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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), | |
fee9ef0d | 45 | fConstraint(kFALSE), |
46 | fOnlyFitter(kFALSE), | |
0c69be49 | 47 | fMinTracks(1), |
fe12e09c | 48 | fMinITSClusters(5), |
07680cae | 49 | fTrkArray(), |
50 | fTrksToSkip(0), | |
51 | fNTrksToSkip(0), | |
52 | fDCAcut(0), | |
53 | fAlgo(1), | |
fe12e09c | 54 | fNSigma(3), |
fee9ef0d | 55 | fMaxd0z0(0.5), |
50ff0bcd | 56 | fITSin(kTRUE), |
57 | fITSrefit(kTRUE), | |
07680cae | 58 | fDebug(0) |
2d57349e | 59 | { |
60 | // | |
61 | // Default constructor | |
62 | // | |
63 | SetVtxStart(); | |
07680cae | 64 | SetVtxStartSigma(); |
2d57349e | 65 | SetMinTracks(); |
07680cae | 66 | SetMinITSClusters(); |
67 | SetNSigmad0(); | |
fee9ef0d | 68 | SetMaxd0z0(); |
2d57349e | 69 | } |
70 | //----------------------------------------------------------------------------- | |
71 | AliVertexerTracks::AliVertexerTracks(Double_t xStart, Double_t yStart): | |
07680cae | 72 | TObject(), |
73 | fVert(), | |
74 | fCurrentVertex(0), | |
fee9ef0d | 75 | fConstraint(kFALSE), |
76 | fOnlyFitter(kFALSE), | |
0c69be49 | 77 | fMinTracks(1), |
fe12e09c | 78 | fMinITSClusters(5), |
07680cae | 79 | fTrkArray(), |
80 | fTrksToSkip(0), | |
81 | fNTrksToSkip(0), | |
82 | fDCAcut(0), | |
83 | fAlgo(1), | |
fe12e09c | 84 | fNSigma(3), |
fee9ef0d | 85 | fMaxd0z0(0.5), |
50ff0bcd | 86 | fITSin(kTRUE), |
87 | fITSrefit(kTRUE), | |
07680cae | 88 | fDebug(0) |
2d57349e | 89 | { |
90 | // | |
91 | // Standard constructor | |
92 | // | |
93 | SetVtxStart(xStart,yStart); | |
07680cae | 94 | SetVtxStartSigma(); |
2d57349e | 95 | SetMinTracks(); |
07680cae | 96 | SetMinITSClusters(); |
97 | SetNSigmad0(); | |
fee9ef0d | 98 | SetMaxd0z0(); |
2d57349e | 99 | } |
100 | //----------------------------------------------------------------------------- | |
fee9ef0d | 101 | AliVertexerTracks::~AliVertexerTracks() |
102 | { | |
2d57349e | 103 | // Default Destructor |
eae1677e | 104 | // The objects pointed by the following pointer are not owned |
2d57349e | 105 | // by this class and are not deleted |
ec1be5d5 | 106 | fCurrentVertex = 0; |
07680cae | 107 | delete[] fTrksToSkip; |
ec1be5d5 | 108 | } |
c5e3e5d1 | 109 | //---------------------------------------------------------------------------- |
ec1be5d5 | 110 | AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const AliESD *esdEvent) |
111 | { | |
c5e3e5d1 | 112 | // |
ec1be5d5 | 113 | // Primary vertex for current ESD event |
eae1677e | 114 | // (Two iterations: |
fee9ef0d | 115 | // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex |
116 | // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE | |
117 | // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration) | |
318aecb9 | 118 | // All ESD tracks with inside the beam pipe are then propagated to found vertex |
07680cae | 119 | // |
120 | fCurrentVertex = 0; | |
121 | ||
fee9ef0d | 122 | // read tracks from ESD |
50ff0bcd | 123 | Int_t nTrksTot = (Int_t)esdEvent->GetNumberOfTracks(); |
80d36431 | 124 | if (nTrksTot<=0) { |
125 | if(fDebug) printf("TooFewTracks\n"); | |
126 | TooFewTracks(esdEvent); | |
127 | return fCurrentVertex; | |
128 | } | |
713e5fbf | 129 | |
07680cae | 130 | TTree *trkTree = new TTree("TreeT","tracks"); |
131 | AliESDtrack *esdTrack = 0; | |
132 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
133 | ||
eae1677e | 134 | Bool_t skipThis; |
50ff0bcd | 135 | for(Int_t i=0; i<nTrksTot; i++) { |
fee9ef0d | 136 | AliESDtrack *et = esdEvent->GetTrack(i); |
137 | esdTrack = new AliESDtrack(*et); | |
eae1677e | 138 | // check tracks to skip |
139 | skipThis = kFALSE; | |
140 | for(Int_t j=0; j<fNTrksToSkip; j++) { | |
fee9ef0d | 141 | if(et->GetID()==fTrksToSkip[j]) { |
eae1677e | 142 | if(fDebug) printf("skipping track: %d\n",i); |
143 | skipThis = kTRUE; | |
144 | } | |
145 | } | |
50ff0bcd | 146 | if(skipThis) {delete esdTrack;continue;} |
147 | if(fITSin) { | |
148 | if(!(esdTrack->GetStatus()&AliESDtrack::kITSin)) {delete esdTrack;continue;} | |
149 | if(fITSrefit && !(esdTrack->GetStatus()&AliESDtrack::kITSrefit)) {delete esdTrack;continue;} | |
150 | Int_t nclus=esdTrack->GetNcls(0); // check number of clusters in ITS | |
151 | if(nclus<fMinITSClusters) {delete esdTrack;continue;} | |
152 | } | |
07680cae | 153 | trkTree->Fill(); |
5834e9a1 | 154 | delete esdTrack; |
07680cae | 155 | } |
fee9ef0d | 156 | |
157 | // If fConstraint=kFALSE | |
158 | // run VertexFinder(1) to get rough estimate of initVertex (x,y) | |
159 | if(!fConstraint) { | |
160 | // fill fTrkArray, for VertexFinder() | |
161 | if(!fTrkArray.IsEmpty()) fTrkArray.Delete(); | |
162 | PrepareTracks(*trkTree,0); | |
163 | Double_t cutsave = fDCAcut; fDCAcut = 0.1; // 1 mm | |
164 | VertexFinder(1); // using weights, cutting dca < fDCAcut | |
165 | fDCAcut = cutsave; | |
5834e9a1 | 166 | fTrkArray.Delete(); |
fee9ef0d | 167 | if(fVert.GetNContributors()>0) { |
168 | fVert.GetXYZ(fNominalPos); | |
169 | fNominalPos[0] = fVert.GetXv(); | |
170 | fNominalPos[1] = fVert.GetYv(); | |
171 | fNominalPos[2] = fVert.GetZv(); | |
172 | if(fDebug) printf("No mean vertex: VertexFinder gives (%f, %f, %f)\n",fNominalPos[0],fNominalPos[1],fNominalPos[2]); | |
173 | } else { | |
174 | fNominalPos[0] = 0.; | |
175 | fNominalPos[1] = 0.; | |
176 | fNominalPos[2] = 0.; | |
177 | if(fDebug) printf("No mean vertex and VertexFinder failed\n"); | |
0c69be49 | 178 | } |
07680cae | 179 | } |
fee9ef0d | 180 | |
181 | // TWO ITERATIONS: | |
182 | // | |
183 | // ITERATION 1 | |
184 | // propagate tracks to fNominalPos vertex | |
185 | // preselect them: | |
186 | // if(constraint) reject for |d0|>5*fNSigma*sigma w.r.t. fNominal... vertex | |
187 | // else reject for |d0|\oplus|z0| > 5 mm w.r.t. fNominal... vertex | |
07680cae | 188 | // ITERATION 2 |
189 | // propagate tracks to best between initVertex and fCurrentVertex | |
