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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), | |
0c69be49 | 45 | fMinTracks(1), |
fe12e09c | 46 | fMinITSClusters(5), |
07680cae | 47 | fTrkArray(), |
48 | fTrksToSkip(0), | |
49 | fNTrksToSkip(0), | |
50 | fDCAcut(0), | |
51 | fAlgo(1), | |
fe12e09c | 52 | fNSigma(3), |
50ff0bcd | 53 | fITSin(kTRUE), |
54 | fITSrefit(kTRUE), | |
07680cae | 55 | fDebug(0) |
2d57349e | 56 | { |
57 | // | |
58 | // Default constructor | |
59 | // | |
60 | SetVtxStart(); | |
07680cae | 61 | SetVtxStartSigma(); |
2d57349e | 62 | SetMinTracks(); |
07680cae | 63 | SetMinITSClusters(); |
64 | SetNSigmad0(); | |
2d57349e | 65 | } |
66 | //----------------------------------------------------------------------------- | |
67 | AliVertexerTracks::AliVertexerTracks(Double_t xStart, Double_t yStart): | |
07680cae | 68 | TObject(), |
69 | fVert(), | |
70 | fCurrentVertex(0), | |
0c69be49 | 71 | fMinTracks(1), |
fe12e09c | 72 | fMinITSClusters(5), |
07680cae | 73 | fTrkArray(), |
74 | fTrksToSkip(0), | |
75 | fNTrksToSkip(0), | |
76 | fDCAcut(0), | |
77 | fAlgo(1), | |
fe12e09c | 78 | fNSigma(3), |
50ff0bcd | 79 | fITSin(kTRUE), |
80 | fITSrefit(kTRUE), | |
07680cae | 81 | fDebug(0) |
2d57349e | 82 | { |
83 | // | |
84 | // Standard constructor | |
85 | // | |
86 | SetVtxStart(xStart,yStart); | |
07680cae | 87 | SetVtxStartSigma(); |
2d57349e | 88 | SetMinTracks(); |
07680cae | 89 | SetMinITSClusters(); |
90 | SetNSigmad0(); | |
2d57349e | 91 | } |
92 | //----------------------------------------------------------------------------- | |
93 | AliVertexerTracks::~AliVertexerTracks() { | |
94 | // Default Destructor | |
eae1677e | 95 | // The objects pointed by the following pointer are not owned |
2d57349e | 96 | // by this class and are not deleted |
ec1be5d5 | 97 | fCurrentVertex = 0; |
07680cae | 98 | delete[] fTrksToSkip; |
ec1be5d5 | 99 | } |
c5e3e5d1 | 100 | //---------------------------------------------------------------------------- |
ec1be5d5 | 101 | AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const AliESD *esdEvent) |
102 | { | |
c5e3e5d1 | 103 | // |
ec1be5d5 | 104 | // Primary vertex for current ESD event |
eae1677e | 105 | // (Two iterations: |
106 | // 1st with 5*fNSigma*sigma(pt) cut w.r.t. to initial vertex; | |
107 | // 2nd with fNSigma*sigma(pt) cut w.r.t. to vertex found in 1st iteration) | |
318aecb9 | 108 | // All ESD tracks with inside the beam pipe are then propagated to found vertex |
07680cae | 109 | // |
110 | fCurrentVertex = 0; | |
111 | ||
50ff0bcd | 112 | Int_t nTrksTot = (Int_t)esdEvent->GetNumberOfTracks(); |
07680cae | 113 | TTree *trkTree = new TTree("TreeT","tracks"); |
114 | AliESDtrack *esdTrack = 0; | |
115 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
116 | ||
eae1677e | 117 | Bool_t skipThis; |
50ff0bcd | 118 | for(Int_t i=0; i<nTrksTot; i++) { |
eae1677e | 119 | // check tracks to skip |
120 | skipThis = kFALSE; | |
121 | for(Int_t j=0; j<fNTrksToSkip; j++) { | |
122 | if(i==fTrksToSkip[j]) { | |
123 | if(fDebug) printf("skipping track: %d\n",i); | |
124 | skipThis = kTRUE; | |
125 | } | |
126 | } | |
07680cae | 127 | AliESDtrack *et = esdEvent->GetTrack(i); |
128 | esdTrack = new AliESDtrack(*et); | |
50ff0bcd | 129 | if(skipThis) {delete esdTrack;continue;} |
130 | if(fITSin) { | |
131 | if(!(esdTrack->GetStatus()&AliESDtrack::kITSin)) {delete esdTrack;continue;} | |
132 | if(fITSrefit && !(esdTrack->GetStatus()&AliESDtrack::kITSrefit)) {delete esdTrack;continue;} | |
133 | Int_t nclus=esdTrack->GetNcls(0); // check number of clusters in ITS | |
134 | if(nclus<fMinITSClusters) {delete esdTrack;continue;} | |
135 | } | |
07680cae | 136 | trkTree->Fill(); |
5834e9a1 | 137 | delete esdTrack; |
07680cae | 138 | } |
318aecb9 | 139 | |
07680cae | 140 | |
141 | // ITERATION 1 | |
142 | // propagate tracks to initVertex | |
eae1677e | 143 | // preselect them (reject for |d0|>5*fNSigma*sigma w.r.t. initVertex) |
50ff0bcd | 144 | Int_t nTrksPrep; |
145 | nTrksPrep = PrepareTracks(*trkTree,1); | |
146 | if(fDebug) printf(" tracks prepared - step 1: %d\n",nTrksPrep); | |
147 | if(nTrksPrep < fMinTracks) { | |
148 | if(fDebug) printf("TooFewTracks\n"); | |
eae1677e | 149 | TooFewTracks(esdEvent); |
150 | if(fDebug) fCurrentVertex->PrintStatus(); | |
5834e9a1 | 151 | fTrkArray.Delete(); |
152 | delete trkTree; | |
07680cae | 153 | return fCurrentVertex; |
154 | } | |
155 | ||
0c69be49 | 156 | if(nTrksPrep==1){ |
157 | if(fDebug) printf("Just one track\n"); | |
158 | OneTrackVertFinder(); | |
159 | }else{ | |
07680cae | 160 | // vertex finder |
0c69be49 | 161 | switch (fAlgo) { |
07680cae | 162 | case 1: StrLinVertexFinderMinDist(1); break; |
