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():
77 // Default constructor
82 //----------------------------------------------------------------------------
83 AliVertexerTracks::AliVertexerTracks(Double_t fieldkG):
111 // Standard constructor
116 //-----------------------------------------------------------------------------
117 AliVertexerTracks::~AliVertexerTracks()
119 // Default Destructor
120 // The objects pointed by the following pointer are not owned
121 // by this class and are not deleted
123 if(fTrksToSkip) { delete fTrksToSkip; fTrksToSkip=NULL; }
124 if(fIdSel) { delete fIdSel; fIdSel=NULL; }
126 //----------------------------------------------------------------------------
127 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(AliVEvent *vEvent)
130 // Primary vertex for current ESD or AOD event
132 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
133 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
134 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
138 TString evtype = vEvent->IsA()->GetName();
139 Bool_t inputAOD = ((evtype=="AliAODEvent") ? kTRUE : kFALSE);
141 if(inputAOD && fMode==1) {
142 printf("Error : AliVertexerTracks: no TPC-only vertex from AOD\n");
144 return fCurrentVertex;
147 // accept 1-track case only if constraint is available
148 if(!fConstraint && fMinTracks==1) fMinTracks=2;
150 // read tracks from AlivEvent
151 Int_t nTrks = (Int_t)vEvent->GetNumberOfTracks();
152 if(nTrks<fMinTracks) {
154 return fCurrentVertex;
158 TDirectory * olddir = gDirectory;
160 if(nTrks>500) f = new TFile("VertexerTracks.root","recreate");
161 TObjArray trkArrayOrig(nTrks);
162 UShort_t *idOrig = new UShort_t[nTrks];
165 AliExternalTrackParam *t=0;
167 for(Int_t i=0; i<nTrks; i++) {
168 AliVTrack *track = (AliVTrack*)vEvent->GetTrack(i);
169 // check tracks to skip
170 Bool_t skipThis = kFALSE;
171 for(Int_t j=0; j<fNTrksToSkip; j++) {
172 if(track->GetID()==fTrksToSkip[j]) {
173 AliDebug(1,Form("skipping track: %d",i));
177 if(skipThis) continue;
179 // skip pure ITS SA tracks
180 if(track->GetStatus()&AliESDtrack::kITSpureSA) continue;
183 if(fMode==0 && fITSrefit && !(track->GetStatus()&AliESDtrack::kITSrefit)) continue;
185 if(!inputAOD) { // ESD
186 AliESDtrack* esdt = (AliESDtrack*)track;
187 if(esdt->GetNcls(fMode) < fMinClusters) continue;
188 if(fMode==0) { // ITS mode
189 Double_t x,p[5],cov[15];
190 esdt->GetExternalParameters(x,p);
191 esdt->GetExternalCovariance(cov);
192 t = new AliExternalTrackParam(x,esdt->GetAlpha(),p,cov);
193 } else if(fMode==1) { // TPC mode
194 t = (AliExternalTrackParam*)esdt->GetTPCInnerParam();
196 Double_t radius = 2.8; //something less than the beam pipe radius
197 if(!PropagateTrackTo(t,radius)) continue;
199 } else { // AOD (only ITS mode)
201 for(Int_t l=0;l<6;l++) if(TESTBIT(track->GetITSClusterMap(),l)) ncls0++;
202 if(ncls0 < fMinClusters) continue;
203 t = new AliExternalTrackParam(track);
205 trkArrayOrig.AddLast(t);
206 idOrig[nTrksOrig]=(UShort_t)track->GetID();
208 } // end loop on tracks
210 // call method that will reconstruct the vertex
211 FindPrimaryVertex(&trkArrayOrig,idOrig);
213 if(fMode==0) trkArrayOrig.Delete();
214 delete idOrig; idOrig=NULL;
217 f->Close(); delete f; f = NULL;
218 gSystem->Unlink("VertexerTracks.root");
222 // set vertex ID for tracks used in the fit
225 Int_t nIndices = fCurrentVertex->GetNIndices();
226 UShort_t *indices = fCurrentVertex->GetIndices();
227 for(Int_t ind=0; ind<nIndices; ind++) {
228 AliESDtrack *esdt = (AliESDtrack*)vEvent->GetTrack(indices[ind]);
229 esdt->SetVertexID(-1);
233 return fCurrentVertex;
235 //----------------------------------------------------------------------------
236 AliESDVertex* AliVertexerTracks::FindPrimaryVertex(TObjArray *trkArrayOrig,
240 // Primary vertex using the AliExternalTrackParam's in the TObjArray.
