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a9e2aefa | 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 | $Log$ | |
762647ff | 18 | Revision 1.6 2001/02/05 14:49:29 hristov |
19 | Compare() declared const (R.Brun) | |
20 | ||
2a941f4e | 21 | Revision 1.5 2001/01/08 11:01:02 gosset |
22 | Modifications used for addendum to Dimuon TDR (JP Cussonneau): | |
23 | *. MaxBendingMomentum to make both a segment and a track (default 500) | |
24 | *. MaxChi2 per degree of freedom to make a track (default 100) | |
25 | *. MinBendingMomentum used also to make a track | |
26 | and not only a segment (default 3) | |
27 | *. wider roads for track search in stations 1 to 3 | |
28 | *. extrapolation to actual Z instead of Z(chamber) in FollowTracks | |
29 | *. in track fit: | |
30 | - limits on parameters X and Y (+/-500) | |
31 | - covariance matrices in double precision | |
32 | - normalization of covariance matrices before inversion | |
33 | - suppression of Minuit printouts | |
34 | *. correction against memory leak (delete extrapHit) in FollowTracks | |
35 | *. RMax to 10 degrees with Z(chamber) instead of fixed values; | |
36 | RMin and Rmax cuts suppressed in NewHitForRecFromGEANT, | |
37 | because useless with realistic geometry | |
38 | ||
d0bfce8d | 39 | Revision 1.4 2000/06/30 10:15:48 gosset |
40 | Changes to EventReconstructor...: | |
41 | precision fit with multiple Coulomb scattering; | |
42 | extrapolation to vertex with Branson correction in absorber (JPC) | |
43 | ||
04b5ea16 | 44 | Revision 1.3 2000/06/25 13:06:39 hristov |
45 | Inline functions moved from *.cxx to *.h files instead of forward declarations | |
46 | ||
9b03f36b | 47 | Revision 1.2 2000/06/15 07:58:48 morsch |
48 | Code from MUON-dev joined | |
49 | ||
a9e2aefa | 50 | Revision 1.1.2.4 2000/06/12 10:10:21 morsch |
51 | Dummy copy constructor and assignment operator added | |
52 | ||
53 | Revision 1.1.2.3 2000/06/09 21:01:16 morsch | |
54 | Make includes consistent with new file structure. | |
55 | ||
56 | Revision 1.1.2.2 2000/06/09 12:58:05 gosset | |
57 | Removed comment beginnings in Log sections of .cxx files | |
58 | Suppressed most violations of coding rules | |
59 | ||
60 | Revision 1.1.2.1 2000/06/07 14:44:53 gosset | |
61 | Addition of files for track reconstruction in C++ | |
62 | */ | |
63 | ||
64 | //__________________________________________________________________________ | |
65 | // | |
66 | // Segment for reconstruction in ALICE dimuon spectrometer: | |
67 | // two hits for reconstruction in the two chambers of one station | |
68 | //__________________________________________________________________________ | |
69 | ||
70 | #include "AliMUONSegment.h" | |
71 | ||
72 | #include "AliMUON.h" | |
73 | #include "AliMUONHitForRec.h" | |
74 | #include "AliMUONTrackParam.h" | |
75 | #include "AliMUONChamber.h" | |
76 | #include "AliRun.h" | |
77 | ||
78 | ClassImp(AliMUONSegment) // Class implementation in ROOT context | |
79 | ||
762647ff | 80 | //__________________________________________________________________________ |
81 | AliMUONSegment::AliMUONSegment() | |
82 | { | |
83 | // Default constructor | |
84 | fHitForRecPtr1 = 0; // pointer to HitForRec in first chamber | |
85 | fHitForRecPtr2 = 0; // pointer to HitForRec in second chamber | |
86 | // Bending plane: | |
87 | fBendingCoor = 0.0; // Coordinate in bending plane | |
88 | fBendingSlope = 0.0; // Slope in bending plane | |
89 | // Covariance in bending plane: | |
90 | fBendingCoorReso2 = 0.0; // Covariance(coordinate C1 in first chamber) | |
91 | fBendingSlopeReso2 = 0.0; // Covariance(slope) | |
92 | fBendingCoorSlopeReso2 = 0.0; // Covariance(C1,slope) | |
