTrack:: AddTimeStep(Double_t length) | |
93 | { | |
94 | // | |
95 | // Add step to integrated time | |
96 | // this method should be called by a sublasses at the end | |
97 | // of the PropagateTo function or by a tracker | |
98 | // each time step is made. | |
99 | // | |
100 | // If integration not started function does nothing | |
101 | // | |
102 | // Formula | |
103 | // dt = dl * sqrt(p^2 + m^2) / p | |
104 | // p = pT * (1 + tg^2 (lambda) ) | |
105 | // | |
106 | // pt = 1/external parameter [4] | |
107 | // tg lambda = external parameter [3] | |
108 | // | |
109 | // | |
110 | // Sylwester Radomski, GSI | |
111 | // S.Radomski@gsi.de | |
112 | // | |
113 | ||
5d8718b8 | 114 | static const Double_t kcc = 2.99792458e-2; |
74f9526e | 115 | |
116 | if (!fStartTimeIntegral) return; | |
117 | ||
118 | fIntegratedLength += length; | |
119 | ||
74f9526e | 120 | Double_t xr, param[5]; |
121 | Double_t pt, tgl; | |
122 | ||
123 | GetExternalParameters(xr, param); | |
124 | pt = 1/param[4] ; | |
125 | tgl = param[3]; | |
126 | ||
127 | Double_t p = TMath::Abs(pt * TMath::Sqrt(1+tgl*tgl)); | |
128 | ||
129 | if (length > 100) return; | |
130 | ||
304864ab | 131 | for (Int_t i=0; i<AliPID::kSPECIES; i++) { |
74f9526e | 132 | |
304864ab | 133 | Double_t mass = AliPID::ParticleMass(i); |
74f9526e | 134 | Double_t correction = TMath::Sqrt( pt*pt * (1 + tgl*tgl) + mass * mass ) / p; |
5d8718b8 | 135 | Double_t time = length * correction / kcc; |
74f9526e | 136 | |
74f9526e | 137 | fIntegratedTime[i] += time; |
138 | } | |
e2afb3b6 | 139 | } |
140 | ||
74f9526e | 141 | //_______________________________________________________________________ |
74f9526e | 142 | Double_t AliKalmanTrack::GetIntegratedTime(Int_t pdg) const |
143 | { | |
49a7a79a | 144 | // Sylwester Radomski, GSI |
145 | // S.Radomski@gsi.de | |
74f9526e | 146 | // |
147 | // Return integrated time hypothesis for a given particle | |
148 | // type assumption. | |
149 | // | |
150 | // Input parameter: | |
151 | // pdg - Pdg code of a particle type | |
152 | // | |
153 | ||
154 | ||
155 | if (!fStartTimeIntegral) { | |
f37d970d | 156 | AliWarning("Time integration not started"); |
74f9526e | 157 | return 0.; |
158 | } | |
159 | ||
304864ab | 160 | for (Int_t i=0; i<AliPID::kSPECIES; i++) |
161 | if (AliPID::ParticleCode(i) == TMath::Abs(pdg)) return fIntegratedTime[i]; | |
74f9526e | 162 | |
f37d970d | 163 | AliWarning(Form("Particle type [%d] not found", pdg)); |
74f9526e | 164 | return 0; |
165 | } | |
ae982df3 | 166 | |
167 | void AliKalmanTrack::GetIntegratedTimes(Double_t *times) const { | |
304864ab | 168 | for (Int_t i=0; i<AliPID::kSPECIES; i++) times[i]=fIntegratedTime[i]; |
ae982df3 | 169 | } |
170 | ||
171 | void AliKalmanTrack::SetIntegratedTimes(const Double_t *times) { | |
304864ab | 172 | for (Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i]=times[i]; |
ae982df3 | 173 | } |
174 | ||
c84a5e9e | 175 | void AliKalmanTrack::External2Helix(Double_t helix[6]) const { |
49a7a79a | 176 | //-------------------------------------------------------------------- |