163 | case 2: StrLinVertexFinderMinDist(0); break; | |
164 | case 3: HelixVertexFinder(); break; | |
165 | case 4: VertexFinder(1); break; | |
166 | case 5: VertexFinder(0); break; | |
167 | default: printf("Wrong algorithm\n"); break; | |
0c69be49 | 168 | } |
07680cae | 169 | } |
170 | if(fDebug) printf(" vertex finding completed\n"); | |
171 | ||
172 | // vertex fitter | |
eae1677e | 173 | VertexFitter(kTRUE); |
07680cae | 174 | if(fDebug) printf(" vertex fit completed\n"); |
5834e9a1 | 175 | fTrkArray.Delete(); |
07680cae | 176 | // ITERATION 2 |
177 | // propagate tracks to best between initVertex and fCurrentVertex | |
178 | // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best | |
179 | // between initVertex and fCurrentVertex) | |
50ff0bcd | 180 | nTrksPrep = PrepareTracks(*trkTree,2); |
07680cae | 181 | delete trkTree; |
50ff0bcd | 182 | if(fDebug) printf(" tracks prepared - step 2: %d\n",nTrksPrep); |
183 | if(nTrksPrep < fMinTracks) { | |
184 | if(fDebug) printf("TooFewTracks\n"); | |
eae1677e | 185 | TooFewTracks(esdEvent); |
186 | if(fDebug) fCurrentVertex->PrintStatus(); | |
5834e9a1 | 187 | fTrkArray.Delete(); |
07680cae | 188 | return fCurrentVertex; |
189 | } | |
190 | ||
191 | // vertex finder | |
0c69be49 | 192 | if(nTrksPrep==1){ |
193 | if(fDebug) printf("Just one track\n"); | |
194 | OneTrackVertFinder(); | |
195 | }else{ | |
196 | switch (fAlgo) { | |
07680cae | 197 | case 1: StrLinVertexFinderMinDist(1); break; |
198 | case 2: StrLinVertexFinderMinDist(0); break; | |
199 | case 3: HelixVertexFinder(); break; | |
200 | case 4: VertexFinder(1); break; | |
201 | case 5: VertexFinder(0); break; | |
202 | default: printf("Wrong algorithm\n"); break; | |
0c69be49 | 203 | } |
07680cae | 204 | } |
205 | if(fDebug) printf(" vertex finding completed\n"); | |
206 | ||
207 | // fitter | |
eae1677e | 208 | VertexFitter(kTRUE); |
07680cae | 209 | if(fDebug) printf(" vertex fit completed\n"); |
210 | ||
eae1677e | 211 | |
eae1677e | 212 | // take true pos from ESD |
07680cae | 213 | Double_t tp[3]; |
214 | esdEvent->GetVertex()->GetTruePos(tp); | |
215 | fCurrentVertex->SetTruePos(tp); | |
50ff0bcd | 216 | if(fNominalCov[0]>1.) { |
eae1677e | 217 | fCurrentVertex->SetTitle("VertexerTracksNoConstraint"); |
218 | } else { | |
219 | fCurrentVertex->SetTitle("VertexerTracksWithConstraint"); | |
220 | } | |
221 | ||
318aecb9 | 222 | |
223 | // propagate tracks to found vertex | |
224 | if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) { | |
50ff0bcd | 225 | for(Int_t ii=0; ii<nTrksTot; ii++) { |
318aecb9 | 226 | AliESDtrack *et = esdEvent->GetTrack(ii); |
50ff0bcd | 227 | if(!(et->GetStatus()&AliESDtrack::kITSin)) continue; |
318aecb9 | 228 | if(et->GetX()>3.) continue; |
229 | et->RelateToVertex(fCurrentVertex,GetField(),100.); | |
230 | } | |
231 | } else { | |
232 | AliWarning("Found vertex outside beam pipe!"); | |
233 | } | |
50ff0bcd | 234 | |
235 | // set indices of used tracks | |
236 | UShort_t *indices = 0; | |
237 | AliESDtrack *ett = 0; | |
238 | if(fCurrentVertex->GetNContributors()>0) { | |
239 | indices = new UShort_t[fCurrentVertex->GetNContributors()]; | |
240 | for(Int_t jj=0;jj<(Int_t)fTrkArray.GetEntriesFast();jj++) { | |
241 | ett = (AliESDtrack*)fTrkArray.At(jj); | |
242 | indices[jj] = (UShort_t)ett->GetID(); | |
243 | } | |
244 | fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices); | |
245 | } | |
246 | delete [] indices; | |
247 | fTrkArray.Delete(); | |
248 | ||
249 | if(fTrksToSkip) delete [] fTrksToSkip; | |
250 | ||
251 | ||
252 | if(fDebug) fCurrentVertex->PrintStatus(); | |
253 | if(fDebug) fCurrentVertex->PrintIndices(); | |
318aecb9 | 254 | |
07680cae | 255 | return fCurrentVertex; |
256 | } | |
50ff0bcd | 257 | //------------------------------------------------------------------------ |
258 | Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3]){ | |
259 | // | |
260 | 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]; | |
261 | return det; | |
262 | } | |
263 | //------------------------------------------------------------------------- | |
264 | void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d){ | |
ec1be5d5 | 265 | |
50ff0bcd | 266 | // |
267 | Double_t x12=p0[0]-p1[0]; | |
268 | Double_t y12=p0[1]-p1[1]; | |
269 | Double_t z12=p0[2]-p1[2]; | |
270 | Double_t kk=x12*x12+y12*y12+z12*z12; | |
271 | m[0][0]=2-2/kk*x12*x12; | |
272 | m[0][1]=-2/kk*x12*y12; | |
273 | m[0][2]=-2/kk*x12*z12; | |
274 | m[1][0]=-2/kk*x12*y12; | |
275 | m[1][1]=2-2/kk*y12*y12; | |
276 | m[1][2]=-2/kk*y12*z12; | |
277 | m[2][0]=-2/kk*x12*z12; | |
278 | m[2][1]=-2*y12*z12; | |
279 | m[2][2]=2-2/kk*z12*z12; | |
280 | d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12; | |
