1 /**************************************************************************
2 * Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
16 //-----------------------------------------------------------------
17 // Implementation of the vertexer from tracks
19 // Origin: AliITSVertexerTracks
21 // andrea.dainese@pd.infn.it
23 // massimo.masera@to.infn.it
24 // Moved to STEER and adapted to ESD tracks:
25 // F.Prino, Torino, prino@to.infn.it
26 //-----------------------------------------------------------------
28 //---- Root headers --------
30 #include <TDirectory.h>
34 //---- AliRoot headers -----
36 #include "AliStrLine.h"
37 #include "AliExternalTrackParam.h"
38 #include "AliNeutralTrackParam.h"
39 #include "AliVEvent.h"
40 #include "AliVTrack.h"
41 #include "AliESDEvent.h"
42 #include "AliESDtrack.h"
43 #include "AliVertexerTracks.h"
45 ClassImp(AliVertexerTracks)
48 //----------------------------------------------------------------------------
49 AliVertexerTracks::AliVertexerTracks():
78 // Default constructor
83 //----------------------------------------------------------------------------
84 AliVertexerTracks::AliVertexerTracks(Double_t fieldkG):
113 // Standard constructor
118 //-----------------------------------------------------------------------------
119 AliVertexerTracks::~AliVertexerTracks()
121 // Default Destructor
122 // The objects pointed by the following pointer are not owned
123 // by this class and are not deleted
125 if(fTrksToSkip) { delete fTrksToSkip; fTrksToSkip=NULL; }
126 if(fIdSel) { delete fIdSel; fIdSel=NULL; }
128 //----------------------------------------------------------------------------
129 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(AliVEvent *vEvent)
132 // Primary vertex for current ESD or AOD event
134 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
135 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
136 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
140 TString evtype = vEvent->IsA()->GetName();
141 Bool_t inputAOD = ((evtype=="AliAODEvent") ? kTRUE : kFALSE);
143 if(inputAOD && fMode==1) {
144 printf("Error : AliVertexerTracks: no TPC-only vertex from AOD\n");
146 return fCurrentVertex;
149 // accept 1-track case only if constraint is available
150 if(!fConstraint && fMinTracks==1) fMinTracks=2;
152 // read tracks from AlivEvent
153 Int_t nTrks = (Int_t)vEvent->GetNumberOfTracks();
154 if(nTrks<fMinTracks) {
156 return fCurrentVertex;
160 TDirectory * olddir = gDirectory;
162 if(nTrks>500) f = new TFile("VertexerTracks.root","recreate");
163 TObjArray trkArrayOrig(nTrks);
164 UShort_t *idOrig = new UShort_t[nTrks];
167 AliExternalTrackParam *t=0;
169 for(Int_t i=0; i<nTrks; i++) {
170 AliVTrack *track = (AliVTrack*)vEvent->GetTrack(i);
171 // check tracks to skip
172 Bool_t skipThis = kFALSE;
173 for(Int_t j=0; j<fNTrksToSkip; j++) {
174 if(track->GetID()==fTrksToSkip[j]) {
175 AliDebug(1,Form("skipping track: %d",i));
179 if(skipThis) continue;
181 // skip pure ITS SA tracks (default)
182 if(!fITSpureSA && (track->GetStatus()&AliESDtrack::kITSpureSA)) continue;
183 // or use only pure ITS SA tracks
184 if(fITSpureSA && !(track->GetStatus()&AliESDtrack::kITSpureSA)) continue;
187 if(fMode==0 && fITSrefit && !(track->GetStatus()&AliESDtrack::kITSrefit)) continue;
189 if(!inputAOD) { // ESD
190 AliESDtrack* esdt = (AliESDtrack*)track;
191 if(esdt->GetNcls(fMode) < fMinClusters) continue;
192 if(fMode==0) { // ITS mode
193 Double_t x,p[5],cov[15];
194 esdt->GetExternalParameters(x,p);
195 esdt->GetExternalCovariance(cov);
196 t = new AliExternalTrackParam(x,esdt->GetAlpha(),p,cov);
197 } else if(fMode==1) { // TPC mode
198 t = (AliExternalTrackParam*)esdt->GetTPCInnerParam();
200 Double_t radius = 2.8; //something less than the beam pipe radius
201 if(!PropagateTrackTo(t,radius)) continue;
203 } else { // AOD (only ITS mode)
205 for(Int_t l=0;l<6;l++) if(TESTBIT(track->GetITSClusterMap(),l)) ncls0++;
206 if(ncls0 < fMinClusters) continue;
207 t = new AliExternalTrackParam(track);
209 trkArrayOrig.AddLast(t);
210 idOrig[nTrksOrig]=(UShort_t)track->GetID();
212 } // end loop on tracks
214 // call method that will reconstruct the vertex
215 FindPrimaryVertex(&trkArrayOrig,idOrig);
217 if(fMode==0) trkArrayOrig.Delete();
218 delete idOrig; idOrig=NULL;
221 f->Close(); delete f; f = NULL;
222 gSystem->Unlink("VertexerTracks.root");
226 // set vertex ID for tracks used in the fit
229 Int_t nIndices = fCurrentVertex->GetNIndices();
230 UShort_t *indices = fCurrentVertex->GetIndices();
231 for(Int_t ind=0; ind<nIndices; ind++) {
232 AliESDtrack *esdt = (AliESDtrack*)vEvent->GetTrack(indices[ind]);
233 esdt->SetVertexID(-1);
237 return fCurrentVertex;
239 //----------------------------------------------------------------------------
240 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(TObjArray *trkArrayOrig,
244 // Primary vertex using the AliExternalTrackParam's in the TObjArray.