190 | // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best | |
191 | // between initVertex and fCurrentVertex) | |
fee9ef0d | 192 | for(Int_t iter=0; iter<2; iter++) { |
193 | if(fOnlyFitter && iter==0) continue; | |
194 | Int_t nTrksPrep = PrepareTracks(*trkTree,iter+1); | |
195 | if(fDebug) printf(" tracks prepared - iteration %d: %d\n",iter+1,nTrksPrep); | |
196 | if(nTrksPrep < fMinTracks) { | |
197 | if(fDebug) printf("TooFewTracks\n"); | |
198 | TooFewTracks(esdEvent); | |
199 | if(fDebug) fCurrentVertex->PrintStatus(); | |
200 | fTrkArray.Delete(); | |
201 | delete trkTree; | |
202 | return fCurrentVertex; | |
203 | } | |
07680cae | 204 | |
fee9ef0d | 205 | // vertex finder |
206 | if(!fOnlyFitter) { | |
207 | if(nTrksPrep==1){ | |
208 | if(fDebug) printf("Just one track\n"); | |
209 | OneTrackVertFinder(); | |
210 | }else{ | |
211 | switch (fAlgo) { | |
212 | case 1: StrLinVertexFinderMinDist(1); break; | |
213 | case 2: StrLinVertexFinderMinDist(0); break; | |
214 | case 3: HelixVertexFinder(); break; | |
215 | case 4: VertexFinder(1); break; | |
216 | case 5: VertexFinder(0); break; | |
217 | default: printf("Wrong algorithm\n"); break; | |
218 | } | |
219 | } | |
220 | if(fDebug) printf(" Vertex finding completed\n"); | |
0c69be49 | 221 | } |
07680cae | 222 | |
fee9ef0d | 223 | // vertex fitter |
224 | VertexFitter(fConstraint); | |
225 | if(fDebug) printf(" Vertex fit completed\n"); | |
226 | if(iter==0) fTrkArray.Delete(); | |
227 | } // end loop on the two iterations | |
07680cae | 228 | |
eae1677e | 229 | |
fee9ef0d | 230 | // take true pos from SPD vertex in ESD and write it in tracks' vertex |
07680cae | 231 | Double_t tp[3]; |
232 | esdEvent->GetVertex()->GetTruePos(tp); | |
233 | fCurrentVertex->SetTruePos(tp); | |
eae1677e | 234 | |
fee9ef0d | 235 | if(fConstraint) { |
236 | if(fOnlyFitter) { | |
237 | fCurrentVertex->SetTitle("VertexerTracksWithConstraintOnlyFitter"); | |
238 | } else { | |
239 | fCurrentVertex->SetTitle("VertexerTracksWithConstraint"); | |
318aecb9 | 240 | } |
241 | } else { | |
fee9ef0d | 242 | fCurrentVertex->SetTitle("VertexerTracksNoConstraint"); |
318aecb9 | 243 | } |
50ff0bcd | 244 | |
fee9ef0d | 245 | |
50ff0bcd | 246 | // set indices of used tracks |
247 | UShort_t *indices = 0; | |
248 | AliESDtrack *ett = 0; | |
249 | if(fCurrentVertex->GetNContributors()>0) { | |
250 | indices = new UShort_t[fCurrentVertex->GetNContributors()]; | |
251 | for(Int_t jj=0;jj<(Int_t)fTrkArray.GetEntriesFast();jj++) { | |
252 | ett = (AliESDtrack*)fTrkArray.At(jj); | |
253 | indices[jj] = (UShort_t)ett->GetID(); | |
254 | } | |
255 | fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices); | |
256 | } | |
257 | delete [] indices; | |
fee9ef0d | 258 | |
259 | delete trkTree; | |
260 | ||
50ff0bcd | 261 | fTrkArray.Delete(); |
262 | ||
263 | if(fTrksToSkip) delete [] fTrksToSkip; | |
264 | ||
265 | ||
266 | if(fDebug) fCurrentVertex->PrintStatus(); | |
267 | if(fDebug) fCurrentVertex->PrintIndices(); | |
fee9ef0d | 268 | |
269 | ||
07680cae | 270 | return fCurrentVertex; |
271 | } | |
50ff0bcd | 272 | //------------------------------------------------------------------------ |
fee9ef0d | 273 | Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3]) |
274 | { | |
50ff0bcd | 275 | // |
276 | 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]; | |
277 | return det; | |
278 | } | |
279 | //------------------------------------------------------------------------- | |
fee9ef0d | 280 | void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d) |
281 | { | |
50ff0bcd | 282 | // |
283 | Double_t x12=p0[0]-p1[0]; | |
284 | Double_t y12=p0[1]-p1[1]; | |
285 | Double_t z12=p0[2]-p1[2]; | |
286 | Double_t kk=x12*x12+y12*y12+z12*z12; | |
287 | m[0][0]=2-2/kk*x12*x12; | |
288 | m[0][1]=-2/kk*x12*y12; | |
289 | m[0][2]=-2/kk*x12*z12; | |
290 | m[1][0]=-2/kk*x12*y12; | |
291 | m[1][1]=2-2/kk*y12*y12; | |
292 | m[1][2]=-2/kk*y12*z12; | |
293 | m[2][0]=-2/kk*x12*z12; | |
294 | m[2][1]=-2*y12*z12; | |
295 | m[2][2]=2-2/kk*z12*z12; | |
296 | d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12; | |
297 | d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12; | |
298 | d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12; | |
c5e3e5d1 | 299 | |
50ff0bcd | 300 | } |
301 | //-------------------------------------------------------------------------- | |
fee9ef0d | 302 | void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d) |
303 | { | |
50ff0bcd | 304 | // |
305 | Double_t x12=p1[0]-p0[0]; | |
306 | Double_t y12=p1[1]-p0[1]; | |
307 | Double_t z12=p1[2]-p0[2]; | |
c5e3e5d1 | 308 | |
50ff0bcd | 309 | Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1]; |
c5e3e5d1 | 310 | |
50ff0bcd | 311 | Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]); |
c5e3e5d1 | 312 | |
50ff0bcd | 313 | Double_t cc[3]; |
314 | cc[0]=-x12/sigmasq[0]; | |
315 | cc[1]=-y12/sigmasq[1]; | |
316 | cc[2]=-z12/sigmasq[2]; | |
ec1be5d5 | 317 | |
50ff0bcd | 318 | 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 | 319 | |
50ff0bcd | 320 | Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2]; |
2d57349e | 321 | |
50ff0bcd | 322 | Double_t aa[3]; |
323 | aa[0]=x12*sigmasq[1]*sigmasq[2]/den; | |
324 | aa[1]=y12*sigmasq[0]*sigmasq[2]/den; | |
325 | aa[2]=z12*sigmasq[0]*sigmasq[1]/den; | |
2d57349e | 326 | |
50ff0bcd | 327 | m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0]; |
328 | m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0]; | |
329 | m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0]; | |
2d57349e | 330 | |
50ff0bcd | 331 | m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1]; |
332 | m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1]; | |
333 | m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1]; | |
2d57349e | 334 | |
50ff0bcd | 335 | m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2]; |
