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2d57349e | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-2003, 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 | // Implementation of the vertexer from ESD tracks | |
18 | // | |
19 | // Origin: AliITSVertexerTracks | |
20 | // A.Dainese, Padova, | |
21 | // andrea.dainese@pd.infn.it | |
22 | // M.Masera, Torino, | |
23 | // massimo.masera@to.infn.it | |
24 | // Moved to STEER and adapted to ESD tracks: | |
25 | // F.Prino, Torino, prino@to.infn.it | |
26 | //----------------------------------------------------------------- | |
27 | ||
28 | //---- Root headers -------- | |
29 | #include <TTree.h> | |
ec1be5d5 | 30 | #include <TMatrixD.h> |
2d57349e | 31 | //---- AliRoot headers ----- |
32 | #include "AliStrLine.h" | |
33 | #include "AliVertexerTracks.h" | |
c5e3e5d1 | 34 | #include "AliESD.h" |
2d57349e | 35 | #include "AliESDtrack.h" |
36 | ||
37 | ClassImp(AliVertexerTracks) | |
38 | ||
39 | ||
40 | //---------------------------------------------------------------------------- | |
41 | AliVertexerTracks::AliVertexerTracks(): | |
07680cae | 42 | TObject(), |
43 | fVert(), | |
44 | fCurrentVertex(0), | |
fe12e09c | 45 | fMinTracks(2), |
46 | fMinITSClusters(5), | |
07680cae | 47 | fTrkArray(), |
48 | fTrksToSkip(0), | |
49 | fNTrksToSkip(0), | |
50 | fDCAcut(0), | |
51 | fAlgo(1), | |
fe12e09c | 52 | fNSigma(3), |
07680cae | 53 | fDebug(0) |
2d57349e | 54 | { |
55 | // | |
56 | // Default constructor | |
57 | // | |
58 | SetVtxStart(); | |
07680cae | 59 | SetVtxStartSigma(); |
2d57349e | 60 | SetMinTracks(); |
07680cae | 61 | SetMinITSClusters(); |
62 | SetNSigmad0(); | |
2d57349e | 63 | } |
64 | //----------------------------------------------------------------------------- | |
65 | AliVertexerTracks::AliVertexerTracks(Double_t xStart, Double_t yStart): | |
07680cae | 66 | TObject(), |
67 | fVert(), | |
68 | fCurrentVertex(0), | |
fe12e09c | 69 | fMinTracks(2), |
70 | fMinITSClusters(5), | |
07680cae | 71 | fTrkArray(), |
72 | fTrksToSkip(0), | |
73 | fNTrksToSkip(0), | |
74 | fDCAcut(0), | |
75 | fAlgo(1), | |
fe12e09c | 76 | fNSigma(3), |
07680cae | 77 | fDebug(0) |
2d57349e | 78 | { |
79 | // | |
80 | // Standard constructor | |
81 | // | |
82 | SetVtxStart(xStart,yStart); | |
07680cae | 83 | SetVtxStartSigma(); |
2d57349e | 84 | SetMinTracks(); |
07680cae | 85 | SetMinITSClusters(); |
86 | SetNSigmad0(); | |
2d57349e | 87 | } |
88 | //----------------------------------------------------------------------------- | |
89 | AliVertexerTracks::~AliVertexerTracks() { | |
90 | // Default Destructor | |
eae1677e | 91 | // The objects pointed by the following pointer are not owned |
2d57349e | 92 | // by this class and are not deleted |
ec1be5d5 | 93 | fCurrentVertex = 0; |
07680cae | 94 | delete[] fTrksToSkip; |
ec1be5d5 | 95 | } |
96 | //--------------------------------------------------------------------------- | |
97 | void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped) { | |
98 | // | |
99 | // Mark the tracks not ot be used in the vertex finding | |
100 | // | |
101 | fNTrksToSkip = n; | |
102 | fTrksToSkip = new Int_t[n]; | |
103 | for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i]; | |
104 | return; | |
105 | } | |
2d57349e | 106 | //---------------------------------------------------------------------------- |
ec1be5d5 | 107 | Int_t AliVertexerTracks::PrepareTracks(TTree &trkTree, Int_t OptImpParCut) { |
2d57349e | 108 | // |
109 | // Propagate tracks to initial vertex position and store them in a TObjArray | |
110 | // | |
ec1be5d5 | 111 | Double_t maxd0rphi = 3.; |
2d57349e | 112 | Int_t nTrks = 0; |
07680cae | 113 | Double_t sigmaCurr[3],sigmaVtx[3],posVtx[3]; |
eae1677e | 114 | Double_t covVtx[6],covVtxXY; |
07680cae | 115 | Float_t d0z0[2],covd0z0[3]; |
116 | Double_t momentum[3],postrk[3]; | |
117 | Double_t pt,sigma,sigmavtxphi,phitrk; | |
ec1be5d5 | 118 | Double_t field=GetField(); |
2d57349e | 119 | |
07680cae | 120 | AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalSigma); |
121 | ||
2d57349e | 122 | Int_t nEntries = (Int_t)trkTree.GetEntries(); |
123 | if(!fTrkArray.IsEmpty()) fTrkArray.Clear(); | |
124 | fTrkArray.Expand(nEntries); | |
125 | ||
ec1be5d5 | 126 | if(fDebug) { |
127 | printf(" PrepareTracks()\n"); | |
128 | } | |
129 | ||
2d57349e | 130 | for(Int_t i=0; i<nEntries; i++) { |
131 | AliESDtrack *track = new AliESDtrack; | |
132 | trkTree.SetBranchAddress("tracks",&track); | |
133 | trkTree.GetEvent(i); | |
134 | ||
07680cae | 135 | |
136 | ||
137 | // propagate track to vertex | |
eae1677e | 138 | if(OptImpParCut==1) { // OptImpParCut==1 |
07680cae | 139 | track->RelateToVertex(initVertex,field,100.); |
140 | initVertex->GetXYZ(posVtx); | |
141 | initVertex->GetSigmaXYZ(sigmaVtx); | |