177 | // External track parameters -> helix parameters | |
178 | //-------------------------------------------------------------------- | |
179 | Double_t alpha,x,cs,sn; | |
c84a5e9e | 180 | GetExternalParameters(x,helix); alpha=GetAlpha(); |
49a7a79a | 181 | |
182 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
183 | helix[5]=x*cs - helix[0]*sn; // x0 | |
184 | helix[0]=x*sn + helix[0]*cs; // y0 | |
185 | //helix[1]= // z0 | |
186 | helix[2]=TMath::ASin(helix[2]) + alpha; // phi0 | |
187 | //helix[3]= // tgl | |
c84a5e9e | 188 | helix[4]=helix[4]/GetLocalConvConst(); // C |
49a7a79a | 189 | } |
190 | ||
191 | static void Evaluate(const Double_t *h, Double_t t, | |
192 | Double_t r[3], //radius vector | |
193 | Double_t g[3], //first defivatives | |
194 | Double_t gg[3]) //second derivatives | |
195 | { | |
196 | //-------------------------------------------------------------------- | |
197 | // Calculate position of a point on a track and some derivatives | |
198 | //-------------------------------------------------------------------- | |
199 | Double_t phase=h[4]*t+h[2]; | |
200 | Double_t sn=TMath::Sin(phase), cs=TMath::Cos(phase); | |
201 | ||
202 | r[0] = h[5] + (sn - h[6])/h[4]; | |
203 | r[1] = h[0] - (cs - h[7])/h[4]; | |
204 | r[2] = h[1] + h[3]*t; | |
205 | ||
206 | g[0] = cs; g[1]=sn; g[2]=h[3]; | |
207 | ||
208 | gg[0]=-h[4]*sn; gg[1]=h[4]*cs; gg[2]=0.; | |
209 | } | |
210 | ||
211 | Double_t AliKalmanTrack:: | |
212 | GetDCA(const AliKalmanTrack *p, Double_t &xthis, Double_t &xp) const { | |
213 | //------------------------------------------------------------ | |
214 | // Returns the (weighed !) distance of closest approach between | |
215 | // this track and the track passed as the argument. | |
216 | // Other returned values: | |
217 | // xthis, xt - coordinates of tracks' reference planes at the DCA | |
218 | //----------------------------------------------------------- | |
219 | Double_t dy2=GetSigmaY2() + p->GetSigmaY2(); | |
220 | Double_t dz2=GetSigmaZ2() + p->GetSigmaZ2(); | |
221 | Double_t dx2=dy2; | |
222 | ||
223 | //dx2=dy2=dz2=1.; | |
224 | ||
c84a5e9e | 225 | Double_t p1[8]; External2Helix(p1); |
49a7a79a | 226 | p1[6]=TMath::Sin(p1[2]); p1[7]=TMath::Cos(p1[2]); |
c84a5e9e | 227 | Double_t p2[8]; p->External2Helix(p2); |
49a7a79a | 228 | p2[6]=TMath::Sin(p2[2]); p2[7]=TMath::Cos(p2[2]); |
229 | ||
230 | ||
231 | Double_t r1[3],g1[3],gg1[3]; Double_t t1=0.; | |
232 | Evaluate(p1,t1,r1,g1,gg1); | |
233 | Double_t r2[3],g2[3],gg2[3]; Double_t t2=0.; | |
234 | Evaluate(p2,t2,r2,g2,gg2); | |
74f9526e | 235 | |
49a7a79a | 236 | Double_t dx=r2[0]-r1[0], dy=r2[1]-r1[1], dz=r2[2]-r1[2]; |
237 | Double_t dm=dx*dx/dx2 + dy*dy/dy2 + dz*dz/dz2; | |
238 | ||
239 | Int_t max=27; | |
240 | while (max--) { | |
241 | Double_t gt1=-(dx*g1[0]/dx2 + dy*g1[1]/dy2 + dz*g1[2]/dz2); | |
242 | Double_t gt2=+(dx*g2[0]/dx2 + dy*g2[1]/dy2 + dz*g2[2]/dz2); | |
243 | Double_t h11=(g1[0]*g1[0] - dx*gg1[0])/dx2 + | |
244 | (g1[1]*g1[1] - dy*gg1[1])/dy2 + | |
245 | (g1[2]*g1[2] - dz*gg1[2])/dz2; | |
