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73042f01 | 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 | ||
803d1ab0 | 16 | /* $Id$ */ |
0938c7d3 | 17 | |
73042f01 | 18 | //----------------------------------------------------------------- |
19 | // Implementation of the TPC track class | |
7c27857f | 20 | // This class is used by the AliTPCtracker class |
21 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch | |
73042f01 | 22 | //----------------------------------------------------------------- |
23 | ||
19364939 | 24 | #include <Riostream.h> |
b19a0509 | 25 | |
73042f01 | 26 | #include "AliTPCtrack.h" |
7c27857f | 27 | #include "AliCluster.h" |
9c9d2487 | 28 | #include "AliBarrelTrack.h" |
83d73500 | 29 | #include "AliESDtrack.h" |
73042f01 | 30 | |
31 | ClassImp(AliTPCtrack) | |
b9de75e1 | 32 | |
e3f7105e | 33 | //_________________________________________________________________________ |
34 | AliTPCtrack::AliTPCtrack(): AliKalmanTrack() | |
35 | { | |
36 | fX = fP0 = fP1 = fP2 = fP3 = fP3 = fP4 = 0.0; | |
37 | fAlpha = fdEdx = 0.0; | |
9c9d2487 | 38 | fNWrong = fNRotation = fNumber = 0; // [SR, 01.04.2003] |
e3f7105e | 39 | } |
40 | ||
73042f01 | 41 | //_________________________________________________________________________ |
42 | AliTPCtrack::AliTPCtrack(UInt_t index, const Double_t xx[5], | |
b19a0509 | 43 | const Double_t cc[15], Double_t xref, Double_t alpha) : AliKalmanTrack() { |
73042f01 | 44 | //----------------------------------------------------------------- |
45 | // This is the main track constructor. | |
46 | //----------------------------------------------------------------- | |
73042f01 | 47 | fX=xref; |
be9c5115 | 48 | fAlpha=alpha; |
49 | if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi(); | |
50 | if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
51 | fdEdx=0.; | |
73042f01 | 52 | |
b19a0509 | 53 | fP0=xx[0]; fP1=xx[1]; fP2=xx[2]; fP3=xx[3]; fP4=xx[4]; |
73042f01 | 54 | |
b19a0509 | 55 | fC00=cc[0]; |
56 | fC10=cc[1]; fC11=cc[2]; | |
57 | fC20=cc[3]; fC21=cc[4]; fC22=cc[5]; | |
58 | fC30=cc[6]; fC31=cc[7]; fC32=cc[8]; fC33=cc[9]; | |
59 | fC40=cc[10]; fC41=cc[11]; fC42=cc[12]; fC43=cc[13]; fC44=cc[14]; | |
73042f01 | 60 | |
be9c5115 | 61 | fIndex[0]=index; |
62 | SetNumberOfClusters(1); | |
b9de75e1 | 63 | |
64 | } | |
65 | ||
66 | //_____________________________________________________________________________ | |
e1a65e92 | 67 | AliTPCtrack::AliTPCtrack(const AliKalmanTrack& t,Double_t alpha) : |
68 | AliKalmanTrack(t) { | |
b9de75e1 | 69 | //----------------------------------------------------------------- |
70 | // Conversion AliKalmanTrack -> AliTPCtrack. | |
71 | //----------------------------------------------------------------- | |
b9de75e1 | 72 | SetChi2(0.); |
73 | SetNumberOfClusters(0); | |
b9de75e1 | 74 | |
75 | fdEdx = 0.; | |
76 | fAlpha = alpha; | |
77 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); | |
78 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
79 | ||
80 | //Conversion of the track parameters | |
81 | Double_t x,p[5]; t.GetExternalParameters(x,p); | |
82 | fX=x; x=GetConvConst(); | |
83 | fP0=p[0]; | |
84 | fP1=p[1]; | |
85 | fP3=p[3]; | |
86 | fP4=p[4]/x; | |