eae1677e | 142 | covVtxXY = 0.; |
143 | } else { // OptImpParCut==2 | |
07680cae | 144 | fCurrentVertex->GetSigmaXYZ(sigmaCurr); |
145 | if((sigmaCurr[0]+sigmaCurr[1])<(fNominalSigma[0]+fNominalSigma[1])) { | |
146 | track->RelateToVertex(fCurrentVertex,field,100.); | |
147 | fCurrentVertex->GetXYZ(posVtx); | |
148 | fCurrentVertex->GetSigmaXYZ(sigmaVtx); | |
eae1677e | 149 | fCurrentVertex->GetCovMatrix(covVtx); |
150 | covVtxXY = covVtx[1]; | |
07680cae | 151 | } else { |
152 | track->RelateToVertex(initVertex,field,100.); | |
153 | initVertex->GetXYZ(posVtx); | |
154 | initVertex->GetSigmaXYZ(sigmaVtx); | |
eae1677e | 155 | covVtxXY = 0.; |
07680cae | 156 | } |
157 | } | |
158 | ||
159 | // select tracks with d0rphi < maxd0rphi | |
160 | track->GetImpactParameters(d0z0,covd0z0); | |
161 | ||
eae1677e | 162 | track->GetXYZ(postrk); |
163 | track->GetPxPyPz(momentum); | |
164 | pt = TMath::Sqrt(momentum[0]*momentum[0]+momentum[1]*momentum[1]); | |
165 | ||
166 | phitrk = TMath::ATan2(postrk[1]-posVtx[1],postrk[0]-posVtx[0]); | |
167 | sigmavtxphi = TMath::Sqrt(sigmaVtx[0]*sigmaVtx[0]* | |
168 | TMath::Cos(phitrk)*TMath::Cos(phitrk)+ | |
169 | sigmaVtx[1]*sigmaVtx[1]* | |
170 | TMath::Sin(phitrk)*TMath::Sin(phitrk)+ | |
171 | covVtxXY* | |
172 | TMath::Cos(phitrk)*TMath::Sin(phitrk)); | |
173 | sigma = TMath::Sqrt(Sigmad0rphi(pt)*Sigmad0rphi(pt)+ | |
174 | sigmavtxphi*sigmavtxphi); | |
175 | maxd0rphi = fNSigma*sigma; | |
176 | if(OptImpParCut==1) maxd0rphi *= 5.; | |
177 | ||
178 | if(fDebug) printf("trk %d; lab %d; |d0| = %f; cut = %f\n",i,track->GetLabel(),TMath::Abs(d0z0[0]),maxd0rphi); | |
07680cae | 179 | if(TMath::Abs(d0z0[0]) > maxd0rphi) { |
eae1677e | 180 | if(fDebug) printf(" rejected\n"); |
07680cae | 181 | delete track; continue; |
182 | } | |
183 | ||
2d57349e | 184 | fTrkArray.AddLast(track); |
185 | nTrks++; | |
186 | } | |
07680cae | 187 | |
07680cae | 188 | delete initVertex; |
189 | ||
2d57349e | 190 | return nTrks; |
191 | } | |
192 | //---------------------------------------------------------------------------- | |
07680cae | 193 | Double_t AliVertexerTracks::Sigmad0rphi(Double_t pt) const { |
194 | // | |
195 | // Impact parameter resolution in rphi [cm] vs pt [GeV/c] | |
196 | // | |
197 | Double_t a_meas = 11.6; | |
198 | Double_t a_scatt = 65.8; | |
199 | Double_t b = 1.878; | |
200 | ||
201 | Double_t sigma = a_meas*a_meas+a_scatt*a_scatt/TMath::Power(pt,b); | |
202 | sigma = 0.0001*TMath::Sqrt(sigma); | |
203 | ||
204 | return sigma; | |
205 | } | |
206 | //---------------------------------------------------------------------------- | |
2d57349e | 207 | AliVertex* AliVertexerTracks::VertexForSelectedTracks(TTree *trkTree) { |
208 | // | |
209 | // Return vertex from tracks in trkTree | |
210 | // | |
211 | ||
212 | // get tracks and propagate them to initial vertex position | |
ec1be5d5 | 213 | Int_t nTrks = PrepareTracks(*trkTree,1); |
2d57349e | 214 | if(nTrks < fMinTracks) { |
215 | printf("TooFewTracks\n"); | |
216 | Double_t vtx[3]={0,0,0}; | |
217 | fVert.SetXYZ(vtx); | |
218 | fVert.SetDispersion(999); | |
219 | fVert.SetNContributors(-5); | |
220 | return &fVert; | |
221 | } | |
222 | ||
223 | // Set initial vertex position from ESD | |
224 | if(fAlgo==1) StrLinVertexFinderMinDist(1); | |
225 | if(fAlgo==2) StrLinVertexFinderMinDist(0); | |
226 | if(fAlgo==3) HelixVertexFinder(); | |
227 | if(fAlgo==4) VertexFinder(1); | |
228 | if(fAlgo==5) VertexFinder(0); | |
229 | return &fVert; | |
230 | } | |
c5e3e5d1 | 231 | //---------------------------------------------------------------------------- |
ec1be5d5 | 232 | AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const AliESD *esdEvent) |
233 | { | |
c5e3e5d1 | 234 | // |
ec1be5d5 | 235 | // Primary vertex for current ESD event |
eae1677e | 236 | // (Two iterations: |
237 | // 1st with 5*fNSigma*sigma(pt) cut w.r.t. to initial vertex; | |
238 | // 2nd with fNSigma*sigma(pt) cut w.r.t. to vertex found in 1st iteration) | |
318aecb9 | 239 | // All ESD tracks with inside the beam pipe are then propagated to found vertex |
07680cae | 240 | // |
241 | fCurrentVertex = 0; | |
242 | ||
243 | Int_t entr = (Int_t)esdEvent->GetNumberOfTracks(); | |
244 | TTree *trkTree = new TTree("TreeT","tracks"); | |
245 | AliESDtrack *esdTrack = 0; | |
246 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
247 | ||
eae1677e | 248 | Bool_t skipThis; |
07680cae | 249 | for(Int_t i=0; i<entr; i++) { |
eae1677e | 250 | // check tracks to skip |
251 | skipThis = kFALSE; | |
252 | for(Int_t j=0; j<fNTrksToSkip; j++) { | |
253 | if(i==fTrksToSkip[j]) { | |
254 | if(fDebug) printf("skipping track: %d\n",i); | |
255 | skipThis = kTRUE; | |
256 | } | |
257 | } | |
258 | if(skipThis) continue; | |