336 | m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2]; | |
337 | m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2]; | |
08df6187 | 338 | |
50ff0bcd | 339 | d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0]; |
340 | d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1]; | |
341 | d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2]; | |
2d57349e | 342 | |
2d57349e | 343 | } |
50ff0bcd | 344 | //-------------------------------------------------------------------------- |
fee9ef0d | 345 | Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0) |
346 | { | |
50ff0bcd | 347 | // |
348 | Double_t x12=p0[0]-p1[0]; | |
349 | Double_t y12=p0[1]-p1[1]; | |
350 | Double_t z12=p0[2]-p1[2]; | |
351 | Double_t x10=p0[0]-x0[0]; | |
352 | Double_t y10=p0[1]-x0[1]; | |
353 | Double_t z10=p0[2]-x0[2]; | |
354 | 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 | 355 | } |
356 | //--------------------------------------------------------------------------- | |
fee9ef0d | 357 | void AliVertexerTracks::OneTrackVertFinder() |
358 | { | |
0c69be49 | 359 | // find vertex for events with 1 track, using DCA to nominal beam axis |
360 | if(fDebug) printf("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArray.GetEntries()); | |
361 | AliESDtrack *track1; | |
362 | track1 = (AliESDtrack*)fTrkArray.At(0); | |
363 | Double_t field=GetField(); | |
364 | Double_t alpha=track1->GetAlpha(); | |
365 | Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
366 | Double_t pos[3],dir[3]; | |
367 | track1->GetXYZAt(mindist,field,pos); | |
368 | track1->GetPxPyPzAt(mindist,field,dir); | |
369 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
370 | Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.}; | |
371 | Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.}; | |
372 | AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE); | |
373 | Double_t crosspoint[3]={0.,0.,0.}; | |
374 | Double_t sigma=999.; | |
375 | Int_t nContrib=-1; | |
376 | Int_t retcode = zeta->Cross(line1,crosspoint); | |
377 | if(retcode>=0){ | |
378 | sigma=line1->GetDistFromPoint(crosspoint); | |
379 | nContrib=1; | |
380 | } | |
381 | delete zeta; | |
382 | delete line1; | |
383 | fVert.SetXYZ(crosspoint); | |
384 | fVert.SetDispersion(sigma); | |
385 | fVert.SetNContributors(nContrib); | |
386 | } | |
387 | //--------------------------------------------------------------------------- | |
fee9ef0d | 388 | void AliVertexerTracks::HelixVertexFinder() |
389 | { | |
2d57349e | 390 | // Get estimate of vertex position in (x,y) from tracks DCA |
391 | ||
392 | ||
393 | Double_t initPos[3]; | |
394 | initPos[2] = 0.; | |
395 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
396 | Double_t field=GetField(); | |
397 | ||
398 | Int_t nacc = (Int_t)fTrkArray.GetEntriesFast(); | |
399 | ||
400 | Double_t aver[3]={0.,0.,0.}; | |
401 | Double_t averquad[3]={0.,0.,0.}; | |
402 | Double_t sigmaquad[3]={0.,0.,0.}; | |
403 | Double_t sigma=0; | |
404 | Int_t ncombi = 0; | |
405 | AliESDtrack *track1; | |
406 | AliESDtrack *track2; | |
407 | Double_t distCA; | |
408 | Double_t x, par[5]; | |
409 | Double_t alpha, cs, sn; | |
410 | Double_t crosspoint[3]; | |
411 | for(Int_t i=0; i<nacc; i++){ | |
412 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
413 | ||
414 | ||
415 | for(Int_t j=i+1; j<nacc; j++){ | |
416 | track2 = (AliESDtrack*)fTrkArray.At(j); | |
417 | ||
418 | distCA=track2->PropagateToDCA(track1,field); | |
2d57349e | 419 | if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){ |
420 | track1->GetExternalParameters(x,par); | |
421 | alpha=track1->GetAlpha(); | |
422 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
423 | Double_t x1=x*cs - par[0]*sn; | |
424 | Double_t y1=x*sn + par[0]*cs; | |
425 | Double_t z1=par[1]; | |
426 | Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2(); | |
427 | track2->GetExternalParameters(x,par); | |
428 | alpha=track2->GetAlpha(); | |
429 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
430 | Double_t x2=x*cs - par[0]*sn; | |
431 | Double_t y2=x*sn + par[0]*cs; | |
432 | Double_t z2=par[1]; | |
433 | Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2(); | |
434 | Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2(); | |
435 | Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1; | |
436 | Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1; | |
437 | Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1; | |
438 | crosspoint[0]=wx1*x1 + wx2*x2; | |
439 | crosspoint[1]=wy1*y1 + wy2*y2; | |
440 | crosspoint[2]=wz1*z1 + wz2*z2; | |
441 | ||
442 | ncombi++; | |
443 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
444 | for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
445 | } | |
446 | } | |
447 | ||
448 | } | |
449 | if(ncombi>0){ | |
450 | for(Int_t jj=0;jj<3;jj++){ | |
451 | initPos[jj] = aver[jj]/ncombi; | |
452 | averquad[jj]/=ncombi; | |
453 | sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj]; | |
454 | sigma+=sigmaquad[jj]; | |
455 | } | |
456 | sigma=TMath::Sqrt(TMath::Abs(sigma)); | |
457 | } | |
458 | else { | |
459 | Warning("HelixVertexFinder","Finder did not succed"); | |
460 | sigma=999; | |
461 | } | |
462 | fVert.SetXYZ(initPos); | |
463 | fVert.SetDispersion(sigma); | |
464 | fVert.SetNContributors(ncombi); | |
465 | } | |
50ff0bcd | 466 | //---------------------------------------------------------------------------- |
fee9ef0d | 467 | Int_t AliVertexerTracks::PrepareTracks(TTree &trkTree,Int_t optImpParCut) |
468 | { | |
50ff0bcd | 469 | // |
470 | // Propagate tracks to initial vertex position and store them in a TObjArray | |
471 | // | |
fee9ef0d | 472 | Double_t maxd0rphi; |
473 | Double_t maxd0z0 = fMaxd0z0; // default is 5 mm | |
50ff0bcd | 474 | Int_t nTrks = 0; |
475 | Double_t sigmaCurr[3]; | |
fee9ef0d | 476 | Double_t normdistx,normdisty; |
50ff0bcd | 477 | Float_t d0z0[2],covd0z0[3]; |
478 | Double_t sigma; | |