87 | fP2=fP4*fX - p[2]; | |
88 | ||
89 | //Conversion of the covariance matrix | |
90 | Double_t c[15]; t.GetExternalCovariance(c); | |
91 | c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x; | |
92 | ||
93 | Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5]; | |
94 | Double_t c32=fX*c[13] - c[8]; | |
95 | Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12]; | |
96 | ||
97 | fC00=c[0 ]; | |
98 | fC10=c[1 ]; fC11=c[2 ]; | |
99 | fC20=c20; fC21=c21; fC22=c22; | |
100 | fC30=c[6 ]; fC31=c[7 ]; fC32=c32; fC33=c[9 ]; | |
101 | fC40=c[10]; fC41=c[11]; fC42=c42; fC43=c[13]; fC44=c[14]; | |
102 | ||
73042f01 | 103 | } |
104 | ||
83d73500 | 105 | //_____________________________________________________________________________ |
106 | AliTPCtrack::AliTPCtrack(const AliESDtrack& t) : AliKalmanTrack() { | |
107 | //----------------------------------------------------------------- | |
108 | // Conversion AliESDtrack -> AliTPCtrack. | |
109 | //----------------------------------------------------------------- | |
110 | SetNumberOfClusters(t.GetTPCclusters(fIndex)); | |
111 | SetLabel(t.GetLabel()); | |
112 | SetMass(t.GetMass()); | |
113 | ||
114 | fdEdx = t.GetTPCsignal(); | |
115 | fAlpha = t.GetAlpha(); | |
116 | if (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi(); | |
117 | else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
118 | ||
119 | //Conversion of the track parameters | |
120 | Double_t x,p[5]; t.GetExternalParameters(x,p); | |
121 | fX=x; x=GetConvConst(); | |
122 | fP0=p[0]; | |
123 | fP1=p[1]; | |
124 | fP3=p[3]; | |
125 | fP4=p[4]/x; | |
126 | fP2=fP4*fX - p[2]; | |
127 | ||
128 | //Conversion of the covariance matrix | |
129 | Double_t c[15]; t.GetExternalCovariance(c); | |
130 | c[10]/=x; c[11]/=x; c[12]/=x; c[13]/=x; c[14]/=x*x; | |
131 | ||
132 | Double_t c22=fX*fX*c[14] - 2*fX*c[12] + c[5]; | |
133 | Double_t c32=fX*c[13] - c[8]; | |
134 | Double_t c20=fX*c[10] - c[3], c21=fX*c[11] - c[4], c42=fX*c[14] - c[12]; | |
135 | ||
136 | fC00=c[0 ]; | |
137 | fC10=c[1 ]; fC11=c[2 ]; | |
138 | fC20=c20; fC21=c21; fC22=c22; | |
139 | fC30=c[6 ]; fC31=c[7 ]; fC32=c32; fC33=c[9 ]; | |
140 | fC40=c[10]; fC41=c[11]; fC42=c42; fC43=c[13]; fC44=c[14]; | |
141 | ||
0798b21e | 142 | if ((t.GetStatus()&AliESDtrack::kTIME) == 0) return; |
83d73500 | 143 | StartTimeIntegral(); |
144 | Double_t times[10]; t.GetIntegratedTimes(times); SetIntegratedTimes(times); | |
145 | SetIntegratedLength(t.GetIntegratedLength()); | |
146 | } | |
147 | ||
73042f01 | 148 | //_____________________________________________________________________________ |
b19a0509 | 149 | AliTPCtrack::AliTPCtrack(const AliTPCtrack& t) : AliKalmanTrack(t) { |
73042f01 | 150 | //----------------------------------------------------------------- |
151 | // This is a track copy constructor. | |
152 | //----------------------------------------------------------------- | |
be9c5115 | 153 | fX=t.fX; |
154 | fAlpha=t.fAlpha; | |
73042f01 | 155 | fdEdx=t.fdEdx; |
156 | ||
be9c5115 | 157 | fP0=t.fP0; fP1=t.fP1; fP2=t.fP2; fP3=t.fP3; fP4=t.fP4; |
158 | ||
159 | fC00=t.fC00; | |
160 | fC10=t.fC10; fC11=t.fC11; | |
161 | fC20=t.fC20; fC21=t.fC21; fC22=t.fC22; | |