93 | fBendingImpact = 0.0; // Impact parameter in bending plane | |
94 | // Non Bending plane: | |
95 | fNonBendingCoor = 0.0; // Coordinate in non bending plane | |
96 | fNonBendingSlope = 0.0; // Slope in non bending plane | |
97 | // Covariance in non bending plane: | |
98 | fNonBendingCoorReso2 = 0.0; // Covariance(coordinate C1 in first chamber) | |
99 | fNonBendingSlopeReso2 = 0.0; // Covariance(slope) | |
100 | fNonBendingCoorSlopeReso2 = 0.0; // Covariance(C1,slope) | |
101 | fNonBendingImpact = 0.0; // Impact parameter in non bending plane | |
102 | fInTrack = kFALSE; // TRUE if segment belongs to one track | |
103 | } | |
104 | ||
a9e2aefa | 105 | //__________________________________________________________________________ |
106 | AliMUONSegment::AliMUONSegment(AliMUONHitForRec* Hit1, AliMUONHitForRec* Hit2) | |
107 | { | |
108 | // Constructor for AliMUONSegment from two HitForRec's, | |
109 | // one, in the first chamber of the station, pointed to by "Hit1", | |
110 | // the other one, in the second chamber of the station, pointed to by "Hit1". | |
111 | // Fills the pointers to both hits, | |
112 | // the slope, the covariance for (coordinate in first chamber, slope), | |
113 | // and the impact parameter at vertex (Z=0), | |
114 | // in bending and non bending planes. | |
115 | // Puts the "fInTrack" flag to "kFALSE". | |
116 | Double_t dz; | |
117 | // pointers to HitForRec's | |
118 | fHitForRecPtr1 = Hit1; | |
119 | fHitForRecPtr2 = Hit2; | |
120 | dz = Hit1->GetZ() - Hit2->GetZ(); | |
121 | // bending plane | |
122 | fBendingCoor = Hit1->GetBendingCoor(); | |
123 | fBendingSlope = (fBendingCoor - Hit2->GetBendingCoor()) / dz; | |
124 | fBendingImpact = fBendingCoor - Hit1->GetZ() * fBendingSlope; | |
125 | fBendingCoorReso2 = Hit1->GetBendingReso2(); | |
126 | fBendingSlopeReso2 = ( Hit1->GetBendingReso2() + | |
127 | Hit2->GetBendingReso2() ) / dz / dz; | |
128 | fBendingCoorSlopeReso2 = Hit1->GetBendingReso2() / dz; | |
129 | // non bending plane | |
130 | fNonBendingCoor = Hit1->GetNonBendingCoor(); | |
131 | fNonBendingSlope = (fNonBendingCoor - Hit2->GetNonBendingCoor()) / dz; | |
132 | fNonBendingImpact = fNonBendingCoor - Hit1->GetZ() * fNonBendingSlope; | |
133 | fNonBendingCoorReso2 = Hit1->GetNonBendingReso2(); | |
134 | fNonBendingSlopeReso2 = ( Hit1->GetNonBendingReso2() + | |
135 | Hit2->GetNonBendingReso2() ) / dz / dz; | |
136 | fNonBendingCoorSlopeReso2 = Hit1->GetNonBendingReso2() / dz; | |
137 | // "fInTrack" flag to "kFALSE" | |
138 | fInTrack = kFALSE; | |
139 | return; | |
140 | } | |
141 | ||
142 | AliMUONSegment::AliMUONSegment (const AliMUONSegment& MUONSegment) | |
143 | { | |
144 | // Dummy copy constructor | |
145 | } | |
146 | ||
147 | AliMUONSegment & AliMUONSegment::operator=(const AliMUONSegment& MUONSegment) | |
148 | { | |
149 | // Dummy assignment operator | |
150 | return *this; | |
151 | } | |
152 | ||
a9e2aefa | 153 | //__________________________________________________________________________ |
2a941f4e | 154 | Int_t AliMUONSegment::Compare(const TObject* Segment) const |
a9e2aefa | 155 | { |
156 | // "Compare" function to sort with increasing absolute value | |
157 | // of the "impact parameter" in bending plane. | |
158 | // Returns -1 (0, +1) if |impact parameter| of current Segment | |
159 | // is smaller than (equal to, larger than) |impact parameter| of Segment | |
160 | if (TMath::Abs(((AliMUONSegment*)this)->fBendingSlope) | |
161 | < TMath::Abs(((AliMUONSegment*)Segment)->fBendingSlope)) | |
162 | return(-1); | |
163 | // continuous parameter, hence no need for testing equal case | |
164 | else return(+1); | |
