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69209e2c | 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 | // This class stores a tracklet (a track that lives only in a single TPC | |
18 | // sector). Its objects can be constructed out of TPCseeds, that are | |
19 | // holding the necessary cluster information. | |
20 | //// | |
21 | //// | |
22 | //// | |
23 | ||
69209e2c | 24 | #include "AliTPCTracklet.h" |
25 | #include "TObjArray.h" | |
9318a5b4 | 26 | #include "TLinearFitter.h" |
69209e2c | 27 | #include "AliTPCseed.h" |
28 | #include "AliESDVertex.h" | |
9318a5b4 | 29 | #include "AliTracker.h" |
30 | #include "TTreeStream.h" | |
31 | #include "TRandom3.h" | |
32 | #include "TDecompChol.h" | |
33 | ||
34 | #include <iostream> | |
35 | using namespace std; | |
69209e2c | 36 | |
37 | ClassImp(AliTPCTracklet) | |
38 | ||
9318a5b4 | 39 | const Double_t AliTPCTracklet::kB2C=0.299792458e-3; |
967eae0d | 40 | Float_t AliTPCTracklet::fgEdgeCutY=3; |
41 | Float_t AliTPCTracklet::fgEdgeCutX=0; | |
9318a5b4 | 42 | |
69209e2c | 43 | AliTPCTracklet::AliTPCTracklet() |
9318a5b4 | 44 | : fNClusters(0),fNStoredClusters(0),fClusters(0),fSector(-1),fOuter(0), |
45 | fInner(0),fPrimary(0) { | |
69209e2c | 46 | //// |
47 | // The default constructor. It is intended to be used for I/O only. | |
48 | //// | |
49 | } | |
50 | ||
9318a5b4 | 51 | AliTPCTracklet::AliTPCTracklet(const AliTPCseed *track,Int_t sector, |
52 | TrackType type,Bool_t storeClusters) | |
53 | : fNClusters(0),fNStoredClusters(0),fClusters(0),fSector(sector),fOuter(0), | |
54 | fInner(0),fPrimary(0) { | |
69209e2c | 55 | //// |
56 | // Contructor for a tracklet out of a track. Only clusters within a given | |
57 | // sector are used. | |
58 | /// | |
69209e2c | 59 | |
9318a5b4 | 60 | //TODO: only kalman works |
61 | ||
69209e2c | 62 | for (Int_t i=0;i<160;++i) { |
9318a5b4 | 63 | AliTPCclusterMI *c=track->GetClusterPointer(i); |
967eae0d | 64 | if (c && RejectCluster(c)) continue; |
9318a5b4 | 65 | if (c&&c->GetDetector()==sector) |
66 | ++fNClusters; | |
69209e2c | 67 | } |
9318a5b4 | 68 | |
69 | if (storeClusters) { | |
70 | fClusters=new AliTPCclusterMI[fNClusters]; | |
71 | for (Int_t i=0;i<160;++i) { | |
72 | AliTPCclusterMI *c=track->GetClusterPointer(i); | |
967eae0d | 73 | if (c && RejectCluster(c)) continue; |
9318a5b4 | 74 | if (c&&c->GetDetector()==sector) |
d47d1dfd | 75 | fClusters[fNStoredClusters]=*c; |
9318a5b4 | 76 | ++fNStoredClusters; |
69209e2c | 77 | } |
78 | } | |
9318a5b4 | 79 | |
80 | switch (type) { | |
81 | case kKalman: | |
82 | FitKalman(track,sector); | |
83 | break; | |
84 | case kLinear: | |
85 | case kQuadratic: | |
86 | FitLinear(track,sector,type); | |
87 | break; | |
88 | case kRiemann: | |
89 | FitRiemann(track,sector); | |
90 | break; | |
69209e2c | 91 | } |
69209e2c | 92 | |
9318a5b4 | 93 | } |
69209e2c | 94 | |
c94a79e1 | 95 | AliTPCTracklet::AliTPCTracklet(const TObjArray &/*clusters*/,Int_t sector, |
96 | TrackType /*type*/,Bool_t /*storeClusters*/) | |
97 | : fNClusters(0),fNStoredClusters(0),fClusters(0),fSector(sector),fOuter(0), | |
98 | fInner(0),fPrimary(0) { | |
9318a5b4 | 99 | //TODO: write it! |
69209e2c | 100 | } |
101 | ||