162 | fC30=t.fC30; fC31=t.fC31; fC32=t.fC32; fC33=t.fC33; | |
163 | fC40=t.fC40; fC41=t.fC41; fC42=t.fC42; fC43=t.fC43; fC44=t.fC44; | |
164 | ||
165 | Int_t n=GetNumberOfClusters(); | |
166 | for (Int_t i=0; i<n; i++) fIndex[i]=t.fIndex[i]; | |
167 | } | |
9c9d2487 | 168 | //_____________________________________________________________________________ |
169 | ||
170 | void AliTPCtrack::GetBarrelTrack(AliBarrelTrack *track) { | |
171 | // | |
172 | // Create a Barrel Track out of this track | |
173 | // Current track is propagated to the reference plane | |
174 | // by the tracker | |
175 | // | |
176 | // [SR, 01.04.2003] | |
177 | ||
178 | if (!track) return; | |
179 | Double_t xr, vec[5], cov[15]; | |
180 | ||
181 | track->SetLabel(GetLabel()); | |
182 | track->SetX(fX, fAlpha); | |
183 | track->SetNClusters(GetNumberOfClusters(), GetChi2()); | |
2b5dc063 | 184 | Double_t times[10]; |
185 | GetIntegratedTimes(times); | |
186 | track->SetTime(times, GetIntegratedLength()); | |
9c9d2487 | 187 | |
2b5dc063 | 188 | track->SetMass(GetMass()); |
189 | track->SetdEdX(GetdEdx()); | |
9c9d2487 | 190 | |
191 | track->SetNWrongClusters(fNWrong); | |
192 | track->SetNRotate(fNRotation); | |
be9c5115 | 193 | |
9c9d2487 | 194 | GetExternalParameters(xr, vec); |
195 | track->SetStateVector(vec); | |
196 | ||
197 | GetExternalCovariance(cov); | |
198 | track->SetCovarianceMatrix(cov); | |
199 | ||
200 | } | |
be9c5115 | 201 | //_____________________________________________________________________________ |
202 | Int_t AliTPCtrack::Compare(const TObject *o) const { | |
203 | //----------------------------------------------------------------- | |
204 | // This function compares tracks according to the their curvature | |
205 | //----------------------------------------------------------------- | |
206 | AliTPCtrack *t=(AliTPCtrack*)o; | |
024a7fe9 | 207 | //Double_t co=TMath::Abs(t->Get1Pt()); |
208 | //Double_t c =TMath::Abs(Get1Pt()); | |
209 | Double_t co=t->GetSigmaY2()*t->GetSigmaZ2(); | |
210 | Double_t c =GetSigmaY2()*GetSigmaZ2(); | |
be9c5115 | 211 | if (c>co) return 1; |
212 | else if (c<co) return -1; | |
213 | return 0; | |
214 | } | |
215 | ||
216 | //_____________________________________________________________________________ | |
217 | void AliTPCtrack::GetExternalCovariance(Double_t cc[15]) const { | |
218 | //------------------------------------------------------------------------- | |
219 | // This function returns an external representation of the covriance matrix. | |
220 | // (See comments in AliTPCtrack.h about external track representation) | |
221 | //------------------------------------------------------------------------- | |
9b280d80 | 222 | Double_t a=GetConvConst(); |
be9c5115 | 223 | |
b9de75e1 | 224 | Double_t c22=fX*fX*fC44-2*fX*fC42+fC22; |
225 | Double_t c32=fX*fC43-fC32; | |
226 | Double_t c20=fX*fC40-fC20, c21=fX*fC41-fC21, c42=fX*fC44-fC42; | |
be9c5115 | 227 | |
228 | cc[0 ]=fC00; | |
229 | cc[1 ]=fC10; cc[2 ]=fC11; | |
230 | cc[3 ]=c20; cc[4 ]=c21; cc[5 ]=c22; | |
b9de75e1 | 231 | cc[6 ]=fC30; cc[7 ]=fC31; cc[8 ]=c32; cc[9 ]=fC33; |
232 | cc[10]=fC40*a; cc[11]=fC41*a; cc[12]=c42*a; cc[13]=fC43*a; cc[14]=fC44*a*a; | |
be9c5115 | 233 | |