479 | Double_t field=GetField(); | |
480 | ||
481 | AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1); | |
482 | ||
483 | Int_t nEntries = (Int_t)trkTree.GetEntries(); | |
484 | if(!fTrkArray.IsEmpty()) fTrkArray.Delete(); | |
485 | ||
486 | if(fDebug) { | |
487 | printf(" PrepareTracks()\n"); | |
488 | } | |
489 | ||
490 | for(Int_t i=0; i<nEntries; i++) { | |
491 | AliESDtrack *track = new AliESDtrack; | |
492 | trkTree.SetBranchAddress("tracks",&track); | |
493 | trkTree.GetEvent(i); | |
494 | ||
495 | // propagate track to vertex | |
fee9ef0d | 496 | if(optImpParCut<=1 || fOnlyFitter) { // optImpParCut==1 or 0 |
50ff0bcd | 497 | track->RelateToVertex(initVertex,field,100.); |
fee9ef0d | 498 | } else { // optImpParCut==2 |
50ff0bcd | 499 | fCurrentVertex->GetSigmaXYZ(sigmaCurr); |
fee9ef0d | 500 | normdistx = TMath::Abs(fCurrentVertex->GetXv()-fNominalPos[0])/TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0]); |
80d36431 | 501 | normdisty = TMath::Abs(fCurrentVertex->GetYv()-fNominalPos[1])/TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2]); |
fee9ef0d | 502 | if(normdistx < 3. && normdisty < 3. && |
80d36431 | 503 | (sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) { |
50ff0bcd | 504 | track->RelateToVertex(fCurrentVertex,field,100.); |
505 | } else { | |
506 | track->RelateToVertex(initVertex,field,100.); | |
507 | } | |
508 | } | |
509 | ||
50ff0bcd | 510 | track->GetImpactParameters(d0z0,covd0z0); |
511 | sigma = TMath::Sqrt(covd0z0[0]); | |
512 | maxd0rphi = fNSigma*sigma; | |
fee9ef0d | 513 | if(optImpParCut==1) maxd0rphi *= 5.; |
514 | ||
515 | ||
50ff0bcd | 516 | |
fee9ef0d | 517 | if(fDebug) printf("trk %d; lab %d; |d0| = %f; d0 cut = %f; |z0| = %f; |d0|oplus|z0| = %f; d0z0 cut = %f\n",i,track->GetLabel(),TMath::Abs(d0z0[0]),maxd0rphi,TMath::Abs(d0z0[1]),TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]),maxd0z0); |
518 | ||
80d36431 | 519 | // during iterations 1 and 2, if fConstraint=kFALSE, |
fee9ef0d | 520 | // select tracks with d0oplusz0 < maxd0z0 |
80d36431 | 521 | if(optImpParCut>=1 && !fConstraint && nEntries>=3 && |
fee9ef0d | 522 | fVert.GetNContributors()>0) { |
523 | if(TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]) > maxd0z0) { | |
524 | if(fDebug) printf(" rejected\n"); | |
525 | delete track; continue; | |
526 | } | |
527 | } | |
528 | ||
529 | // select tracks with d0rphi < maxd0rphi | |
530 | if(optImpParCut>0 && TMath::Abs(d0z0[0]) > maxd0rphi) { | |
50ff0bcd | 531 | if(fDebug) printf(" rejected\n"); |
532 | delete track; continue; | |
533 | } | |
534 | ||
535 | fTrkArray.AddLast(track); | |
536 | nTrks++; | |
537 | } | |
538 | ||
539 | delete initVertex; | |
540 | ||
541 | return nTrks; | |
542 | } | |
543 | //--------------------------------------------------------------------------- | |
fee9ef0d | 544 | AliESDVertex* AliVertexerTracks::RemoveTracksFromVertex(AliESDVertex *inVtx, |
545 | TTree *trksTree, | |
546 | Float_t *diamondxy) | |
547 | { | |
50ff0bcd | 548 | // |
fee9ef0d | 549 | // Removes tracks in trksTree from fit of inVtx |
50ff0bcd | 550 | // |
fee9ef0d | 551 | |
552 | if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraintOnlyFitter")) | |
553 | printf("WARNING: result of tracks' removal will be only approximately correct\n"); | |
554 | ||
555 | TMatrixD rv(3,1); | |
556 | rv(0,0) = inVtx->GetXv(); | |
557 | rv(1,0) = inVtx->GetYv(); | |
558 | rv(2,0) = inVtx->GetZv(); | |
559 | TMatrixD vV(3,3); | |
560 | Double_t cov[6]; | |
561 | inVtx->GetCovMatrix(cov); | |
562 | vV(0,0) = cov[0]; | |
563 | vV(0,1) = cov[1]; vV(1,0) = cov[1]; | |
564 | vV(1,1) = cov[2]; | |
565 | vV(0,2) = cov[3]; vV(2,0) = cov[3]; | |
566 | vV(1,2) = cov[4]; vV(2,1) = cov[4]; | |
567 | vV(2,2) = cov[5]; | |
568 | ||
569 | TMatrixD sumWi(TMatrixD::kInverted,vV); | |
570 | TMatrixD sumWiri(sumWi,TMatrixD::kMult,rv); | |
571 | ||
572 | Int_t nUsedTrks = inVtx->GetNContributors(); | |
573 | Double_t chi2 = inVtx->GetChi2(); | |
574 | ||
575 | AliESDtrack *track = 0; | |
576 | trksTree->SetBranchAddress("tracks",&track); | |
577 | Int_t ntrks = trksTree->GetEntries(); | |
578 | for(Int_t i=0;i<ntrks;i++) { | |
579 | trksTree->GetEvent(i); | |
580 | if(!inVtx->UsesTrack(track->GetID())) { | |
581 | printf("track %d was not used in vertex fit\n",track->GetID()); | |
582 | continue; | |
583 | } | |
584 | Double_t alpha = track->GetAlpha(); | |
585 | Double_t xl = diamondxy[0]*TMath::Cos(alpha)+diamondxy[1]*TMath::Sin(alpha); | |
586 | track->AliExternalTrackParam::PropagateTo(xl,AliTracker::GetBz()); | |
587 | // vector of track global coordinates | |
588 | TMatrixD ri(3,1); | |
589 | // covariance matrix of ri | |
590 | TMatrixD wWi(3,3); | |
591 | ||
592 | // get space point from track | |
593 | if(!TrackToPoint(track,ri,wWi)) continue; | |
594 | ||
595 | TMatrixD wWiri(wWi,TMatrixD::kMult,ri); | |
596 | ||
597 | sumWi -= wWi; | |
598 | sumWiri -= wWiri; | |
599 | ||
600 | // track chi2 | |
601 | TMatrixD deltar = rv; deltar -= ri; | |
602 | TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar); | |
603 | Double_t chi2i = deltar(0,0)*wWideltar(0,0)+ | |
604 | deltar(1,0)*wWideltar(1,0)+ | |
605 | deltar(2,0)*wWideltar(2,0); | |
606 | // remove from total chi2 | |
607 | chi2 -= chi2i; | |
608 | ||
609 | nUsedTrks--; | |
610 | if(nUsedTrks<2) { | |
611 | printf("Trying to remove too many tracks!\n"); | |
612 | return 0x0; | |
613 | } | |
614 | } | |
615 | ||
616 | TMatrixD rvnew(3,1); | |
617 | TMatrixD vVnew(3,3); | |
618 | ||
619 | // new inverted of weights matrix | |
620 | TMatrixD invsumWi(TMatrixD::kInverted,sumWi); | |
621 | vVnew = invsumWi; | |
622 | // new position of primary vertex | |
623 | rvnew.Mult(vVnew,sumWiri); | |
624 | ||
625 | Double_t position[3]; | |
626 | position[0] = rvnew(0,0); | |
627 | position[1] = rvnew(1,0); | |
628 | position[2] = rvnew(2,0); | |