07680cae | 259 | AliESDtrack *et = esdEvent->GetTrack(i); |
260 | esdTrack = new AliESDtrack(*et); | |
608e7e22 | 261 | if(!(esdTrack->GetStatus()&AliESDtrack::kITSin)) continue; |
262 | if(!(esdTrack->GetStatus()&AliESDtrack::kITSrefit)) continue; | |
07680cae | 263 | Int_t nclus=esdTrack->GetNcls(0); // check number of clusters in ITS |
264 | if(nclus<fMinITSClusters) continue; | |
07680cae | 265 | trkTree->Fill(); |
266 | } | |
267 | delete esdTrack; | |
318aecb9 | 268 | |
07680cae | 269 | |
270 | // ITERATION 1 | |
271 | // propagate tracks to initVertex | |
eae1677e | 272 | // preselect them (reject for |d0|>5*fNSigma*sigma w.r.t. initVertex) |
07680cae | 273 | Int_t nTrks; |
274 | nTrks = PrepareTracks(*trkTree,1); | |
275 | if(fDebug) printf(" tracks prepared - step 1: %d\n",nTrks); | |
276 | if(nTrks < fMinTracks) { | |
277 | printf("TooFewTracks\n"); | |
eae1677e | 278 | TooFewTracks(esdEvent); |
279 | if(fDebug) fCurrentVertex->PrintStatus(); | |
07680cae | 280 | return fCurrentVertex; |
281 | } | |
282 | ||
283 | // vertex finder | |
284 | switch (fAlgo) { | |
285 | case 1: StrLinVertexFinderMinDist(1); break; | |
286 | case 2: StrLinVertexFinderMinDist(0); break; | |
287 | case 3: HelixVertexFinder(); break; | |
288 | case 4: VertexFinder(1); break; | |
289 | case 5: VertexFinder(0); break; | |
290 | default: printf("Wrong algorithm\n"); break; | |
291 | } | |
292 | if(fDebug) printf(" vertex finding completed\n"); | |
293 | ||
294 | // vertex fitter | |
eae1677e | 295 | VertexFitter(kTRUE); |
07680cae | 296 | if(fDebug) printf(" vertex fit completed\n"); |
297 | ||
298 | // ITERATION 2 | |
299 | // propagate tracks to best between initVertex and fCurrentVertex | |
300 | // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best | |
301 | // between initVertex and fCurrentVertex) | |
302 | nTrks = PrepareTracks(*trkTree,2); | |
303 | delete trkTree; | |
304 | if(fDebug) printf(" tracks prepared - step 2: %d\n",nTrks); | |
305 | if(nTrks < fMinTracks) { | |
306 | printf("TooFewTracks\n"); | |
eae1677e | 307 | TooFewTracks(esdEvent); |
308 | if(fDebug) fCurrentVertex->PrintStatus(); | |
07680cae | 309 | return fCurrentVertex; |
310 | } | |
311 | ||
312 | // vertex finder | |
313 | switch (fAlgo) { | |
314 | case 1: StrLinVertexFinderMinDist(1); break; | |
315 | case 2: StrLinVertexFinderMinDist(0); break; | |
316 | case 3: HelixVertexFinder(); break; | |
317 | case 4: VertexFinder(1); break; | |
318 | case 5: VertexFinder(0); break; | |
319 | default: printf("Wrong algorithm\n"); break; | |
320 | } | |
321 | if(fDebug) printf(" vertex finding completed\n"); | |
322 | ||
323 | // fitter | |
eae1677e | 324 | VertexFitter(kTRUE); |
07680cae | 325 | if(fDebug) printf(" vertex fit completed\n"); |
326 | ||
eae1677e | 327 | |
328 | fTrkArray.Clear(); | |
329 | ||
330 | // take true pos from ESD | |
07680cae | 331 | Double_t tp[3]; |
332 | esdEvent->GetVertex()->GetTruePos(tp); | |
333 | fCurrentVertex->SetTruePos(tp); | |
eae1677e | 334 | if(fNominalSigma[0]>1.) { |
335 | fCurrentVertex->SetTitle("VertexerTracksNoConstraint"); | |
336 | } else { | |
337 | fCurrentVertex->SetTitle("VertexerTracksWithConstraint"); | |
338 | } | |
339 | ||
340 | if(fDebug) fCurrentVertex->PrintStatus(); | |
341 | if(fTrksToSkip) delete [] fTrksToSkip; | |
318aecb9 | 342 | |
343 | // propagate tracks to found vertex | |
344 | if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) { | |
345 | for(Int_t ii=0; ii<entr; ii++) { | |
346 | AliESDtrack *et = esdEvent->GetTrack(ii); | |
347 | if(!et->GetStatus()&AliESDtrack::kITSin) continue; | |
348 | if(et->GetX()>3.) continue; | |
349 | et->RelateToVertex(fCurrentVertex,GetField(),100.); | |
350 | } | |
351 | } else { | |
352 | AliWarning("Found vertex outside beam pipe!"); | |
353 | } | |
354 | ||
07680cae | 355 | return fCurrentVertex; |
356 | } | |
357 | //---------------------------------------------------------------------------- | |
358 | AliESDVertex* AliVertexerTracks::FindPrimaryVertexOld(const AliESD *esdEvent) | |
359 | { | |
360 | // | |
361 | // Primary vertex for current ESD event (one iteration with |d0rphi|<3cm) | |
c5e3e5d1 | 362 | // |
ec1be5d5 | 363 | fCurrentVertex = 0; |
364 | ||
365 | Int_t entr = (Int_t)esdEvent->GetNumberOfTracks(); | |
366 | TTree *trkTree = new TTree("TreeT","tracks"); | |
367 | AliESDtrack *esdTrack = 0; | |
368 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
369 | ||
370 | for(Int_t i=0; i<entr; i++) { | |
371 | AliESDtrack *et = esdEvent->GetTrack(i); | |
372 | esdTrack = new AliESDtrack(*et); | |
608e7e22 | 373 | if(!(esdTrack->GetStatus()&AliESDtrack::kITSin)) continue; |
374 | if(!(esdTrack->GetStatus()&AliESDtrack::kITSrefit)) continue; | |
ec1be5d5 | 375 | Int_t nclus=esdTrack->GetNcls(0); // check number of clusters in ITS |