281 | d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12; | |
282 | d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12; | |
c5e3e5d1 | 283 | |
50ff0bcd | 284 | } |
285 | //-------------------------------------------------------------------------- | |
286 | void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d){ | |
287 | // | |
288 | Double_t x12=p1[0]-p0[0]; | |
289 | Double_t y12=p1[1]-p0[1]; | |
290 | Double_t z12=p1[2]-p0[2]; | |
c5e3e5d1 | 291 | |
50ff0bcd | 292 | Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1]; |
c5e3e5d1 | 293 | |
50ff0bcd | 294 | Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]); |
c5e3e5d1 | 295 | |
50ff0bcd | 296 | Double_t cc[3]; |
297 | cc[0]=-x12/sigmasq[0]; | |
298 | cc[1]=-y12/sigmasq[1]; | |
299 | cc[2]=-z12/sigmasq[2]; | |
ec1be5d5 | 300 | |
50ff0bcd | 301 | 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; |
ec1be5d5 | 302 | |
50ff0bcd | 303 | Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2]; |
2d57349e | 304 | |
50ff0bcd | 305 | Double_t aa[3]; |
306 | aa[0]=x12*sigmasq[1]*sigmasq[2]/den; | |
307 | aa[1]=y12*sigmasq[0]*sigmasq[2]/den; | |
308 | aa[2]=z12*sigmasq[0]*sigmasq[1]/den; | |
2d57349e | 309 | |
50ff0bcd | 310 | m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0]; |
311 | m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0]; | |
312 | m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0]; | |
2d57349e | 313 | |
50ff0bcd | 314 | m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1]; |
315 | m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1]; | |
316 | m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1]; | |
2d57349e | 317 | |
50ff0bcd | 318 | m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2]; |
319 | m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2]; | |
320 | m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2]; | |
08df6187 | 321 | |
50ff0bcd | 322 | d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0]; |
323 | d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1]; | |
324 | d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2]; | |
2d57349e | 325 | |
2d57349e | 326 | } |
50ff0bcd | 327 | //-------------------------------------------------------------------------- |
328 | Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0){ | |
329 | // | |
330 | Double_t x12=p0[0]-p1[0]; | |
331 | Double_t y12=p0[1]-p1[1]; | |
332 | Double_t z12=p0[2]-p1[2]; | |
333 | Double_t x10=p0[0]-x0[0]; | |
334 | Double_t y10=p0[1]-x0[1]; | |
335 | Double_t z10=p0[2]-x0[2]; | |
336 | 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); | |
2d57349e | 337 | } |
338 | //--------------------------------------------------------------------------- | |
0c69be49 | 339 | void AliVertexerTracks::OneTrackVertFinder() { |
340 | // find vertex for events with 1 track, using DCA to nominal beam axis | |
341 | if(fDebug) printf("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArray.GetEntries()); | |
342 | AliESDtrack *track1; | |
343 | track1 = (AliESDtrack*)fTrkArray.At(0); | |
344 | Double_t field=GetField(); | |
345 | Double_t alpha=track1->GetAlpha(); | |
346 | Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
347 | Double_t pos[3],dir[3]; | |
348 | track1->GetXYZAt(mindist,field,pos); | |
349 | track1->GetPxPyPzAt(mindist,field,dir); | |
350 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
351 | Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.}; | |
352 | Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.}; | |
353 | AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE); | |
354 | Double_t crosspoint[3]={0.,0.,0.}; | |
355 | Double_t sigma=999.; | |
356 | Int_t nContrib=-1; | |
357 | Int_t retcode = zeta->Cross(line1,crosspoint); | |
358 | if(retcode>=0){ | |
359 | sigma=line1->GetDistFromPoint(crosspoint); | |
360 | nContrib=1; | |
361 | } | |
362 | delete zeta; | |
363 | delete line1; | |
364 | fVert.SetXYZ(crosspoint); | |
365 | fVert.SetDispersion(sigma); | |
366 | fVert.SetNContributors(nContrib); | |
367 | } | |
368 | //--------------------------------------------------------------------------- | |
2d57349e | 369 | void AliVertexerTracks::HelixVertexFinder() { |
370 | ||
371 | // Get estimate of vertex position in (x,y) from tracks DCA | |
372 | ||
373 | ||
374 | Double_t initPos[3]; | |
375 | initPos[2] = 0.; | |
376 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
377 | Double_t field=GetField(); | |
378 | ||
379 | Int_t nacc = (Int_t)fTrkArray.GetEntriesFast(); | |
380 | ||
381 | Double_t aver[3]={0.,0.,0.}; | |
382 | Double_t averquad[3]={0.,0.,0.}; | |
383 | Double_t sigmaquad[3]={0.,0.,0.}; | |
384 | Double_t sigma=0; | |
385 | Int_t ncombi = 0; | |
386 | AliESDtrack *track1; | |