102 | AliTPCTracklet::AliTPCTracklet(const AliTPCTracklet &t) | |
c94a79e1 | 103 | : TObject(t),fNClusters(t.fNClusters),fNStoredClusters(t.fNStoredClusters),fClusters(0), |
9318a5b4 | 104 | fSector(t.fSector),fOuter(0),fInner(0), |
69209e2c | 105 | fPrimary(0) { |
106 | //// | |
107 | // The copy constructor. You can copy tracklets! | |
108 | //// | |
109 | ||
9318a5b4 | 110 | if (t.fClusters) { |
111 | fClusters=new AliTPCclusterMI[t.fNStoredClusters]; | |
112 | for (int i=0;i<t.fNStoredClusters;++i) | |
113 | fClusters[i]=t.fClusters[i]; | |
114 | } | |
69209e2c | 115 | if (t.fOuter) |
116 | fOuter=new AliExternalTrackParam(*t.fOuter); | |
117 | if (t.fInner) | |
118 | fInner=new AliExternalTrackParam(*t.fInner); | |
119 | if (t.fPrimary) | |
120 | fPrimary=new AliExternalTrackParam(*t.fPrimary); | |
121 | } | |
122 | ||
123 | AliTPCTracklet& AliTPCTracklet::operator=(const AliTPCTracklet &t) { | |
124 | //// | |
125 | // The assignment constructor. You can assign tracklets! | |
126 | //// | |
69209e2c | 127 | if (this!=&t) { |
9318a5b4 | 128 | fNClusters=t.fNClusters; |
129 | fNStoredClusters=fNStoredClusters; | |
130 | delete fClusters; | |
131 | if (t.fClusters) { | |
132 | fClusters=new AliTPCclusterMI[t.fNStoredClusters]; | |
133 | for (int i=0;i<t.fNStoredClusters;++i) | |
134 | fClusters[i]=t.fClusters[i]; | |
135 | } | |
136 | else | |
137 | fClusters=0; | |
138 | fSector=t.fSector; | |
69209e2c | 139 | if (t.fOuter) { |
140 | if (fOuter) | |
141 | *fOuter=*t.fOuter; | |
142 | else | |
143 | fOuter=new AliExternalTrackParam(*t.fOuter); | |
144 | } | |
145 | else { | |
146 | delete fOuter; | |
147 | fOuter=0; | |
148 | } | |
149 | ||
150 | if (t.fInner) { | |
151 | if (fInner) | |
152 | *fInner=*t.fInner; | |
153 | else | |
154 | fInner=new AliExternalTrackParam(*t.fInner); | |
155 | } | |
156 | else { | |
157 | delete fInner; | |
158 | fInner=0; | |
159 | } | |
160 | ||
161 | if (t.fPrimary) { | |
162 | if (fPrimary) | |
163 | *fPrimary=*t.fPrimary; | |
164 | else | |
165 | fPrimary=new AliExternalTrackParam(*t.fPrimary); | |
166 | } | |
167 | else { | |
168 | delete fPrimary; | |
169 | fPrimary=0; | |
170 | } | |
171 | } | |
172 | return *this; | |
173 | } | |
174 | ||
175 | AliTPCTracklet::~AliTPCTracklet() { | |
176 | // | |
177 | // The destructor. Yes, you can even destruct tracklets. | |
178 | // | |
9318a5b4 | 179 | delete fClusters; |
69209e2c | 180 | delete fOuter; |
181 | delete fInner; | |
182 | delete fPrimary; | |
183 | } | |
184 | ||
9318a5b4 | 185 | void AliTPCTracklet::FitKalman(const AliTPCseed *track,Int_t sector) { |
8b3c60d8 | 186 | // |
187 | // Fit using Kalman filter | |
188 | // | |
9318a5b4 | 189 | AliTPCseed *t=new AliTPCseed(*track); |
190 | if (!t->Rotate(TMath::DegToRad()*(sector%18*20.+10.)-t->GetAlpha())) { | |
191 | delete t; | |
192 | return; | |
193 | } | |
194 | // fit from inner to outer row | |
195 | AliTPCseed *outerSeed=new AliTPCseed(*t); | |
196 | Int_t n=0; | |
197 | for (Int_t i=0;i<160;++i) { | |
198 | AliTPCclusterMI *c=t->GetClusterPointer(i); | |
967eae0d | 199 | if (c && RejectCluster(c,outerSeed)) continue; |
9318a5b4 | 200 | if (c&&c->GetDetector()==sector) { |
201 | if (n==1) { | |
