//---- Root headers --------
#include <TTree.h>
+#include <TMatrixD.h>
//---- AliRoot headers -----
#include "AliStrLine.h"
#include "AliVertexerTracks.h"
+#include "AliESD.h"
#include "AliESDtrack.h"
ClassImp(AliVertexerTracks)
//----------------------------------------------------------------------------
AliVertexerTracks::AliVertexerTracks():
- TObject(),fVert()
+TObject(),
+fVert(),
+fCurrentVertex(0),
+fConstraint(kFALSE),
+fOnlyFitter(kFALSE),
+fMinTracks(1),
+fMinITSClusters(5),
+fTrkArray(),
+fTrksToSkip(0),
+fNTrksToSkip(0),
+fDCAcut(0),
+fAlgo(1),
+fNSigma(3),
+fMaxd0z0(0.5),
+fITSin(kTRUE),
+fITSrefit(kTRUE),
+fDebug(0)
{
//
// Default constructor
//
SetVtxStart();
+ SetVtxStartSigma();
SetMinTracks();
- fDCAcut=0;
- fAlgo=1;
+ SetMinITSClusters();
+ SetNSigmad0();
+ SetMaxd0z0();
}
//-----------------------------------------------------------------------------
AliVertexerTracks::AliVertexerTracks(Double_t xStart, Double_t yStart):
- TObject(),fVert()
+TObject(),
+fVert(),
+fCurrentVertex(0),
+fConstraint(kFALSE),
+fOnlyFitter(kFALSE),
+fMinTracks(1),
+fMinITSClusters(5),
+fTrkArray(),
+fTrksToSkip(0),
+fNTrksToSkip(0),
+fDCAcut(0),
+fAlgo(1),
+fNSigma(3),
+fMaxd0z0(0.5),
+fITSin(kTRUE),
+fITSrefit(kTRUE),
+fDebug(0)
{
//
// Standard constructor
//
SetVtxStart(xStart,yStart);
+ SetVtxStartSigma();
SetMinTracks();
- fDCAcut=0;
- fAlgo=1;
+ SetMinITSClusters();
+ SetNSigmad0();
+ SetMaxd0z0();
}
//-----------------------------------------------------------------------------
-AliVertexerTracks::~AliVertexerTracks() {
+AliVertexerTracks::~AliVertexerTracks()
+{
// Default Destructor
- // The objects poited by the following pointers are not owned
+ // The objects pointed by the following pointer are not owned
// by this class and are not deleted
+ fCurrentVertex = 0;
+ delete[] fTrksToSkip;
+}
+//----------------------------------------------------------------------------
+AliESDVertex* AliVertexerTracks::FindPrimaryVertex(const AliESD *esdEvent)
+{
+//
+// Primary vertex for current ESD event
+// (Two iterations:
+// 1st with 5*fNSigma*sigma cut w.r.t. to initial vertex
+// + cut on sqrt(d0d0+z0z0) if fConstraint=kFALSE
+// 2nd with fNSigma*sigma cut w.r.t. to vertex found in 1st iteration)
+// All ESD tracks with inside the beam pipe are then propagated to found vertex
+//
+ fCurrentVertex = 0;
+
+ // read tracks from ESD
+ Int_t nTrksTot = (Int_t)esdEvent->GetNumberOfTracks();
+ if (nTrksTot<=0) {
+ if(fDebug) printf("TooFewTracks\n");
+ TooFewTracks(esdEvent);
+ return fCurrentVertex;
+ }
+
+ TTree *trkTree = new TTree("TreeT","tracks");
+ AliESDtrack *esdTrack = 0;
+ trkTree->Branch("tracks","AliESDtrack",&esdTrack);
+
+ Bool_t skipThis;
+ for(Int_t i=0; i<nTrksTot; i++) {
+ AliESDtrack *et = esdEvent->GetTrack(i);
+ esdTrack = new AliESDtrack(*et);
+ // check tracks to skip
+ skipThis = kFALSE;
+ for(Int_t j=0; j<fNTrksToSkip; j++) {
+ if(et->GetID()==fTrksToSkip[j]) {
+ if(fDebug) printf("skipping track: %d\n",i);
+ skipThis = kTRUE;
+ }
+ }
+ if(skipThis) {delete esdTrack;continue;}
+ if(fITSin) {
+ if(!(esdTrack->GetStatus()&AliESDtrack::kITSin)) {delete esdTrack;continue;}
+ if(fITSrefit && !(esdTrack->GetStatus()&AliESDtrack::kITSrefit)) {delete esdTrack;continue;}
+ Int_t nclus=esdTrack->GetNcls(0); // check number of clusters in ITS
+ if(nclus<fMinITSClusters) {delete esdTrack;continue;}
+ }
+ trkTree->Fill();
+ delete esdTrack;
+ }
+
+ // If fConstraint=kFALSE
+ // run VertexFinder(1) to get rough estimate of initVertex (x,y)
+ if(!fConstraint) {
+ // fill fTrkArray, for VertexFinder()
+ if(!fTrkArray.IsEmpty()) fTrkArray.Delete();
+ PrepareTracks(*trkTree,0);
+ Double_t cutsave = fDCAcut; fDCAcut = 0.1; // 1 mm