629 | cov[0] = vVnew(0,0); | |
630 | cov[1] = vVnew(0,1); | |
631 | cov[2] = vVnew(1,1); | |
632 | cov[3] = vVnew(0,2); | |
633 | cov[4] = vVnew(1,2); | |
634 | cov[5] = vVnew(2,2); | |
635 | ||
636 | // store data in the vertex object | |
637 | AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,nUsedTrks); | |
638 | outVtx->SetTitle(inVtx->GetTitle()); | |
639 | Double_t tp[3]; | |
640 | inVtx->GetTruePos(tp); | |
641 | outVtx->SetTruePos(tp); | |
642 | UShort_t *inindices = inVtx->GetIndices(); | |
643 | UShort_t *outindices = new UShort_t[outVtx->GetNContributors()]; | |
644 | Int_t j=0; | |
645 | Bool_t copyindex; | |
646 | for(Int_t k=0; k<inVtx->GetNIndices(); k++) { | |
647 | copyindex=kTRUE; | |
648 | for(Int_t l=0; l<ntrks; l++) { | |
649 | trksTree->GetEvent(l); | |
650 | if(inindices[k]==track->GetID()) copyindex=kFALSE; | |
651 | } | |
652 | if(copyindex) { | |
653 | outindices[j] = inindices[k]; j++; | |
654 | } | |
655 | } | |
656 | outVtx->SetIndices(outVtx->GetNContributors(),outindices); | |
657 | delete [] outindices; | |
658 | ||
659 | if(fDebug) { | |
660 | printf("Vertex before removing tracks:\n"); | |
661 | inVtx->PrintStatus(); | |
662 | inVtx->PrintIndices(); | |
663 | printf("Vertex after removing tracks:\n"); | |
664 | outVtx->PrintStatus(); | |
665 | outVtx->PrintIndices(); | |
666 | } | |
667 | ||
668 | return outVtx; | |
669 | } | |
670 | //--------------------------------------------------------------------------- | |
671 | void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped) | |
672 | { | |
673 | // | |
674 | // Mark the tracks not to be used in the vertex reconstruction. | |
675 | // Tracks are identified by AliESDtrack::GetID() | |
676 | // | |
677 | fNTrksToSkip = n; fTrksToSkip = new Int_t[n]; | |
50ff0bcd | 678 | for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i]; |
679 | return; | |
680 | } | |
681 | //--------------------------------------------------------------------------- | |
fee9ef0d | 682 | void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx) |
683 | { | |
50ff0bcd | 684 | // |
685 | // Set initial vertex knowledge | |
686 | // | |
687 | vtx->GetXYZ(fNominalPos); | |
688 | vtx->GetCovMatrix(fNominalCov); | |
fee9ef0d | 689 | SetConstraintOn(); |
50ff0bcd | 690 | return; |
691 | } | |
2d57349e | 692 | //--------------------------------------------------------------------------- |
fee9ef0d | 693 | void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights) |
694 | { | |
2d57349e | 695 | // Calculate the point at minimum distance to prepared tracks |
696 | ||
697 | Double_t initPos[3]; | |
698 | initPos[2] = 0.; | |
699 | Double_t sigma=0; | |
700 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
701 | const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast(); | |
702 | Double_t field=GetField(); | |
703 | ||
704 | AliESDtrack *track1; | |
705 | Double_t (*vectP0)[3]=new Double_t [knacc][3]; | |
706 | Double_t (*vectP1)[3]=new Double_t [knacc][3]; | |
707 | ||
708 | Double_t sum[3][3]; | |
709 | Double_t dsum[3]={0,0,0}; | |
710 | for(Int_t i=0;i<3;i++) | |
711 | for(Int_t j=0;j<3;j++)sum[i][j]=0; | |
712 | for(Int_t i=0; i<knacc; i++){ | |
713 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
714 | Double_t alpha=track1->GetAlpha(); | |
715 | Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
ec1be5d5 | 716 | Double_t pos[3],dir[3]; |
717 | track1->GetXYZAt(mindist,field,pos); | |
718 | track1->GetPxPyPzAt(mindist,field,dir); | |
719 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
720 | // AliStrLine *line1 = new AliStrLine(); | |
721 | // track1->ApproximateHelixWithLine(mindist,field,line1); | |
2d57349e | 722 | |
723 | Double_t p0[3],cd[3]; | |
724 | line1->GetP0(p0); | |
725 | line1->GetCd(cd); | |
726 | Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]}; | |
727 | vectP0[i][0]=p0[0]; | |
728 | vectP0[i][1]=p0[1]; | |
729 | vectP0[i][2]=p0[2]; | |
730 | vectP1[i][0]=p1[0]; | |
731 | vectP1[i][1]=p1[1]; | |
732 | vectP1[i][2]=p1[2]; | |
733 | ||
734 | Double_t matr[3][3]; | |
735 | Double_t dknow[3]; | |
736 | if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow); | |
737 | if(optUseWeights==1){ | |
738 | Double_t sigmasq[3]; | |
739 | sigmasq[0]=track1->GetSigmaY2(); | |
740 | sigmasq[1]=track1->GetSigmaY2(); | |
741 | sigmasq[2]=track1->GetSigmaZ2(); | |
742 | GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow); | |
743 | } | |
744 | ||
745 | for(Int_t iii=0;iii<3;iii++){ | |
746 | dsum[iii]+=dknow[iii]; | |
747 | for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj]; | |
748 | } | |
749 | delete line1; | |
750 | } | |
751 | ||
752 | Double_t vett[3][3]; | |
753 | Double_t det=GetDeterminant3X3(sum); | |
754 | ||
fee9ef0d | 755 | if(det!=0){ |
756 | for(Int_t zz=0;zz<3;zz++){ | |
757 | for(Int_t ww=0;ww<3;ww++){ | |
758 | for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk]; | |
759 | } | |
760 | for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk]; | |
761 | initPos[zz]=GetDeterminant3X3(vett)/det; | |
762 | } | |
763 | ||
764 | ||
765 | for(Int_t i=0; i<knacc; i++){ | |
766 | Double_t p0[3]={0,0,0},p1[3]={0,0,0}; | |
767 | for(Int_t ii=0;ii<3;ii++){ | |
768 | p0[ii]=vectP0[i][ii]; | |
769 | p1[ii]=vectP1[i][ii]; | |
770 | } | |
771 | sigma+=GetStrLinMinDist(p0,p1,initPos); | |
772 | } | |
773 | ||
774 | sigma=TMath::Sqrt(sigma); | |
775 | }else{ | |
50ff0bcd | 776 | Warning("StrLinVertexFinderMinDist","Finder did not succed"); |
777 | sigma=999; | |
778 | } | |
779 | delete vectP0; | |
780 | delete vectP1; | |
781 | fVert.SetXYZ(initPos); | |
782 | fVert.SetDispersion(sigma); | |
783 | fVert.SetNContributors(knacc); | |
784 | } | |
785 | //--------------------------------------------------------------------------- | |
fee9ef0d | 786 | Bool_t AliVertexerTracks::TrackToPoint(AliESDtrack *t, |
787 | TMatrixD &ri,TMatrixD &wWi) const | |
788 | { | |