202 | outerSeed->ResetCovariance(100.); | |
203 | } | |
204 | ++n; | |
205 | Double_t r[3]={c->GetX(),c->GetY(),c->GetZ()}; | |
206 | Double_t cov[3]={0.1,0.,0.1}; //TODO: correct error parametrisation | |
207 | if (!outerSeed->PropagateTo(r[0]) || | |
208 | !static_cast<AliExternalTrackParam*>(outerSeed)->Update(&r[1],cov)) { | |
209 | delete outerSeed; | |
210 | outerSeed=0; | |
211 | break; | |
212 | } | |
213 | } | |
214 | } | |
215 | if (outerSeed) | |
216 | fOuter=new AliExternalTrackParam(*outerSeed); | |
217 | delete outerSeed; | |
218 | // fit from outer to inner rows | |
219 | AliTPCseed *innerSeed=new AliTPCseed(*t); | |
220 | n=0; | |
221 | for (Int_t i=159;i>=0;--i) { | |
222 | AliTPCclusterMI *c=t->GetClusterPointer(i); | |
967eae0d | 223 | if (c && RejectCluster(c, innerSeed)) continue; |
9318a5b4 | 224 | if (c&&c->GetDetector()==sector) { |
225 | if (n==1) { | |
226 | innerSeed->ResetCovariance(100.); | |
227 | } | |
228 | ++n; | |
229 | Double_t r[3]={c->GetX(),c->GetY(),c->GetZ()}; | |
230 | Double_t cov[3]={0.1,0.,0.1}; | |
231 | if (!innerSeed->PropagateTo(r[0]) || | |
232 | !static_cast<AliExternalTrackParam*>(innerSeed)->Update(&r[1],cov)) { | |
233 | delete innerSeed; | |
234 | innerSeed=0; | |
235 | break; | |
236 | } | |
237 | } | |
238 | } | |
239 | if (innerSeed) | |
240 | fInner=new AliExternalTrackParam(*innerSeed); | |
241 | // propagate to the primary vertex | |
242 | if (innerSeed) { | |
243 | AliTPCseed *primarySeed=new AliTPCseed(*innerSeed); | |
244 | Double_t pos[]={0.,0.,0.}; | |
245 | Double_t sigma[]={.1,.1,.1}; //TODO: is this correct? | |
246 | AliESDVertex vertex(pos,sigma); | |
247 | if (primarySeed->PropagateToVertex(&vertex)) | |
248 | fPrimary=new AliExternalTrackParam(*primarySeed); | |
249 | delete primarySeed; | |
250 | // for better comparison one does not want to have alpha changed... | |
7eaa723e | 251 | if (fPrimary) if (!fPrimary->Rotate(fInner->GetAlpha())) { |
9318a5b4 | 252 | delete fPrimary; |
253 | fPrimary=0; | |
254 | } | |
255 | } | |
256 | delete innerSeed; | |
257 | ||
258 | delete t; | |
259 | } | |
260 | ||
261 | void AliTPCTracklet::FitLinear(const AliTPCseed *track,Int_t sector, | |
262 | TrackType type) { | |
263 | TLinearFitter fy(1); | |
264 | TLinearFitter fz(1); | |
265 | fy.StoreData(kFALSE); | |
266 | fz.StoreData(kFALSE); | |
267 | switch (type) { | |
268 | case kLinear: | |
269 | fy.SetFormula("1 ++ x"); | |
270 | fz.SetFormula("1 ++ x"); | |
271 | break; | |
272 | case kQuadratic: | |
273 | fy.SetFormula("1 ++ x ++ x*x"); | |
274 | fz.SetFormula("1 ++ x"); | |
275 | break; | |
c94a79e1 | 276 | case kKalman: |
277 | case kRiemann: | |
278 | break; | |
9318a5b4 | 279 | } |
280 | Double_t xmax=-1.; | |
281 | Double_t xmin=1000.; | |
282 | for (Int_t i=0;i<160;++i) { | |
283 | AliTPCclusterMI *c=track->GetClusterPointer(i); | |
967eae0d | 284 | if (c && RejectCluster(c)) continue; |
9318a5b4 | 285 | if (c&&c->GetDetector()==sector) { |
286 | Double_t x=c->GetX(); | |
287 | fy.AddPoint(&x,c->GetY()); | |
288 | fz.AddPoint(&x,c->GetZ()); | |
289 | xmax=TMath::Max(xmax,x); | |
290 | xmin=TMath::Min(xmin,x); | |
291 | } | |
292 | } | |
293 | fy.Eval(); | |
294 | fz.Eval(); | |