07680cae | 376 | if(nclus<fMinITSClusters) continue; |
ec1be5d5 | 377 | |
378 | trkTree->Fill(); | |
c5e3e5d1 | 379 | } |
ec1be5d5 | 380 | delete esdTrack; |
c5e3e5d1 | 381 | |
ec1be5d5 | 382 | // preselect tracks and propagate them to initial vertex position |
07680cae | 383 | Int_t nTrks = PrepareTracks(*trkTree,1); |
ec1be5d5 | 384 | delete trkTree; |
385 | if(fDebug) printf(" tracks prepared: %d\n",nTrks); | |
386 | if(nTrks < fMinTracks) { | |
c5e3e5d1 | 387 | printf("TooFewTracks\n"); |
ec1be5d5 | 388 | fCurrentVertex = new AliESDVertex(0.,0.,-1); |
389 | return fCurrentVertex; | |
390 | } | |
c5e3e5d1 | 391 | |
ec1be5d5 | 392 | // VERTEX FINDER |
393 | switch (fAlgo) { | |
394 | case 1: StrLinVertexFinderMinDist(1); break; | |
395 | case 2: StrLinVertexFinderMinDist(0); break; | |
396 | case 3: HelixVertexFinder(); break; | |
397 | case 4: VertexFinder(1); break; | |
398 | case 5: VertexFinder(0); break; | |
399 | default: printf("Wrong algorithm\n"); break; | |
400 | } | |
c5e3e5d1 | 401 | |
ec1be5d5 | 402 | // VERTEX FITTER |
ec1be5d5 | 403 | VertexFitter(); |
404 | if(fDebug) printf(" vertex fit completed\n"); | |
c5e3e5d1 | 405 | |
ec1be5d5 | 406 | |
407 | Double_t tp[3]; | |
408 | esdEvent->GetVertex()->GetTruePos(tp); | |
409 | fCurrentVertex->SetTruePos(tp); | |
410 | fCurrentVertex->SetTitle("VertexerTracks"); | |
411 | ||
412 | fTrkArray.Clear(); | |
413 | return fCurrentVertex; | |
414 | } | |
2d57349e | 415 | //---------------------------------------------------------------------------- |
416 | AliVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray) { | |
417 | // | |
418 | // Return vertex from array of tracks | |
419 | // | |
420 | ||
421 | // get tracks and propagate them to initial vertex position | |
422 | Int_t nTrks = trkArray->GetEntriesFast(); | |
423 | if(nTrks < fMinTracks) { | |
424 | printf("TooFewTracks\n"); | |
425 | Double_t vtx[3]={0,0,0}; | |
426 | fVert.SetXYZ(vtx); | |
427 | fVert.SetDispersion(999); | |
428 | fVert.SetNContributors(-5); | |
429 | return &fVert; | |
430 | } | |
431 | TTree *trkTree = new TTree("TreeT","tracks"); | |
432 | AliESDtrack *esdTrack = 0; | |
433 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
434 | for(Int_t i=0; i<nTrks; i++){ | |
435 | esdTrack = (AliESDtrack*)trkArray->At(i); | |
436 | trkTree->Fill(); | |
437 | } | |
438 | ||
2e5c8fc7 | 439 | AliVertex *vtx = VertexForSelectedTracks(trkTree); |
440 | delete trkTree; | |
441 | return vtx; | |
2d57349e | 442 | } |
443 | ||
444 | //--------------------------------------------------------------------------- | |
445 | void AliVertexerTracks::VertexFinder(Int_t optUseWeights) { | |
446 | ||
447 | // Get estimate of vertex position in (x,y) from tracks DCA | |
448 | ||
449 | Double_t initPos[3]; | |
450 | initPos[2] = 0.; | |
451 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
452 | Int_t nacc = (Int_t)fTrkArray.GetEntriesFast(); | |
453 | Double_t aver[3]={0.,0.,0.}; | |
454 | Double_t aversq[3]={0.,0.,0.}; | |
455 | Double_t sigmasq[3]={0.,0.,0.}; | |
456 | Double_t sigma=0; | |
457 | Int_t ncombi = 0; | |
458 | AliESDtrack *track1; | |
459 | AliESDtrack *track2; | |
ec1be5d5 | 460 | Double_t pos[3],dir[3]; |
2d57349e | 461 | Double_t alpha,mindist; |
462 | Double_t field=GetField(); | |
463 | ||
464 | for(Int_t i=0; i<nacc; i++){ | |
465 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
466 | alpha=track1->GetAlpha(); | |
467 | mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
ec1be5d5 | 468 | track1->GetXYZAt(mindist,field,pos); |
469 | track1->GetPxPyPzAt(mindist,field,dir); | |
470 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
08df6187 | 471 | |
ec1be5d5 | 472 | // AliStrLine *line1 = new AliStrLine(); |
473 | // track1->ApproximateHelixWithLine(mindist,field,line1); | |
2d57349e | 474 | |
475 | for(Int_t j=i+1; j<nacc; j++){ | |
476 | track2 = (AliESDtrack*)fTrkArray.At(j); | |
477 | alpha=track2->GetAlpha(); | |
478 | mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
ec1be5d5 | 479 | track2->GetXYZAt(mindist,field,pos); |
480 | track2->GetPxPyPzAt(mindist,field,dir); | |
481 | AliStrLine *line2 = new AliStrLine(pos,dir); | |
482 | // AliStrLine *line2 = new AliStrLine(); | |
483 | // track2->ApproximateHelixWithLine(mindist,field,line2); | |
2d57349e | 484 | Double_t distCA=line2->GetDCA(line1); |
485 | if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){ | |
486 | Double_t pnt1[3],pnt2[3],crosspoint[3]; | |
487 | ||
488 | if(optUseWeights<=0){ | |
489 | Int_t retcode = line2->Cross(line1,crosspoint); | |
490 | if(retcode>=0){ | |
491 | ncombi++; | |
492 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
493 | for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
494 | } | |
495 | } | |
496 | if(optUseWeights>0){ | |