789 | // | |
790 | // Extract from the AliESDtrack the global coordinates ri and covariance matrix | |
791 | // wWi of the space point that it represents (to be used in VertexFitter()) | |
792 | // | |
793 | ||
794 | ||
795 | Double_t rotAngle = t->GetAlpha(); | |
796 | if(rotAngle<0.) rotAngle += 2.*TMath::Pi(); | |
797 | Double_t cosRot = TMath::Cos(rotAngle); | |
798 | Double_t sinRot = TMath::Sin(rotAngle); | |
799 | ||
800 | ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot; | |
801 | ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot; | |
802 | ri(2,0) = t->GetZ(); | |
803 | ||
804 | // matrix to go from global (x,y,z) to local (y,z); | |
805 | TMatrixD qQi(2,3); | |
806 | qQi(0,0) = -sinRot; | |
807 | qQi(0,1) = cosRot; | |
808 | qQi(0,2) = 0.; | |
809 | qQi(1,0) = 0.; | |
810 | qQi(1,1) = 0.; | |
811 | qQi(1,2) = 1.; | |
812 | ||
813 | // covariance matrix of local (y,z) - inverted | |
814 | TMatrixD uUi(2,2); | |
815 | Double_t cc[15]; | |
816 | t->GetExternalCovariance(cc); | |
817 | uUi(0,0) = cc[0]; | |
818 | uUi(0,1) = cc[1]; | |
819 | uUi(1,0) = cc[1]; | |
820 | uUi(1,1) = cc[2]; | |
821 | if(uUi.Determinant() <= 0.) return kFALSE; | |
822 | TMatrixD uUiInv(TMatrixD::kInverted,uUi); | |
823 | ||
824 | // weights matrix: wWi = qQiT * uUiInv * qQi | |
825 | TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi); | |
826 | TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi); | |
827 | wWi = m; | |
828 | ||
829 | return kTRUE; | |
830 | } | |
831 | //--------------------------------------------------------------------------- | |
832 | void AliVertexerTracks::TooFewTracks(const AliESD* esdEvent) | |
833 | { | |
50ff0bcd | 834 | // |
835 | // When the number of tracks is < fMinTracks | |
836 | // | |
2d57349e | 837 | |
50ff0bcd | 838 | // deal with vertices not found |
839 | Double_t pos[3],err[3]; | |
840 | Int_t ncontr=0; | |
841 | pos[0] = fNominalPos[0]; | |
842 | err[0] = TMath::Sqrt(fNominalCov[0]); | |
843 | pos[1] = fNominalPos[1]; | |
844 | err[1] = TMath::Sqrt(fNominalCov[2]); | |
845 | pos[2] = esdEvent->GetVertex()->GetZv(); | |
846 | err[2] = esdEvent->GetVertex()->GetZRes(); | |
847 | if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()<=0) | |
848 | ncontr = -1; // (x,y,z) = (0,0,0) | |
849 | if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()>0) | |
850 | ncontr = -2; // (x,y,z) = (0,0,z_fromSPD) | |
851 | if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()<=0) | |
852 | ncontr = -3; // (x,y,z) = (x_mean,y_mean,0) | |
853 | if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()>0) | |
854 | ncontr = -4; // (x,y,z) = (x_mean,y_mean,z_fromSPD) | |
855 | fCurrentVertex = 0; | |
856 | fCurrentVertex = new AliESDVertex(pos,err); | |
857 | fCurrentVertex->SetNContributors(ncontr); | |
2d57349e | 858 | |
50ff0bcd | 859 | Double_t tp[3]; |
860 | esdEvent->GetVertex()->GetTruePos(tp); | |
861 | fCurrentVertex->SetTruePos(tp); | |
fee9ef0d | 862 | if(fConstraint) { |
863 | fCurrentVertex->SetTitle("VertexerTracksWithConstraint"); | |
864 | } else { | |
50ff0bcd | 865 | fCurrentVertex->SetTitle("VertexerTracksNoConstraint"); |
fee9ef0d | 866 | } |
2d57349e | 867 | |
50ff0bcd | 868 | return; |
869 | } | |
870 | //--------------------------------------------------------------------------- | |
fee9ef0d | 871 | void AliVertexerTracks::VertexFinder(Int_t optUseWeights) |
872 | { | |
2d57349e | 873 | |
50ff0bcd | 874 | // Get estimate of vertex position in (x,y) from tracks DCA |
875 | ||
876 | Double_t initPos[3]; | |
877 | initPos[2] = 0.; | |
878 | for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i]; | |
879 | Int_t nacc = (Int_t)fTrkArray.GetEntriesFast(); | |
880 | Double_t aver[3]={0.,0.,0.}; | |
881 | Double_t aversq[3]={0.,0.,0.}; | |
882 | Double_t sigmasq[3]={0.,0.,0.}; | |
883 | Double_t sigma=0; | |
884 | Int_t ncombi = 0; | |
885 | AliESDtrack *track1; | |
886 | AliESDtrack *track2; | |
887 | Double_t pos[3],dir[3]; | |
888 | Double_t alpha,mindist; | |
889 | Double_t field=GetField(); | |
2d57349e | 890 | |
50ff0bcd | 891 | for(Int_t i=0; i<nacc; i++){ |
892 | track1 = (AliESDtrack*)fTrkArray.At(i); | |
893 | alpha=track1->GetAlpha(); | |
894 | mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
895 | track1->GetXYZAt(mindist,field,pos); | |
896 | track1->GetPxPyPzAt(mindist,field,dir); | |
897 | AliStrLine *line1 = new AliStrLine(pos,dir); | |
2d57349e | 898 | |
50ff0bcd | 899 | // AliStrLine *line1 = new AliStrLine(); |
900 | // track1->ApproximateHelixWithLine(mindist,field,line1); | |
901 | ||
902 | for(Int_t j=i+1; j<nacc; j++){ | |
903 | track2 = (AliESDtrack*)fTrkArray.At(j); | |
904 | alpha=track2->GetAlpha(); | |
905 | mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1]; | |
906 | track2->GetXYZAt(mindist,field,pos); | |
907 | track2->GetPxPyPzAt(mindist,field,dir); | |
908 | AliStrLine *line2 = new AliStrLine(pos,dir); | |
909 | // AliStrLine *line2 = new AliStrLine(); | |
910 | // track2->ApproximateHelixWithLine(mindist,field,line2); | |
911 | Double_t distCA=line2->GetDCA(line1); | |
fee9ef0d | 912 | //printf("%d %d %f\n",i,j,distCA); |
913 | if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){ | |
50ff0bcd | 914 | Double_t pnt1[3],pnt2[3],crosspoint[3]; |
2d57349e | 915 | |
50ff0bcd | 916 | if(optUseWeights<=0){ |
917 | Int_t retcode = line2->Cross(line1,crosspoint); | |
918 | if(retcode>=0){ | |
919 | ncombi++; | |
920 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
921 | for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
922 | } | |
923 | } | |
924 | if(optUseWeights>0){ | |
925 | Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2); | |
926 | if(retcode>=0){ | |
5c03260f | 927 | Double_t cs, sn; |
50ff0bcd | 928 | alpha=track1->GetAlpha(); |
929 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
930 | Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2(); | |