295 | Double_t a[3]={fy.GetParameter(0), | |
296 | fy.GetParameter(1), | |
297 | type==kQuadratic?fy.GetParameter(2):0.}; | |
298 | Double_t ca[6]={fy.GetCovarianceMatrixElement(0,0), | |
299 | fy.GetCovarianceMatrixElement(1,0), | |
300 | fy.GetCovarianceMatrixElement(1,1), | |
301 | type==kQuadratic?fy.GetCovarianceMatrixElement(2,0):0., | |
302 | type==kQuadratic?fy.GetCovarianceMatrixElement(2,1):0., | |
303 | type==kQuadratic?fy.GetCovarianceMatrixElement(2,2):0.}; | |
304 | for (int i=0;i<6;++i) ca[i]*=fy.GetChisquare()/fNClusters; | |
305 | Double_t b[2]={fz.GetParameter(0), | |
306 | fz.GetParameter(1)}; | |
307 | Double_t cb[3]={fz.GetCovarianceMatrixElement(0,0), | |
308 | fz.GetCovarianceMatrixElement(1,0), | |
309 | fz.GetCovarianceMatrixElement(1,1)}; | |
310 | for (int i=0;i<3;++i) cb[i]*=fz.GetChisquare()/fNClusters; | |
311 | Double_t p[5]; | |
312 | Double_t c[15]; | |
313 | Double_t alpha=track->GetAlpha(); | |
314 | Quadratic2Helix(a,ca,b,cb,0.,p,c); | |
315 | fPrimary=new AliExternalTrackParam(0.,alpha,p,c); | |
316 | Quadratic2Helix(a,ca,b,cb,xmin,p,c); | |
317 | fInner=new AliExternalTrackParam(xmin,alpha,p,c); | |
318 | Quadratic2Helix(a,ca,b,cb,xmax,p,c); | |
319 | fOuter=new AliExternalTrackParam(xmax,alpha,p,c); | |
320 | } | |
321 | ||
322 | void AliTPCTracklet::Quadratic2Helix(Double_t *a,Double_t *ca, | |
323 | Double_t *b,Double_t *cb, | |
324 | Double_t x0, | |
325 | Double_t *p,Double_t *c) { | |
326 | // y(x)=a[0]+a[1]*x+a[2]*x^2 | |
327 | // z(x)=b[0]+b[1]*x | |
328 | // parametrises the corosponding helix at x0 | |
329 | ||
330 | // get the polynoms at x0 | |
331 | Double_t a0=x0*x0*a[2] + x0*a[1] + a[0]; | |
332 | Double_t a1=2.*x0*a[2] + a[1]; | |
333 | Double_t a2= a[2]; | |
334 | Double_t ca00=ca[0]+x0*(2.*ca[1]+x0*(ca[2]+2.*ca[3]+x0*(2.*ca[4]+x0*ca[5]))); | |
335 | Double_t ca10=ca[1]+x0*(ca[2]+2.*ca[3]+x0*(3.*ca[4]+x0*2.*ca[5])); | |
336 | Double_t ca11=ca[2]+x0*4.*(ca[4]+x0*ca[5]); | |
337 | Double_t ca20=ca[3]+x0*(ca[4]+x0*ca[5]); | |
338 | Double_t ca21=ca[3]+x0*2.*ca[5]; | |
339 | Double_t ca22=ca[5]; | |
340 | ||
341 | Double_t b0=x0*b[1] + b[0]; | |
342 | Double_t b1= b[1]; | |
343 | Double_t cb00=cb[0]+x0*(2.*cb[1]+x0*cb[2]); | |
344 | Double_t cb10=cb[1]+x0*cb[2]; | |
345 | Double_t cb11=cb[2]; | |
346 | ||
347 | // transform to helix parameters | |
348 | Double_t f =1.+a1*a1; | |
349 | Double_t f2 =f*f; | |
350 | Double_t fi =1./f; | |
351 | Double_t fi12=TMath::Sqrt(fi); | |
352 | Double_t fi32=fi*fi12; | |
353 | Double_t fi2 =fi*fi; | |
354 | Double_t fi52=fi2*fi12; | |
355 | Double_t fi3 =fi2*fi; | |
356 | Double_t fi5 =fi2*fi3; | |
357 | ||
358 | Double_t xyz[3]={0.}; // TODO... | |
359 | Double_t fc=1./(GetBz(xyz)*kB2C); | |
360 | ||
361 | p[0]=a0; // y0 | |
362 | p[1]=b0; // z0 | |
363 | p[2]=a1*fi12; // snp | |
364 | p[3]=b1; // tgl | |
365 | p[4]=2.*a2*fi32*fc; // 1/pt | |
366 | ||
367 | c[0] =ca00; // y0-y0 | |
368 | c[1] =0.; // z0-y0 | |
369 | c[2] =cb00; // z0-z0 | |
370 | c[3] =ca10*fi32; // snp-y0 | |
371 | c[4] =0.; // snp-z0 | |
372 | c[5] =ca11*fi3; // snp-snp | |
373 | c[6] =0.; // tgl-y0 | |
374 | c[7] =cb10; // tgl-z0 | |
375 | c[8] =0.; // tgl-snp | |
376 | c[9] =cb11; // tgl-tgl | |
