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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) { |
0dea3a06 | 44 | AliError("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 | ||
4557b520 | 191 | Double_t AliKalmanTrack::MeanMaterialBudget(Double_t *start, Double_t *end, Double_t *mparam) |
192 | { | |
193 | // | |
194 | // calculate mean material budget and material properties beween point start and end | |
195 | // mparam - returns parameters used for dEdx and multiple scatering | |
196 | // | |
197 | // mparam[0] - density mean | |
198 | // mparam[1] - rad length | |
199 | // mparam[2] - A mean | |
200 | // mparam[3] - Z mean | |
201 | // mparam[4] - length | |
202 | // mparam[5] - Z/A mean | |
203 | // mparam[6] - number of boundary crosses | |
204 | // | |
205 | mparam[0]=0; mparam[1]=1; mparam[2] =0; mparam[3] =0, mparam[4]=0, mparam[5]=0; mparam[6]=0; | |
206 | // | |
207 | Double_t bparam[6], lparam[6]; // bparam - total param - lparam - local parameters | |
208 | for (Int_t i=0;i<6;i++) bparam[i]=0; // | |
209 | ||
210 | if (!gGeoManager) { | |
211 | printf("ERROR: no TGeo\n"); | |
212 | return 0.; | |
213 | } | |
214 | // | |
215 | Double_t length; | |
216 | Double_t dir[3]; | |
217 | length = TMath::Sqrt((end[0]-start[0])*(end[0]-start[0])+ | |
218 | (end[1]-start[1])*(end[1]-start[1])+ | |
219 | (end[2]-start[2])*(end[2]-start[2])); | |
220 | mparam[4]=length; | |
221 | if (length<TGeoShape::Tolerance()) return 0.0; | |
222 | Double_t invlen = 1./length; | |
223 | dir[0] = (end[0]-start[0])*invlen; | |
224 | dir[1] = (end[1]-start[1])*invlen; | |
225 | dir[2] = (end[2]-start[2])*invlen; | |
226 | // Initialize start point and direction | |
227 | TGeoNode *currentnode = 0; | |
228 | TGeoNode *startnode = gGeoManager->InitTrack(start, dir); | |
229 | // printf("%s length=%f\n",gGeoManager->GetPath(),length); | |
230 | if (!startnode) { | |
231 | printf("ERROR: start point out of geometry\n"); | |
232 | return 0.0; | |
233 | } | |
234 | TGeoMaterial *material = startnode->GetVolume()->GetMedium()->GetMaterial(); | |
235 | lparam[0] = material->GetDensity(); | |
236 | lparam[1] = material->GetRadLen(); | |
237 | lparam[2] = material->GetA(); | |
238 | lparam[3] = material->GetZ(); | |
5df14aca | 239 | lparam[4] = length; |
4557b520 | 240 | lparam[5] = lparam[3]/lparam[2]; |
241 | if (material->IsMixture()) { | |
242 | lparam[1]*=lparam[0]; // different normalization in the modeler for mixture | |
243 | TGeoMixture * mixture = (TGeoMixture*)material; | |
244 | lparam[5] =0; | |
245 | Double_t sum =0; | |
246 | for (Int_t iel=0;iel<mixture->GetNelements();iel++){ | |
247 | sum += mixture->GetWmixt()[iel]; | |
248 | lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel]; | |
249 | } | |
250 | lparam[5]/=sum; | |
251 | } | |
252 | gGeoManager->FindNextBoundary(length); | |
253 | Double_t snext = gGeoManager->GetStep(); | |
254 | Double_t step = 0.0; | |
255 | // If no boundary within proposed length, return current density | |
256 | if (snext>=length) { | |
257 | for (Int_t ip=0;ip<5;ip++) mparam[ip] = lparam[ip]; | |
258 | return lparam[0]; | |
259 | } | |
260 | // Try to cross the boundary and see what is next | |