234 | } | |
235 | ||
236 | //_____________________________________________________________________________ | |
237 | Double_t AliTPCtrack::GetPredictedChi2(const AliCluster *c) const | |
238 | { | |
239 | //----------------------------------------------------------------- | |
240 | // This function calculates a predicted chi2 increment. | |
241 | //----------------------------------------------------------------- | |
242 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); | |
243 | r00+=fC00; r01+=fC10; r11+=fC11; | |
244 | ||
245 | Double_t det=r00*r11 - r01*r01; | |
246 | if (TMath::Abs(det) < 1.e-10) { | |
247 | Int_t n=GetNumberOfClusters(); | |
248 | if (n>4) cerr<<n<<" AliKalmanTrack warning: Singular matrix !\n"; | |
249 | return 1e10; | |
250 | } | |
251 | Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01; | |
252 | ||
253 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; | |
254 | ||
255 | return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det; | |
73042f01 | 256 | } |
257 | ||
c630aafd | 258 | Double_t AliTPCtrack::GetYat(Double_t xk) const { |
259 | //----------------------------------------------------------------- | |
260 | // This function calculates the Y-coordinate of a track at the plane x=xk. | |
261 | //----------------------------------------------------------------- | |
262 | Double_t c1=fP4*fX - fP2, r1=TMath::Sqrt(1.- c1*c1); | |
263 | Double_t c2=fP4*xk - fP2, r2=TMath::Sqrt(1.- c2*c2); | |
264 | return fP0 + (xk-fX)*(c1+c2)/(r1+r2); | |
265 | } | |
266 | ||
73042f01 | 267 | //_____________________________________________________________________________ |
7f6ddf58 | 268 | Int_t AliTPCtrack::PropagateTo(Double_t xk,Double_t x0,Double_t rho) { |
73042f01 | 269 | //----------------------------------------------------------------- |
270 | // This function propagates a track to a reference plane x=xk. | |
271 | //----------------------------------------------------------------- | |
1627d1c4 | 272 | if (TMath::Abs(fP4*xk - fP2) >= 0.9) { |
273 | // Int_t n=GetNumberOfClusters(); | |
274 | //if (n>4) cerr<<n<<" AliTPCtrack warning: Propagation failed !\n"; | |
73042f01 | 275 | return 0; |
276 | } | |
e3f7105e | 277 | |
278 | // old position for time [SR, GSI 17.02.2003] | |
279 | Double_t oldX = fX; | |
280 | Double_t oldY = fP0; | |
281 | Double_t oldZ = fP1; | |
282 | // | |
73042f01 | 283 | |
b19a0509 | 284 | Double_t x1=fX, x2=x1+(xk-x1), dx=x2-x1, y1=fP0, z1=fP1; |
b9de75e1 | 285 | Double_t c1=fP4*x1 - fP2, r1=sqrt(1.- c1*c1); |
286 | Double_t c2=fP4*x2 - fP2, r2=sqrt(1.- c2*c2); | |
73042f01 | 287 | |
b19a0509 | 288 | fP0 += dx*(c1+c2)/(r1+r2); |
b9de75e1 | 289 | fP1 += dx*(c1+c2)/(c1*r2 + c2*r1)*fP3; |
73042f01 | 290 | |
291 | //f = F - 1 | |
292 | Double_t rr=r1+r2, cc=c1+c2, xx=x1+x2; | |
b19a0509 | 293 | Double_t f02=-dx*(2*rr + cc*(c1/r1 + c2/r2))/(rr*rr); |
b9de75e1 | 294 | Double_t f04= dx*(rr*xx + cc*(c1*x1/r1+c2*x2/r2))/(rr*rr); |
73042f01 | 295 | Double_t cr=c1*r2+c2*r1; |
b9de75e1 | 296 | Double_t f12=-dx*fP3*(2*cr + cc*(c2*c1/r1-r1 + c1*c2/r2-r2))/(cr*cr); |
297 | Double_t f13= dx*cc/cr; | |
298 | Double_t f14=dx*fP3*(cr*xx-cc*(r1*x2-c2*c1*x1/r1+r2*x1-c1*c2*x2/r2))/(cr*cr); | |