246 | Double_t h22=(g2[0]*g2[0] + dx*gg2[0])/dx2 + | |
247 | (g2[1]*g2[1] + dy*gg2[1])/dy2 + | |
248 | (g2[2]*g2[2] + dz*gg2[2])/dz2; | |
249 | Double_t h12=-(g1[0]*g2[0]/dx2 + g1[1]*g2[1]/dy2 + g1[2]*g2[2]/dz2); | |
250 | ||
251 | Double_t det=h11*h22-h12*h12; | |
252 | ||
253 | Double_t dt1,dt2; | |
254 | if (TMath::Abs(det)<1.e-33) { | |
255 | //(quasi)singular Hessian | |
256 | dt1=-gt1; dt2=-gt2; | |
257 | } else { | |
258 | dt1=-(gt1*h22 - gt2*h12)/det; | |
259 | dt2=-(h11*gt2 - h12*gt1)/det; | |
260 | } | |
261 | ||
262 | if ((dt1*gt1+dt2*gt2)>0) {dt1=-dt1; dt2=-dt2;} | |
263 | ||
264 | //check delta(phase1) ? | |
265 | //check delta(phase2) ? | |
266 | ||
267 | if (TMath::Abs(dt1)/(TMath::Abs(t1)+1.e-3) < 1.e-4) | |
268 | if (TMath::Abs(dt2)/(TMath::Abs(t2)+1.e-3) < 1.e-4) { | |
269 | if ((gt1*gt1+gt2*gt2) > 1.e-4/dy2/dy2) | |
f37d970d | 270 | AliWarning(" stopped at not a stationary point !"); |
49a7a79a | 271 | Double_t lmb=h11+h22; lmb=lmb-TMath::Sqrt(lmb*lmb-4*det); |
272 | if (lmb < 0.) | |
f37d970d | 273 | AliWarning(" stopped at not a minimum !"); |
49a7a79a | 274 | break; |
275 | } | |
276 | ||
277 | Double_t dd=dm; | |
278 | for (Int_t div=1 ; ; div*=2) { | |
279 | Evaluate(p1,t1+dt1,r1,g1,gg1); | |
280 | Evaluate(p2,t2+dt2,r2,g2,gg2); | |
281 | dx=r2[0]-r1[0]; dy=r2[1]-r1[1]; dz=r2[2]-r1[2]; | |
282 | dd=dx*dx/dx2 + dy*dy/dy2 + dz*dz/dz2; | |
283 | if (dd<dm) break; | |
284 | dt1*=0.5; dt2*=0.5; | |
285 | if (div>512) { | |
f37d970d | 286 | AliWarning(" overshoot !"); break; |
49a7a79a | 287 | } |
288 | } | |
289 | dm=dd; | |
290 | ||
291 | t1+=dt1; | |
292 | t2+=dt2; | |
293 | ||
294 | } | |
295 | ||
f37d970d | 296 | if (max<=0) AliWarning(" too many iterations !"); |
49a7a79a | 297 | |
298 | Double_t cs=TMath::Cos(GetAlpha()); | |
299 | Double_t sn=TMath::Sin(GetAlpha()); | |
300 | xthis=r1[0]*cs + r1[1]*sn; | |
301 | ||
302 | cs=TMath::Cos(p->GetAlpha()); | |
303 | sn=TMath::Sin(p->GetAlpha()); | |
304 | xp=r2[0]*cs + r2[1]*sn; | |
305 | ||
306 | return TMath::Sqrt(dm*TMath::Sqrt(dy2*dz2)); | |
307 | } | |
308 | ||
7d0f8548 | 309 | Double_t |
310 | AliKalmanTrack::PropagateToDCA(AliKalmanTrack *p, Double_t d, Double_t x0) { | |
49a7a79a | 311 | //-------------------------------------------------------------- |
312 | // Propagates this track and the argument track to the position of the | |
313 | // distance of closest approach. | |
314 | // Returns the (weighed !) distance of closest approach. | |
315 | //-------------------------------------------------------------- | |
316 | Double_t xthis,xp; | |
317 | Double_t dca=GetDCA(p,xthis,xp); | |
318 | ||
319 | if (!PropagateTo(xthis,d,x0)) { | |
f37d970d | 320 | //AliWarning(" propagation failed !"); |
49a7a79a | 321 | return 1e+33; |
322 | } | |
323 | ||
324 | if (!p->PropagateTo(xp,d,x0)) { | |
f37d970d | 325 | //AliWarning(" propagation failed !"; |
49a7a79a | 326 | return 1e+33; |
327 | } | |
328 | ||
329 | return dca; | |
330 | } | |
c84a5e9e | 331 | |
4557b520 | 332 | |
333 | ||
334 | ||
335 | ||
336 | Double_t AliKalmanTrack::MeanMaterialBudget(Double_t *start, Double_t *end, Double_t *mparam) | |