241 // idOrig must contain the track IDs from AliESDtrack::GetID()
243 // 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
244 // + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
245 // 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
249 // accept 1-track case only if constraint is available
250 if(!fConstraint && fMinTracks==1) fMinTracks=2;
252 // read tracks from array
253 Int_t nTrksOrig = (Int_t)trkArrayOrig->GetEntriesFast();
254 AliDebug(1,Form("Initial number of tracks: %d",nTrksOrig));
255 if(nTrksOrig<fMinTracks) {
256 AliDebug(1,"TooFewTracks");
258 return fCurrentVertex;
261 // If fConstraint=kFALSE
262 // run VertexFinder(1) to get rough estimate of initVertex (x,y)
264 // fill fTrkArraySel, for VertexFinder()
265 fIdSel = new UShort_t[nTrksOrig];
266 PrepareTracks(*trkArrayOrig,idOrig,0);
267 if(fIdSel) { delete fIdSel; fIdSel=NULL; }
268 Double_t cutsave = fDCAcut;
269 fDCAcut = fDCAcutIter0;
271 switch (fAlgoIter0) {
272 case 1: StrLinVertexFinderMinDist(1); break;
273 case 2: StrLinVertexFinderMinDist(0); break;
274 case 3: HelixVertexFinder(); break;
275 case 4: VertexFinder(1); break;
276 case 5: VertexFinder(0); break;
277 default: printf("Wrong algorithm\n"); break;
280 if(fVert.GetNContributors()>0) {
281 fVert.GetXYZ(fNominalPos);
282 fNominalPos[0] = fVert.GetXv();
283 fNominalPos[1] = fVert.GetYv();
284 fNominalPos[2] = fVert.GetZv();
285 AliDebug(1,Form("No mean vertex: VertexFinder gives (%f, %f, %f)",fNominalPos[0],fNominalPos[1],fNominalPos[2]));
290 AliDebug(1,"No mean vertex and VertexFinder failed");
297 // propagate tracks to fNominalPos vertex
299 // if(constraint) reject for |d0|>5*fNSigma*sigma w.r.t. fNominal... vertex
300 // else reject for |d0|\oplus|z0| > 5 mm w.r.t. fNominal... vertex
302 // propagate tracks to best between initVertex and fCurrentVertex
303 // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best
304 // between initVertex and fCurrentVertex)
305 for(Int_t iter=1; iter<=2; iter++) {
306 if(fOnlyFitter && iter==1) continue;
307 if(fIdSel) { delete fIdSel; fIdSel=NULL; }
308 fIdSel = new UShort_t[nTrksOrig];
309 Int_t nTrksSel = PrepareTracks(*trkArrayOrig,idOrig,iter);
310 AliDebug(1,Form("N tracks selected in iteration %d: %d",iter,nTrksSel));
311 if(nTrksSel < fMinTracks) {
313 return fCurrentVertex;
319 AliDebug(1,"Just one track");
320 OneTrackVertFinder();
323 case 1: StrLinVertexFinderMinDist(1); break;
324 case 2: StrLinVertexFinderMinDist(0); break;
325 case 3: HelixVertexFinder(); break;
326 case 4: VertexFinder(1); break;
327 case 5: VertexFinder(0); break;
328 default: printf("Wrong algorithm"); break;
331 AliDebug(1," Vertex finding completed");
336 } // end loop on the two iterations
339 // set indices of used tracks
340 UShort_t *indices = 0;
341 if(fCurrentVertex->GetNContributors()>0) {
342 Int_t nIndices = (Int_t)fTrkArraySel.GetEntriesFast();
343 indices = new UShort_t[nIndices];
344 for(Int_t jj=0; jj<nIndices; jj++)
345 indices[jj] = fIdSel[jj];
346 fCurrentVertex->SetIndices(nIndices,indices);
348 if (indices) {delete indices; indices=NULL;}
352 TString title="VertexerTracksNoConstraint";
354 title="VertexerTracksWithConstraint";
355 if(fOnlyFitter) title.Append("OnlyFitter");
357 fCurrentVertex->SetTitle(title.Data());
360 AliDebug(1,Form("xyz: %f %f %f; nc %d",fCurrentVertex->GetXv(),fCurrentVertex->GetYv(),fCurrentVertex->GetZv(),fCurrentVertex->GetNContributors()));
363 delete fIdSel; fIdSel=NULL;
364 fTrkArraySel.Delete();
365 if(fTrksToSkip) { delete fTrksToSkip; fTrksToSkip=NULL; }
368 return fCurrentVertex;
370 //------------------------------------------------------------------------
371 Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3])
374 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];
377 //-------------------------------------------------------------------------
378 void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d)
381 Double_t x12=p0[0]-p1[0];
382 Double_t y12=p0[1]-p1[1];
383 Double_t z12=p0[2]-p1[2];
384 Double_t kk=x12*x12+y12*y12+z12*z12;
385 m[0][0]=2-2/kk*x12*x12;
386 m[0][1]=-2/kk*x12*y12;
387 m[0][2]=-2/kk*x12*z12;
388 m[1][0]=-2/kk*x12*y12;
389 m[1][1]=2-2/kk*y12*y12;
390 m[1][2]=-2/kk*y12*z12;
391 m[2][0]=-2/kk*x12*z12;
393 m[2][2]=2-2/kk*z12*z12;
394 d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
395 d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
396 d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
399 //--------------------------------------------------------------------------
400 void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d)
403 Double_t x12=p1[0]-p0[0];
404 Double_t y12=p1[1]-p0[1];
405 Double_t z12=p1[2]-p0[2];
407 Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
409 Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
412 cc[0]=-x12/sigmasq[0];
413 cc[1]=-y12/sigmasq[1];
414 cc[2]=-z12/sigmasq[2];
416 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;
418 Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
421 aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
422 aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
423 aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
425 m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
426 m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
427 m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
429 m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
430 m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
431 m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
433 m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
434 m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
435 m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
437 d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
438 d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
439 d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
442 //--------------------------------------------------------------------------
443 Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0)
446 Double_t x12=p0[0]-p1[0];
447 Double_t y12=p0[1]-p1[1];
448 Double_t z12=p0[2]-p1[2];
449 Double_t x10=p0[0]-x0[0];
450 Double_t y10=p0[1]-x0[1];
451 Double_t z10=p0[2]-x0[2];
452 // 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);
453 return ((y10*z12-z10*y12)*(y10*z12-z10*y12)+
454 (z10*x12-x10*z12)*(z10*x12-x10*z12)+
455 (x10*y12-y10*x12)*(x10*y12-y10*x12))
456 /(x12*x12+y12*y12+z12*z12);
458 //---------------------------------------------------------------------------
459 void AliVertexerTracks::OneTrackVertFinder()
461 // find vertex for events with 1 track, using DCA to nominal beam axis
462 AliDebug(1,Form("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArraySel.GetEntries()));
463 AliExternalTrackParam *track1;
464 track1 = (AliExternalTrackParam*)fTrkArraySel.At(0);
465 Double_t alpha=track1->GetAlpha();