497 | Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2); | |
498 | if(retcode>=0){ | |
499 | Double_t alpha, cs, sn; | |
500 | alpha=track1->GetAlpha(); | |
501 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
502 | Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2(); | |
503 | alpha=track2->GetAlpha(); | |
504 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
505 | Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2(); | |
506 | Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2(); | |
507 | Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1; | |
508 | Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1; | |
509 | Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1; | |
510 | crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0]; | |
511 | crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1]; | |
512 | crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2]; | |
513 | ||
514 | ncombi++; | |
515 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
516 | for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
517 | } | |
518 | } | |
519 | } | |
520 | delete line2; | |
521 | } | |
522 | delete line1; | |
523 | } | |
524 | if(ncombi>0){ | |
525 | for(Int_t jj=0;jj<3;jj++){ | |
526 | initPos[jj] = aver[jj]/ncombi; | |
527 | aversq[jj]/=ncombi; | |
528 | sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj]; | |
529 | sigma+=sigmasq[jj]; | |
530 | } | |
531 | sigma=TMath::Sqrt(TMath::Abs(sigma)); | |
532 | } | |
533 | else { | |
534 | Warning("VertexFinder","Finder did not succed"); | |
535 | sigma=999; | |
536 | } | |
537 | fVert.SetXYZ(initPos); | |
538 | fVert.SetDispersion(sigma); | |
539 | fVert.SetNContributors(ncombi); | |
540 | } | |
541 | //--------------------------------------------------------------------------- | |
542 | void AliVertexerTracks::HelixVertexFinder() { | |
543 | ||
544 | // Get estimate of vertex position in (x,y) from tracks DCA | |
545 | ||
546 | ||
547 | Double_t initPos[3]; | |
548 | initPos[2] = 0.; | |
549 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
550 | Double_t field=GetField(); | |
551 | ||
552 | Int_t nacc = (Int_t)fTrkArray.GetEntriesFast(); | |
553 | ||
554 | Double_t aver[3]={0.,0.,0.}; | |
555 | Double_t averquad[3]={0.,0.,0.}; | |
556 | Double_t sigmaquad[3]={0.,0.,0.}; | |
557 | Double_t sigma=0; | |
558 | Int_t ncombi = 0; | |
559 | AliESDtrack *track1; | |
560 | AliESDtrack *track2; | |
561 | Double_t distCA; | |
562 | Double_t x, par[5]; | |
563 | Double_t alpha, cs, sn; | |
564 | Double_t crosspoint[3]; | |
565 | for(Int_t i=0; i<nacc; i++){ | |
566 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
567 | ||
568 | ||
569 | for(Int_t j=i+1; j<nacc; j++){ | |
570 | track2 = (AliESDtrack*)fTrkArray.At(j); | |
571 | ||
572 | distCA=track2->PropagateToDCA(track1,field); | |
573 | ||
574 | if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){ | |
575 | track1->GetExternalParameters(x,par); | |
576 | alpha=track1->GetAlpha(); | |
577 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
578 | Double_t x1=x*cs - par[0]*sn; | |
579 | Double_t y1=x*sn + par[0]*cs; | |
580 | Double_t z1=par[1]; | |
581 | Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2(); | |
582 | track2->GetExternalParameters(x,par); | |
583 | alpha=track2->GetAlpha(); | |
584 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
585 | Double_t x2=x*cs - par[0]*sn; | |
586 | Double_t y2=x*sn + par[0]*cs; | |
587 | Double_t z2=par[1]; | |
588 | Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2(); | |
589 | Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2(); | |
590 | Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1; | |
591 | Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1; | |
592 | Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1; | |
593 | crosspoint[0]=wx1*x1 + wx2*x2; | |
594 | crosspoint[1]=wy1*y1 + wy2*y2; | |
595 | crosspoint[2]=wz1*z1 + wz2*z2; | |
596 | ||
597 | ncombi++; | |
598 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
599 | for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
600 | } | |
601 | } | |
602 | ||
603 | } | |
604 | if(ncombi>0){ | |
605 | for(Int_t jj=0;jj<3;jj++){ | |
606 | initPos[jj] = aver[jj]/ncombi; | |
607 | averquad[jj]/=ncombi; | |
608 | sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj]; | |
609 | sigma+=sigmaquad[jj]; | |
610 | } | |
611 | sigma=TMath::Sqrt(TMath::Abs(sigma)); | |
612 | } | |
613 | else { | |
614 | Warning("HelixVertexFinder","Finder did not succed"); | |
615 | sigma=999; | |
616 | } | |
617 | fVert.SetXYZ(initPos); | |
618 | fVert.SetDispersion(sigma); | |
619 | fVert.SetNContributors(ncombi); | |
620 | } | |
621 | //--------------------------------------------------------------------------- | |