337 | { | |
338 | // | |
339 | // calculate mean material budget and material properties beween point start and end | |
340 | // mparam - returns parameters used for dEdx and multiple scatering | |
341 | // | |
342 | // mparam[0] - density mean | |
343 | // mparam[1] - rad length | |
344 | // mparam[2] - A mean | |
345 | // mparam[3] - Z mean | |
346 | // mparam[4] - length | |
347 | // mparam[5] - Z/A mean | |
348 | // mparam[6] - number of boundary crosses | |
349 | // | |
350 | mparam[0]=0; mparam[1]=1; mparam[2] =0; mparam[3] =0, mparam[4]=0, mparam[5]=0; mparam[6]=0; | |
351 | // | |
352 | Double_t bparam[6], lparam[6]; // bparam - total param - lparam - local parameters | |
353 | for (Int_t i=0;i<6;i++) bparam[i]=0; // | |
354 | ||
355 | if (!gGeoManager) { | |
356 | printf("ERROR: no TGeo\n"); | |
357 | return 0.; | |
358 | } | |
359 | // | |
360 | Double_t length; | |
361 | Double_t dir[3]; | |
362 | length = TMath::Sqrt((end[0]-start[0])*(end[0]-start[0])+ | |
363 | (end[1]-start[1])*(end[1]-start[1])+ | |
364 | (end[2]-start[2])*(end[2]-start[2])); | |
365 | mparam[4]=length; | |
366 | if (length<TGeoShape::Tolerance()) return 0.0; | |
367 | Double_t invlen = 1./length; | |
368 | dir[0] = (end[0]-start[0])*invlen; | |
369 | dir[1] = (end[1]-start[1])*invlen; | |
370 | dir[2] = (end[2]-start[2])*invlen; | |
371 | // Initialize start point and direction | |
372 | TGeoNode *currentnode = 0; | |
373 | TGeoNode *startnode = gGeoManager->InitTrack(start, dir); | |
374 | // printf("%s length=%f\n",gGeoManager->GetPath(),length); | |
375 | if (!startnode) { | |
376 | printf("ERROR: start point out of geometry\n"); | |
377 | return 0.0; | |
378 | } | |
379 | TGeoMaterial *material = startnode->GetVolume()->GetMedium()->GetMaterial(); | |
380 | lparam[0] = material->GetDensity(); | |
381 | lparam[1] = material->GetRadLen(); | |
382 | lparam[2] = material->GetA(); | |
383 | lparam[3] = material->GetZ(); | |
5df14aca | 384 | lparam[4] = length; |
4557b520 | 385 | lparam[5] = lparam[3]/lparam[2]; |
386 | if (material->IsMixture()) { | |
387 | lparam[1]*=lparam[0]; // different normalization in the modeler for mixture | |
388 | TGeoMixture * mixture = (TGeoMixture*)material; | |
389 | lparam[5] =0; | |
390 | Double_t sum =0; | |
391 | for (Int_t iel=0;iel<mixture->GetNelements();iel++){ | |
392 | sum += mixture->GetWmixt()[iel]; | |
393 | lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel]; | |
394 | } | |
395 | lparam[5]/=sum; | |
396 | } | |
397 | gGeoManager->FindNextBoundary(length); | |
398 | Double_t snext = gGeoManager->GetStep(); | |
399 | Double_t step = 0.0; | |
400 | // If no boundary within proposed length, return current density | |
401 | if (snext>=length) { | |
402 | for (Int_t ip=0;ip<5;ip++) mparam[ip] = lparam[ip]; | |
403 | return lparam[0]; | |
404 | } | |
405 | // Try to cross the boundary and see what is next | |
406 | while (length>TGeoShape::Tolerance()) { | |
407 | mparam[6]+=1.; | |
408 | currentnode = gGeoManager->Step(); | |
409 | step += snext+1.E-6; | |