931 | alpha=track2->GetAlpha(); | |
932 | cs=TMath::Cos(alpha); sn=TMath::Sin(alpha); | |
933 | Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2(); | |
934 | Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2(); | |
935 | Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1; | |
936 | Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1; | |
937 | Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1; | |
938 | crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0]; | |
939 | crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1]; | |
940 | crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2]; | |
941 | ||
942 | ncombi++; | |
943 | for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj]; | |
944 | for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]); | |
945 | } | |
946 | } | |
947 | } | |
948 | delete line2; | |
949 | } | |
950 | delete line1; | |
71d84967 | 951 | } |
50ff0bcd | 952 | if(ncombi>0){ |
953 | for(Int_t jj=0;jj<3;jj++){ | |
954 | initPos[jj] = aver[jj]/ncombi; | |
fee9ef0d | 955 | //printf("%f\n",initPos[jj]); |
50ff0bcd | 956 | aversq[jj]/=ncombi; |
957 | sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj]; | |
958 | sigma+=sigmasq[jj]; | |
959 | } | |
960 | sigma=TMath::Sqrt(TMath::Abs(sigma)); | |
961 | } | |
962 | else { | |
963 | Warning("VertexFinder","Finder did not succed"); | |
964 | sigma=999; | |
965 | } | |
966 | fVert.SetXYZ(initPos); | |
967 | fVert.SetDispersion(sigma); | |
968 | fVert.SetNContributors(ncombi); | |
2d57349e | 969 | } |
ec1be5d5 | 970 | //--------------------------------------------------------------------------- |
fee9ef0d | 971 | void AliVertexerTracks::VertexFitter(Bool_t useConstraint) |
972 | { | |
ec1be5d5 | 973 | // |
974 | // The optimal estimate of the vertex position is given by a "weighted | |
975 | // average of tracks positions" | |
fee9ef0d | 976 | // Original method: V. Karimaki, CMS Note 97/0051 |
ec1be5d5 | 977 | // |
978 | Double_t initPos[3]; | |
979 | fVert.GetXYZ(initPos); | |
fee9ef0d | 980 | Int_t arrEntries = (Int_t)fTrkArray.GetEntries(); |
981 | if(arrEntries==1) useConstraint=kTRUE; | |
ec1be5d5 | 982 | if(fDebug) { |
983 | printf(" VertexFitter(): start\n"); | |
984 | printf(" Number of tracks in array: %d\n",(Int_t)fTrkArray.GetEntriesFast()); | |
985 | printf(" Minimum # tracks required in fit: %d\n",fMinTracks); | |
986 | printf("Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]); | |
fee9ef0d | 987 | if(useConstraint) 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 | 988 | } |
989 | ||
990 | Int_t i,j,k,step=0; | |
991 | TMatrixD rv(3,1); | |
992 | TMatrixD vV(3,3); | |
993 | rv(0,0) = initPos[0]; | |
994 | rv(1,0) = initPos[1]; | |
995 | rv(2,0) = 0.; | |
996 | Double_t xlStart,alpha; | |
ec1be5d5 | 997 | Int_t nUsedTrks; |
fee9ef0d | 998 | Double_t chi2,chi2i,chi2b; |
ec1be5d5 | 999 | AliESDtrack *t = 0; |
1000 | Int_t failed = 0; | |
1001 | ||
50ff0bcd | 1002 | // initial vertex covariance matrix |
1003 | TMatrixD vVb(3,3); | |
1004 | vVb(0,0) = fNominalCov[0]; | |
1005 | vVb(0,1) = fNominalCov[1]; | |
1006 | vVb(0,2) = 0.; | |
1007 | vVb(1,0) = fNominalCov[1]; | |
1008 | vVb(1,1) = fNominalCov[2]; | |
1009 | vVb(1,2) = 0.; | |
1010 | vVb(2,0) = 0.; | |
1011 | vVb(2,1) = 0.; | |
1012 | vVb(2,2) = fNominalCov[5]; | |
1013 | TMatrixD vVbInv(TMatrixD::kInverted,vVb); | |
1014 | TMatrixD rb(3,1); | |
1015 | rb(0,0) = fNominalPos[0]; | |
1016 | rb(1,0) = fNominalPos[1]; | |
1017 | rb(2,0) = fNominalPos[2]; | |
1018 | TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb); | |
1019 | ||
1020 | ||
eae1677e | 1021 | // 2 steps: |
1022 | // 1st - estimate of vtx using all tracks | |
1023 | // 2nd - estimate of global chi2 | |
1024 | for(step=0; step<2; step++) { | |
ec1be5d5 | 1025 | if(fDebug) printf(" step = %d\n",step); |
1026 | chi2 = 0.; | |
1027 | nUsedTrks = 0; | |
1028 | ||
1029 | TMatrixD sumWiri(3,1); | |
1030 | TMatrixD sumWi(3,3); | |
1031 | for(i=0; i<3; i++) { | |
1032 | sumWiri(i,0) = 0.; | |
1033 | for(j=0; j<3; j++) sumWi(j,i) = 0.; | |
1034 | } | |
1035 | ||
fee9ef0d | 1036 | // mean vertex constraint |
1037 | if(useConstraint) { | |
50ff0bcd | 1038 | for(i=0;i<3;i++) { |
1039 | sumWiri(i,0) += vVbInvrb(i,0); | |
1040 | for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k); | |
07680cae | 1041 | } |
fee9ef0d | 1042 | // chi2 |
1043 | TMatrixD deltar = rv; deltar -= rb; | |
1044 | TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar); | |
1045 | chi2b = deltar(0,0)*vVbInvdeltar(0,0)+ | |
1046 | deltar(1,0)*vVbInvdeltar(1,0)+ | |
1047 | deltar(2,0)*vVbInvdeltar(2,0); | |
1048 | chi2 += chi2b; | |
07680cae | 1049 | } |
1050 | ||
1051 | ||
ec1be5d5 | 1052 | // loop on tracks |
1053 | for(k=0; k<arrEntries; k++) { | |
ec1be5d5 | 1054 | // get track from track array |
1055 | t = (AliESDtrack*)fTrkArray.At(k); | |
1056 | alpha = t->GetAlpha(); | |
1057 | xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha); | |
fee9ef0d | 1058 | // to vtxSeed (from finder) |
1059 | t->AliExternalTrackParam::PropagateTo(xlStart,AliTracker::GetBz()); | |
1060 | ||
1061 | ||
ec1be5d5 | 1062 | // vector of track global coordinates |
1063 | TMatrixD ri(3,1); | |
fee9ef0d | 1064 | // covariance matrix of ri |
1065 | TMatrixD wWi(3,3); | |
1066 | ||
1067 | // get space point from track | |
1068 | if(!TrackToPoint(t,ri,wWi)) continue; | |
1069 | ||
1070 | TMatrixD wWiri(wWi,TMatrixD::kMult,ri); | |
ec1be5d5 | 1071 | |
1072 | // track chi2 | |
1073 | TMatrixD deltar = rv; deltar -= ri; | |
1074 | TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar); | |
1075 | chi2i = deltar(0,0)*wWideltar(0,0)+ | |
1076 | deltar(1,0)*wWideltar(1,0)+ | |
1077 | deltar(2,0)*wWideltar(2,0); | |
1078 | ||
ec1be5d5 | 1079 | // add to total chi2 |
1080 | chi2 += chi2i; | |
1081 | ||
ec1be5d5 | 1082 | sumWiri += wWiri; |
1083 | sumWi += wWi; | |
1084 | ||