387 | AliESDtrack *track2; | |
388 | Double_t distCA; | |
389 | Double_t x, par[5]; | |
390 | Double_t alpha, cs, sn; | |
391 | Double_t crosspoint[3]; | |
392 | for(Int_t i=0; i<nacc; i++){ | |
393 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
394 | ||
395 | ||
396 | for(Int_t j=i+1; j<nacc; j++){ | |
397 | track2 = (AliESDtrack*)fTrkArray.At(j); | |
398 | ||
399 | distCA=track2->PropagateToDCA(track1,field); | |
400 | ||
401 | if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){ | |
402 | track1->GetExternalParameters(x,par); | |
403 | alpha=track1->GetAlpha(); | |
404 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
405 | Double_t x1=x*cs - par[0]*sn; | |
406 | Double_t y1=x*sn + par[0]*cs; | |
407 | Double_t z1=par[1]; | |
408 | Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2(); | |
409 | track2->GetExternalParameters(x,par); | |
410 | alpha=track2->GetAlpha(); | |
411 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
412 | Double_t x2=x*cs - par[0]*sn; | |
413 | Double_t y2=x*sn + par[0]*cs; | |
414 | Double_t z2=par[1]; | |
415 | Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2(); | |
416 | Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2(); | |
417 | Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1; | |
418 | Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1; | |
419 | Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1; | |
420 | crosspoint[0]=wx1*x1 + wx2*x2; | |
421 | crosspoint[1]=wy1*y1 + wy2*y2; | |
422 | crosspoint[2]=wz1*z1 + wz2*z2; | |
423 | ||
424 | ncombi++; | |
425 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
426 | for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
427 | } | |
428 | } | |
429 | ||
430 | } | |
431 | if(ncombi>0){ | |
432 | for(Int_t jj=0;jj<3;jj++){ | |
433 | initPos[jj] = aver[jj]/ncombi; | |
434 | averquad[jj]/=ncombi; | |
435 | sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj]; | |
436 | sigma+=sigmaquad[jj]; | |
437 | } | |
438 | sigma=TMath::Sqrt(TMath::Abs(sigma)); | |
439 | } | |
440 | else { | |
441 | Warning("HelixVertexFinder","Finder did not succed"); | |
442 | sigma=999; | |
443 | } | |
444 | fVert.SetXYZ(initPos); | |
445 | fVert.SetDispersion(sigma); | |
446 | fVert.SetNContributors(ncombi); | |
447 | } | |
50ff0bcd | 448 | //---------------------------------------------------------------------------- |
449 | Int_t AliVertexerTracks::PrepareTracks(TTree &trkTree,Int_t OptImpParCut) { | |
450 | // | |
451 | // Propagate tracks to initial vertex position and store them in a TObjArray | |
452 | // | |
453 | Double_t maxd0rphi = 3.; | |
454 | Int_t nTrks = 0; | |
455 | Double_t sigmaCurr[3]; | |
456 | Float_t d0z0[2],covd0z0[3]; | |
457 | Double_t sigma; | |
458 | Double_t field=GetField(); | |
459 | ||
460 | AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1); | |
461 | ||
462 | Int_t nEntries = (Int_t)trkTree.GetEntries(); | |
463 | if(!fTrkArray.IsEmpty()) fTrkArray.Delete(); | |
464 | ||
465 | if(fDebug) { | |
466 | printf(" PrepareTracks()\n"); | |
467 | } | |
468 | ||
469 | for(Int_t i=0; i<nEntries; i++) { | |
470 | AliESDtrack *track = new AliESDtrack; | |
471 | trkTree.SetBranchAddress("tracks",&track); | |
472 | trkTree.GetEvent(i); | |
473 | ||
474 | // propagate track to vertex | |
475 | if(OptImpParCut==1) { // OptImpParCut==1 | |
476 | track->RelateToVertex(initVertex,field,100.); | |
477 | } else { // OptImpParCut==2 | |
478 | fCurrentVertex->GetSigmaXYZ(sigmaCurr); | |
479 | if((sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) { | |
480 | track->RelateToVertex(fCurrentVertex,field,100.); | |
481 | } else { | |
482 | track->RelateToVertex(initVertex,field,100.); | |
483 | } | |
484 | } | |
485 | ||
486 | // select tracks with d0rphi < maxd0rphi | |
487 | track->GetImpactParameters(d0z0,covd0z0); | |
488 | sigma = TMath::Sqrt(covd0z0[0]); | |
489 | maxd0rphi = fNSigma*sigma; | |
490 | if(OptImpParCut==1) maxd0rphi *= 5.; | |
491 | ||
492 | if(fDebug) printf("trk %d; lab %d; |d0| = %f; cut = %f\n",i,track->GetLabel(),TMath::Abs(d0z0[0]),maxd0rphi); | |
493 | if(TMath::Abs(d0z0[0]) > maxd0rphi) { | |
494 | if(fDebug) printf(" rejected\n"); | |
495 | delete track; continue; | |
496 | } | |
497 | ||
498 | fTrkArray.AddLast(track); | |
499 | nTrks++; | |
500 | } | |
501 | ||
502 | delete initVertex; | |
503 | ||
504 | return nTrks; | |
505 | } | |
506 | //--------------------------------------------------------------------------- | |
507 | void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped) { | |
508 | // | |
509 | // Mark the tracks not ot be used in the vertex finding | |
510 | // | |
511 | fNTrksToSkip = n; | |
512 | fTrksToSkip = new Int_t[n]; | |
513 | for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i]; | |