466 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
467 Double_t pos[3],dir[3];
468 track1->GetXYZAt(mindist,GetFieldkG(),pos);
469 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
470 AliStrLine *line1 = new AliStrLine(pos,dir);
471 Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.};
472 Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.};
473 AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE);
474 Double_t crosspoint[3]={0.,0.,0.};
477 Int_t retcode = zeta->Cross(line1,crosspoint);
479 sigma=line1->GetDistFromPoint(crosspoint);
484 fVert.SetXYZ(crosspoint);
485 fVert.SetDispersion(sigma);
486 fVert.SetNContributors(nContrib);
488 //---------------------------------------------------------------------------
489 void AliVertexerTracks::HelixVertexFinder()
491 // Get estimate of vertex position in (x,y) from tracks DCA
496 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
498 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
500 Double_t aver[3]={0.,0.,0.};
501 Double_t averquad[3]={0.,0.,0.};
502 Double_t sigmaquad[3]={0.,0.,0.};
505 AliExternalTrackParam *track1;
506 AliExternalTrackParam *track2;
509 Double_t alpha, cs, sn;
510 Double_t crosspoint[3];
511 for(Int_t i=0; i<nacc; i++){
512 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
515 for(Int_t j=i+1; j<nacc; j++){
516 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
518 distCA=track2->PropagateToDCA(track1,GetFieldkG());
519 if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
521 alpha=track1->GetAlpha();
522 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
523 Double_t x1=x*cs - track1->GetY()*sn;
524 Double_t y1=x*sn + track1->GetY()*cs;
525 Double_t z1=track1->GetZ();
527 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
529 alpha=track2->GetAlpha();
530 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
531 Double_t x2=x*cs - track2->GetY()*sn;
532 Double_t y2=x*sn + track2->GetY()*cs;
533 Double_t z2=track2->GetZ();
534 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
535 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
536 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
537 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
538 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
539 crosspoint[0]=wx1*x1 + wx2*x2;
540 crosspoint[1]=wy1*y1 + wy2*y2;
541 crosspoint[2]=wz1*z1 + wz2*z2;
544 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
545 for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
551 for(Int_t jj=0;jj<3;jj++){
552 initPos[jj] = aver[jj]/ncombi;
553 averquad[jj]/=ncombi;
554 sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
555 sigma+=sigmaquad[jj];
557 sigma=TMath::Sqrt(TMath::Abs(sigma));
560 Warning("HelixVertexFinder","Finder did not succed");
563 fVert.SetXYZ(initPos);
564 fVert.SetDispersion(sigma);
565 fVert.SetNContributors(ncombi);
567 //----------------------------------------------------------------------------
568 Int_t AliVertexerTracks::PrepareTracks(TObjArray &trkArrayOrig,
573 // Propagate tracks to initial vertex position and store them in a TObjArray
575 AliDebug(1," PrepareTracks()");
577 Int_t nTrksOrig = (Int_t)trkArrayOrig.GetEntriesFast();
580 Double_t sigmaCurr[3];
581 Double_t normdistx,normdisty;
582 Double_t d0z0[2],covd0z0[3];
585 AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1);
587 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
589 AliExternalTrackParam *track=0;
592 for(Int_t i=0; i<nTrksOrig; i++) {
593 AliExternalTrackParam *trackOrig=(AliExternalTrackParam*)trkArrayOrig.At(i);
594 if(trackOrig->Charge()!=0) { // normal tracks
595 track = new AliExternalTrackParam(*(AliExternalTrackParam*)trkArrayOrig.At(i));
596 } else { // neutral tracks (from a V0)
597 track = new AliNeutralTrackParam(*(AliNeutralTrackParam*)trkArrayOrig.At(i));
601 if(TMath::Abs(track->GetTgl())>fMaxTgl) {
602 AliDebug(1,Form(" rejecting track with tgl = %f",track->GetTgl()));
603 delete track; continue;
606 Bool_t propagateOK = kFALSE, cutond0z0 = kTRUE;
607 // propagate track to vertex
608 if(optImpParCut<2 || fOnlyFitter) { // optImpParCut==1 or 0
609 propagateOK = track->PropagateToDCA(initVertex,GetFieldkG(),100.,d0z0,covd0z0);
610 } else { // optImpParCut==2
611 fCurrentVertex->GetSigmaXYZ(sigmaCurr);
612 normdistx = TMath::Abs(fCurrentVertex->GetXv()-fNominalPos[0])/TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0]);
613 normdisty = TMath::Abs(fCurrentVertex->GetYv()-fNominalPos[1])/TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2]);
614 AliDebug(1,Form("normdistx %f %f %f",fCurrentVertex->GetXv(),fNominalPos[0],TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0])));
615 AliDebug(1,Form("normdisty %f %f %f",fCurrentVertex->GetYv(),fNominalPos[1],TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2])));
616 AliDebug(1,Form("sigmaCurr %f %f %f",sigmaCurr[0],sigmaCurr[1],TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2])));
617 if(normdistx < 3. && normdisty < 3. &&
618 (sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) {
619 propagateOK = track->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
621 propagateOK = track->PropagateToDCA(initVertex,GetFieldkG(),100.,d0z0,covd0z0);
622 if(fConstraint) cutond0z0=kFALSE;
627 AliDebug(1," rejected");
628 delete track; continue;
631 sigmad0 = TMath::Sqrt(covd0z0[0]);
632 maxd0rphi = fNSigma*sigmad0;
633 if(optImpParCut==1) maxd0rphi *= 5.;
634 maxd0rphi = TMath::Min(maxd0rphi,fFiducialR);
635 //sigmad0z0 = TMath::Sqrt(covd0z0[0]+covd0z0[2]);
637 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));
640 //---- track selection based on impact parameters ----//
642 // always reject tracks outside fiducial volume
643 if(TMath::Abs(d0z0[0])>fFiducialR || TMath::Abs(d0z0[1])>fFiducialZ) {
644 AliDebug(1," rejected");
645 delete track; continue;
648 // during iterations 1 and 2 , reject tracks with d0rphi > maxd0rphi
649 if(optImpParCut>0 && TMath::Abs(d0z0[0])>maxd0rphi) {
650 AliDebug(1," rejected");
651 delete track; continue;
654 // if fConstraint=kFALSE, during iterations 1 and 2 ||
655 // if fConstraint=kTRUE, during iteration 2,
656 // select tracks with d0oplusz0 < fMaxd0z0
657 if((!fConstraint && optImpParCut>0 && fVert.GetNContributors()>0) ||
658 ( fConstraint && optImpParCut==2 && cutond0z0)) {
660 TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1])>fMaxd0z0) {
661 AliDebug(1," rejected");
662 delete track; continue;
666 // track passed all selections
667 fTrkArraySel.AddLast(track);
668 fIdSel[nTrksSel] = idOrig[i];
670 } // end loop on tracks
676 //----------------------------------------------------------------------------
677 Bool_t AliVertexerTracks::PropagateTrackTo(AliExternalTrackParam *track,
679 //----------------------------------------------------------------
680 // COPIED from AliTracker
682 // Propagates the track to the plane X=xk (cm).