245 // idOrig must contain the track IDs from AliESDtrack::GetID()
247 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
248 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
249 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
253 // accept 1-track case only if constraint is available
254 if(!fConstraint && fMinTracks==1) fMinTracks=2;
256 // read tracks from array
257 Int_t nTrksOrig = (Int_t)trkArrayOrig->GetEntriesFast();
258 AliDebug(1,Form("Initial number of tracks: %d",nTrksOrig));
259 if(nTrksOrig<fMinTracks) {
260 AliDebug(1,"TooFewTracks");
262 return fCurrentVertex;
265 // If fConstraint=kFALSE
266 // run VertexFinder(1) to get rough estimate of initVertex (x,y)
268 // fill fTrkArraySel, for VertexFinder()
269 fIdSel = new UShort_t[nTrksOrig];
270 PrepareTracks(*trkArrayOrig,idOrig,0);
271 if(fIdSel) { delete fIdSel; fIdSel=NULL; }
272 Double_t cutsave = fDCAcut;
273 fDCAcut = fDCAcutIter0;
275 switch (fAlgoIter0) {
276 case 1: StrLinVertexFinderMinDist(1); break;
277 case 2: StrLinVertexFinderMinDist(0); break;
278 case 3: HelixVertexFinder(); break;
279 case 4: VertexFinder(1); break;
280 case 5: VertexFinder(0); break;
281 default: printf("Wrong algorithm\n"); break;
284 if(fVert.GetNContributors()>0) {
285 fVert.GetXYZ(fNominalPos);
286 fNominalPos[0] = fVert.GetXv();
287 fNominalPos[1] = fVert.GetYv();
288 fNominalPos[2] = fVert.GetZv();
289 AliDebug(1,Form("No mean vertex: VertexFinder gives (%f, %f, %f)",fNominalPos[0],fNominalPos[1],fNominalPos[2]));
294 AliDebug(1,"No mean vertex and VertexFinder failed");
301 // propagate tracks to fNominalPos vertex
303 // if(constraint) reject for |d0|>5*fNSigma*sigma w.r.t. fNominal... vertex
304 // else reject for |d0|\oplus|z0| > 5 mm w.r.t. fNominal... vertex
306 // propagate tracks to best between initVertex and fCurrentVertex
307 // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best
308 // between initVertex and fCurrentVertex)
309 for(Int_t iter=1; iter<=2; iter++) {
310 if(fOnlyFitter && iter==1) continue;
311 if(fIdSel) { delete fIdSel; fIdSel=NULL; }
312 fIdSel = new UShort_t[nTrksOrig];
313 Int_t nTrksSel = PrepareTracks(*trkArrayOrig,idOrig,iter);
314 AliDebug(1,Form("N tracks selected in iteration %d: %d",iter,nTrksSel));
315 if(nTrksSel < fMinTracks) {
317 return fCurrentVertex;
323 AliDebug(1,"Just one track");
324 OneTrackVertFinder();
327 case 1: StrLinVertexFinderMinDist(1); break;
328 case 2: StrLinVertexFinderMinDist(0); break;
329 case 3: HelixVertexFinder(); break;
330 case 4: VertexFinder(1); break;
331 case 5: VertexFinder(0); break;
332 default: printf("Wrong algorithm"); break;
335 AliDebug(1," Vertex finding completed");
340 } // end loop on the two iterations
343 // set indices of used tracks
344 UShort_t *indices = 0;
345 if(fCurrentVertex->GetNContributors()>0) {
346 Int_t nIndices = (Int_t)fTrkArraySel.GetEntriesFast();
347 indices = new UShort_t[nIndices];
348 for(Int_t jj=0; jj<nIndices; jj++)
349 indices[jj] = fIdSel[jj];
350 fCurrentVertex->SetIndices(nIndices,indices);
352 if (indices) {delete indices; indices=NULL;}
356 TString title="VertexerTracksNoConstraint";
358 title="VertexerTracksWithConstraint";
359 if(fOnlyFitter) title.Append("OnlyFitter");
361 fCurrentVertex->SetTitle(title.Data());
364 AliDebug(1,Form("xyz: %f %f %f; nc %d",fCurrentVertex->GetXv(),fCurrentVertex->GetYv(),fCurrentVertex->GetZv(),fCurrentVertex->GetNContributors()));
367 delete fIdSel; fIdSel=NULL;
368 fTrkArraySel.Delete();
369 if(fTrksToSkip) { delete fTrksToSkip; fTrksToSkip=NULL; }
372 return fCurrentVertex;
374 //------------------------------------------------------------------------
375 Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3])
378 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];
381 //-------------------------------------------------------------------------
382 void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d)
385 Double_t x12=p0[0]-p1[0];
386 Double_t y12=p0[1]-p1[1];
387 Double_t z12=p0[2]-p1[2];
388 Double_t kk=x12*x12+y12*y12+z12*z12;
389 m[0][0]=2-2/kk*x12*x12;
390 m[0][1]=-2/kk*x12*y12;
391 m[0][2]=-2/kk*x12*z12;
392 m[1][0]=-2/kk*x12*y12;
393 m[1][1]=2-2/kk*y12*y12;
394 m[1][2]=-2/kk*y12*z12;
395 m[2][0]=-2/kk*x12*z12;
397 m[2][2]=2-2/kk*z12*z12;
398 d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
399 d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
400 d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
403 //--------------------------------------------------------------------------
404 void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d)
407 Double_t x12=p1[0]-p0[0];
408 Double_t y12=p1[1]-p0[1];
409 Double_t z12=p1[2]-p0[2];
411 Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
413 Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
416 cc[0]=-x12/sigmasq[0];
417 cc[1]=-y12/sigmasq[1];
418 cc[2]=-z12/sigmasq[2];
420 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;
422 Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
425 aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
426 aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
427 aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
429 m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
430 m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
431 m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
433 m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
434 m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
435 m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
437 m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
438 m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
439 m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
441 d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
442 d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
443 d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
446 //--------------------------------------------------------------------------
447 Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0)
450 Double_t x12=p0[0]-p1[0];
451 Double_t y12=p0[1]-p1[1];
452 Double_t z12=p0[2]-p1[2];
453 Double_t x10=p0[0]-x0[0];
454 Double_t y10=p0[1]-x0[1];
455 Double_t z10=p0[2]-x0[2];
456 // 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);
457 return ((y10*z12-z10*y12)*(y10*z12-z10*y12)+
458 (z10*x12-x10*z12)*(z10*x12-x10*z12)+
459 (x10*y12-y10*x12)*(x10*y12-y10*x12))
460 /(x12*x12+y12*y12+z12*z12);
462 //---------------------------------------------------------------------------
463 void AliVertexerTracks::OneTrackVertFinder()
465 // find vertex for events with 1 track, using DCA to nominal beam axis
466 AliDebug(1,Form("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArraySel.GetEntries()));
467 AliExternalTrackParam *track1;
468 track1 = (AliExternalTrackParam*)fTrkArraySel.At(0);
469 Double_t alpha=track1->GetAlpha();
470 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
471 Double_t pos[3],dir[3];