514 | return; | |
515 | } | |
516 | //--------------------------------------------------------------------------- | |
517 | void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx) { | |
518 | // | |
519 | // Set initial vertex knowledge | |
520 | // | |
521 | vtx->GetXYZ(fNominalPos); | |
522 | vtx->GetCovMatrix(fNominalCov); | |
523 | return; | |
524 | } | |
2d57349e | 525 | //--------------------------------------------------------------------------- |
526 | void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights){ | |
527 | ||
528 | // Calculate the point at minimum distance to prepared tracks | |
529 | ||
530 | Double_t initPos[3]; | |
531 | initPos[2] = 0.; | |
532 | Double_t sigma=0; | |
533 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
534 | const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast(); | |
535 | Double_t field=GetField(); | |
536 | ||
537 | AliESDtrack *track1; | |
538 | Double_t (*vectP0)[3]=new Double_t [knacc][3]; | |
539 | Double_t (*vectP1)[3]=new Double_t [knacc][3]; | |
540 | ||
541 | Double_t sum[3][3]; | |
542 | Double_t dsum[3]={0,0,0}; | |
543 | for(Int_t i=0;i<3;i++) | |
544 | for(Int_t j=0;j<3;j++)sum[i][j]=0; | |
545 | for(Int_t i=0; i<knacc; i++){ | |
546 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
547 | Double_t alpha=track1->GetAlpha(); | |
548 | Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
ec1be5d5 | 549 | Double_t pos[3],dir[3]; |
550 | track1->GetXYZAt(mindist,field,pos); | |
551 | track1->GetPxPyPzAt(mindist,field,dir); | |
552 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
553 | // AliStrLine *line1 = new AliStrLine(); | |
554 | // track1->ApproximateHelixWithLine(mindist,field,line1); | |
2d57349e | 555 | |
556 | Double_t p0[3],cd[3]; | |
557 | line1->GetP0(p0); | |
558 | line1->GetCd(cd); | |
559 | Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]}; | |
560 | vectP0[i][0]=p0[0]; | |
561 | vectP0[i][1]=p0[1]; | |
562 | vectP0[i][2]=p0[2]; | |
563 | vectP1[i][0]=p1[0]; | |
564 | vectP1[i][1]=p1[1]; | |
565 | vectP1[i][2]=p1[2]; | |
566 | ||
567 | Double_t matr[3][3]; | |
568 | Double_t dknow[3]; | |
569 | if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow); | |
570 | if(optUseWeights==1){ | |
571 | Double_t sigmasq[3]; | |
572 | sigmasq[0]=track1->GetSigmaY2(); | |
573 | sigmasq[1]=track1->GetSigmaY2(); | |
574 | sigmasq[2]=track1->GetSigmaZ2(); | |
575 | GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow); | |
576 | } | |
577 | ||
578 | for(Int_t iii=0;iii<3;iii++){ | |
579 | dsum[iii]+=dknow[iii]; | |
580 | for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj]; | |
581 | } | |
582 | delete line1; | |
583 | } | |
584 | ||
585 | Double_t vett[3][3]; | |
586 | Double_t det=GetDeterminant3X3(sum); | |
587 | ||
588 | if(det!=0){ | |
589 | for(Int_t zz=0;zz<3;zz++){ | |
590 | for(Int_t ww=0;ww<3;ww++){ | |
591 | for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk]; | |
592 | } | |
593 | for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk]; | |
594 | initPos[zz]=GetDeterminant3X3(vett)/det; | |
595 | } | |
596 | ||
597 | ||
50ff0bcd | 598 | for(Int_t i=0; i<knacc; i++){ |
599 | Double_t p0[3]={0,0,0},p1[3]={0,0,0}; | |
600 | for(Int_t ii=0;ii<3;ii++){ | |
601 | p0[ii]=vectP0[i][ii]; | |
602 | p1[ii]=vectP1[i][ii]; | |
603 | } | |
604 | sigma+=GetStrLinMinDist(p0,p1,initPos); | |
605 | } | |
2d57349e | 606 | |
50ff0bcd | 607 | sigma=TMath::Sqrt(sigma); |
608 | }else{ | |
609 | Warning("StrLinVertexFinderMinDist","Finder did not succed"); | |
610 | sigma=999; | |
611 | } | |
612 | delete vectP0; | |
613 | delete vectP1; | |
614 | fVert.SetXYZ(initPos); | |
615 | fVert.SetDispersion(sigma); | |
616 | fVert.SetNContributors(knacc); | |
617 | } | |
618 | //--------------------------------------------------------------------------- | |
619 | void AliVertexerTracks::TooFewTracks(const AliESD* esdEvent) { | |
620 | // | |
621 | // When the number of tracks is < fMinTracks | |
622 | // | |
2d57349e | 623 | |
50ff0bcd | 624 | // deal with vertices not found |
625 | Double_t pos[3],err[3]; | |
626 | Int_t ncontr=0; | |
627 | pos[0] = fNominalPos[0]; | |
628 | err[0] = TMath::Sqrt(fNominalCov[0]); | |
629 | pos[1] = fNominalPos[1]; | |
630 | err[1] = TMath::Sqrt(fNominalCov[2]); | |
631 | pos[2] = esdEvent->GetVertex()->GetZv(); | |
632 | err[2] = esdEvent->GetVertex()->GetZRes(); | |
633 | if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()<=0) | |
634 | ncontr = -1; // (x,y,z) = (0,0,0) | |
635 | if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()>0) | |
636 | ncontr = -2; // (x,y,z) = (0,0,z_fromSPD) | |
637 | if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()<=0) | |