684 // Origin: Marian Ivanov, Marian.Ivanov@cern.ch
685 //----------------------------------------------------------------
687 const Double_t kEpsilon = 0.00001;
688 Double_t xpos = track->GetX();
689 Double_t dir = (xpos<xToGo) ? 1. : -1.;
690 Double_t maxStep = 5;
691 Double_t maxSnp = 0.8;
693 while ( (xToGo-xpos)*dir > kEpsilon){
694 Double_t step = dir*TMath::Min(TMath::Abs(xToGo-xpos), maxStep);
695 Double_t x = xpos+step;
696 Double_t xyz0[3],xyz1[3];
697 track->GetXYZ(xyz0); //starting global position
699 if(!track->GetXYZAt(x,GetFieldkG(),xyz1)) return kFALSE; // no prolongation
700 xyz1[2]+=kEpsilon; // waiting for bug correction in geo
702 if(TMath::Abs(track->GetSnpAt(x,GetFieldkG())) >= maxSnp) return kFALSE;
703 if(!track->PropagateTo(x,GetFieldkG())) return kFALSE;
705 if(TMath::Abs(track->GetSnp()) >= maxSnp) return kFALSE;
706 track->GetXYZ(xyz0); // global position
707 Double_t alphan = TMath::ATan2(xyz0[1], xyz0[0]);
709 Double_t ca=TMath::Cos(alphan-track->GetAlpha()),
710 sa=TMath::Sin(alphan-track->GetAlpha());
711 Double_t sf=track->GetSnp(), cf=TMath::Sqrt((1.-sf)*(1.+sf));
712 Double_t sinNew = sf*ca - cf*sa;
713 if(TMath::Abs(sinNew) >= maxSnp) return kFALSE;
714 if(!track->Rotate(alphan)) return kFALSE;
716 xpos = track->GetX();
720 //---------------------------------------------------------------------------
721 AliESDVertex* AliVertexerTracks::RemoveTracksFromVertex(AliESDVertex *inVtx,
724 Float_t *diamondxy) const
727 // Removes tracks in trksTree from fit of inVtx
730 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
731 printf("ERROR: primary vertex has no constraint: cannot remove tracks");
734 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraintOnlyFitter"))
735 printf("WARNING: result of tracks' removal will be only approximately correct");
738 rv(0,0) = inVtx->GetXv();
739 rv(1,0) = inVtx->GetYv();
740 rv(2,0) = inVtx->GetZv();
743 inVtx->GetCovMatrix(cov);
745 vV(0,1) = cov[1]; vV(1,0) = cov[1];
747 vV(0,2) = cov[3]; vV(2,0) = cov[3];
748 vV(1,2) = cov[4]; vV(2,1) = cov[4];
751 TMatrixD sumWi(TMatrixD::kInverted,vV);
752 TMatrixD sumWiri(sumWi,TMatrixD::kMult,rv);
754 Int_t nUsedTrks = inVtx->GetNIndices();
755 Double_t chi2 = inVtx->GetChi2();
757 AliExternalTrackParam *track = 0;
758 Int_t ntrks = (Int_t)trkArray->GetEntriesFast();
759 for(Int_t i=0;i<ntrks;i++) {
760 track = (AliExternalTrackParam*)trkArray->At(i);
761 if(!inVtx->UsesTrack(id[i])) {
762 printf("track %d was not used in vertex fit",id[i]);
765 Double_t alpha = track->GetAlpha();
766 Double_t xl = diamondxy[0]*TMath::Cos(alpha)+diamondxy[1]*TMath::Sin(alpha);
767 track->PropagateTo(xl,GetFieldkG());
768 // vector of track global coordinates
770 // covariance matrix of ri
773 // get space point from track
774 if(!TrackToPoint(track,ri,wWi)) continue;
776 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
781 // track contribution to chi2
782 TMatrixD deltar = rv; deltar -= ri;
783 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
784 Double_t chi2i = deltar(0,0)*wWideltar(0,0)+
785 deltar(1,0)*wWideltar(1,0)+
786 deltar(2,0)*wWideltar(2,0);
787 // remove from total chi2
792 printf("Trying to remove too many tracks!");
800 // new inverted of weights matrix
801 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
803 // new position of primary vertex
804 rvnew.Mult(vVnew,sumWiri);
806 Double_t position[3];
807 position[0] = rvnew(0,0);
808 position[1] = rvnew(1,0);
809 position[2] = rvnew(2,0);
817 // store data in the vertex object
818 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,nUsedTrks+1); // the +1 is for the constraint
819 outVtx->SetTitle(inVtx->GetTitle());
820 UShort_t *inindices = inVtx->GetIndices();
821 Int_t nIndices = nUsedTrks;
822 UShort_t *outindices = new UShort_t[nIndices];
824 for(Int_t k=0; k<inVtx->GetNIndices(); k++) {
825 Bool_t copyindex=kTRUE;
826 for(Int_t l=0; l<ntrks; l++) {
827 if(inindices[k]==id[l]) copyindex=kFALSE;
830 outindices[j] = inindices[k]; j++;
833 outVtx->SetIndices(nIndices,outindices);
834 if (outindices) delete outindices;
837 printf("Vertex before removing tracks:");
838 inVtx->PrintStatus();
839 inVtx->PrintIndices();
840 printf("Vertex after removing tracks:");
841 outVtx->PrintStatus();
842 outVtx->PrintIndices();
847 //---------------------------------------------------------------------------
848 AliESDVertex* AliVertexerTracks::RemoveConstraintFromVertex(AliESDVertex *inVtx,
850 Float_t *diamondcov) const
853 // Removes diamond constraint from fit of inVtx
856 if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraint")) {
857 printf("ERROR: primary vertex has no constraint: cannot remove it\n");
860 if(inVtx->GetNContributors()<3) {
861 printf("ERROR: primary vertex has less than 2 tracks: cannot remove contraint\n");
865 // diamond constraint
867 vVb(0,0) = diamondcov[0];
868 vVb(0,1) = diamondcov[1];
870 vVb(1,0) = diamondcov[1];
871 vVb(1,1) = diamondcov[2];
875 vVb(2,2) = diamondcov[5];
876 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
878 rb(0,0) = diamondxyz[0];
879 rb(1,0) = diamondxyz[1];
880 rb(2,0) = diamondxyz[2];
881 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
885 rv(0,0) = inVtx->GetXv();
886 rv(1,0) = inVtx->GetYv();
887 rv(2,0) = inVtx->GetZv();
890 inVtx->GetCovMatrix(cov);
892 vV(0,1) = cov[1]; vV(1,0) = cov[1];
894 vV(0,2) = cov[3]; vV(2,0) = cov[3];
895 vV(1,2) = cov[4]; vV(2,1) = cov[4];