410 | bparam[1] += snext*lparam[1]; | |
411 | bparam[2] += snext*lparam[2]; | |
412 | bparam[3] += snext*lparam[3]; | |
413 | bparam[5] += snext*lparam[5]; | |
414 | bparam[0] += snext*lparam[0]; | |
415 | ||
416 | if (snext>=length) break; | |
58d96064 | 417 | if (!currentnode) break; |
4557b520 | 418 | // printf("%s snext=%f density=%f bparam[0]=%f\n", gGeoManager->GetPath(),snext,density,bparam[0]); |
419 | if (!gGeoManager->IsEntering()) { | |
420 | gGeoManager->SetStep(1.E-3); | |
421 | currentnode = gGeoManager->Step(); | |
422 | if (!gGeoManager->IsEntering() || !currentnode) { | |
423 | // printf("ERROR: cannot cross boundary\n"); | |
424 | mparam[0] = bparam[0]/step; | |
425 | mparam[1] = bparam[1]/step; | |
426 | mparam[2] = bparam[2]/step; | |
427 | mparam[3] = bparam[3]/step; | |
428 | mparam[5] = bparam[5]/step; | |
429 | mparam[4] = step; | |
430 | mparam[0] = 0.; // if crash of navigation take mean density 0 | |
431 | mparam[1] = 1000000; // and infinite rad length | |
432 | return bparam[0]/step; | |
433 | } | |
434 | step += 1.E-3; | |
435 | snext += 1.E-3; | |
436 | bparam[0] += lparam[0]*1.E-3; | |
437 | bparam[1] += lparam[1]*1.E-3; | |
438 | bparam[2] += lparam[2]*1.E-3; | |
439 | bparam[3] += lparam[3]*1.E-3; | |
440 | bparam[5] += lparam[5]*1.E-3; | |
441 | } | |
442 | length -= snext; | |
443 | material = currentnode->GetVolume()->GetMedium()->GetMaterial(); | |
444 | lparam[0] = material->GetDensity(); | |
445 | lparam[1] = material->GetRadLen(); | |
446 | lparam[2] = material->GetA(); | |
447 | lparam[3] = material->GetZ(); | |
448 | lparam[5] = lparam[3]/lparam[2]; | |
449 | if (material->IsMixture()) { | |
450 | lparam[1]*=lparam[0]; | |
451 | TGeoMixture * mixture = (TGeoMixture*)material; | |
452 | lparam[5]=0; | |
453 | Double_t sum =0; | |
454 | for (Int_t iel=0;iel<mixture->GetNelements();iel++){ | |
455 | sum+= mixture->GetWmixt()[iel]; | |
456 | lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel]; | |
457 | } | |
458 | lparam[5]/=sum; | |
459 | } | |
460 | gGeoManager->FindNextBoundary(length); | |
461 | snext = gGeoManager->GetStep(); | |
462 | } | |
463 | mparam[0] = bparam[0]/step; | |
464 | mparam[1] = bparam[1]/step; | |
465 | mparam[2] = bparam[2]/step; | |
466 | mparam[3] = bparam[3]/step; | |
467 | mparam[5] = bparam[5]/step; | |
468 | return bparam[0]/step; | |
469 | ||
470 | } | |
7d0f8548 | 471 | |
472 | Double_t AliKalmanTrack::GetConvConst() { | |
473 | return 1000/0.299792458/AliTracker::GetBz(); | |
474 | } | |
475 | ||
476 | void AliKalmanTrack::SaveLocalConvConst() { | |
477 | //--------------------------------------------------------------------- | |
478 | // Saves local conversion constant "curvature (1/cm) -> pt (GeV/c)" | |
479 | //--------------------------------------------------------------------- | |
480 | if (AliTracker::UniformField()) { | |
481 | fLocalConvConst=1000/0.299792458/AliTracker::GetBz(); | |
482 | } else { | |
483 | Float_t r[3]; GetXYZ(r); | |
484 | fLocalConvConst=1000/0.299792458/AliTracker::GetBz(r); | |
485 | } | |
486 | } | |
487 |