638 | ncontr = -3; // (x,y,z) = (x_mean,y_mean,0) | |
639 | if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()>0) | |
640 | ncontr = -4; // (x,y,z) = (x_mean,y_mean,z_fromSPD) | |
641 | fCurrentVertex = 0; | |
642 | fCurrentVertex = new AliESDVertex(pos,err); | |
643 | fCurrentVertex->SetNContributors(ncontr); | |
2d57349e | 644 | |
50ff0bcd | 645 | Double_t tp[3]; |
646 | esdEvent->GetVertex()->GetTruePos(tp); | |
647 | fCurrentVertex->SetTruePos(tp); | |
648 | fCurrentVertex->SetTitle("VertexerTracksWithConstraint"); | |
649 | if(ncontr==-1||ncontr==-2) | |
650 | fCurrentVertex->SetTitle("VertexerTracksNoConstraint"); | |
2d57349e | 651 | |
50ff0bcd | 652 | return; |
653 | } | |
654 | //--------------------------------------------------------------------------- | |
655 | void AliVertexerTracks::VertexFinder(Int_t optUseWeights) { | |
2d57349e | 656 | |
50ff0bcd | 657 | // Get estimate of vertex position in (x,y) from tracks DCA |
658 | ||
659 | Double_t initPos[3]; | |
660 | initPos[2] = 0.; | |
661 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
662 | Int_t nacc = (Int_t)fTrkArray.GetEntriesFast(); | |
663 | Double_t aver[3]={0.,0.,0.}; | |
664 | Double_t aversq[3]={0.,0.,0.}; | |
665 | Double_t sigmasq[3]={0.,0.,0.}; | |
666 | Double_t sigma=0; | |
667 | Int_t ncombi = 0; | |
668 | AliESDtrack *track1; | |
669 | AliESDtrack *track2; | |
670 | Double_t pos[3],dir[3]; | |
671 | Double_t alpha,mindist; | |
672 | Double_t field=GetField(); | |
2d57349e | 673 | |
50ff0bcd | 674 | for(Int_t i=0; i<nacc; i++){ |
675 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
676 | alpha=track1->GetAlpha(); | |
677 | mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
678 | track1->GetXYZAt(mindist,field,pos); | |
679 | track1->GetPxPyPzAt(mindist,field,dir); | |
680 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
2d57349e | 681 | |
50ff0bcd | 682 | // AliStrLine *line1 = new AliStrLine(); |
683 | // track1->ApproximateHelixWithLine(mindist,field,line1); | |
684 | ||
685 | for(Int_t j=i+1; j<nacc; j++){ | |
686 | track2 = (AliESDtrack*)fTrkArray.At(j); | |
687 | alpha=track2->GetAlpha(); | |
688 | mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
689 | track2->GetXYZAt(mindist,field,pos); | |
690 | track2->GetPxPyPzAt(mindist,field,dir); | |
691 | AliStrLine *line2 = new AliStrLine(pos,dir); | |
692 | // AliStrLine *line2 = new AliStrLine(); | |
693 | // track2->ApproximateHelixWithLine(mindist,field,line2); | |
694 | Double_t distCA=line2->GetDCA(line1); | |
695 | if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){ | |
696 | Double_t pnt1[3],pnt2[3],crosspoint[3]; | |
2d57349e | 697 | |
50ff0bcd | 698 | if(optUseWeights<=0){ |
699 | Int_t retcode = line2->Cross(line1,crosspoint); | |
700 | if(retcode>=0){ | |
701 | ncombi++; | |
702 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
703 | for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
704 | } | |
705 | } | |
706 | if(optUseWeights>0){ | |
707 | Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2); | |
708 | if(retcode>=0){ | |
5c03260f | 709 | Double_t cs, sn; |
50ff0bcd | 710 | alpha=track1->GetAlpha(); |
711 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
712 | Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2(); | |
713 | alpha=track2->GetAlpha(); | |
714 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
715 | Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2(); | |
716 | Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2(); | |
717 | Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1; | |
718 | Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1; | |
719 | Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1; | |
720 | crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0]; | |
721 | crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1]; | |
722 | crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2]; | |
723 | ||
724 | ncombi++; | |
725 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
726 | for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
727 | } | |
728 | } | |
729 | } | |
730 | delete line2; | |
731 | } | |
732 | delete line1; | |
71d84967 | 733 | } |
50ff0bcd | 734 | if(ncombi>0){ |
735 | for(Int_t jj=0;jj<3;jj++){ | |
736 | initPos[jj] = aver[jj]/ncombi; | |
737 | aversq[jj]/=ncombi; | |
738 | sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj]; | |
739 | sigma+=sigmasq[jj]; | |
740 | } | |
741 | sigma=TMath::Sqrt(TMath::Abs(sigma)); | |
742 | } | |
743 | else { | |
744 | Warning("VertexFinder","Finder did not succed"); | |
745 | sigma=999; | |
746 | } | |
747 | fVert.SetXYZ(initPos); | |
748 | fVert.SetDispersion(sigma); | |
749 | fVert.SetNContributors(ncombi); | |
2d57349e | 750 | } |