261 | while (length>TGeoShape::Tolerance()) { | |
262 | mparam[6]+=1.; | |
263 | currentnode = gGeoManager->Step(); | |
264 | step += snext+1.E-6; | |
265 | bparam[1] += snext*lparam[1]; | |
266 | bparam[2] += snext*lparam[2]; | |
267 | bparam[3] += snext*lparam[3]; | |
268 | bparam[5] += snext*lparam[5]; | |
269 | bparam[0] += snext*lparam[0]; | |
270 | ||
271 | if (snext>=length) break; | |
58d96064 | 272 | if (!currentnode) break; |
4557b520 | 273 | // printf("%s snext=%f density=%f bparam[0]=%f\n", gGeoManager->GetPath(),snext,density,bparam[0]); |
274 | if (!gGeoManager->IsEntering()) { | |
275 | gGeoManager->SetStep(1.E-3); | |
276 | currentnode = gGeoManager->Step(); | |
277 | if (!gGeoManager->IsEntering() || !currentnode) { | |
278 | // printf("ERROR: cannot cross boundary\n"); | |
279 | mparam[0] = bparam[0]/step; | |
280 | mparam[1] = bparam[1]/step; | |
281 | mparam[2] = bparam[2]/step; | |
282 | mparam[3] = bparam[3]/step; | |
283 | mparam[5] = bparam[5]/step; | |
284 | mparam[4] = step; | |
285 | mparam[0] = 0.; // if crash of navigation take mean density 0 | |
286 | mparam[1] = 1000000; // and infinite rad length | |
287 | return bparam[0]/step; | |
288 | } | |
289 | step += 1.E-3; | |
290 | snext += 1.E-3; | |
291 | bparam[0] += lparam[0]*1.E-3; | |
292 | bparam[1] += lparam[1]*1.E-3; | |
293 | bparam[2] += lparam[2]*1.E-3; | |
294 | bparam[3] += lparam[3]*1.E-3; | |
295 | bparam[5] += lparam[5]*1.E-3; | |
296 | } | |
297 | length -= snext; | |
298 | material = currentnode->GetVolume()->GetMedium()->GetMaterial(); | |
299 | lparam[0] = material->GetDensity(); | |
300 | lparam[1] = material->GetRadLen(); | |
301 | lparam[2] = material->GetA(); | |
302 | lparam[3] = material->GetZ(); | |
303 | lparam[5] = lparam[3]/lparam[2]; | |
304 | if (material->IsMixture()) { | |
305 | lparam[1]*=lparam[0]; | |
306 | TGeoMixture * mixture = (TGeoMixture*)material; | |
307 | lparam[5]=0; | |
308 | Double_t sum =0; | |
309 | for (Int_t iel=0;iel<mixture->GetNelements();iel++){ | |
310 | sum+= mixture->GetWmixt()[iel]; | |
311 | lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel]; | |
312 | } | |
313 | lparam[5]/=sum; | |
314 | } | |
315 | gGeoManager->FindNextBoundary(length); | |
316 | snext = gGeoManager->GetStep(); | |
317 | } | |
318 | mparam[0] = bparam[0]/step; | |
319 | mparam[1] = bparam[1]/step; | |
320 | mparam[2] = bparam[2]/step; | |
321 | mparam[3] = bparam[3]/step; | |
322 | mparam[5] = bparam[5]/step; | |
323 | return bparam[0]/step; | |
324 | ||
325 | } | |
7d0f8548 | 326 | |
327 | Double_t AliKalmanTrack::GetConvConst() { | |
328 | return 1000/0.299792458/AliTracker::GetBz(); | |
329 | } | |
330 | ||
331 | void AliKalmanTrack::SaveLocalConvConst() { | |
332 | //--------------------------------------------------------------------- | |
333 | // Saves local conversion constant "curvature (1/cm) -> pt (GeV/c)" | |
334 | //--------------------------------------------------------------------- | |
335 | if (AliTracker::UniformField()) { | |
336 | fLocalConvConst=1000/0.299792458/AliTracker::GetBz(); | |
337 | } else { | |
338 | Float_t r[3]; GetXYZ(r); | |
339 | fLocalConvConst=1000/0.299792458/AliTracker::GetBz(r); | |
340 | } | |
341 | } | |
342 |