73042f01 | 299 | |
300 | //b = C*ft | |
b9de75e1 | 301 | Double_t b00=f02*fC20 + f04*fC40, b01=f12*fC20 + f14*fC40 + f13*fC30; |
302 | Double_t b10=f02*fC21 + f04*fC41, b11=f12*fC21 + f14*fC41 + f13*fC31; | |
303 | Double_t b20=f02*fC22 + f04*fC42, b21=f12*fC22 + f14*fC42 + f13*fC32; | |
304 | Double_t b30=f02*fC32 + f04*fC43, b31=f12*fC32 + f14*fC43 + f13*fC33; | |
305 | Double_t b40=f02*fC42 + f04*fC44, b41=f12*fC42 + f14*fC44 + f13*fC43; | |
73042f01 | 306 | |
307 | //a = f*b = f*C*ft | |
b9de75e1 | 308 | Double_t a00=f02*b20+f04*b40,a01=f02*b21+f04*b41,a11=f12*b21+f14*b41+f13*b31; |
73042f01 | 309 | |
310 | //F*C*Ft = C + (a + b + bt) | |
b19a0509 | 311 | fC00 += a00 + 2*b00; |
312 | fC10 += a01 + b01 + b10; | |
313 | fC20 += b20; | |
314 | fC30 += b30; | |
315 | fC40 += b40; | |
316 | fC11 += a11 + 2*b11; | |
317 | fC21 += b21; | |
318 | fC31 += b31; | |
319 | fC41 += b41; | |
73042f01 | 320 | |
321 | fX=x2; | |
322 | ||
323 | //Multiple scattering****************** | |
b19a0509 | 324 | Double_t d=sqrt((x1-fX)*(x1-fX)+(y1-fP0)*(y1-fP0)+(z1-fP1)*(z1-fP1)); |
be9c5115 | 325 | Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt()); |
7f6ddf58 | 326 | Double_t beta2=p2/(p2 + GetMass()*GetMass()); |
024a7fe9 | 327 | //Double_t theta2=14.1*14.1/(beta2*p2*1e6)*d/x0*rho; |
328 | Double_t theta2=1.0259e-6*10*10/20/(beta2*p2)*d*rho; | |
73042f01 | 329 | |
b9de75e1 | 330 | Double_t ey=fP4*fX - fP2, ez=fP3; |
331 | Double_t xz=fP4*ez, zz1=ez*ez+1, xy=fP2+ey; | |
73042f01 | 332 | |
b19a0509 | 333 | fC22 += (2*ey*ez*ez*fP2+1-ey*ey+ez*ez+fP2*fP2*ez*ez)*theta2; |
b9de75e1 | 334 | fC32 += ez*zz1*xy*theta2; |
335 | fC33 += zz1*zz1*theta2; | |
336 | fC42 += xz*ez*xy*theta2; | |
337 | fC43 += xz*zz1*theta2; | |
338 | fC44 += xz*xz*theta2; | |
73042f01 | 339 | |
340 | //Energy losses************************ | |
341 | Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d*rho; | |
342 | if (x1 < x2) dE=-dE; | |
b9de75e1 | 343 | cc=fP4; |
7f6ddf58 | 344 | fP4*=(1.- sqrt(p2+GetMass()*GetMass())/p2*dE); |
b9de75e1 | 345 | fP2+=fX*(fP4-cc); |
73042f01 | 346 | |
e3f7105e | 347 | // Integrated Time [SR, GSI, 17.02.2003] |
348 | if (IsStartedTimeIntegral()) { | |
349 | Double_t l2 = (fX-oldX)*(fX-oldX)+(fP0-oldY)*(fP0-oldY)+(fP1-oldZ)*(fP1-oldZ); | |
350 | AddTimeStep(TMath::Sqrt(l2)); | |
351 | } | |
352 | // | |
353 | ||
73042f01 | 354 | return 1; |
355 | } | |
356 | ||
357 | //_____________________________________________________________________________ | |
7f6ddf58 | 358 | Int_t AliTPCtrack::PropagateToVertex(Double_t x0,Double_t rho) |
73042f01 | 359 | { |
360 | //----------------------------------------------------------------- | |
361 | // This function propagates tracks to the "vertex". | |
362 | //----------------------------------------------------------------- | |
b9de75e1 | 363 | Double_t c=fP4*fX - fP2; |
364 | Double_t tgf=-fP2/(fP4*fP0 + sqrt(1-c*c)); | |
73042f01 | 365 | Double_t snf=tgf/sqrt(1.+ tgf*tgf); |
b9de75e1 | 366 | Double_t xv=(fP2+snf)/fP4; |
7f6ddf58 | 367 | return PropagateTo(xv,x0,rho); |
73042f01 | 368 | } |
369 | ||
370 | //_____________________________________________________________________________ | |