472 track1->GetXYZAt(mindist,GetFieldkG(),pos);
473 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
474 AliStrLine *line1 = new AliStrLine(pos,dir);
475 Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.};
476 Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.};
477 AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE);
478 Double_t crosspoint[3]={0.,0.,0.};
481 Int_t retcode = zeta->Cross(line1,crosspoint);
483 sigma=line1->GetDistFromPoint(crosspoint);
488 fVert.SetXYZ(crosspoint);
489 fVert.SetDispersion(sigma);
490 fVert.SetNContributors(nContrib);
492 //---------------------------------------------------------------------------
493 void AliVertexerTracks::HelixVertexFinder()
495 // Get estimate of vertex position in (x,y) from tracks DCA
500 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
502 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
504 Double_t aver[3]={0.,0.,0.};
505 Double_t averquad[3]={0.,0.,0.};
506 Double_t sigmaquad[3]={0.,0.,0.};
509 AliExternalTrackParam *track1;
510 AliExternalTrackParam *track2;
513 Double_t alpha, cs, sn;
514 Double_t crosspoint[3];
515 for(Int_t i=0; i<nacc; i++){
516 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
519 for(Int_t j=i+1; j<nacc; j++){
520 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
522 distCA=track2->PropagateToDCA(track1,GetFieldkG());
523 if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
525 alpha=track1->GetAlpha();
526 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
527 Double_t x1=x*cs - track1->GetY()*sn;
528 Double_t y1=x*sn + track1->GetY()*cs;
529 Double_t z1=track1->GetZ();
531 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
533 alpha=track2->GetAlpha();
534 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
535 Double_t x2=x*cs - track2->GetY()*sn;
536 Double_t y2=x*sn + track2->GetY()*cs;
537 Double_t z2=track2->GetZ();
538 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
539 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
540 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
541 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
542 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
543 crosspoint[0]=wx1*x1 + wx2*x2;
544 crosspoint[1]=wy1*y1 + wy2*y2;
545 crosspoint[2]=wz1*z1 + wz2*z2;
548 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
549 for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
555 for(Int_t jj=0;jj<3;jj++){
556 initPos[jj] = aver[jj]/ncombi;
557 averquad[jj]/=ncombi;
558 sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
559 sigma+=sigmaquad[jj];
561 sigma=TMath::Sqrt(TMath::Abs(sigma));
564 Warning("HelixVertexFinder","Finder did not succed");
567 fVert.SetXYZ(initPos);
568 fVert.SetDispersion(sigma);
569 fVert.SetNContributors(ncombi);
571 //----------------------------------------------------------------------------
572 Int_t AliVertexerTracks::PrepareTracks(TObjArray &trkArrayOrig,
577 // Propagate tracks to initial vertex position and store them in a TObjArray
579 AliDebug(1," PrepareTracks()");
581 Int_t nTrksOrig = (Int_t)trkArrayOrig.GetEntriesFast();
584 Double_t sigmaCurr[3];
585 Double_t normdistx,normdisty;
586 Double_t d0z0[2],covd0z0[3];
589 AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1);
591 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
593 AliExternalTrackParam *track=0;
596 for(Int_t i=0; i<nTrksOrig; i++) {
597 AliExternalTrackParam *trackOrig=(AliExternalTrackParam*)trkArrayOrig.At(i);
598 if(trackOrig->Charge()!=0) { // normal tracks
599 track = new AliExternalTrackParam(*(AliExternalTrackParam*)trkArrayOrig.At(i));
600 } else { // neutral tracks (from a V0)
601 track = new AliNeutralTrackParam(*(AliNeutralTrackParam*)trkArrayOrig.At(i));
605 if(TMath::Abs(track->GetTgl())>fMaxTgl) {
606 AliDebug(1,Form(" rejecting track with tgl = %f",track->GetTgl()));
607 delete track; continue;
610 Bool_t propagateOK = kFALSE, cutond0z0 = kTRUE;
611 // propagate track to vertex
612 if(optImpParCut<2 || fOnlyFitter) { // optImpParCut==1 or 0
613 propagateOK = track->PropagateToDCA(initVertex,GetFieldkG(),100.,d0z0,covd0z0);
614 } else { // optImpParCut==2
615 fCurrentVertex->GetSigmaXYZ(sigmaCurr);
616 normdistx = TMath::Abs(fCurrentVertex->GetXv()-fNominalPos[0])/TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0]);
617 normdisty = TMath::Abs(fCurrentVertex->GetYv()-fNominalPos[1])/TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2]);
618 AliDebug(1,Form("normdistx %f %f %f",fCurrentVertex->GetXv(),fNominalPos[0],TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0])));
619 AliDebug(1,Form("normdisty %f %f %f",fCurrentVertex->GetYv(),fNominalPos[1],TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2])));
620 AliDebug(1,Form("sigmaCurr %f %f %f",sigmaCurr[0],sigmaCurr[1],TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2])));
621 if(normdistx < 3. && normdisty < 3. &&
622 (sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) {
623 propagateOK = track->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
625 propagateOK = track->PropagateToDCA(initVertex,GetFieldkG(),100.,d0z0,covd0z0);
626 if(fConstraint) cutond0z0=kFALSE;
631 AliDebug(1," rejected");
632 delete track; continue;
635 sigmad0 = TMath::Sqrt(covd0z0[0]);
636 maxd0rphi = fNSigma*sigmad0;
637 if(optImpParCut==1) maxd0rphi *= 5.;
638 maxd0rphi = TMath::Min(maxd0rphi,fFiducialR);
639 //sigmad0z0 = TMath::Sqrt(covd0z0[0]+covd0z0[2]);
641 AliDebug(1,Form("trk %d; id %d; |d0| = %f; d0 cut = %f; |z0| = %f; |d0|oplus|z0| = %f; d0z0 cut = %f",i,(Int_t)idOrig[i],TMath::Abs(d0z0[0]),maxd0rphi,TMath::Abs(d0z0[1]),TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]),fMaxd0z0));
644 //---- track selection based on impact parameters ----//
646 // always reject tracks outside fiducial volume
647 if(TMath::Abs(d0z0[0])>fFiducialR || TMath::Abs(d0z0[1])>fFiducialZ) {
648 AliDebug(1," rejected");
649 delete track; continue;
652 // during iterations 1 and 2 , reject tracks with d0rphi > maxd0rphi
653 if(optImpParCut>0 && TMath::Abs(d0z0[0])>maxd0rphi) {
654 AliDebug(1," rejected");
655 delete track; continue;
658 // if fConstraint=kFALSE, during iterations 1 and 2 ||
659 // if fConstraint=kTRUE, during iteration 2,
660 // select tracks with d0oplusz0 < fMaxd0z0
661 if((!fConstraint && optImpParCut>0 && fVert.GetNContributors()>0) ||
662 ( fConstraint && optImpParCut==2 && cutond0z0)) {
664 TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1])>fMaxd0z0) {
665 AliDebug(1," rejected");
666 delete track; continue;
670 // track passed all selections
671 fTrkArraySel.AddLast(track);
672 fIdSel[nTrksSel] = idOrig[i];
674 } // end loop on tracks
680 //----------------------------------------------------------------------------
681 Bool_t AliVertexerTracks::PropagateTrackTo(AliExternalTrackParam *track,
683 //----------------------------------------------------------------
684 // COPIED from AliTracker
686 // Propagates the track to the plane X=xk (cm).