165 | } | |
166 | ||
167 | //__________________________________________________________________________ | |
168 | Double_t AliMUONSegment::NormalizedChi2WithSegment(AliMUONSegment* Segment, Double_t Sigma2Cut) | |
169 | { | |
170 | // Calculate the normalized Chi2 between the current Segment (this) | |
171 | // and the Segment pointed to by "Segment", | |
172 | // i.e. the square deviations between the coordinates and the slopes, | |
173 | // in both the bending and the non bending plane, | |
174 | // divided by the variance of the same quantities and by "Sigma2Cut". | |
175 | // Returns 5 if none of the 4 quantities is OK, | |
176 | // something smaller than or equal to 4 otherwise. | |
177 | // Would it be more correct to use a real chi square | |
178 | // including the non diagonal term ???? | |
179 | Double_t chi2, chi2Max, diff, normDiff; | |
180 | chi2 = 0.0; | |
181 | chi2Max = 5.0; | |
182 | // coordinate in bending plane | |
183 | diff = this->fBendingCoor - Segment->fBendingCoor; | |
184 | normDiff = diff * diff / | |
185 | (this->fBendingCoorReso2 + Segment->fBendingCoorReso2) / Sigma2Cut; | |
186 | if (normDiff > 1.0) return chi2Max; | |
187 | chi2 = chi2 + normDiff; | |
188 | // slope in bending plane | |
189 | diff = this->fBendingSlope - Segment->fBendingSlope; | |
190 | normDiff = diff * diff / | |
191 | (this->fBendingSlopeReso2 + Segment->fBendingSlopeReso2) / Sigma2Cut; | |
192 | if (normDiff > 1.0) return chi2Max; | |
193 | chi2 = chi2 + normDiff; | |
194 | // coordinate in non bending plane | |
195 | diff = this->fNonBendingCoor - Segment->fNonBendingCoor; | |
196 | normDiff = diff * diff / | |
197 | (this->fNonBendingCoorReso2 + Segment->fNonBendingCoorReso2) / Sigma2Cut; | |
198 | if (normDiff > 1.0) return chi2Max; | |
199 | chi2 = chi2 + normDiff; | |
200 | // slope in non bending plane | |
201 | diff = this->fNonBendingSlope - Segment->fNonBendingSlope; | |
202 | normDiff = diff * diff / | |
203 | (this->fNonBendingSlopeReso2 + Segment->fNonBendingSlopeReso2) / Sigma2Cut; | |
204 | if (normDiff > 1.0) return chi2Max; | |
205 | chi2 = chi2 + normDiff; | |
206 | return chi2; | |
207 | } | |
208 | ||
209 | //__________________________________________________________________________ | |
210 | AliMUONSegment* AliMUONSegment::CreateSegmentFromLinearExtrapToStation (Int_t Station, Double_t MCSfactor) | |
211 | { | |
212 | // Extrapolates linearly the current Segment (this) to station (0..) "Station". | |
213 | // Multiple Coulomb scattering calculated from "MCSfactor" | |
214 | // corresponding to one chamber, | |
215 | // with one chamber for the coordinate, two chambers for the angle, | |
216 | // due to the arrangement in stations. | |
217 | // Valid from station(1..) 4 to 5 or vice versa. | |
218 | // Returns the pointer to the created AliMUONSegment object | |
219 | // corresponding to this extrapolation. | |
220 | // The caller has the responsibility to delete this object. | |
221 | AliMUONSegment* extrapSegment = new AliMUONSegment(); // creates empty new segment | |
222 | // dZ from first hit of current Segment to first chamber of station "Station" | |
223 | AliMUON *pMUON = (AliMUON*) gAlice->GetModule("MUON"); // necessary ???? | |
224 | Double_t dZ = | |
225 | (&(pMUON->Chamber(2 * Station)))->Z() - (this->fHitForRecPtr1)->GetZ(); | |
226 | // Data in bending plane | |
227 | // coordinate | |
228 | extrapSegment->fBendingCoor = this->fBendingCoor + this->fBendingSlope * dZ; | |
229 | // slope | |
230 | extrapSegment->fBendingSlope = this->fBendingSlope; | |
231 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
232 | extrapSegment->fBendingCoorReso2 = this->fBendingCoorReso2 + | |