622 | void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights){ | |
623 | ||
624 | // Calculate the point at minimum distance to prepared tracks | |
625 | ||
626 | Double_t initPos[3]; | |
627 | initPos[2] = 0.; | |
628 | Double_t sigma=0; | |
629 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
630 | const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast(); | |
631 | Double_t field=GetField(); | |
632 | ||
633 | AliESDtrack *track1; | |
634 | Double_t (*vectP0)[3]=new Double_t [knacc][3]; | |
635 | Double_t (*vectP1)[3]=new Double_t [knacc][3]; | |
636 | ||
637 | Double_t sum[3][3]; | |
638 | Double_t dsum[3]={0,0,0}; | |
639 | for(Int_t i=0;i<3;i++) | |
640 | for(Int_t j=0;j<3;j++)sum[i][j]=0; | |
641 | for(Int_t i=0; i<knacc; i++){ | |
642 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
643 | Double_t alpha=track1->GetAlpha(); | |
644 | Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
ec1be5d5 | 645 | Double_t pos[3],dir[3]; |
646 | track1->GetXYZAt(mindist,field,pos); | |
647 | track1->GetPxPyPzAt(mindist,field,dir); | |
648 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
649 | // AliStrLine *line1 = new AliStrLine(); | |
650 | // track1->ApproximateHelixWithLine(mindist,field,line1); | |
2d57349e | 651 | |
652 | Double_t p0[3],cd[3]; | |
653 | line1->GetP0(p0); | |
654 | line1->GetCd(cd); | |
655 | Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]}; | |
656 | vectP0[i][0]=p0[0]; | |
657 | vectP0[i][1]=p0[1]; | |
658 | vectP0[i][2]=p0[2]; | |
659 | vectP1[i][0]=p1[0]; | |
660 | vectP1[i][1]=p1[1]; | |
661 | vectP1[i][2]=p1[2]; | |
662 | ||
663 | Double_t matr[3][3]; | |
664 | Double_t dknow[3]; | |
665 | if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow); | |
666 | if(optUseWeights==1){ | |
667 | Double_t sigmasq[3]; | |
668 | sigmasq[0]=track1->GetSigmaY2(); | |
669 | sigmasq[1]=track1->GetSigmaY2(); | |
670 | sigmasq[2]=track1->GetSigmaZ2(); | |
671 | GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow); | |
672 | } | |
673 | ||
674 | for(Int_t iii=0;iii<3;iii++){ | |
675 | dsum[iii]+=dknow[iii]; | |
676 | for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj]; | |
677 | } | |
678 | delete line1; | |
679 | } | |
680 | ||
681 | Double_t vett[3][3]; | |
682 | Double_t det=GetDeterminant3X3(sum); | |
683 | ||
684 | if(det!=0){ | |
685 | for(Int_t zz=0;zz<3;zz++){ | |
686 | for(Int_t ww=0;ww<3;ww++){ | |
687 | for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk]; | |
688 | } | |
689 | for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk]; | |
690 | initPos[zz]=GetDeterminant3X3(vett)/det; | |
691 | } | |
692 | ||
693 | ||
694 | for(Int_t i=0; i<knacc; i++){ | |
695 | Double_t p0[3]={0,0,0},p1[3]={0,0,0}; | |
696 | for(Int_t ii=0;ii<3;ii++){ | |
697 | p0[ii]=vectP0[i][ii]; | |
698 | p1[ii]=vectP1[i][ii]; | |
699 | } | |
700 | sigma+=GetStrLinMinDist(p0,p1,initPos); | |
701 | } | |
702 | ||
703 | sigma=TMath::Sqrt(sigma); | |
704 | }else{ | |
705 | Warning("StrLinVertexFinderMinDist","Finder did not succed"); | |
706 | sigma=999; | |
707 | } | |
708 | delete vectP0; | |
709 | delete vectP1; | |
710 | fVert.SetXYZ(initPos); | |
711 | fVert.SetDispersion(sigma); | |
712 | fVert.SetNContributors(knacc); | |
713 | } | |
714 | //_______________________________________________________________________ | |
715 | Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3]){ | |
716 | // | |
717 | Double_t det=matr[0][0]*matr[1][1]*matr[2][2]-matr[0][0]*matr[1][2]*matr[2][1]-matr[0][1]*matr[1][0]*matr[2][2]+matr[0][1]*matr[1][2]*matr[2][0]+matr[0][2]*matr[1][0]*matr[2][1]-matr[0][2]*matr[1][1]*matr[2][0]; | |
718 | return det; | |
719 | } | |
720 | //____________________________________________________________________________ | |
71d84967 | 721 | void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d){ |
2d57349e | 722 | |
723 | // | |
724 | Double_t x12=p0[0]-p1[0]; | |
725 | Double_t y12=p0[1]-p1[1]; | |
726 | Double_t z12=p0[2]-p1[2]; | |
727 | Double_t kk=x12*x12+y12*y12+z12*z12; | |
728 | m[0][0]=2-2/kk*x12*x12; | |
729 | m[0][1]=-2/kk*x12*y12; | |
730 | m[0][2]=-2/kk*x12*z12; | |
731 | m[1][0]=-2/kk*x12*y12; | |
732 | m[1][1]=2-2/kk*y12*y12; | |
733 | m[1][2]=-2/kk*y12*z12; | |
734 | m[2][0]=-2/kk*x12*z12; | |
735 | m[2][1]=-2*y12*z12; | |
736 | m[2][2]=2-2/kk*z12*z12; | |
737 | d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12; | |
738 | d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12; | |
739 | d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12; | |
740 | ||
741 | } | |
742 | //____________________________________________________________________________ | |
71d84967 | 743 | void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d){ |
2d57349e | 744 | // |
745 | Double_t x12=p1[0]-p0[0]; | |
746 | Double_t y12=p1[1]-p0[1]; | |