ec1be5d5 | 751 | //--------------------------------------------------------------------------- |
07680cae | 752 | void AliVertexerTracks::VertexFitter(Bool_t useNominalVtx) { |
ec1be5d5 | 753 | // |
754 | // The optimal estimate of the vertex position is given by a "weighted | |
755 | // average of tracks positions" | |
756 | // Original method: CMS Note 97/0051 | |
757 | // | |
758 | Double_t initPos[3]; | |
759 | fVert.GetXYZ(initPos); | |
760 | if(fDebug) { | |
761 | printf(" VertexFitter(): start\n"); | |
762 | printf(" Number of tracks in array: %d\n",(Int_t)fTrkArray.GetEntriesFast()); | |
763 | printf(" Minimum # tracks required in fit: %d\n",fMinTracks); | |
764 | printf("Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]); | |
50ff0bcd | 765 | if(useNominalVtx) printf(" This vertex will be used in fit: (%f+-%f,%f+-%f)\n",fNominalPos[0],TMath::Sqrt(fNominalCov[0]),fNominalPos[1],TMath::Sqrt(fNominalCov[2])); |
ec1be5d5 | 766 | } |
767 | ||
768 | Int_t i,j,k,step=0; | |
769 | TMatrixD rv(3,1); | |
770 | TMatrixD vV(3,3); | |
771 | rv(0,0) = initPos[0]; | |
772 | rv(1,0) = initPos[1]; | |
773 | rv(2,0) = 0.; | |
774 | Double_t xlStart,alpha; | |
775 | Double_t rotAngle; | |
776 | Double_t cosRot,sinRot; | |
777 | Double_t cc[15]; | |
778 | Int_t nUsedTrks; | |
779 | Double_t chi2,chi2i; | |
780 | Int_t arrEntries = (Int_t)fTrkArray.GetEntries(); | |
781 | AliESDtrack *t = 0; | |
782 | Int_t failed = 0; | |
783 | ||
50ff0bcd | 784 | // initial vertex covariance matrix |
785 | TMatrixD vVb(3,3); | |
786 | vVb(0,0) = fNominalCov[0]; | |
787 | vVb(0,1) = fNominalCov[1]; | |
788 | vVb(0,2) = 0.; | |
789 | vVb(1,0) = fNominalCov[1]; | |
790 | vVb(1,1) = fNominalCov[2]; | |
791 | vVb(1,2) = 0.; | |
792 | vVb(2,0) = 0.; | |
793 | vVb(2,1) = 0.; | |
794 | vVb(2,2) = fNominalCov[5]; | |
795 | TMatrixD vVbInv(TMatrixD::kInverted,vVb); | |
796 | TMatrixD rb(3,1); | |
797 | rb(0,0) = fNominalPos[0]; | |
798 | rb(1,0) = fNominalPos[1]; | |
799 | rb(2,0) = fNominalPos[2]; | |
800 | TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb); | |
801 | ||
802 | ||
eae1677e | 803 | // 2 steps: |
804 | // 1st - estimate of vtx using all tracks | |
805 | // 2nd - estimate of global chi2 | |
806 | for(step=0; step<2; step++) { | |
ec1be5d5 | 807 | if(fDebug) printf(" step = %d\n",step); |
808 | chi2 = 0.; | |
809 | nUsedTrks = 0; | |
810 | ||
811 | TMatrixD sumWiri(3,1); | |
812 | TMatrixD sumWi(3,3); | |
813 | for(i=0; i<3; i++) { | |
814 | sumWiri(i,0) = 0.; | |
815 | for(j=0; j<3; j++) sumWi(j,i) = 0.; | |
816 | } | |
817 | ||
50ff0bcd | 818 | |
07680cae | 819 | if(useNominalVtx) { |
50ff0bcd | 820 | for(i=0;i<3;i++) { |
821 | sumWiri(i,0) += vVbInvrb(i,0); | |
822 | for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k); | |
07680cae | 823 | } |
824 | } | |
825 | ||
826 | ||
ec1be5d5 | 827 | // loop on tracks |
828 | for(k=0; k<arrEntries; k++) { | |
ec1be5d5 | 829 | // get track from track array |
830 | t = (AliESDtrack*)fTrkArray.At(k); | |
831 | alpha = t->GetAlpha(); | |
832 | xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha); | |
6c94f330 | 833 | t->AliExternalTrackParam::PropagateTo(xlStart,AliTracker::GetBz()); // to vtxSeed |
ec1be5d5 | 834 | rotAngle = alpha; |
835 | if(alpha<0.) rotAngle += 2.*TMath::Pi(); | |
836 | cosRot = TMath::Cos(rotAngle); | |
837 | sinRot = TMath::Sin(rotAngle); | |
838 | ||
839 | // vector of track global coordinates | |
840 | TMatrixD ri(3,1); | |
841 | ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot; | |
842 | ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot; | |
843 | ri(2,0) = t->GetZ(); | |
844 | ||
845 | // matrix to go from global (x,y,z) to local (y,z); | |
846 | TMatrixD qQi(2,3); | |
847 | qQi(0,0) = -sinRot; | |
848 | qQi(0,1) = cosRot; | |
849 | qQi(0,2) = 0.; | |
850 | qQi(1,0) = 0.; | |
851 | qQi(1,1) = 0.; | |
852 | qQi(1,2) = 1.; | |
853 | ||
854 | // covariance matrix of local (y,z) - inverted | |
855 | TMatrixD uUi(2,2); | |
856 | t->GetExternalCovariance(cc); | |
857 | uUi(0,0) = cc[0]; | |
858 | uUi(0,1) = cc[1]; | |
859 | uUi(1,0) = cc[1]; | |
860 | uUi(1,1) = cc[2]; | |
861 | ||
862 | // weights matrix: wWi = qQiT * uUiInv * qQi | |
863 | if(uUi.Determinant() <= 0.) continue; | |
864 | TMatrixD uUiInv(TMatrixD::kInverted,uUi); | |
865 | TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi); | |
866 | TMatrixD wWi(qQi,TMatrixD::kTransposeMult,uUiInvQi); | |
867 | ||
868 | // track chi2 | |
869 | TMatrixD deltar = rv; deltar -= ri; | |
870 | TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar); | |
871 | chi2i = deltar(0,0)*wWideltar(0,0)+ | |
872 | deltar(1,0)*wWideltar(1,0)+ | |
873 | deltar(2,0)*wWideltar(2,0); | |
874 | ||
875 | ||