233 | (this->fBendingSlopeReso2 + MCSfactor) * dZ * dZ; // missing non diagonal term: "2.0 * this->fBendingCoorSlopeReso2 * dZ" !!!! | |
234 | extrapSegment->fBendingSlopeReso2 = this->fBendingSlopeReso2 + 2.0 * MCSfactor; | |
235 | extrapSegment->fBendingCoorSlopeReso2 = | |
236 | this->fBendingCoorSlopeReso2 + this->fBendingSlopeReso2 * dZ; // missing: contribution from multiple Coulomb scattering !!!! | |
237 | // Data in non bending plane | |
238 | // coordinate | |
239 | extrapSegment->fNonBendingCoor = | |
240 | this->fNonBendingCoor + this->fNonBendingSlope * dZ; | |
241 | // slope | |
242 | extrapSegment->fNonBendingSlope = this->fNonBendingSlope; | |
243 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
244 | extrapSegment->fNonBendingCoorReso2 = this->fNonBendingCoorReso2 + | |
245 | (this->fNonBendingSlopeReso2 + MCSfactor) *dZ * dZ; // missing non diagonal term: "2.0 * this->fNonBendingCoorSlopeReso2 * dZ" !!!! | |
246 | extrapSegment->fNonBendingSlopeReso2 = | |
247 | this->fNonBendingSlopeReso2 + 2.0 * MCSfactor; | |
248 | extrapSegment->fNonBendingCoorSlopeReso2 = | |
249 | this->fNonBendingCoorSlopeReso2 + this->fNonBendingSlopeReso2 * dZ; // missing: contribution from multiple Coulomb scattering !!!! | |
250 | return extrapSegment; | |
251 | } | |
252 | ||
253 | //__________________________________________________________________________ | |
254 | AliMUONHitForRec* AliMUONSegment::CreateHitForRecFromLinearExtrapToChamber (Int_t Chamber, Double_t MCSfactor) | |
255 | { | |
256 | // Extrapolates linearly the current Segment (this) to chamber(0..) "Chamber". | |
257 | // Multiple Coulomb scattering calculated from "MCSfactor" | |
258 | // corresponding to one chamber. | |
259 | // Valid from station(1..) 4 to 5 or vice versa. | |
260 | // Returns the pointer to the created AliMUONHitForRec object | |
261 | // corresponding to this extrapolation. | |
262 | // The caller has the responsibility to delete this object. | |
263 | AliMUONHitForRec* extrapHitForRec = new AliMUONHitForRec(); // creates empty new HitForRec | |
264 | // dZ from first hit of current Segment to chamber | |
265 | AliMUON *pMUON = (AliMUON*) gAlice->GetModule("MUON"); // necessary ???? | |
266 | Double_t dZ = | |
267 | (&(pMUON->Chamber(Chamber)))->Z() - (this->fHitForRecPtr1)->GetZ(); | |
268 | // Data in bending plane | |
269 | // coordinate | |
270 | extrapHitForRec->SetBendingCoor(this->fBendingCoor + this->fBendingSlope * dZ); | |
271 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
272 | extrapHitForRec->SetBendingReso2(this->fBendingCoorReso2 + | |
273 | (this->fBendingSlopeReso2 + MCSfactor) * dZ * dZ); // missing non diagonal term: "2.0 * this->fBendingCoorSlopeReso2 * dZ" !!!! | |
274 | // Data in non bending plane | |
275 | // coordinate | |
276 | extrapHitForRec ->SetNonBendingCoor(this->fNonBendingCoor + | |
277 | this->fNonBendingSlope * dZ); | |
278 | // covariance, including multiple Coulomb scattering over dZ due to one chamber | |
279 | extrapHitForRec-> | |
280 | SetNonBendingReso2(this->fNonBendingCoorReso2 + | |
281 | (this->fNonBendingSlopeReso2 + MCSfactor) * dZ * dZ); // missing non diagonal term: "2.0 * this->fNonBendingCoorSlopeReso2 * dZ" !!!! | |
282 | return extrapHitForRec; | |
283 | } | |
284 | ||
285 | //__________________________________________________________________________ | |
04b5ea16 | 286 | void AliMUONSegment::UpdateFromStationTrackParam(AliMUONTrackParam *TrackParam, Double_t MCSfactor, Double_t Dz1, Double_t Dz2, Double_t Dz3, Int_t Station, Double_t InverseMomentum) |
a9e2aefa | 287 | { |