377 | c[10]=2.*(-3.*a1*a2*ca10+f*ca20)*fi3*fc; // 1/pt-y0 | |
378 | c[11]=0.; // 1/pt-z0 | |
379 | c[12]=2.*(-3.*a1*a2*ca11+f*ca21)*fi52*fc; // 1/pt-snp | |
380 | c[13]=0.; // 1/pt-tgl | |
381 | c[14]=(-12.*a1*a2*(-3.*a1*a2*ca11+2.*f*ca21)+4.*f2*ca22)*fi5 | |
382 | *fc*fc; // 1/pt-1/pt | |
383 | } | |
384 | ||
385 | ||
386 | void AliTPCTracklet::FitRiemann(const AliTPCseed *track,Int_t sector) { | |
387 | TLinearFitter fy(2); | |
388 | fy.StoreData(kFALSE); | |
389 | fy.SetFormula("hyp2"); | |
390 | Double_t xmax=-1.; | |
391 | Double_t xmin=1000.; | |
392 | for (Int_t i=0;i<160;++i) { | |
393 | AliTPCclusterMI *c=track->GetClusterPointer(i); | |
967eae0d | 394 | if (c && RejectCluster(c)) continue; |
9318a5b4 | 395 | if (c&&c->GetDetector()==sector) { |
396 | Double_t x=c->GetX(); | |
397 | Double_t y=c->GetY(); | |
398 | Double_t xy[2]={x,y}; | |
399 | Double_t r=x*x+y*y; | |
400 | Double_t errx=1.,erry=1.;//TODO! | |
401 | Double_t err=TMath::Sqrt(4.*x*x*errx+4.*y*y*erry); | |
402 | err=1.; | |
403 | fy.AddPoint(xy,r,err); | |
404 | xmax=TMath::Max(xmax,x); | |
405 | xmin=TMath::Min(xmin,x); | |
406 | } | |
407 | } | |
408 | fy.Eval(); | |
409 | Double_t a[3]={fy.GetParameter(0), | |
410 | fy.GetParameter(1), | |
411 | fy.GetParameter(2)}; | |
412 | Double_t ca[6]={fy.GetCovarianceMatrixElement(0,0), | |
413 | fy.GetCovarianceMatrixElement(1,0), | |
414 | fy.GetCovarianceMatrixElement(1,1), | |
415 | fy.GetCovarianceMatrixElement(2,0), | |
416 | fy.GetCovarianceMatrixElement(2,1), | |
417 | fy.GetCovarianceMatrixElement(2,2)}; | |
418 | ||
419 | TLinearFitter fz(1); | |
420 | fz.StoreData(kFALSE); | |
421 | fz.SetFormula("hyp1"); | |
422 | Double_t R=.5*TMath::Sqrt(4.*a[0]+a[1]*a[1]+a[2]*a[2]); | |
423 | Double_t oldx=0.; | |
424 | Double_t oldy=R; | |
425 | Double_t phi=0.; | |
426 | for (Int_t i=0;i<160;++i) { | |
427 | AliTPCclusterMI *c=track->GetClusterPointer(i); | |
967eae0d | 428 | if (c && RejectCluster(c)) continue; |
9318a5b4 | 429 | if (c&&c->GetDetector()==sector) { |
430 | Double_t x=c->GetX(); | |
431 | Double_t y=c->GetY(); | |
432 | Double_t dx=x-oldx; | |
433 | Double_t dy=y-oldy; | |
434 | phi+=2.*TMath::Abs(TMath::ATan2(.5*TMath::Sqrt(dx*dx+dy*dy),R)); | |
435 | Double_t err=1.; | |
436 | fz.AddPoint(&phi,c->GetZ(),err); | |
437 | oldx=x; | |
438 | oldy=y; | |
439 | } | |
440 | } | |
441 | fz.Eval(); | |
442 | Double_t b[2]={fz.GetParameter(0), | |
443 | fz.GetParameter(1)}; | |
444 | Double_t cb[3]={fz.GetCovarianceMatrixElement(0,0), | |
445 | fz.GetCovarianceMatrixElement(1,0), | |
446 | fz.GetCovarianceMatrixElement(1,1)}; | |
447 | ||
448 | Double_t p[5]; | |
449 | Double_t c[15]; | |
450 | Double_t alpha=track->GetAlpha(); | |
451 | if (Riemann2Helix(a,ca,b,cb,0.,p,c)) | |
452 | fPrimary=new AliExternalTrackParam(0.,alpha,p,c); | |
453 | if (Riemann2Helix(a,ca,b,cb,xmin,p,c)) | |
454 | fInner=new AliExternalTrackParam(xmin,alpha,p,c); | |
455 | if (Riemann2Helix(a,ca,b,cb,xmax,p,c)) | |
456 | fOuter=new AliExternalTrackParam(xmax,alpha,p,c); | |
457 | } | |
458 | ||
c94a79e1 | 459 | Bool_t AliTPCTracklet::Riemann2Helix(Double_t *a,Double_t */*ca*/, |
460 | Double_t *b,Double_t */*cb*/, | |
9318a5b4 | 461 | Double_t x0, |