be9c5115 | 371 | Int_t AliTPCtrack::Update(const AliCluster *c, Double_t chisq, UInt_t index) { |
73042f01 | 372 | //----------------------------------------------------------------- |
373 | // This function associates a cluster with this track. | |
374 | //----------------------------------------------------------------- | |
9c9d2487 | 375 | |
376 | // update the number of wrong SR[20.03.2003] | |
377 | Int_t absLabel = TMath::Abs(GetLabel()); | |
378 | if ( (c->GetLabel(0) != absLabel) && | |
379 | (c->GetLabel(0) != absLabel) && | |
380 | (c->GetLabel(0) != absLabel)) fNWrong++; | |
381 | // | |
382 | ||
73042f01 | 383 | Double_t r00=c->GetSigmaY2(), r01=0., r11=c->GetSigmaZ2(); |
b19a0509 | 384 | r00+=fC00; r01+=fC10; r11+=fC11; |
73042f01 | 385 | Double_t det=r00*r11 - r01*r01; |
386 | Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det; | |
387 | ||
b19a0509 | 388 | Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11; |
389 | Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11; | |
390 | Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11; | |
391 | Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11; | |
392 | Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11; | |
73042f01 | 393 | |
b19a0509 | 394 | Double_t dy=c->GetY() - fP0, dz=c->GetZ() - fP1; |
b9de75e1 | 395 | Double_t cur=fP4 + k40*dy + k41*dz, eta=fP2 + k20*dy + k21*dz; |
1627d1c4 | 396 | if (TMath::Abs(cur*fX-eta) >= 0.9) { |
397 | // Int_t n=GetNumberOfClusters(); | |
398 | //if (n>4) cerr<<n<<" AliTPCtrack warning: Filtering failed !\n"; | |
be9c5115 | 399 | return 0; |
73042f01 | 400 | } |
401 | ||
b19a0509 | 402 | fP0 += k00*dy + k01*dz; |
403 | fP1 += k10*dy + k11*dz; | |
404 | fP2 = eta; | |
b9de75e1 | 405 | fP3 += k30*dy + k31*dz; |
406 | fP4 = cur; | |
73042f01 | 407 | |
b19a0509 | 408 | Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40; |
409 | Double_t c12=fC21, c13=fC31, c14=fC41; | |
73042f01 | 410 | |
b19a0509 | 411 | fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11; |
412 | fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13; | |
413 | fC40-=k00*c04+k01*c14; | |
73042f01 | 414 | |
b19a0509 | 415 | fC11-=k10*c01+k11*fC11; |
416 | fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13; | |
417 | fC41-=k10*c04+k11*c14; | |
73042f01 | 418 | |
b19a0509 | 419 | fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13; |
420 | fC42-=k20*c04+k21*c14; | |
73042f01 | 421 | |
b19a0509 | 422 | fC33-=k30*c03+k31*c13; |
b9de75e1 | 423 | fC43-=k40*c03+k41*c13; |
73042f01 | 424 | |
b19a0509 | 425 | fC44-=k40*c04+k41*c14; |
73042f01 | 426 | |
be9c5115 | 427 | Int_t n=GetNumberOfClusters(); |
428 | fIndex[n]=index; | |
429 | SetNumberOfClusters(n+1); | |
430 | SetChi2(GetChi2()+chisq); | |
431 | ||
432 | return 1; | |
73042f01 | 433 | } |
434 | ||
435 | //_____________________________________________________________________________ | |
436 | Int_t AliTPCtrack::Rotate(Double_t alpha) | |
437 | { | |
438 | //----------------------------------------------------------------- | |
439 | // This function rotates this track. | |
440 | //----------------------------------------------------------------- | |
9c9d2487 | 441 | |
442 | if (alpha != 0) fNRotation++; // [SR, 01.04.2003] | |
443 | ||