288 | // Fill data members with values calculated from the array of track parameters | |
289 | // pointed to by "TrackParam" (index = 0 and 1 for first and second chambers | |
290 | // of the station, respectively). | |
291 | // Multiple Coulomb scattering is taking into account with "MCSfactor" | |
292 | // corresponding to one chamber, | |
293 | // with one chamber for the coordinate, two chambers for the angle, | |
294 | // due to the arrangement in stations. | |
295 | // Resolution coming from: | |
04b5ea16 | 296 | // coordinate in closest station at "Dz1" from current "Station", |
a9e2aefa | 297 | // slope between closest stations, with "Dz2" interval between them, |
04b5ea16 | 298 | // interval "Dz3" between chambers of closest station, |
299 | // extrapolation over "Dz1" from closest station, | |
300 | // "InverseMomentum". | |
a9e2aefa | 301 | // When called, "fBendingCoorReso2" and "fNonBendingCoorReso2" |
302 | // are assumed to be filled | |
303 | // with the variance on bending and non bending coordinates. | |
04b5ea16 | 304 | // The "road" is parametrized from the old reco_muon.F |
305 | // with 8 cm between stations. | |
a9e2aefa | 306 | AliMUONTrackParam *param0; |
d0bfce8d | 307 | // Double_t cReso2, sReso2; |
04b5ea16 | 308 | // parameters to define the widths of the searching roads in station 0,1,2 |
309 | // width = p0 + p1/ (momentum)^2 | |
310 | // station number: 0 1 2 | |
d0bfce8d | 311 | // static Double_t p0BendingCoor[3] = { 6.43e-2, 1.64e-2, 0.034 }; |
312 | // static Double_t p1BendingCoor[3] = { 986., 821., 446. }; | |
313 | // static Double_t p0BendingSlope[3] = { 3.54e-6, 3.63e-6, 3.6e-6 }; | |
314 | // static Double_t p1BendingSlope[3] = { 4.49e-3, 4.8e-3, 0.011 }; | |
315 | // static Double_t p0NonBendingCoor[3] = { 4.66e-2, 4.83e-2, 0.049 }; | |
316 | // static Double_t p1NonBendingCoor[3] = { 1444., 866., 354. }; | |
317 | // static Double_t p0NonBendingSlope[3] = { 6.14e-4, 6.49e-4, 6.85e-4 }; | |
318 | // static Double_t p1NonBendingSlope[3] = { 0., 0., 0. }; | |
319 | ||
320 | static Double_t p0BendingCoor[3] = { 6.43e-2, 6.43e-2, 6.43e-2 }; | |
321 | static Double_t p1BendingCoor[3] = { 986., 986., 986. }; | |
322 | static Double_t p0BendingSlope[3] = { 3.6e-6, 3.6e-6, 3.6e-6 }; | |
323 | static Double_t p1BendingSlope[3] = { 1.1e-2, 1.1e-2, 1.1e-2 }; | |
324 | static Double_t p0NonBendingCoor[3] = { 0.049, 0.049, 0.049 }; | |
325 | static Double_t p1NonBendingCoor[3] = { 1444., 1444., 1444. }; | |
326 | static Double_t p0NonBendingSlope[3] = { 6.8e-4, 6.8e-4, 6.8e-4 }; | |
327 | static Double_t p1NonBendingSlope[3] = { 0., 0., 0. }; | |
a9e2aefa | 328 | param0 = &(TrackParam[0]); |
04b5ea16 | 329 | |
330 | // OLD version | |
331 | // // Bending plane | |
332 | // fBendingCoor = param0->GetBendingCoor(); // coordinate | |
333 | // fBendingSlope = param0->GetBendingSlope(); // slope | |
334 | // cReso2 = fBendingCoorReso2; | |
335 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
336 | // fBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
337 | // fBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
338 | // // Non bending plane | |
339 | // fNonBendingCoor = param0->GetNonBendingCoor(); // coordinate | |
340 | // fNonBendingSlope = param0->GetNonBendingSlope(); // slope | |
341 | // cReso2 = fNonBendingCoorReso2; | |
342 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
343 | // fNonBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
344 | // fNonBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
345 | ||
346 | // Coordinate and slope | |
a9e2aefa | 347 | // Bending plane |
348 | fBendingCoor = param0->GetBendingCoor(); // coordinate | |