ec1be5d5 | 876 | // add to total chi2 |
877 | chi2 += chi2i; | |
878 | ||
879 | TMatrixD wWiri(wWi,TMatrixD::kMult,ri); | |
880 | ||
881 | sumWiri += wWiri; | |
882 | sumWi += wWi; | |
883 | ||
884 | nUsedTrks++; | |
885 | } // end loop on tracks | |
886 | ||
887 | if(nUsedTrks < fMinTracks) { | |
888 | failed=1; | |
889 | continue; | |
890 | } | |
891 | ||
892 | Double_t determinant = sumWi.Determinant(); | |
893 | //cerr<<" determinant: "<<determinant<<endl; | |
894 | if(determinant < 100.) { | |
895 | printf("det(V) = 0\n"); | |
896 | failed=1; | |
897 | continue; | |
898 | } | |
899 | ||
900 | // inverted of weights matrix | |
901 | TMatrixD invsumWi(TMatrixD::kInverted,sumWi); | |
902 | vV = invsumWi; | |
903 | ||
904 | // position of primary vertex | |
905 | rv.Mult(vV,sumWiri); | |
906 | ||
eae1677e | 907 | } // end loop on the 2 steps |
ec1be5d5 | 908 | |
5834e9a1 | 909 | // delete t; |
ec1be5d5 | 910 | |
911 | if(failed) { | |
50ff0bcd | 912 | if(fDebug) printf("TooFewTracks\n"); |
ec1be5d5 | 913 | fCurrentVertex = new AliESDVertex(0.,0.,-1); |
914 | return; | |
915 | } | |
916 | ||
917 | Double_t position[3]; | |
918 | position[0] = rv(0,0); | |
919 | position[1] = rv(1,0); | |
920 | position[2] = rv(2,0); | |
921 | Double_t covmatrix[6]; | |
922 | covmatrix[0] = vV(0,0); | |
923 | covmatrix[1] = vV(0,1); | |
924 | covmatrix[2] = vV(1,1); | |
925 | covmatrix[3] = vV(0,2); | |
926 | covmatrix[4] = vV(1,2); | |
927 | covmatrix[5] = vV(2,2); | |
928 | ||
929 | // store data in the vertex object | |
930 | fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nUsedTrks); | |
931 | ||
932 | if(fDebug) { | |
933 | printf(" VertexFitter(): finish\n"); | |
934 | printf(" rv = ( %f , %f , %f )\n\n",rv(0,0),rv(1,0),rv(2,0)); | |
935 | fCurrentVertex->PrintStatus(); | |
936 | } | |
937 | ||
938 | return; | |
939 | } | |
50ff0bcd | 940 | //---------------------------------------------------------------------------- |
941 | AliVertex* AliVertexerTracks::VertexForSelectedTracks(TTree *trkTree) { | |
eae1677e | 942 | // |
50ff0bcd | 943 | // Return vertex from tracks in trkTree |
eae1677e | 944 | // |
945 | ||
50ff0bcd | 946 | // get tracks and propagate them to initial vertex position |
947 | Int_t nTrksPrep = PrepareTracks(*trkTree,1); | |
0c69be49 | 948 | if(nTrksPrep < TMath::Max(2,fMinTracks) ) { |
50ff0bcd | 949 | if(fDebug) printf("TooFewTracks\n"); |
950 | Double_t vtx[3]={0,0,0}; | |
951 | fVert.SetXYZ(vtx); | |
952 | fVert.SetDispersion(999); | |
953 | fVert.SetNContributors(-5); | |
954 | fTrkArray.Delete(); | |
955 | return &fVert; | |
956 | } | |
957 | ||
958 | // Set initial vertex position from ESD | |
959 | if(fAlgo==1) StrLinVertexFinderMinDist(1); | |
960 | if(fAlgo==2) StrLinVertexFinderMinDist(0); | |
961 | if(fAlgo==3) HelixVertexFinder(); | |
962 | if(fAlgo==4) VertexFinder(1); | |
963 | if(fAlgo==5) VertexFinder(0); | |
eae1677e | 964 | |
50ff0bcd | 965 | |
966 | // set indices of used tracks | |
967 | UShort_t *indices = 0; | |
968 | AliESDtrack *eta = 0; | |
969 | if(fVert.GetNContributors()>0) { | |
970 | indices = new UShort_t[fVert.GetNContributors()]; | |
971 | for(Int_t jj=0;jj<(Int_t)fTrkArray.GetEntriesFast();jj++) { | |
972 | eta = (AliESDtrack*)fTrkArray.At(jj); | |
973 | indices[jj] = (UShort_t)eta->GetID(); | |
974 | } | |
975 | fVert.SetIndices(fVert.GetNContributors(),indices); | |
976 | } | |
977 | delete [] indices; | |
978 | fTrkArray.Delete(); | |
979 | ||
980 | return &fVert; | |
eae1677e | 981 | } |
50ff0bcd | 982 | //---------------------------------------------------------------------------- |
983 | AliVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray) { | |
984 | // | |
985 | // Return vertex from array of tracks | |
986 | // | |
5834e9a1 | 987 | |
50ff0bcd | 988 | // get tracks and propagate them to initial vertex position |
989 | Int_t nTrks = trkArray->GetEntriesFast(); | |
0c69be49 | 990 | if(nTrks < TMath::Max(2,fMinTracks) ) { |
50ff0bcd | 991 | if(fDebug) printf("TooFewTracks\n"); |
992 | Double_t vtx[3]={0,0,0}; | |
993 | fVert.SetXYZ(vtx); | |
994 | fVert.SetDispersion(999); | |
995 | fVert.SetNContributors(-5); | |
996 | fTrkArray.Delete(); | |
997 | return &fVert; | |
998 | } | |
999 | TTree *trkTree = new TTree("TreeT","tracks"); | |
1000 | AliESDtrack *esdTrack = 0; | |
1001 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
1002 | for(Int_t i=0; i<nTrks; i++){ | |
1003 | esdTrack = (AliESDtrack*)trkArray->At(i); | |
1004 | trkTree->Fill(); | |
1005 | } | |
1006 | ||
1007 | AliVertex *vtx = VertexForSelectedTracks(trkTree); | |
1008 | delete trkTree; | |
1009 | return vtx; | |
1010 | } | |
1011 | //-------------------------------------------------------------------------- |