688 // Origin: Marian Ivanov, Marian.Ivanov@cern.ch
689 //----------------------------------------------------------------
691 const Double_t kEpsilon = 0.00001;
692 Double_t xpos = track->GetX();
693 Double_t dir = (xpos<xToGo) ? 1. : -1.;
694 Double_t maxStep = 5;
695 Double_t maxSnp = 0.8;
697 while ( (xToGo-xpos)*dir > kEpsilon){
698 Double_t step = dir*TMath::Min(TMath::Abs(xToGo-xpos), maxStep);
699 Double_t x = xpos+step;
700 Double_t xyz0[3],xyz1[3];
701 track->GetXYZ(xyz0); //starting global position
703 if(!track->GetXYZAt(x,GetFieldkG(),xyz1)) return kFALSE; // no prolongation
704 xyz1[2]+=kEpsilon; // waiting for bug correction in geo
706 if(TMath::Abs(track->GetSnpAt(x,GetFieldkG())) >= maxSnp) return kFALSE;
707 if(!track->PropagateTo(x,GetFieldkG())) return kFALSE;
709 if(TMath::Abs(track->GetSnp()) >= maxSnp) return kFALSE;
710 track->GetXYZ(xyz0); // global position
711 Double_t alphan = TMath::ATan2(xyz0[1], xyz0[0]);
713 Double_t ca=TMath::Cos(alphan-track->GetAlpha()),
714 sa=TMath::Sin(alphan-track->GetAlpha());
715 Double_t sf=track->GetSnp(), cf=TMath::Sqrt((1.-sf)*(1.+sf));
716 Double_t sinNew = sf*ca - cf*sa;
717 if(TMath::Abs(sinNew) >= maxSnp) return kFALSE;
718 if(!track->Rotate(alphan)) return kFALSE;
720 xpos = track->GetX();
724 //---------------------------------------------------------------------------
725 AliESDVertex* AliVertexerTracks::RemoveTracksFromVertex(AliESDVertex *inVtx,
728 Float_t *diamondxy) const
731 // Removes tracks in trksTree from fit of inVtx
734 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
735 printf("ERROR: primary vertex has no constraint: cannot remove tracks");
738 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraintOnlyFitter"))
739 printf("WARNING: result of tracks' removal will be only approximately correct");
742 rv(0,0) = inVtx->GetXv();
743 rv(1,0) = inVtx->GetYv();
744 rv(2,0) = inVtx->GetZv();
747 inVtx->GetCovMatrix(cov);
749 vV(0,1) = cov[1]; vV(1,0) = cov[1];
751 vV(0,2) = cov[3]; vV(2,0) = cov[3];
752 vV(1,2) = cov[4]; vV(2,1) = cov[4];
755 TMatrixD sumWi(TMatrixD::kInverted,vV);
756 TMatrixD sumWiri(sumWi,TMatrixD::kMult,rv);
758 Int_t nUsedTrks = inVtx->GetNIndices();
759 Double_t chi2 = inVtx->GetChi2();
761 AliExternalTrackParam *track = 0;
762 Int_t ntrks = (Int_t)trkArray->GetEntriesFast();
763 for(Int_t i=0;i<ntrks;i++) {
764 track = (AliExternalTrackParam*)trkArray->At(i);
765 if(!inVtx->UsesTrack(id[i])) {
766 printf("track %d was not used in vertex fit",id[i]);
769 Double_t alpha = track->GetAlpha();
770 Double_t xl = diamondxy[0]*TMath::Cos(alpha)+diamondxy[1]*TMath::Sin(alpha);
771 track->PropagateTo(xl,GetFieldkG());
772 // vector of track global coordinates
774 // covariance matrix of ri
777 // get space point from track
778 if(!TrackToPoint(track,ri,wWi)) continue;
780 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
785 // track contribution to chi2
786 TMatrixD deltar = rv; deltar -= ri;
787 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
788 Double_t chi2i = deltar(0,0)*wWideltar(0,0)+
789 deltar(1,0)*wWideltar(1,0)+
790 deltar(2,0)*wWideltar(2,0);
791 // remove from total chi2
796 printf("Trying to remove too many tracks!");
804 // new inverted of weights matrix
805 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
807 // new position of primary vertex
808 rvnew.Mult(vVnew,sumWiri);
810 Double_t position[3];
811 position[0] = rvnew(0,0);
812 position[1] = rvnew(1,0);
813 position[2] = rvnew(2,0);
821 // store data in the vertex object
822 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,nUsedTrks+1); // the +1 is for the constraint
823 outVtx->SetTitle(inVtx->GetTitle());
824 UShort_t *inindices = inVtx->GetIndices();
825 Int_t nIndices = nUsedTrks;
826 UShort_t *outindices = new UShort_t[nIndices];
828 for(Int_t k=0; k<inVtx->GetNIndices(); k++) {
829 Bool_t copyindex=kTRUE;
830 for(Int_t l=0; l<ntrks; l++) {
831 if(inindices[k]==id[l]) copyindex=kFALSE;
834 outindices[j] = inindices[k]; j++;
837 outVtx->SetIndices(nIndices,outindices);
838 if (outindices) delete outindices;
841 printf("Vertex before removing tracks:");
842 inVtx->PrintStatus();
843 inVtx->PrintIndices();
844 printf("Vertex after removing tracks:");
845 outVtx->PrintStatus();
846 outVtx->PrintIndices();
851 //---------------------------------------------------------------------------
852 AliESDVertex* AliVertexerTracks::RemoveConstraintFromVertex(AliESDVertex *inVtx,
854 Float_t *diamondcov) const
857 // Removes diamond constraint from fit of inVtx
860 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
861 printf("ERROR: primary vertex has no constraint: cannot remove it\n");
864 if(inVtx->GetNContributors()<3) {
865 printf("ERROR: primary vertex has less than 2 tracks: cannot remove contraint\n");
869 // diamond constraint
871 vVb(0,0) = diamondcov[0];
872 vVb(0,1) = diamondcov[1];
874 vVb(1,0) = diamondcov[1];
875 vVb(1,1) = diamondcov[2];
879 vVb(2,2) = diamondcov[5];
880 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
882 rb(0,0) = diamondxyz[0];
883 rb(1,0) = diamondxyz[1];
884 rb(2,0) = diamondxyz[2];
885 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
889 rv(0,0) = inVtx->GetXv();
890 rv(1,0) = inVtx->GetYv();
891 rv(2,0) = inVtx->GetZv();
894 inVtx->GetCovMatrix(cov);
896 vV(0,1) = cov[1]; vV(1,0) = cov[1];
898 vV(0,2) = cov[3]; vV(2,0) = cov[3];
899 vV(1,2) = cov[4]; vV(2,1) = cov[4];
901 TMatrixD vVInv(TMatrixD::kInverted,vV);