462 | Double_t *p,Double_t *c) { | |
463 | //TODO: signs! | |
464 | ||
465 | Double_t xr0=.5*a[1]; | |
466 | Double_t yr0=.5*a[2]; | |
467 | Double_t R=.5*TMath::Sqrt(4.*a[0]+a[1]*a[1]+a[2]*a[2]); | |
468 | Double_t dx=x0-xr0; | |
469 | if (dx*dx>=R*R) return kFALSE; | |
470 | Double_t dy=TMath::Sqrt(R*R-dx*dx); //sign!! | |
471 | if (TMath::Abs(yr0+dy)>TMath::Abs(yr0-dy)) | |
472 | dy=-dy; | |
473 | Double_t y0=yr0+dy; | |
474 | Double_t tgp=-dx/dy; //TODO: dy!=0 | |
475 | Double_t z0=b[0]+TMath::ATan(tgp)*b[1]; | |
476 | Double_t xyz[3]={x0,y0,z0}; | |
477 | Double_t fc=1./(GetBz(xyz)*kB2C); | |
478 | fc=1; | |
479 | p[0]=y0; // y0 | |
480 | p[1]=z0; // z0 | |
481 | p[2]=tgp/TMath::Sqrt(1.+tgp*tgp); // snp | |
482 | p[3]=b[1]; // tgl | |
483 | p[4]=1./R*fc; // 1/pt | |
484 | ||
485 | c[0] =0.; // y0-y0 | |
486 | c[1] =0.; // z0-y0 | |
487 | c[2] =0.; // z0-z0 | |
488 | c[3] =0.; // snp-y0 | |
489 | c[4] =0.; // snp-z0 | |
490 | c[5] =0.; // snp-snp | |
491 | c[6] =0.; // tgl-y0 | |
492 | c[7] =0.; // tgl-z0 | |
493 | c[8] =0.; // tgl-snp | |
494 | c[9] =0.; // tgl-tgl | |
495 | c[10]=0.; // 1/pt-y0 | |
496 | c[11]=0.; // 1/pt-z0 | |
497 | c[12]=0.; // 1/pt-snp | |
498 | c[13]=0.; // 1/pt-tgl | |
499 | c[14]=0.; // 1/pt-1/pt | |
500 | ||
501 | return kTRUE; | |
502 | } | |
503 | ||
504 | TObjArray AliTPCTracklet::CreateTracklets(const AliTPCseed *track, | |
505 | TrackType type, | |
506 | Bool_t storeClusters, | |
69209e2c | 507 | Int_t minClusters, |
508 | Int_t maxTracklets) { | |
509 | // The tracklet factory: It creates several tracklets out of a track. They | |
510 | // are created for sectors that fullfill the constraint of having enough | |
511 | // clusters inside. Futhermore you can specify the maximum amount of | |
512 | // tracklets that are to be created. | |
513 | // The tracklets appear in a sorted fashion, beginning with those having the | |
514 | // most clusters. | |
515 | ||
516 | Int_t sectors[72]={0}; | |
517 | for (Int_t i=0;i<160;++i) { | |
9318a5b4 | 518 | AliTPCclusterMI *c=track->GetClusterPointer(i); |
967eae0d | 519 | if (c && RejectCluster(c)) continue; |
69209e2c | 520 | if (c) |
521 | ++sectors[c->GetDetector()]; | |
522 | } | |
523 | Int_t indices[72]; | |
524 | TMath::Sort(72,sectors,indices); | |
525 | TObjArray tracklets; | |
526 | if (maxTracklets>72) maxTracklets=72; // just to protect against "users". | |
527 | for (Int_t i=0;i<maxTracklets&§ors[indices[i]]>=minClusters;++i) { | |
9318a5b4 | 528 | tracklets.Add(new AliTPCTracklet(track,indices[i],type,storeClusters)); |
69209e2c | 529 | } |
530 | return tracklets; | |
531 | } | |
9318a5b4 | 532 | |
c94a79e1 | 533 | TObjArray AliTPCTracklet::CreateTracklets(const TObjArray &/*clusters*/, |
534 | TrackType /*type*/, | |
535 | Bool_t /*storeClusters*/, | |
536 | Int_t /*minClusters*/, | |
537 | Int_t /*maxTracklets*/) { | |
538 | // TODO! | |
539 | ||
71d2416b | 540 | TObjArray tracklets; |
541 | return tracklets; | |
9318a5b4 | 542 | } |
543 | ||
544 | Bool_t AliTPCTracklet::PropagateToMeanX(const AliTPCTracklet &t1, | |
545 | const AliTPCTracklet &t2, | |
546 | AliExternalTrackParam *&t1m, | |
547 | AliExternalTrackParam *&t2m) { | |
548 | // This function propagates two Tracklets to a common x-coordinate. This | |