897 TMatrixD vVInv(TMatrixD::kInverted,vV);
898 TMatrixD vVInvrv(vVInv,TMatrixD::kMult,rv);
901 TMatrixD sumWi = vVInv - vVbInv;
904 TMatrixD sumWiri = vVInvrv - vVbInvrb;
909 // new inverted of weights matrix
910 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
912 // new position of primary vertex
913 rvnew.Mult(vVnew,sumWiri);
915 Double_t position[3];
916 position[0] = rvnew(0,0);
917 position[1] = rvnew(1,0);
918 position[2] = rvnew(2,0);
927 Double_t chi2 = inVtx->GetChi2();
929 // diamond constribution to chi2
930 TMatrixD deltar = rv; deltar -= rb;
931 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
932 Double_t chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
933 deltar(1,0)*vVbInvdeltar(1,0)+
934 deltar(2,0)*vVbInvdeltar(2,0);
935 // remove from total chi2
938 // store data in the vertex object
939 AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,inVtx->GetNContributors()-1);
940 outVtx->SetTitle("VertexerTracksNoConstraint");
941 UShort_t *inindices = inVtx->GetIndices();
942 Int_t nIndices = inVtx->GetNIndices();
943 outVtx->SetIndices(nIndices,inindices);
947 //---------------------------------------------------------------------------
948 void AliVertexerTracks::SetCuts(Double_t *cuts)
954 SetDCAcutIter0(cuts[1]);
956 if(fMode==0 && cuts[3]<0) SetITSrefitNotRequired();
957 SetMinClusters((Int_t)(TMath::Abs(cuts[3])));
958 SetMinTracks((Int_t)(cuts[4]));
959 SetNSigmad0(cuts[5]);
960 SetMinDetFitter(cuts[6]);
962 SetFiducialRZ(cuts[8],cuts[9]);
963 fAlgo=(Int_t)(cuts[10]);
964 fAlgoIter0=(Int_t)(cuts[11]);
968 //---------------------------------------------------------------------------
969 void AliVertexerTracks::SetITSMode(Double_t dcacut,
970 Double_t dcacutIter0,
975 Double_t mindetfitter,
980 Int_t finderAlgoIter0)
983 // Cut values for ITS mode
987 SetITSrefitRequired();
989 SetITSrefitNotRequired();
992 SetDCAcutIter0(dcacutIter0);
994 SetMinClusters(TMath::Abs(minCls));
995 SetMinTracks(mintrks);
997 SetMinDetFitter(mindetfitter);
999 SetFiducialRZ(fidR,fidZ);
1001 fAlgoIter0=finderAlgoIter0;
1005 //---------------------------------------------------------------------------
1006 void AliVertexerTracks::SetTPCMode(Double_t dcacut,
1007 Double_t dcacutIter0,
1012 Double_t mindetfitter,
1017 Int_t finderAlgoIter0)
1020 // Cut values for TPC mode
1023 SetITSrefitNotRequired();
1025 SetDCAcutIter0(dcacutIter0);
1026 SetMaxd0z0(maxd0z0);
1027 SetMinClusters(minCls);
1028 SetMinTracks(mintrks);
1029 SetNSigmad0(nsigma);
1030 SetMinDetFitter(mindetfitter);
1032 SetFiducialRZ(fidR,fidZ);
1034 fAlgoIter0=finderAlgoIter0;
1038 //---------------------------------------------------------------------------
1039 void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped)
1042 // Mark the tracks not to be used in the vertex reconstruction.
1043 // Tracks are identified by AliESDtrack::GetID()
1045 fNTrksToSkip = n; fTrksToSkip = new Int_t[n];
1046 for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i];
1049 //---------------------------------------------------------------------------
1050 void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx)
1053 // Set initial vertex knowledge
1055 vtx->GetXYZ(fNominalPos);
1056 vtx->GetCovMatrix(fNominalCov);
1060 //---------------------------------------------------------------------------
1061 void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights)
1063 AliExternalTrackParam *track1;
1064 const Int_t knacc = (Int_t)fTrkArraySel.GetEntriesFast();
1065 AliStrLine **linarray = new AliStrLine* [knacc];
1066 for(Int_t i=0; i<knacc; i++){
1067 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1068 Double_t alpha=track1->GetAlpha();
1069 Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1070 Double_t pos[3],dir[3],sigmasq[3];
1071 track1->GetXYZAt(mindist,GetFieldkG(),pos);
1072 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1073 sigmasq[0]=TMath::Sin(alpha)*TMath::Sin(alpha)*track1->GetSigmaY2();
1074 sigmasq[1]=TMath::Cos(alpha)*TMath::Cos(alpha)*track1->GetSigmaY2();
1075 sigmasq[2]=track1->GetSigmaZ2();
1078 if(!TrackToPoint(track1,ri,wWi)) {optUseWeights=kFALSE;printf("WARNING\n");}
1081 for(Int_t ia=0;ia<3;ia++){
1082 for(Int_t ib=0;ib<3;ib++){
1083 wmat[iel]=wWi(ia,ib);
1087 linarray[i] = new AliStrLine(pos,sigmasq,wmat,dir);
1089 fVert=TrackletVertexFinder(linarray,knacc,optUseWeights);
1090 for(Int_t i=0; i<knacc; i++) delete linarray[i];
1093 //---------------------------------------------------------------------------
1094 AliESDVertex AliVertexerTracks::TrackletVertexFinder(TClonesArray *lines, Int_t optUseWeights)
1096 // Calculate the point at minimum distance to prepared tracks (TClonesArray)
1097 const Int_t knacc = (Int_t)lines->GetEntriesFast();
1098 AliStrLine** lines2 = new AliStrLine* [knacc];
1099 for(Int_t i=0; i<knacc; i++){
1100 lines2[i]= (AliStrLine*)lines->At(i);
1102 AliESDVertex vert = TrackletVertexFinder(lines2,knacc,optUseWeights);
1107 //---------------------------------------------------------------------------
1108 AliESDVertex AliVertexerTracks::TrackletVertexFinder(AliStrLine **lines, const Int_t knacc, Int_t optUseWeights)
1110 // Calculate the point at minimum distance to prepared tracks (array of AliStrLine)
1112 Double_t initPos[3]={0.,0.,0.};
1114 Double_t (*vectP0)[3]=new Double_t [knacc][3];
1115 Double_t (*vectP1)[3]=new Double_t [knacc][3];