902 TMatrixD vVInvrv(vVInv,TMatrixD::kMult,rv);
905 TMatrixD sumWi = vVInv - vVbInv;
908 TMatrixD sumWiri = vVInvrv - vVbInvrb;
913 // new inverted of weights matrix
914 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
916 // new position of primary vertex
917 rvnew.Mult(vVnew,sumWiri);
919 Double_t position[3];
920 position[0] = rvnew(0,0);
921 position[1] = rvnew(1,0);
922 position[2] = rvnew(2,0);
931 Double_t chi2 = inVtx->GetChi2();
933 // diamond constribution to chi2
934 TMatrixD deltar = rv; deltar -= rb;
935 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
936 Double_t chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
937 deltar(1,0)*vVbInvdeltar(1,0)+
938 deltar(2,0)*vVbInvdeltar(2,0);
939 // remove from total chi2
942 // store data in the vertex object
943 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,inVtx->GetNContributors()-1);
944 outVtx->SetTitle("VertexerTracksNoConstraint");
945 UShort_t *inindices = inVtx->GetIndices();
946 Int_t nIndices = inVtx->GetNIndices();
947 outVtx->SetIndices(nIndices,inindices);
951 //---------------------------------------------------------------------------
952 void AliVertexerTracks::SetCuts(Double_t *cuts)
958 SetDCAcutIter0(cuts[1]);
960 if(fMode==0 && cuts[3]<0) SetITSrefitNotRequired();
961 SetMinClusters((Int_t)(TMath::Abs(cuts[3])));
962 SetMinTracks((Int_t)(cuts[4]));
963 SetNSigmad0(cuts[5]);
964 SetMinDetFitter(cuts[6]);
966 SetFiducialRZ(cuts[8],cuts[9]);
967 fAlgo=(Int_t)(cuts[10]);
968 fAlgoIter0=(Int_t)(cuts[11]);
972 //---------------------------------------------------------------------------
973 void AliVertexerTracks::SetITSMode(Double_t dcacut,
974 Double_t dcacutIter0,
979 Double_t mindetfitter,
984 Int_t finderAlgoIter0)
987 // Cut values for ITS mode
991 SetITSrefitRequired();
993 SetITSrefitNotRequired();
996 SetDCAcutIter0(dcacutIter0);
998 SetMinClusters(TMath::Abs(minCls));
999 SetMinTracks(mintrks);
1000 SetNSigmad0(nsigma);
1001 SetMinDetFitter(mindetfitter);
1003 SetFiducialRZ(fidR,fidZ);
1005 fAlgoIter0=finderAlgoIter0;
1009 //---------------------------------------------------------------------------
1010 void AliVertexerTracks::SetTPCMode(Double_t dcacut,
1011 Double_t dcacutIter0,
1016 Double_t mindetfitter,
1021 Int_t finderAlgoIter0)
1024 // Cut values for TPC mode
1027 SetITSrefitNotRequired();
1029 SetDCAcutIter0(dcacutIter0);
1030 SetMaxd0z0(maxd0z0);
1031 SetMinClusters(minCls);
1032 SetMinTracks(mintrks);
1033 SetNSigmad0(nsigma);
1034 SetMinDetFitter(mindetfitter);
1036 SetFiducialRZ(fidR,fidZ);
1038 fAlgoIter0=finderAlgoIter0;
1042 //---------------------------------------------------------------------------
1043 void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped)
1046 // Mark the tracks not to be used in the vertex reconstruction.
1047 // Tracks are identified by AliESDtrack::GetID()
1049 fNTrksToSkip = n; fTrksToSkip = new Int_t[n];
1050 for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i];
1053 //---------------------------------------------------------------------------
1054 void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx)
1057 // Set initial vertex knowledge
1059 vtx->GetXYZ(fNominalPos);
1060 vtx->GetCovMatrix(fNominalCov);
1064 //---------------------------------------------------------------------------
1065 void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights)
1067 AliExternalTrackParam *track1;
1068 const Int_t knacc = (Int_t)fTrkArraySel.GetEntriesFast();
1069 AliStrLine **linarray = new AliStrLine* [knacc];
1070 for(Int_t i=0; i<knacc; i++){
1071 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1072 Double_t alpha=track1->GetAlpha();
1073 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1074 Double_t pos[3],dir[3],sigmasq[3];
1075 track1->GetXYZAt(mindist,GetFieldkG(),pos);
1076 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1077 sigmasq[0]=TMath::Sin(alpha)*TMath::Sin(alpha)*track1->GetSigmaY2();
1078 sigmasq[1]=TMath::Cos(alpha)*TMath::Cos(alpha)*track1->GetSigmaY2();
1079 sigmasq[2]=track1->GetSigmaZ2();
1082 if(!TrackToPoint(track1,ri,wWi)) {optUseWeights=kFALSE;printf("WARNING\n");}
1085 for(Int_t ia=0;ia<3;ia++){
1086 for(Int_t ib=0;ib<3;ib++){
1087 wmat[iel]=wWi(ia,ib);
1091 linarray[i] = new AliStrLine(pos,sigmasq,wmat,dir);
1093 fVert=TrackletVertexFinder(linarray,knacc,optUseWeights);
1094 for(Int_t i=0; i<knacc; i++) delete linarray[i];
1097 //---------------------------------------------------------------------------
1098 AliESDVertex AliVertexerTracks::TrackletVertexFinder(TClonesArray *lines, Int_t optUseWeights)
1100 // Calculate the point at minimum distance to prepared tracks (TClonesArray)
1101 const Int_t knacc = (Int_t)lines->GetEntriesFast();
1102 AliStrLine** lines2 = new AliStrLine* [knacc];
1103 for(Int_t i=0; i<knacc; i++){
1104 lines2[i]= (AliStrLine*)lines->At(i);
1106 AliESDVertex vert = TrackletVertexFinder(lines2,knacc,optUseWeights);
1111 //---------------------------------------------------------------------------
1112 AliESDVertex AliVertexerTracks::TrackletVertexFinder(AliStrLine **lines, const Int_t knacc, Int_t optUseWeights)
1114 // Calculate the point at minimum distance to prepared tracks (array of AliStrLine)
1116 Double_t initPos[3]={0.,0.,0.};
1118 Double_t (*vectP0)[3]=new Double_t [knacc][3];
1119 Double_t (*vectP1)[3]=new Double_t [knacc][3];
1122 Double_t dsum[3]={0,0,0};
1123 TMatrixD sumWi(3,3);