549 | // x is dermined as the one that is in the middle of the two tracklets (they | |
550 | // are assumed to live on two distinct x-intervalls). | |
551 | // The inner parametrisation of the outer Tracklet and the outer | |
552 | // parametrisation of the inner Tracklet are used and propagated to this | |
553 | // common x. This result is saved not inside the Tracklets but two new | |
554 | // ExternalTrackParams are created (that means you might want to delete | |
555 | // them). | |
556 | // In the case that the alpha angles of the Tracklets differ both angles | |
557 | // are tried out for this propagation. | |
558 | // In case of any failure kFALSE is returned, no AliExternalTrackParam | |
559 | // is created und the pointers are set to 0. | |
560 | ||
561 | if (t1.GetInner() && t1.GetOuter() && | |
562 | t2.GetInner() && t2.GetOuter()) { | |
563 | if (t1.GetOuter()->GetX()<t2.GetInner()->GetX()) { | |
564 | t1m=new AliExternalTrackParam(*t1.GetOuter()); | |
565 | t2m=new AliExternalTrackParam(*t2.GetInner()); | |
566 | } | |
567 | else { | |
568 | t1m=new AliExternalTrackParam(*t1.GetInner()); | |
569 | t2m=new AliExternalTrackParam(*t2.GetOuter()); | |
570 | } | |
571 | Double_t mx=.5*(t1m->GetX()+t2m->GetX()); | |
572 | Double_t b1,b2; | |
573 | Double_t xyz[3]; | |
574 | t1m->GetXYZ(xyz); | |
575 | b1=GetBz(xyz); | |
576 | t2m->GetXYZ(xyz); | |
577 | b2=GetBz(xyz); | |
578 | if (t1m->Rotate(t2m->GetAlpha()) | |
579 | && t1m->PropagateTo(mx,b1) | |
580 | && t2m->PropagateTo(mx,b2)); | |
581 | else | |
582 | if (t2m->Rotate(t1m->GetAlpha()) | |
583 | && t1m->PropagateTo(mx,b1) | |
584 | && t2m->PropagateTo(mx,b2)); | |
585 | else { | |
586 | delete t1m; | |
587 | delete t2m; | |
588 | t1m=t2m=0; | |
589 | } | |
590 | } | |
591 | else { | |
592 | t1m=t2m=0; | |
593 | } | |
594 | return t1m&&t2m; | |
595 | } | |
596 | ||
597 | double AliTPCTracklet::GetBz(Double_t *xyz) { | |
598 | if (AliTracker::UniformField()) | |
599 | return AliTracker::GetBz(); | |
600 | else | |
601 | return AliTracker::GetBz(xyz); | |
602 | } | |
603 | ||
604 | void AliTPCTracklet::RandomND(Int_t ndim,const Double_t *p,const Double_t *c, | |
605 | Double_t *x) { | |
606 | // This function generates a n-dimensional random variable x with mean | |
607 | // p and covariance c. | |
608 | // That is done using the cholesky decomposition of the covariance matrix, | |
609 | // Begin_Latex C=U^{t} U End_Latex, with Begin_Latex U End_Latex being an | |
610 | // upper triangular matrix. Given a vector v of iid gausian random variables | |
611 | // with variance 1 one obtains the asked result as: Begin_Latex x=U^t v | |
612 | // End_Latex. | |
613 | // c is expected to be in a lower triangular format: | |
614 | // c[0] | |
615 | // c[1] c[2] | |
616 | // c[3] c[4] c[5] | |
617 | // etc. | |
618 | static TRandom3 random; | |
619 | Double_t *c2= new Double_t[ndim*ndim]; | |
620 | Int_t k=0; | |
621 | for (Int_t i=0;i<ndim;++i) | |
622 | for (Int_t j=0;j<=i;++j) | |
623 | c2[i*ndim+j]=c2[j*ndim+i]=c[k++]; | |
624 | TMatrixDSym cm(ndim,c2); | |
625 | delete[] c2; | |
626 | TDecompChol chol(cm); | |
627 | chol.Decompose(); | |
628 | const TVectorD pv(ndim); | |