349 | fBendingSlope = param0->GetBendingSlope(); // slope | |
a9e2aefa | 350 | // Non bending plane |
351 | fNonBendingCoor = param0->GetNonBendingCoor(); // coordinate | |
352 | fNonBendingSlope = param0->GetNonBendingSlope(); // slope | |
04b5ea16 | 353 | |
354 | // Resolutions | |
355 | // cReso2 and sReso2 have to be subtracted here from the parametrization | |
356 | // because they are added in the functions "NormalizedChi2WithSegment" | |
357 | // and "NormalizedChi2WithHitForRec" | |
358 | // Bending plane | |
d0bfce8d | 359 | // cReso2 = fBendingCoorReso2; |
360 | // sReso2 = (2. * cReso2 )/ (Dz3*Dz3) ; | |
361 | fBendingCoorReso2 = p0BendingCoor[Station] + p1BendingCoor[Station]*InverseMomentum*InverseMomentum ; // - cReso2 | |
362 | fBendingSlopeReso2 = p0BendingSlope[Station] + p1BendingSlope[Station]*InverseMomentum*InverseMomentum; // - sReso2; | |
04b5ea16 | 363 | // Non bending plane |
d0bfce8d | 364 | // cReso2 = fNonBendingCoorReso2; |
365 | // sReso2 = (2. * cReso2 )/ (Dz3*Dz3) ; | |
366 | fNonBendingCoorReso2 = p0NonBendingCoor[Station] + p1NonBendingCoor[Station]*InverseMomentum*InverseMomentum; // - cReso2; | |
367 | fNonBendingSlopeReso2 = p0NonBendingSlope[Station] + p1NonBendingSlope[Station]*InverseMomentum*InverseMomentum; // - sReso2; | |
a9e2aefa | 368 | return; |
369 | } | |
04b5ea16 | 370 | |
371 | // OLD function, with roads automatically calculated instead from being parametrized | |
372 | // kept because it would be a better solution, | |
373 | // if one can really find the right values. | |
374 | // //__________________________________________________________________________ | |
375 | // void AliMUONSegment::UpdateFromStationTrackParam(AliMUONTrackParam *TrackParam, Double_t MCSfactor, Double_t Dz1, Double_t Dz2) | |
376 | // { | |
377 | // // Fill data members with values calculated from the array of track parameters | |
378 | // // pointed to by "TrackParam" (index = 0 and 1 for first and second chambers | |
379 | // // of the station, respectively). | |
380 | // // Multiple Coulomb scattering is taking into account with "MCSfactor" | |
381 | // // corresponding to one chamber, | |
382 | // // with one chamber for the coordinate, two chambers for the angle, | |
383 | // // due to the arrangement in stations. | |
384 | // // Resolution coming from: | |
385 | // // coordinate in closest station at "Dz1", | |
386 | // // slope between closest stations, with "Dz2" interval between them, | |
387 | // // extrapolation over "Dz" from closest station. | |
388 | // // When called, "fBendingCoorReso2" and "fNonBendingCoorReso2" | |
389 | // // are assumed to be filled | |
390 | // // with the variance on bending and non bending coordinates. | |
391 | // AliMUONTrackParam *param0; | |
392 | // Double_t cReso2, sReso2; | |
393 | // param0 = &(TrackParam[0]); | |
394 | // // Bending plane | |
395 | // fBendingCoor = param0->GetBendingCoor(); // coordinate | |
396 | // fBendingSlope = param0->GetBendingSlope(); // slope | |
397 | // cReso2 = fBendingCoorReso2; | |
398 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
399 | // fBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
400 | // fBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
401 | // // Non bending plane | |
402 | // fNonBendingCoor = param0->GetNonBendingCoor(); // coordinate | |
403 | // fNonBendingSlope = param0->GetNonBendingSlope(); // slope | |
404 | // cReso2 = fNonBendingCoorReso2; | |
405 | // sReso2 = 2.0 * cReso2 / Dz2 / Dz2; | |
406 | // fNonBendingCoorReso2 = cReso2 + (sReso2 + MCSfactor) * Dz1 * Dz1; | |
407 | // fNonBendingSlopeReso2 = sReso2 + 2.0 * MCSfactor; | |
408 | // return; | |
409 | // } |