1118 Double_t dsum[3]={0,0,0};
1119 TMatrixD sumWi(3,3);
1120 for(Int_t i=0;i<3;i++){
1121 for(Int_t j=0;j<3;j++){
1127 for(Int_t i=0; i<knacc; i++){
1128 AliStrLine *line1 = lines[i];
1129 Double_t p0[3],cd[3],sigmasq[3];
1131 if(!line1) printf("ERROR %d %d\n",i,knacc);
1134 line1->GetSigma2P0(sigmasq);
1135 line1->GetWMatrix(wmat);
1138 for(Int_t ia=0;ia<3;ia++){
1139 for(Int_t ib=0;ib<3;ib++){
1140 wWi(ia,ib)=wmat[iel];
1147 Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
1155 Double_t matr[3][3];
1157 if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
1158 else GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
1161 for(Int_t iii=0;iii<3;iii++){
1162 dsum[iii]+=dknow[iii];
1163 for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
1167 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1168 Double_t covmatrix[6];
1169 covmatrix[0] = invsumWi(0,0);
1170 covmatrix[1] = invsumWi(0,1);
1171 covmatrix[2] = invsumWi(1,1);
1172 covmatrix[3] = invsumWi(0,2);
1173 covmatrix[4] = invsumWi(1,2);
1174 covmatrix[5] = invsumWi(2,2);
1176 Double_t vett[3][3];
1177 Double_t det=GetDeterminant3X3(sum);
1181 for(Int_t zz=0;zz<3;zz++){
1182 for(Int_t ww=0;ww<3;ww++){
1183 for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
1185 for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
1186 initPos[zz]=GetDeterminant3X3(vett)/det;
1190 for(Int_t i=0; i<knacc; i++){
1191 Double_t p0[3]={0,0,0},p1[3]={0,0,0};
1192 for(Int_t ii=0;ii<3;ii++){
1193 p0[ii]=vectP0[i][ii];
1194 p1[ii]=vectP1[i][ii];
1196 sigma+=GetStrLinMinDist(p0,p1,initPos);
1199 if(sigma>0.) {sigma=TMath::Sqrt(sigma);}else{sigma=999;}
1203 AliESDVertex theVert(initPos,covmatrix,99999.,knacc);
1204 theVert.SetDispersion(sigma);
1210 //---------------------------------------------------------------------------
1211 Bool_t AliVertexerTracks::TrackToPoint(AliExternalTrackParam *t,
1212 TMatrixD &ri,TMatrixD &wWi,
1213 Bool_t uUi3by3) const
1216 // Extract from the AliExternalTrackParam the global coordinates ri and covariance matrix
1217 // wWi of the space point that it represents (to be used in VertexFitter())
1221 Double_t rotAngle = t->GetAlpha();
1222 if(rotAngle<0.) rotAngle += 2.*TMath::Pi();
1223 Double_t cosRot = TMath::Cos(rotAngle);
1224 Double_t sinRot = TMath::Sin(rotAngle);
1226 ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot;
1227 ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot;
1228 ri(2,0) = t->GetZ();
1233 // matrix to go from global (x,y,z) to local (y,z);
1242 // covariance matrix of local (y,z) - inverted
1244 uUi(0,0) = t->GetSigmaY2();
1245 uUi(0,1) = t->GetSigmaZY();
1246 uUi(1,0) = t->GetSigmaZY();
1247 uUi(1,1) = t->GetSigmaZ2();
1249 //printf(" %f %f",uUi(0,0),uUi(0,1));
1250 //printf(" %f %f",uUi(1,0),uUi(1,1));
1252 if(uUi.Determinant() <= 0.) return kFALSE;
1253 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
1255 // weights matrix: wWi = qQiT * uUiInv * qQi
1256 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
1257 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
1260 if(fVert.GetNContributors()<1) AliFatal("Vertex from finder is empty");
1261 // matrix to go from global (x,y,z) to local (x,y,z);
1273 // covariance of fVert along the track
1274 Double_t p[3],pt,ptot;
1276 pt = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
1277 ptot = TMath::Sqrt(pt*pt+p[2]*p[2]);
1278 Double_t cphi = p[0]/pt; //cos(phi)=px/pt
1279 Double_t sphi = p[1]/pt; //sin(phi)=py/pt
1280 Double_t clambda = pt/ptot; //cos(lambda)=pt/ptot
1281 Double_t slambda = p[2]/ptot; //sin(lambda)=pz/ptot
1282 Double_t covfVert[6];
1283 fVert.GetCovMatrix(covfVert);
1284 Double_t covfVertalongt =
1285 covfVert[0]*cphi*cphi*clambda*clambda
1286 +covfVert[1]*2.*cphi*sphi*clambda*clambda
1287 +covfVert[3]*2.*cphi*clambda*slambda
1288 +covfVert[2]*sphi*sphi*clambda*clambda
1289 +covfVert[4]*2.*sphi*clambda*slambda
1290 +covfVert[5]*slambda*slambda;
1291 // covariance matrix of local (x,y,z) - inverted
1293 uUi(0,0) = covfVertalongt * fnSigmaForUi00 * fnSigmaForUi00;
1294 AliDebug(1,Form("=====> sqrtUi00 cm %f",TMath::Sqrt(uUi(0,0))));
1298 uUi(1,1) = t->GetSigmaY2();
1299 uUi(1,2) = t->GetSigmaZY();
1301 uUi(2,1) = t->GetSigmaZY();
1302 uUi(2,2) = t->GetSigmaZ2();
1303 //printf(" Ui :\n");
1304 //printf(" %f %f\n",uUi(0,0),uUi(0,1));
1305 //printf(" %f %f\n",uUi(1,0),uUi(1,1));
1307 if(uUi.Determinant() <= 0.) return kFALSE;
1308 TMatrixD uUiInv(TMatrixD::kInverted,uUi);
1310 // weights matrix: wWi = qQiT * uUiInv * qQi
1311 TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
1312 TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
1319 //---------------------------------------------------------------------------
1320 void AliVertexerTracks::TooFewTracks()
1323 // When the number of tracks is < fMinTracks,
1324 // deal with vertices not found and prepare to exit
1326 AliDebug(1,"TooFewTracks");
1328 Double_t pos[3],err[3];
1329 pos[0] = fNominalPos[0];
1330 err[0] = TMath::Sqrt(fNominalCov[0]);
1331 pos[1] = fNominalPos[1];
1332 err[1] = TMath::Sqrt(fNominalCov[2]);
1333 pos[2] = fNominalPos[2];
1334 err[2] = TMath::Sqrt(fNominalCov[5]);
1335 Int_t ncontr = (err[0]>1. ? -1 : -3);
1336 if(fCurrentVertex) { delete fCurrentVertex; fCurrentVertex=0; }
1337 fCurrentVertex = new AliESDVertex(pos,err);
1338 fCurrentVertex->SetNContributors(ncontr);
1341 fCurrentVertex->SetTitle("VertexerTracksWithConstraint");