1124 for(Int_t i=0;i<3;i++){
1125 for(Int_t j=0;j<3;j++){
1131 for(Int_t i=0; i<knacc; i++){
1132 AliStrLine *line1 = lines[i];
1133 Double_t p0[3],cd[3],sigmasq[3];
1135 if(!line1) printf("ERROR %d %d\n",i,knacc);
1138 line1->GetSigma2P0(sigmasq);
1139 line1->GetWMatrix(wmat);
1142 for(Int_t ia=0;ia<3;ia++){
1143 for(Int_t ib=0;ib<3;ib++){
1144 wWi(ia,ib)=wmat[iel];
1151 Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
1159 Double_t matr[3][3];
1161 if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
1162 else GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
1165 for(Int_t iii=0;iii<3;iii++){
1166 dsum[iii]+=dknow[iii];
1167 for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
1171 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1172 Double_t covmatrix[6];
1173 covmatrix[0] = invsumWi(0,0);
1174 covmatrix[1] = invsumWi(0,1);
1175 covmatrix[2] = invsumWi(1,1);
1176 covmatrix[3] = invsumWi(0,2);
1177 covmatrix[4] = invsumWi(1,2);
1178 covmatrix[5] = invsumWi(2,2);
1180 Double_t vett[3][3];
1181 Double_t det=GetDeterminant3X3(sum);
1185 for(Int_t zz=0;zz<3;zz++){
1186 for(Int_t ww=0;ww<3;ww++){
1187 for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
1189 for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
1190 initPos[zz]=GetDeterminant3X3(vett)/det;
1194 for(Int_t i=0; i<knacc; i++){
1195 Double_t p0[3]={0,0,0},p1[3]={0,0,0};
1196 for(Int_t ii=0;ii<3;ii++){
1197 p0[ii]=vectP0[i][ii];
1198 p1[ii]=vectP1[i][ii];
1200 sigma+=GetStrLinMinDist(p0,p1,initPos);
1203 if(sigma>0.) {sigma=TMath::Sqrt(sigma);}else{sigma=999;}
1207 AliESDVertex theVert(initPos,covmatrix,99999.,knacc);
1208 theVert.SetDispersion(sigma);
1214 //---------------------------------------------------------------------------
1215 Bool_t AliVertexerTracks::TrackToPoint(AliExternalTrackParam *t,
1216 TMatrixD &ri,TMatrixD &wWi,
1217 Bool_t uUi3by3) const
1220 // Extract from the AliExternalTrackParam the global coordinates ri and covariance matrix
1221 // wWi of the space point that it represents (to be used in VertexFitter())
1225 Double_t rotAngle = t->GetAlpha();
1226 if(rotAngle<0.) rotAngle += 2.*TMath::Pi();
1227 Double_t cosRot = TMath::Cos(rotAngle);
1228 Double_t sinRot = TMath::Sin(rotAngle);
1230 ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot;
1231 ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot;
1232 ri(2,0) = t->GetZ();
1237 // matrix to go from global (x,y,z) to local (y,z);
1246 // covariance matrix of local (y,z) - inverted
1248 uUi(0,0) = t->GetSigmaY2();
1249 uUi(0,1) = t->GetSigmaZY();
1250 uUi(1,0) = t->GetSigmaZY();
1251 uUi(1,1) = t->GetSigmaZ2();
1253 //printf(" %f %f",uUi(0,0),uUi(0,1));
1254 //printf(" %f %f",uUi(1,0),uUi(1,1));
1256 if(uUi.Determinant() <= 0.) return kFALSE;
1257 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
1259 // weights matrix: wWi = qQiT * uUiInv * qQi
1260 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
1261 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
1264 if(fVert.GetNContributors()<1) AliFatal("Vertex from finder is empty");
1265 // matrix to go from global (x,y,z) to local (x,y,z);
1277 // covariance of fVert along the track
1278 Double_t p[3],pt,ptot;
1280 pt = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
1281 ptot = TMath::Sqrt(pt*pt+p[2]*p[2]);
1282 Double_t cphi = p[0]/pt; //cos(phi)=px/pt
1283 Double_t sphi = p[1]/pt; //sin(phi)=py/pt
1284 Double_t clambda = pt/ptot; //cos(lambda)=pt/ptot
1285 Double_t slambda = p[2]/ptot; //sin(lambda)=pz/ptot
1286 Double_t covfVert[6];
1287 fVert.GetCovMatrix(covfVert);
1288 Double_t covfVertalongt =
1289 covfVert[0]*cphi*cphi*clambda*clambda
1290 +covfVert[1]*2.*cphi*sphi*clambda*clambda
1291 +covfVert[3]*2.*cphi*clambda*slambda
1292 +covfVert[2]*sphi*sphi*clambda*clambda
1293 +covfVert[4]*2.*sphi*clambda*slambda
1294 +covfVert[5]*slambda*slambda;
1295 // covariance matrix of local (x,y,z) - inverted
1297 uUi(0,0) = covfVertalongt * fnSigmaForUi00 * fnSigmaForUi00;
1298 AliDebug(1,Form("=====> sqrtUi00 cm %f",TMath::Sqrt(uUi(0,0))));
1302 uUi(1,1) = t->GetSigmaY2();
1303 uUi(1,2) = t->GetSigmaZY();
1305 uUi(2,1) = t->GetSigmaZY();
1306 uUi(2,2) = t->GetSigmaZ2();
1307 //printf(" Ui :\n");
1308 //printf(" %f %f\n",uUi(0,0),uUi(0,1));
1309 //printf(" %f %f\n",uUi(1,0),uUi(1,1));
1311 if(uUi.Determinant() <= 0.) return kFALSE;
1312 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
1314 // weights matrix: wWi = qQiT * uUiInv * qQi
1315 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
1316 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
1323 //---------------------------------------------------------------------------
1324 void AliVertexerTracks::TooFewTracks()
1327 // When the number of tracks is < fMinTracks,
1328 // deal with vertices not found and prepare to exit
1330 AliDebug(1,"TooFewTracks");
1332 Double_t pos[3],err[3];
1333 pos[0] = fNominalPos[0];
1334 err[0] = TMath::Sqrt(fNominalCov[0]);
1335 pos[1] = fNominalPos[1];
1336 err[1] = TMath::Sqrt(fNominalCov[2]);
1337 pos[2] = fNominalPos[2];
1338 err[2] = TMath::Sqrt(fNominalCov[5]);
1339 Int_t ncontr = (err[0]>1. ? -1 : -3);
1340 if(fCurrentVertex) { delete fCurrentVertex; fCurrentVertex=0; }
1341 fCurrentVertex = new AliESDVertex(pos,err);
1342 fCurrentVertex->SetNContributors(ncontr);
1345 fCurrentVertex->SetTitle("VertexerTracksWithConstraint");
1347 fCurrentVertex->SetTitle("VertexerTracksNoConstraint");