747 | Double_t z12=p1[2]-p0[2]; | |
748 | ||
749 | Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1]; | |
750 | ||
751 | Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]); | |
752 | ||
753 | Double_t cc[3]; | |
754 | cc[0]=-x12/sigmasq[0]; | |
755 | cc[1]=-y12/sigmasq[1]; | |
756 | cc[2]=-z12/sigmasq[2]; | |
757 | ||
758 | Double_t ww=(-p0[0]*x12*sigmasq[1]*sigmasq[2]-p0[1]*y12*sigmasq[0]*sigmasq[2]-p0[2]*z12*sigmasq[0]*sigmasq[1])/den; | |
759 | ||
760 | Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2]; | |
761 | ||
762 | Double_t aa[3]; | |
763 | aa[0]=x12*sigmasq[1]*sigmasq[2]/den; | |
764 | aa[1]=y12*sigmasq[0]*sigmasq[2]/den; | |
765 | aa[2]=z12*sigmasq[0]*sigmasq[1]/den; | |
766 | ||
767 | m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0]; | |
768 | m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0]; | |
769 | m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0]; | |
770 | ||
771 | m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1]; | |
772 | m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1]; | |
773 | m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1]; | |
774 | ||
775 | m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2]; | |
776 | m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2]; | |
777 | m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2]; | |
778 | ||
779 | d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0]; | |
780 | d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1]; | |
781 | d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2]; | |
782 | ||
71d84967 | 783 | } |
2d57349e | 784 | //_____________________________________________________________________________ |
785 | Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0){ | |
786 | // | |
787 | Double_t x12=p0[0]-p1[0]; | |
788 | Double_t y12=p0[1]-p1[1]; | |
789 | Double_t z12=p0[2]-p1[2]; | |
790 | Double_t x10=p0[0]-x0[0]; | |
791 | Double_t y10=p0[1]-x0[1]; | |
792 | Double_t z10=p0[2]-x0[2]; | |
793 | return ((x10*x10+y10*y10+z10*z10)*(x12*x12+y12*y12+z12*z12)-(x10*x12+y10*y12+z10*z12)*(x10*x12+y10*y12+z10*z12))/(x12*x12+y12*y12+z12*z12); | |
794 | } | |
ec1be5d5 | 795 | //--------------------------------------------------------------------------- |
07680cae | 796 | void AliVertexerTracks::VertexFitter(Bool_t useNominalVtx) { |
ec1be5d5 | 797 | // |
798 | // The optimal estimate of the vertex position is given by a "weighted | |
799 | // average of tracks positions" | |
800 | // Original method: CMS Note 97/0051 | |
801 | // | |
802 | Double_t initPos[3]; | |
803 | fVert.GetXYZ(initPos); | |
804 | if(fDebug) { | |
805 | printf(" VertexFitter(): start\n"); | |
806 | printf(" Number of tracks in array: %d\n",(Int_t)fTrkArray.GetEntriesFast()); | |
807 | printf(" Minimum # tracks required in fit: %d\n",fMinTracks); | |
808 | printf("Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]); | |
eae1677e | 809 | if(useNominalVtx) printf(" This vertex will be used in fit: (%f+-%f,%f+-%f)\n",fNominalPos[0],fNominalSigma[0],fNominalPos[1],fNominalSigma[1]); |
ec1be5d5 | 810 | } |
811 | ||
812 | Int_t i,j,k,step=0; | |
813 | TMatrixD rv(3,1); | |
814 | TMatrixD vV(3,3); | |
815 | rv(0,0) = initPos[0]; | |
816 | rv(1,0) = initPos[1]; | |
817 | rv(2,0) = 0.; | |
818 | Double_t xlStart,alpha; | |
819 | Double_t rotAngle; | |
820 | Double_t cosRot,sinRot; | |
821 | Double_t cc[15]; | |
822 | Int_t nUsedTrks; | |
823 | Double_t chi2,chi2i; | |
824 | Int_t arrEntries = (Int_t)fTrkArray.GetEntries(); | |
825 | AliESDtrack *t = 0; | |
826 | Int_t failed = 0; | |
827 | ||
eae1677e | 828 | // 2 steps: |
829 | // 1st - estimate of vtx using all tracks | |
830 | // 2nd - estimate of global chi2 | |
831 | for(step=0; step<2; step++) { | |
ec1be5d5 | 832 | if(fDebug) printf(" step = %d\n",step); |
833 | chi2 = 0.; | |
834 | nUsedTrks = 0; | |
835 | ||
836 | TMatrixD sumWiri(3,1); | |
837 | TMatrixD sumWi(3,3); | |
838 | for(i=0; i<3; i++) { | |
839 | sumWiri(i,0) = 0.; | |
840 | for(j=0; j<3; j++) sumWi(j,i) = 0.; | |
841 | } | |
842 | ||
07680cae | 843 | if(useNominalVtx) { |
844 | for(i=0; i<3; i++) { | |
845 | sumWiri(i,0) += fNominalPos[i]/fNominalSigma[i]/fNominalSigma[i]; | |
846 | sumWi(i,i) += 1./fNominalSigma[i]/fNominalSigma[i]; | |
847 | } | |
848 | } | |
849 | ||
850 | ||
ec1be5d5 | 851 | // loop on tracks |
852 | for(k=0; k<arrEntries; k++) { | |
ec1be5d5 | 853 | // get track from track array |
854 | t = (AliESDtrack*)fTrkArray.At(k); | |
855 | alpha = t->GetAlpha(); | |
856 | xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha); | |
6c94f330 | 857 | t->AliExternalTrackParam::PropagateTo(xlStart,AliTracker::GetBz()); // to vtxSeed |
ec1be5d5 | 858 | rotAngle = alpha; |
859 | if(alpha<0.) rotAngle += 2.*TMath::Pi(); | |
860 | cosRot = TMath::Cos(rotAngle); | |