629 | const_cast<TVectorD*>(&pv)->Use(ndim,const_cast<Double_t*>(p)); | |
630 | TVectorD xv(ndim); | |
631 | xv.Use(ndim,x); | |
632 | for (Int_t i=0;i<ndim;++i) | |
633 | xv[i]=random.Gaus(); | |
634 | TMatrixD L=chol.GetU(); | |
635 | L.T(); | |
636 | xv=L*xv+pv; | |
637 | } | |
638 | ||
639 | TEllipse AliTPCTracklet::ErrorEllipse(Double_t x,Double_t y, | |
640 | Double_t sx,Double_t sy,Double_t sxy) { | |
641 | /* Begin_Latex | |
642 | r_{1,2}=1/2 (a+c#pm#sqrt{(a-c)^{2}+(2b)^{2}}) | |
643 | End_Latex */ | |
644 | Double_t det1=1./(sx*sy-sxy*sxy); | |
645 | Double_t a=sy*det1; | |
646 | Double_t b=-sxy*det1; | |
647 | Double_t c=sx*det1; | |
648 | Double_t d=c-a; | |
649 | Double_t s=TMath::Sqrt(d*d+4.*b*b); | |
650 | Double_t r1=TMath::Sqrt(.5*(a+c-s)); | |
651 | Double_t r2=TMath::Sqrt(.5*(a+c+s)); | |
652 | Double_t alpha=.5*TMath::ATan2(2.*b,d); | |
653 | return TEllipse(x,y,r1,r2,0.,360.,alpha*TMath::RadToDeg()); | |
654 | } | |
655 | ||
656 | void AliTPCTracklet::Test(const char* filename) { | |
657 | /* | |
658 | aliroot | |
659 | AliTPCTracklet::Test(""); | |
660 | TFile f("AliTPCTrackletDebug.root"); | |
661 | TTree *t=f.Get("AliTPCTrackletDebug"); | |
662 | t->Draw("p0:p4"); | |
663 | TEllipse e=AliTPCTracklet::ErrorEllipse(0.,0.,4.,1.,1.8); | |
664 | e.Draw(); | |
665 | */ | |
c94a79e1 | 666 | TTreeSRedirector ds(filename); |
9318a5b4 | 667 | Double_t p[5]={0.}; |
668 | Double_t c[15]={4., | |
669 | 0.,4., | |
670 | 0.,0.,9., | |
671 | 0.,0.,0.,16., | |
672 | 1.8,0.,0.,0.,1.}; | |
673 | for (Int_t i=0;i<10000;++i) { | |
674 | Double_t x[5]; | |
675 | RandomND(5,p,c,x); | |
676 | ds<<"AliTPCTrackletDebug" | |
677 | <<"p0="<<x[0] | |
678 | <<"p1="<<x[1] | |
679 | <<"p2="<<x[2] | |
680 | <<"p3="<<x[3] | |
681 | <<"p4="<<x[4] | |
682 | <<"\n"; | |
683 | } | |
684 | ||
685 | /* | |
686 | Double_t b; | |
687 | Double_t x=0.; | |
688 | Double_t alpha=0.; | |
689 | Double_t param[5]={0.}; | |
690 | Double_t covar[15]={1., | |
691 | 0.,1., | |
692 | 0.,0.,1., | |
693 | 0.,0.,0.,1., | |
694 | 0.,0.,0.,0.,1.}; | |
695 | AliExternalTrackParam track(x,alpha,param,covar); | |
696 | ||
697 | ||
698 | ||
699 | for (Int_t i=0;i<points.GetNPoints();++i) { | |
700 | Double_t x=0.; | |
701 | Double_t alpha=0.; | |
702 | Double_t param[5]={0.}; | |
703 | Double_t covar[15]={1., | |
704 | 0.,1., | |
705 | 0.,0.,1., | |
706 | 0.,0.,0.,1., | |
707 | 0.,0.,0.,0.,1.}; | |
708 | AliExternalTrackParam track(x,alpha,param,covar); | |
709 | for (x=90.;x<250.;x+=1.) { | |
710 | track.PropagateTo(x,b); | |
711 | AliTPCclusterMI c(); | |
712 | } | |
713 | } | |
714 | */ | |
715 | } | |
967eae0d | 716 | |
717 | ||
718 | Bool_t AliTPCTracklet::RejectCluster(AliTPCclusterMI* cl, AliExternalTrackParam * param){ | |
719 | // | |
720 | // check the acceptance of cluster | |
721 | // Cut on edge effects | |
722 | // | |
723 | Bool_t isReject = kFALSE; | |
724 | Float_t edgeY = cl->GetX()*TMath::Tan(TMath::Pi()/18); | |
725 | Float_t dist = edgeY - TMath::Abs(cl->GetY()); | |
726 | if (param) dist = edgeY - TMath::Abs(param->GetY()); | |
727 | if (dist<fgEdgeCutY) isReject=kTRUE; | |
728 | if (cl->GetType()<0) isReject=kTRUE; | |
729 | return isReject; | |
730 | } |