1350 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
1351 if(fIdSel) {delete fIdSel; fIdSel=NULL;}
1352 if(fTrksToSkip) {delete fTrksToSkip; fTrksToSkip=NULL;}
1356 //---------------------------------------------------------------------------
1357 void AliVertexerTracks::VertexFinder(Int_t optUseWeights)
1360 // Get estimate of vertex position in (x,y) from tracks DCA
1362 Double_t initPos[3];
1364 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
1365 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
1366 Double_t aver[3]={0.,0.,0.};
1367 Double_t aversq[3]={0.,0.,0.};
1368 Double_t sigmasq[3]={0.,0.,0.};
1371 AliExternalTrackParam *track1;
1372 AliExternalTrackParam *track2;
1373 Double_t pos[3],dir[3];
1374 Double_t alpha,mindist;
1376 for(Int_t i=0; i<nacc; i++){
1377 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1378 alpha=track1->GetAlpha();
1379 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1380 track1->GetXYZAt(mindist,GetFieldkG(),pos);
1381 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1382 AliStrLine *line1 = new AliStrLine(pos,dir);
1384 // AliStrLine *line1 = new AliStrLine();
1385 // track1->ApproximateHelixWithLine(mindist,GetFieldkG(),line1);
1387 for(Int_t j=i+1; j<nacc; j++){
1388 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
1389 alpha=track2->GetAlpha();
1390 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1391 track2->GetXYZAt(mindist,GetFieldkG(),pos);
1392 track2->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1393 AliStrLine *line2 = new AliStrLine(pos,dir);
1394 // AliStrLine *line2 = new AliStrLine();
1395 // track2->ApproximateHelixWithLine(mindist,GetFieldkG(),line2);
1396 Double_t distCA=line2->GetDCA(line1);
1397 //printf("%d %d %f\n",i,j,distCA);
1398 if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
1399 Double_t pnt1[3],pnt2[3],crosspoint[3];
1401 if(optUseWeights<=0){
1402 Int_t retcode = line2->Cross(line1,crosspoint);
1405 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1406 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1409 if(optUseWeights>0){
1410 Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
1413 alpha=track1->GetAlpha();
1414 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1415 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
1416 alpha=track2->GetAlpha();
1417 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1418 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
1419 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
1420 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
1421 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
1422 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
1423 crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0];
1424 crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1];
1425 crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2];
1428 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1429 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1438 for(Int_t jj=0;jj<3;jj++){
1439 initPos[jj] = aver[jj]/ncombi;
1440 //printf("%f\n",initPos[jj]);
1442 sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
1445 sigma=TMath::Sqrt(TMath::Abs(sigma));
1448 Warning("VertexFinder","Finder did not succed");
1451 fVert.SetXYZ(initPos);
1452 fVert.SetDispersion(sigma);
1453 fVert.SetNContributors(ncombi);
1455 //---------------------------------------------------------------------------
1456 void AliVertexerTracks::VertexFitter()
1459 // The optimal estimate of the vertex position is given by a "weighted
1460 // average of tracks positions".
1461 // Original method: V. Karimaki, CMS Note 97/0051
1463 Bool_t useConstraint = fConstraint;
1464 Double_t initPos[3];
1466 fVert.GetXYZ(initPos);
1468 initPos[0]=fNominalPos[0];
1469 initPos[1]=fNominalPos[1];
1470 initPos[2]=fNominalPos[2];
1473 Int_t nTrksSel = (Int_t)fTrkArraySel.GetEntries();
1474 if(nTrksSel==1) useConstraint=kTRUE;
1475 AliDebug(1,"--- VertexFitter(): start");
1476 AliDebug(1,Form(" Number of tracks in array: %d\n",nTrksSel));
1477 AliDebug(1,Form(" Minimum # tracks required in fit: %d\n",fMinTracks));
1478 AliDebug(1,Form(" Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]));
1479 if(useConstraint) AliDebug(1,Form(" This vertex will be used in fit: (%f+-%f,%f+-%f)\n",fNominalPos[0],TMath::Sqrt(fNominalCov[0]),fNominalPos[1],TMath::Sqrt(fNominalCov[2])));
1481 // special treatment for few-tracks fits (e.g. secondary vertices)
1482 Bool_t uUi3by3 = kFALSE; if(nTrksSel<5 && !useConstraint) uUi3by3 = kTRUE;
1487 rv(0,0) = initPos[0];
1488 rv(1,0) = initPos[1];
1490 Double_t xlStart,alpha;
1492 Double_t chi2,chi2i,chi2b;
1493 AliExternalTrackParam *t = 0;
1496 // initial vertex covariance matrix
1498 vVb(0,0) = fNominalCov[0];
1499 vVb(0,1) = fNominalCov[1];
1501 vVb(1,0) = fNominalCov[1];
1502 vVb(1,1) = fNominalCov[2];
1506 vVb(2,2) = fNominalCov[5];
1507 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
1509 rb(0,0) = fNominalPos[0];
1510 rb(1,0) = fNominalPos[1];
1511 rb(2,0) = fNominalPos[2];
1512 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
1516 // 1st - estimate of vtx using all tracks
1517 // 2nd - estimate of global chi2
1518 for(step=0; step<2; step++) {
1519 AliDebug(1,Form(" step = %d\n",step));
1523 if(step==1) { initPos[0]=rv(0,0); initPos[0]=rv(1,0); }
1525 TMatrixD sumWiri(3,1);
1526 TMatrixD sumWi(3,3);
1527 for(i=0; i<3; i++) {
1529 for(j=0; j<3; j++) sumWi(j,i) = 0.;
1532 // mean vertex constraint