861 | sinRot = TMath::Sin(rotAngle); | |
862 | ||
863 | // vector of track global coordinates | |
864 | TMatrixD ri(3,1); | |
865 | ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot; | |
866 | ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot; | |
867 | ri(2,0) = t->GetZ(); | |
868 | ||
869 | // matrix to go from global (x,y,z) to local (y,z); | |
870 | TMatrixD qQi(2,3); | |
871 | qQi(0,0) = -sinRot; | |
872 | qQi(0,1) = cosRot; | |
873 | qQi(0,2) = 0.; | |
874 | qQi(1,0) = 0.; | |
875 | qQi(1,1) = 0.; | |
876 | qQi(1,2) = 1.; | |
877 | ||
878 | // covariance matrix of local (y,z) - inverted | |
879 | TMatrixD uUi(2,2); | |
880 | t->GetExternalCovariance(cc); | |
881 | uUi(0,0) = cc[0]; | |
882 | uUi(0,1) = cc[1]; | |
883 | uUi(1,0) = cc[1]; | |
884 | uUi(1,1) = cc[2]; | |
885 | ||
886 | // weights matrix: wWi = qQiT * uUiInv * qQi | |
887 | if(uUi.Determinant() <= 0.) continue; | |
888 | TMatrixD uUiInv(TMatrixD::kInverted,uUi); | |
889 | TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi); | |
890 | TMatrixD wWi(qQi,TMatrixD::kTransposeMult,uUiInvQi); | |
891 | ||
892 | // track chi2 | |
893 | TMatrixD deltar = rv; deltar -= ri; | |
894 | TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar); | |
895 | chi2i = deltar(0,0)*wWideltar(0,0)+ | |
896 | deltar(1,0)*wWideltar(1,0)+ | |
897 | deltar(2,0)*wWideltar(2,0); | |
898 | ||
899 | ||
ec1be5d5 | 900 | // add to total chi2 |
901 | chi2 += chi2i; | |
902 | ||
903 | TMatrixD wWiri(wWi,TMatrixD::kMult,ri); | |
904 | ||
905 | sumWiri += wWiri; | |
906 | sumWi += wWi; | |
907 | ||
908 | nUsedTrks++; | |
909 | } // end loop on tracks | |
910 | ||
911 | if(nUsedTrks < fMinTracks) { | |
912 | failed=1; | |
913 | continue; | |
914 | } | |
915 | ||
916 | Double_t determinant = sumWi.Determinant(); | |
917 | //cerr<<" determinant: "<<determinant<<endl; | |
918 | if(determinant < 100.) { | |
919 | printf("det(V) = 0\n"); | |
920 | failed=1; | |
921 | continue; | |
922 | } | |
923 | ||
924 | // inverted of weights matrix | |
925 | TMatrixD invsumWi(TMatrixD::kInverted,sumWi); | |
926 | vV = invsumWi; | |
927 | ||
928 | // position of primary vertex | |
929 | rv.Mult(vV,sumWiri); | |
930 | ||
eae1677e | 931 | } // end loop on the 2 steps |
ec1be5d5 | 932 | |
ec1be5d5 | 933 | delete t; |
934 | ||
935 | if(failed) { | |
936 | printf("TooFewTracks\n"); | |
937 | fCurrentVertex = new AliESDVertex(0.,0.,-1); | |
938 | return; | |
939 | } | |
940 | ||
941 | Double_t position[3]; | |
942 | position[0] = rv(0,0); | |
943 | position[1] = rv(1,0); | |
944 | position[2] = rv(2,0); | |
945 | Double_t covmatrix[6]; | |
946 | covmatrix[0] = vV(0,0); | |
947 | covmatrix[1] = vV(0,1); | |
948 | covmatrix[2] = vV(1,1); | |
949 | covmatrix[3] = vV(0,2); | |
950 | covmatrix[4] = vV(1,2); | |
951 | covmatrix[5] = vV(2,2); | |
952 | ||
953 | // store data in the vertex object | |
954 | fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nUsedTrks); | |
955 | ||
956 | if(fDebug) { | |
957 | printf(" VertexFitter(): finish\n"); | |
958 | printf(" rv = ( %f , %f , %f )\n\n",rv(0,0),rv(1,0),rv(2,0)); | |
959 | fCurrentVertex->PrintStatus(); | |
960 | } | |
961 | ||
962 | return; | |
963 | } | |
eae1677e | 964 | //--------------------------------------------------------------------------- |
965 | void AliVertexerTracks::TooFewTracks(const AliESD* esdEvent) { | |
966 | // | |
967 | // When the number of tracks is < fMinTracks | |
968 | // | |
969 | ||
970 | // deal with vertices not found | |
971 | Double_t pos[3],err[3]; | |
972 | Int_t ncontr=0; | |
973 | pos[0] = fNominalPos[0]; | |
974 | err[0] = fNominalSigma[0]; | |
975 | pos[1] = fNominalPos[1]; | |
976 | err[1] = fNominalSigma[1]; | |
977 | pos[2] = esdEvent->GetVertex()->GetZv(); | |
978 | err[2] = esdEvent->GetVertex()->GetZRes(); | |
979 | if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()<=0) | |
980 | ncontr = -1; // (x,y,z) = (0,0,0) | |
981 | if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()>0) | |
982 | ncontr = -2; // (x,y,z) = (0,0,z_fromSPD) | |
983 | if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()<=0) | |
984 | ncontr = -3; // (x,y,z) = (x_mean,y_mean,0) | |
985 | if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()>0) | |
986 | ncontr = -4; // (x,y,z) = (x_mean,y_mean,z_fromSPD) | |
987 | fCurrentVertex = 0; | |
988 | fCurrentVertex = new AliESDVertex(pos,err); | |
989 | fCurrentVertex->SetNContributors(ncontr); | |
990 | ||
991 | Double_t tp[3]; | |
992 | esdEvent->GetVertex()->GetTruePos(tp); | |
993 | fCurrentVertex->SetTruePos(tp); | |
994 | fCurrentVertex->SetTitle("VertexerTracksWithConstraint"); | |
995 | if(ncontr==-1||ncontr==-2) | |
996 | fCurrentVertex->SetTitle("VertexerTracksNoConstraint"); | |
997 | ||
998 | return; | |
999 | } |