1343 fCurrentVertex->SetTitle("VertexerTracksNoConstraint");
1346 if(!fTrkArraySel.IsEmpty()) fTrkArraySel.Delete();
1347 if(fIdSel) {delete fIdSel; fIdSel=NULL;}
1348 if(fTrksToSkip) {delete fTrksToSkip; fTrksToSkip=NULL;}
1352 //---------------------------------------------------------------------------
1353 void AliVertexerTracks::VertexFinder(Int_t optUseWeights)
1356 // Get estimate of vertex position in (x,y) from tracks DCA
1358 Double_t initPos[3];
1360 for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
1361 Int_t nacc = (Int_t)fTrkArraySel.GetEntriesFast();
1362 Double_t aver[3]={0.,0.,0.};
1363 Double_t aversq[3]={0.,0.,0.};
1364 Double_t sigmasq[3]={0.,0.,0.};
1367 AliExternalTrackParam *track1;
1368 AliExternalTrackParam *track2;
1369 Double_t pos[3],dir[3];
1370 Double_t alpha,mindist;
1372 for(Int_t i=0; i<nacc; i++){
1373 track1 = (AliExternalTrackParam*)fTrkArraySel.At(i);
1374 alpha=track1->GetAlpha();
1375 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1376 track1->GetXYZAt(mindist,GetFieldkG(),pos);
1377 track1->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1378 AliStrLine *line1 = new AliStrLine(pos,dir);
1380 // AliStrLine *line1 = new AliStrLine();
1381 // track1->ApproximateHelixWithLine(mindist,GetFieldkG(),line1);
1383 for(Int_t j=i+1; j<nacc; j++){
1384 track2 = (AliExternalTrackParam*)fTrkArraySel.At(j);
1385 alpha=track2->GetAlpha();
1386 mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
1387 track2->GetXYZAt(mindist,GetFieldkG(),pos);
1388 track2->GetPxPyPzAt(mindist,GetFieldkG(),dir);
1389 AliStrLine *line2 = new AliStrLine(pos,dir);
1390 // AliStrLine *line2 = new AliStrLine();
1391 // track2->ApproximateHelixWithLine(mindist,GetFieldkG(),line2);
1392 Double_t distCA=line2->GetDCA(line1);
1393 //printf("%d %d %f\n",i,j,distCA);
1394 if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
1395 Double_t pnt1[3],pnt2[3],crosspoint[3];
1397 if(optUseWeights<=0){
1398 Int_t retcode = line2->Cross(line1,crosspoint);
1401 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1402 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1405 if(optUseWeights>0){
1406 Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
1409 alpha=track1->GetAlpha();
1410 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1411 Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
1412 alpha=track2->GetAlpha();
1413 cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
1414 Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
1415 Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
1416 Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
1417 Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
1418 Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
1419 crosspoint[0]=wx1*pnt1[0] + wx2*pnt2[0];
1420 crosspoint[1]=wy1*pnt1[1] + wy2*pnt2[1];
1421 crosspoint[2]=wz1*pnt1[2] + wz2*pnt2[2];
1424 for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
1425 for(Int_t jj=0;jj<3;jj++)aversq[jj]+=(crosspoint[jj]*crosspoint[jj]);
1434 for(Int_t jj=0;jj<3;jj++){
1435 initPos[jj] = aver[jj]/ncombi;
1436 //printf("%f\n",initPos[jj]);
1438 sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
1441 sigma=TMath::Sqrt(TMath::Abs(sigma));
1444 Warning("VertexFinder","Finder did not succed");
1447 fVert.SetXYZ(initPos);
1448 fVert.SetDispersion(sigma);
1449 fVert.SetNContributors(ncombi);
1451 //---------------------------------------------------------------------------
1452 void AliVertexerTracks::VertexFitter()
1455 // The optimal estimate of the vertex position is given by a "weighted
1456 // average of tracks positions".
1457 // Original method: V. Karimaki, CMS Note 97/0051
1459 Bool_t useConstraint = fConstraint;
1460 Double_t initPos[3];
1462 fVert.GetXYZ(initPos);
1464 initPos[0]=fNominalPos[0];
1465 initPos[1]=fNominalPos[1];
1466 initPos[2]=fNominalPos[2];
1469 Int_t nTrksSel = (Int_t)fTrkArraySel.GetEntries();
1470 if(nTrksSel==1) useConstraint=kTRUE;
1471 AliDebug(1,"--- VertexFitter(): start");
1472 AliDebug(1,Form(" Number of tracks in array: %d\n",nTrksSel));
1473 AliDebug(1,Form(" Minimum # tracks required in fit: %d\n",fMinTracks));
1474 AliDebug(1,Form(" Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]));
1475 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])));
1477 // special treatment for few-tracks fits (e.g. secondary vertices)
1478 Bool_t uUi3by3 = kFALSE; if(nTrksSel<5 && !useConstraint) uUi3by3 = kTRUE;
1483 rv(0,0) = initPos[0];
1484 rv(1,0) = initPos[1];
1486 Double_t xlStart,alpha;
1488 Double_t chi2,chi2i,chi2b;
1489 AliExternalTrackParam *t = 0;
1492 // initial vertex covariance matrix
1494 vVb(0,0) = fNominalCov[0];
1495 vVb(0,1) = fNominalCov[1];
1497 vVb(1,0) = fNominalCov[1];
1498 vVb(1,1) = fNominalCov[2];
1502 vVb(2,2) = fNominalCov[5];
1503 TMatrixD vVbInv(TMatrixD::kInverted,vVb);
1505 rb(0,0) = fNominalPos[0];
1506 rb(1,0) = fNominalPos[1];
1507 rb(2,0) = fNominalPos[2];
1508 TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
1512 // 1st - estimate of vtx using all tracks
1513 // 2nd - estimate of global chi2
1514 for(step=0; step<2; step++) {
1515 AliDebug(1,Form(" step = %d\n",step));
1519 if(step==1) { initPos[0]=rv(0,0); initPos[0]=rv(1,0); }
1521 TMatrixD sumWiri(3,1);
1522 TMatrixD sumWi(3,3);
1523 for(i=0; i<3; i++) {
1525 for(j=0; j<3; j++) sumWi(j,i) = 0.;
1528 // mean vertex constraint
1531 sumWiri(i,0) += vVbInvrb(i,0);