1535 sumWiri(i,0) += vVbInvrb(i,0);
1536 for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k);
1539 TMatrixD deltar = rv; deltar -= rb;
1540 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
1541 chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
1542 deltar(1,0)*vVbInvdeltar(1,0)+
1543 deltar(2,0)*vVbInvdeltar(2,0);
1548 for(k=0; k<nTrksSel; k++) {
1549 // get track from track array
1550 t = (AliExternalTrackParam*)fTrkArraySel.At(k);
1551 alpha = t->GetAlpha();
1552 xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha);
1553 // to vtxSeed (from finder)
1554 t->PropagateTo(xlStart,GetFieldkG());
1556 // vector of track global coordinates
1558 // covariance matrix of ri
1561 // get space point from track
1562 if(!TrackToPoint(t,ri,wWi,uUi3by3)) continue;
1563 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
1566 TMatrixD deltar = rv; deltar -= ri;
1567 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
1568 chi2i = deltar(0,0)*wWideltar(0,0)+
1569 deltar(1,0)*wWideltar(1,0)+
1570 deltar(2,0)*wWideltar(2,0);
1572 // add to total chi2
1579 } // end loop on tracks
1581 if(nTrksUsed < fMinTracks) {
1586 Double_t determinant = sumWi.Determinant();
1587 if(determinant < fMinDetFitter) {
1588 AliDebug(1,Form("det(V) = %f (<%f)\n",determinant,fMinDetFitter));
1594 // inverted of weights matrix
1595 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1597 // position of primary vertex
1598 rv.Mult(vV,sumWiri);
1600 } // end loop on the 2 steps
1607 Double_t position[3];
1608 position[0] = rv(0,0);
1609 position[1] = rv(1,0);
1610 position[2] = rv(2,0);
1611 Double_t covmatrix[6];
1612 covmatrix[0] = vV(0,0);
1613 covmatrix[1] = vV(0,1);
1614 covmatrix[2] = vV(1,1);
1615 covmatrix[3] = vV(0,2);
1616 covmatrix[4] = vV(1,2);
1617 covmatrix[5] = vV(2,2);
1619 // for correct chi2/ndf, count constraint as additional "track"
1620 if(fConstraint) nTrksUsed++;
1621 // store data in the vertex object
1622 if(fCurrentVertex) { delete fCurrentVertex; fCurrentVertex=0; }
1623 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1625 AliDebug(1," Vertex after fit:");
1626 AliDebug(1,Form("xyz: %f %f %f; nc %d",fCurrentVertex->GetXv(),fCurrentVertex->GetYv(),fCurrentVertex->GetZv(),fCurrentVertex->GetNContributors()));
1627 AliDebug(1,"--- VertexFitter(): finish\n");
1632 //----------------------------------------------------------------------------
1633 AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray,
1635 Bool_t optUseFitter,
1636 Bool_t optPropagate,
1637 Bool_t optUseDiamondConstraint)
1640 // Return vertex from tracks (AliExternalTrackParam) in array
1643 // set optUseDiamondConstraint=TRUE only if you are reconstructing the
1645 if(optUseDiamondConstraint) {
1651 // get tracks and propagate them to initial vertex position
1652 fIdSel = new UShort_t[(Int_t)trkArray->GetEntriesFast()];
1653 Int_t nTrksSel = PrepareTracks(*trkArray,id,0);
1654 if((!optUseDiamondConstraint && nTrksSel<TMath::Max(2,fMinTracks)) ||
1655 (optUseDiamondConstraint && nTrksSel<1)) {
1657 return fCurrentVertex;
1662 AliDebug(1,"Just one track");
1663 OneTrackVertFinder();
1666 case 1: StrLinVertexFinderMinDist(1); break;
1667 case 2: StrLinVertexFinderMinDist(0); break;
1668 case 3: HelixVertexFinder(); break;
1669 case 4: VertexFinder(1); break;
1670 case 5: VertexFinder(0); break;
1671 default: printf("Wrong algorithm\n"); break;
1674 AliDebug(1," Vertex finding completed\n");
1680 Double_t position[3]={fVert.GetXv(),fVert.GetYv(),fVert.GetZv()};
1681 Double_t covmatrix[6];
1682 fVert.GetCovMatrix(covmatrix);
1683 Double_t chi2=99999.;
1684 Int_t nTrksUsed=fVert.GetNContributors();
1685 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1687 fCurrentVertex->SetDispersion(fVert.GetDispersion());
1690 // set indices of used tracks and propagate track to found vertex
1691 UShort_t *indices = 0;
1692 Double_t d0z0[2],covd0z0[3];
1693 AliExternalTrackParam *t = 0;
1694 if(fCurrentVertex->GetNContributors()>0) {
1695 indices = new UShort_t[fTrkArraySel.GetEntriesFast()];
1696 for(Int_t jj=0; jj<(Int_t)fTrkArraySel.GetEntriesFast(); jj++) {
1697 indices[jj] = fIdSel[jj];
1698 t = (AliExternalTrackParam*)fTrkArraySel.At(jj);
1699 if(optPropagate && optUseFitter) {
1700 if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) {
1701 t->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
1702 AliDebug(1,Form("Track %d propagated to found vertex",jj));
1704 AliWarning("Found vertex outside beam pipe!");
1708 fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices);
1712 if (indices) {delete indices; indices=NULL;}
1713 delete fIdSel; fIdSel=NULL;
1714 fTrkArraySel.Delete();
1716 return fCurrentVertex;
1718 //----------------------------------------------------------------------------
1719 AliESDVertex* AliVertexerTracks::VertexForSelectedESDTracks(TObjArray *trkArray,
1720 Bool_t optUseFitter,
1721 Bool_t optPropagate,
1722 Bool_t optUseDiamondConstraint)
1726 // Return vertex from array of ESD tracks
1729 Int_t nTrks = (Int_t)trkArray->GetEntriesFast();
1730 UShort_t *id = new UShort_t[nTrks];
1732 AliESDtrack *esdt = 0;
1733 for(Int_t i=0; i<nTrks; i++){
1734 esdt = (AliESDtrack*)trkArray->At(i);
1735 id[i] = (UShort_t)esdt->GetID();
1738 VertexForSelectedTracks(trkArray,id,optUseFitter,optPropagate,optUseDiamondConstraint);
1742 return fCurrentVertex;
1744 //--------------------------------------------------------------------------