1085 | nUsedTrks++; | |
1086 | } // end loop on tracks | |
1087 | ||
1088 | if(nUsedTrks < fMinTracks) { | |
1089 | failed=1; | |
1090 | continue; | |
1091 | } | |
1092 | ||
1093 | Double_t determinant = sumWi.Determinant(); | |
1094 | //cerr<<" determinant: "<<determinant<<endl; | |
1095 | if(determinant < 100.) { | |
1096 | printf("det(V) = 0\n"); | |
1097 | failed=1; | |
1098 | continue; | |
1099 | } | |
1100 | ||
1101 | // inverted of weights matrix | |
1102 | TMatrixD invsumWi(TMatrixD::kInverted,sumWi); | |
1103 | vV = invsumWi; | |
1104 | ||
1105 | // position of primary vertex | |
1106 | rv.Mult(vV,sumWiri); | |
1107 | ||
eae1677e | 1108 | } // end loop on the 2 steps |
ec1be5d5 | 1109 | |
5834e9a1 | 1110 | // delete t; |
ec1be5d5 | 1111 | |
1112 | if(failed) { | |
50ff0bcd | 1113 | if(fDebug) printf("TooFewTracks\n"); |
ec1be5d5 | 1114 | fCurrentVertex = new AliESDVertex(0.,0.,-1); |
1115 | return; | |
1116 | } | |
1117 | ||
1118 | Double_t position[3]; | |
1119 | position[0] = rv(0,0); | |
1120 | position[1] = rv(1,0); | |
1121 | position[2] = rv(2,0); | |
1122 | Double_t covmatrix[6]; | |
1123 | covmatrix[0] = vV(0,0); | |
1124 | covmatrix[1] = vV(0,1); | |
1125 | covmatrix[2] = vV(1,1); | |
1126 | covmatrix[3] = vV(0,2); | |
1127 | covmatrix[4] = vV(1,2); | |
1128 | covmatrix[5] = vV(2,2); | |
1129 | ||
1130 | // store data in the vertex object | |
1131 | fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nUsedTrks); | |
1132 | ||
1133 | if(fDebug) { | |
1134 | printf(" VertexFitter(): finish\n"); | |
1135 | printf(" rv = ( %f , %f , %f )\n\n",rv(0,0),rv(1,0),rv(2,0)); | |
1136 | fCurrentVertex->PrintStatus(); | |
1137 | } | |
1138 | ||
1139 | return; | |
1140 | } | |
50ff0bcd | 1141 | //---------------------------------------------------------------------------- |
fee9ef0d | 1142 | AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TTree *trkTree,Bool_t optUseFitter,Bool_t optPropagate) |
1143 | { | |
eae1677e | 1144 | // |
50ff0bcd | 1145 | // Return vertex from tracks in trkTree |
eae1677e | 1146 | // |
1147 | ||
fee9ef0d | 1148 | SetConstraintOff(); |
1149 | ||
50ff0bcd | 1150 | // get tracks and propagate them to initial vertex position |
fee9ef0d | 1151 | Int_t nTrksPrep = PrepareTracks(*trkTree,0); |
0c69be49 | 1152 | if(nTrksPrep < TMath::Max(2,fMinTracks) ) { |
50ff0bcd | 1153 | if(fDebug) printf("TooFewTracks\n"); |
fee9ef0d | 1154 | fCurrentVertex = new AliESDVertex(0.,0.,-1); |
1155 | return fCurrentVertex; | |
50ff0bcd | 1156 | } |
1157 | ||
fee9ef0d | 1158 | switch (fAlgo) { |
1159 | case 1: StrLinVertexFinderMinDist(1); break; | |
1160 | case 2: StrLinVertexFinderMinDist(0); break; | |
1161 | case 3: HelixVertexFinder(); break; | |
1162 | case 4: VertexFinder(1); break; | |
1163 | case 5: VertexFinder(0); break; | |
1164 | default: printf("Wrong algorithm\n"); break; | |
1165 | } | |
50ff0bcd | 1166 | |
fee9ef0d | 1167 | if(fDebug) printf(" Vertex finding completed\n"); |
1168 | ||
1169 | // vertex fitter | |
1170 | if(optUseFitter){ | |
1171 | VertexFitter(fConstraint); | |
1172 | if(fDebug) printf(" Vertex fit completed\n"); | |
1173 | }else{ | |
1174 | Double_t position[3]={fVert.GetXv(),fVert.GetYv(),fVert.GetZv()}; | |
1175 | Double_t covmatrix[6]={0.,0.,0.,0.,0.,0.}; | |
1176 | Double_t chi2=99999.; | |
1177 | Int_t nUsedTrks=fVert.GetNContributors(); | |
1178 | fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nUsedTrks); | |
1179 | } | |
1180 | fCurrentVertex->SetDispersion(fVert.GetDispersion()); | |
1181 | ||
1182 | ||
1183 | // set indices of used tracks and propagate track to found vertex | |
50ff0bcd | 1184 | UShort_t *indices = 0; |
1185 | AliESDtrack *eta = 0; | |
fee9ef0d | 1186 | if(fCurrentVertex->GetNContributors()>0) { |
1187 | indices = new UShort_t[fCurrentVertex->GetNContributors()]; | |
50ff0bcd | 1188 | for(Int_t jj=0;jj<(Int_t)fTrkArray.GetEntriesFast();jj++) { |
1189 | eta = (AliESDtrack*)fTrkArray.At(jj); | |
1190 | indices[jj] = (UShort_t)eta->GetID(); | |
fee9ef0d | 1191 | if(optPropagate&&optUseFitter){ |
1192 | if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) { | |
1193 | eta->RelateToVertex(fCurrentVertex,GetField(),100.); | |
1194 | if(fDebug) printf("Track %d propagated to found vertex\n",jj); | |
1195 | }else{ | |
1196 | AliWarning("Found vertex outside beam pipe!"); | |
1197 | } | |
1198 | } | |
50ff0bcd | 1199 | } |
fee9ef0d | 1200 | fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices); |
50ff0bcd | 1201 | } |
1202 | delete [] indices; | |
1203 | fTrkArray.Delete(); | |
1204 | ||
fee9ef0d | 1205 | return fCurrentVertex; |
eae1677e | 1206 | } |
50ff0bcd | 1207 | //---------------------------------------------------------------------------- |
fee9ef0d | 1208 | AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray,Bool_t optUseFitter, Bool_t optPropagate) |
1209 | { | |
50ff0bcd | 1210 | // |
1211 | // Return vertex from array of tracks | |
1212 | // | |
5834e9a1 | 1213 | |
50ff0bcd | 1214 | // get tracks and propagate them to initial vertex position |
1215 | Int_t nTrks = trkArray->GetEntriesFast(); | |
0c69be49 | 1216 | if(nTrks < TMath::Max(2,fMinTracks) ) { |
50ff0bcd | 1217 | if(fDebug) printf("TooFewTracks\n"); |
fee9ef0d | 1218 | fCurrentVertex = new AliESDVertex(0.,0.,-1); |
1219 | return fCurrentVertex; | |
50ff0bcd | 1220 | } |
1221 | TTree *trkTree = new TTree("TreeT","tracks"); | |
1222 | AliESDtrack *esdTrack = 0; | |
1223 | trkTree->Branch("tracks","AliESDtrack",&esdTrack); | |
1224 | for(Int_t i=0; i<nTrks; i++){ | |
1225 | esdTrack = (AliESDtrack*)trkArray->At(i); | |
1226 | trkTree->Fill(); | |
1227 | } | |
1228 | ||
fee9ef0d | 1229 | AliESDVertex *vtx = VertexForSelectedTracks(trkTree,optUseFitter,optPropagate); |
50ff0bcd | 1230 | delete trkTree; |
1231 | return vtx; | |
1232 | } | |
1233 | //-------------------------------------------------------------------------- |