1532 for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k);
1535 TMatrixD deltar = rv; deltar -= rb;
1536 TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
1537 chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
1538 deltar(1,0)*vVbInvdeltar(1,0)+
1539 deltar(2,0)*vVbInvdeltar(2,0);
1544 for(k=0; k<nTrksSel; k++) {
1545 // get track from track array
1546 t = (AliExternalTrackParam*)fTrkArraySel.At(k);
1547 alpha = t->GetAlpha();
1548 xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha);
1549 // to vtxSeed (from finder)
1550 t->PropagateTo(xlStart,GetFieldkG());
1552 // vector of track global coordinates
1554 // covariance matrix of ri
1557 // get space point from track
1558 if(!TrackToPoint(t,ri,wWi,uUi3by3)) continue;
1559 TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
1562 TMatrixD deltar = rv; deltar -= ri;
1563 TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
1564 chi2i = deltar(0,0)*wWideltar(0,0)+
1565 deltar(1,0)*wWideltar(1,0)+
1566 deltar(2,0)*wWideltar(2,0);
1568 // add to total chi2
1575 } // end loop on tracks
1577 if(nTrksUsed < fMinTracks) {
1582 Double_t determinant = sumWi.Determinant();
1583 if(determinant < fMinDetFitter) {
1584 AliDebug(1,Form("det(V) = %f (<%f)\n",determinant,fMinDetFitter));
1590 // inverted of weights matrix
1591 TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
1593 // position of primary vertex
1594 rv.Mult(vV,sumWiri);
1596 } // end loop on the 2 steps
1603 Double_t position[3];
1604 position[0] = rv(0,0);
1605 position[1] = rv(1,0);
1606 position[2] = rv(2,0);
1607 Double_t covmatrix[6];
1608 covmatrix[0] = vV(0,0);
1609 covmatrix[1] = vV(0,1);
1610 covmatrix[2] = vV(1,1);
1611 covmatrix[3] = vV(0,2);
1612 covmatrix[4] = vV(1,2);
1613 covmatrix[5] = vV(2,2);
1615 // for correct chi2/ndf, count constraint as additional "track"
1616 if(fConstraint) nTrksUsed++;
1617 // store data in the vertex object
1618 if(fCurrentVertex) { delete fCurrentVertex; fCurrentVertex=0; }
1619 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1621 AliDebug(1," Vertex after fit:");
1622 AliDebug(1,Form("xyz: %f %f %f; nc %d",fCurrentVertex->GetXv(),fCurrentVertex->GetYv(),fCurrentVertex->GetZv(),fCurrentVertex->GetNContributors()));
1623 AliDebug(1,"--- VertexFitter(): finish\n");
1628 //----------------------------------------------------------------------------
1629 AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray,
1631 Bool_t optUseFitter,
1632 Bool_t optPropagate,
1633 Bool_t optUseDiamondConstraint)
1636 // Return vertex from tracks (AliExternalTrackParam) in array
1639 // set optUseDiamondConstraint=TRUE only if you are reconstructing the
1641 if(optUseDiamondConstraint) {
1647 // get tracks and propagate them to initial vertex position
1648 fIdSel = new UShort_t[(Int_t)trkArray->GetEntriesFast()];
1649 Int_t nTrksSel = PrepareTracks(*trkArray,id,0);
1650 if((!optUseDiamondConstraint && nTrksSel<TMath::Max(2,fMinTracks)) ||
1651 (optUseDiamondConstraint && nTrksSel<1)) {
1653 return fCurrentVertex;
1658 AliDebug(1,"Just one track");
1659 OneTrackVertFinder();
1662 case 1: StrLinVertexFinderMinDist(1); break;
1663 case 2: StrLinVertexFinderMinDist(0); break;
1664 case 3: HelixVertexFinder(); break;
1665 case 4: VertexFinder(1); break;
1666 case 5: VertexFinder(0); break;
1667 default: printf("Wrong algorithm\n"); break;
1670 AliDebug(1," Vertex finding completed\n");
1676 Double_t position[3]={fVert.GetXv(),fVert.GetYv(),fVert.GetZv()};
1677 Double_t covmatrix[6];
1678 fVert.GetCovMatrix(covmatrix);
1679 Double_t chi2=99999.;
1680 Int_t nTrksUsed=fVert.GetNContributors();
1681 fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nTrksUsed);
1683 fCurrentVertex->SetDispersion(fVert.GetDispersion());
1686 // set indices of used tracks and propagate track to found vertex
1687 UShort_t *indices = 0;
1688 Double_t d0z0[2],covd0z0[3];
1689 AliExternalTrackParam *t = 0;
1690 if(fCurrentVertex->GetNContributors()>0) {
1691 indices = new UShort_t[fTrkArraySel.GetEntriesFast()];
1692 for(Int_t jj=0; jj<(Int_t)fTrkArraySel.GetEntriesFast(); jj++) {
1693 indices[jj] = fIdSel[jj];
1694 t = (AliExternalTrackParam*)fTrkArraySel.At(jj);
1695 if(optPropagate && optUseFitter) {
1696 if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) {
1697 t->PropagateToDCA(fCurrentVertex,GetFieldkG(),100.,d0z0,covd0z0);
1698 AliDebug(1,Form("Track %d propagated to found vertex",jj));
1700 AliWarning("Found vertex outside beam pipe!");
1704 fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices);
1708 if (indices) {delete indices; indices=NULL;}
1709 delete fIdSel; fIdSel=NULL;
1710 fTrkArraySel.Delete();
1712 return fCurrentVertex;
1714 //----------------------------------------------------------------------------
1715 AliESDVertex* AliVertexerTracks::VertexForSelectedESDTracks(TObjArray *trkArray,
1716 Bool_t optUseFitter,
1717 Bool_t optPropagate,
1718 Bool_t optUseDiamondConstraint)
1722 // Return vertex from array of ESD tracks
1725 Int_t nTrks = (Int_t)trkArray->GetEntriesFast();
1726 UShort_t *id = new UShort_t[nTrks];
1728 AliESDtrack *esdt = 0;
1729 for(Int_t i=0; i<nTrks; i++){
1730 esdt = (AliESDtrack*)trkArray->At(i);
1731 id[i] = (UShort_t)esdt->GetID();
1734 VertexForSelectedTracks(trkArray,id,optUseFitter,optPropagate,optUseDiamondConstraint);
1738 return fCurrentVertex;
1740 //--------------------------------------------------------------------------