73042f01 | 444 | fAlpha += alpha; |
be9c5115 | 445 | if (fAlpha<-TMath::Pi()) fAlpha += 2*TMath::Pi(); |
446 | if (fAlpha>=TMath::Pi()) fAlpha -= 2*TMath::Pi(); | |
73042f01 | 447 | |
b19a0509 | 448 | Double_t x1=fX, y1=fP0; |
73042f01 | 449 | Double_t ca=cos(alpha), sa=sin(alpha); |
b9de75e1 | 450 | Double_t r1=fP4*fX - fP2; |
73042f01 | 451 | |
452 | fX = x1*ca + y1*sa; | |
b19a0509 | 453 | fP0=-x1*sa + y1*ca; |
b9de75e1 | 454 | fP2=fP2*ca + (fP4*y1 + sqrt(1.- r1*r1))*sa; |
73042f01 | 455 | |
b9de75e1 | 456 | Double_t r2=fP4*fX - fP2; |
73042f01 | 457 | if (TMath::Abs(r2) >= 0.99999) { |
be9c5115 | 458 | Int_t n=GetNumberOfClusters(); |
459 | if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !\n"; | |
73042f01 | 460 | return 0; |
461 | } | |
462 | ||
b9de75e1 | 463 | Double_t y0=fP0 + sqrt(1.- r2*r2)/fP4; |
464 | if ((fP0-y0)*fP4 >= 0.) { | |
be9c5115 | 465 | Int_t n=GetNumberOfClusters(); |
466 | if (n>4) cerr<<n<<" AliTPCtrack warning: Rotation failed !!!\n"; | |
73042f01 | 467 | return 0; |
468 | } | |
469 | ||
470 | //f = F - 1 | |
b9de75e1 | 471 | Double_t f00=ca-1, f24=(y1 - r1*x1/sqrt(1.- r1*r1))*sa, |
472 | f20=fP4*sa, f22=(ca + sa*r1/sqrt(1.- r1*r1))-1; | |
73042f01 | 473 | |
474 | //b = C*ft | |
b9de75e1 | 475 | Double_t b00=fC00*f00, b02=fC00*f20+fC40*f24+fC20*f22; |
476 | Double_t b10=fC10*f00, b12=fC10*f20+fC41*f24+fC21*f22; | |
477 | Double_t b20=fC20*f00, b22=fC20*f20+fC42*f24+fC22*f22; | |
478 | Double_t b30=fC30*f00, b32=fC30*f20+fC43*f24+fC32*f22; | |
479 | Double_t b40=fC40*f00, b42=fC40*f20+fC44*f24+fC42*f22; | |
73042f01 | 480 | |
481 | //a = f*b = f*C*ft | |
b9de75e1 | 482 | Double_t a00=f00*b00, a02=f00*b02, a22=f20*b02+f24*b42+f22*b22; |
73042f01 | 483 | |
484 | // *** Double_t dy2=fCyy; | |
485 | ||
486 | //F*C*Ft = C + (a + b + bt) | |
b19a0509 | 487 | fC00 += a00 + 2*b00; |
488 | fC10 += b10; | |
489 | fC20 += a02+b20+b02; | |
490 | fC30 += b30; | |
491 | fC40 += b40; | |
492 | fC21 += b12; | |
493 | fC32 += b32; | |
494 | fC22 += a22 + 2*b22; | |
495 | fC42 += b42; | |
73042f01 | 496 | |
497 | // *** fCyy+=dy2*sa*sa*r1*r1/(1.- r1*r1); | |
498 | // *** fCzz+=d2y*sa*sa*fT*fT/(1.- r1*r1); | |
499 | ||
500 | return 1; | |
501 | } | |
502 | ||
b9de75e1 | 503 | void AliTPCtrack::ResetCovariance() { |
504 | //------------------------------------------------------------------ | |
505 | //This function makes a track forget its history :) | |
506 | //------------------------------------------------------------------ | |
507 | ||
508 | fC00*=10.; | |
509 | fC10=0.; fC11*=10.; | |
510 | fC20=0.; fC21=0.; fC22*=10.; | |
511 | fC30=0.; fC31=0.; fC32=0.; fC33*=10.; | |
512 | fC40=0.; fC41=0.; fC42=0.; fC43=0.; fC44*=10.; | |
513 | ||
73042f01 | 514 | } |
77e58468 | 515 | |
516 | //////////////////////////////////////////////////////////////////////// | |
517 | Double_t AliTPCtrack::Phi() const { | |
7c27857f | 518 | // |
519 | // | |
520 | // | |
77e58468 | 521 | Double_t phi = TMath::ASin(GetSnp()) + fAlpha; |
522 | if (phi<0) phi+=2*TMath::Pi(); | |
523 | if (phi>=2*TMath::Pi()) phi-=2*TMath::Pi(); | |
524 | return phi; | |
525 | } | |
526 | //////////////////////////////////////////////////////////////////////// | |
527 |