+ VertexFinder(1); // using weights, cutting dca < fDCAcut
+ fDCAcut = cutsave;
+ fTrkArray.Delete();
+ if(fVert.GetNContributors()>0) {
+ fVert.GetXYZ(fNominalPos);
+ fNominalPos[0] = fVert.GetXv();
+ fNominalPos[1] = fVert.GetYv();
+ fNominalPos[2] = fVert.GetZv();
+ if(fDebug) printf("No mean vertex: VertexFinder gives (%f, %f, %f)\n",fNominalPos[0],fNominalPos[1],fNominalPos[2]);
+ } else {
+ fNominalPos[0] = 0.;
+ fNominalPos[1] = 0.;
+ fNominalPos[2] = 0.;
+ if(fDebug) printf("No mean vertex and VertexFinder failed\n");
+ }
+ }
+
+ // TWO ITERATIONS:
+ //
+ // ITERATION 1
+ // propagate tracks to fNominalPos vertex
+ // preselect them:
+ // if(constraint) reject for |d0|>5*fNSigma*sigma w.r.t. fNominal... vertex
+ // else reject for |d0|\oplus|z0| > 5 mm w.r.t. fNominal... vertex
+ // ITERATION 2
+ // propagate tracks to best between initVertex and fCurrentVertex
+ // preselect tracks (reject for |d0|>fNSigma*sigma w.r.t. best
+ // between initVertex and fCurrentVertex)
+ for(Int_t iter=0; iter<2; iter++) {
+ if(fOnlyFitter && iter==0) continue;
+ Int_t nTrksPrep = PrepareTracks(*trkTree,iter+1);
+ if(fDebug) printf(" tracks prepared - iteration %d: %d\n",iter+1,nTrksPrep);
+ if(nTrksPrep < fMinTracks) {
+ if(fDebug) printf("TooFewTracks\n");
+ TooFewTracks(esdEvent);
+ if(fDebug) fCurrentVertex->PrintStatus();
+ fTrkArray.Delete();
+ delete trkTree;
+ return fCurrentVertex;
+ }
+
+ // vertex finder
+ if(!fOnlyFitter) {
+ if(nTrksPrep==1){
+ if(fDebug) printf("Just one track\n");
+ OneTrackVertFinder();
+ }else{
+ switch (fAlgo) {
+ case 1: StrLinVertexFinderMinDist(1); break;
+ case 2: StrLinVertexFinderMinDist(0); break;
+ case 3: HelixVertexFinder(); break;
+ case 4: VertexFinder(1); break;
+ case 5: VertexFinder(0); break;
+ default: printf("Wrong algorithm\n"); break;
+ }
+ }
+ if(fDebug) printf(" Vertex finding completed\n");
+ }
+
+ // vertex fitter
+ VertexFitter(fConstraint);
+ if(fDebug) printf(" Vertex fit completed\n");
+ if(iter==0) fTrkArray.Delete();
+ } // end loop on the two iterations
+
+
+ // take true pos from SPD vertex in ESD and write it in tracks' vertex
+ Double_t tp[3];
+ esdEvent->GetVertex()->GetTruePos(tp);
+ fCurrentVertex->SetTruePos(tp);
+
+ if(fConstraint) {
+ if(fOnlyFitter) {
+ fCurrentVertex->SetTitle("VertexerTracksWithConstraintOnlyFitter");
+ } else {
+ fCurrentVertex->SetTitle("VertexerTracksWithConstraint");
+ }
+ } else {
+ fCurrentVertex->SetTitle("VertexerTracksNoConstraint");
+ }
+
+
+ // set indices of used tracks
+ UShort_t *indices = 0;
+ AliESDtrack *ett = 0;
+ if(fCurrentVertex->GetNContributors()>0) {
+ indices = new UShort_t[fCurrentVertex->GetNContributors()];
+ for(Int_t jj=0;jj<(Int_t)fTrkArray.GetEntriesFast();jj++) {
+ ett = (AliESDtrack*)fTrkArray.At(jj);
+ indices[jj] = (UShort_t)ett->GetID();
+ }
+ fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices);
+ }
+ delete [] indices;
+
+ delete trkTree;
+
+ fTrkArray.Delete();
+
+ if(fTrksToSkip) delete [] fTrksToSkip;
+
+
+ if(fDebug) fCurrentVertex->PrintStatus();
+ if(fDebug) fCurrentVertex->PrintIndices();
+
+
+ return fCurrentVertex;
+}
+//------------------------------------------------------------------------
+Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3])
+{
+ //
+ 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];
+ return det;
+}
+//-------------------------------------------------------------------------
+void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t (*m)[3],Double_t *d)
+{
+ //
+ Double_t x12=p0[0]-p1[0];
+ Double_t y12=p0[1]-p1[1];
+ Double_t z12=p0[2]-p1[2];
+ Double_t kk=x12*x12+y12*y12+z12*z12;
+ m[0][0]=2-2/kk*x12*x12;
+ m[0][1]=-2/kk*x12*y12;
+ m[0][2]=-2/kk*x12*z12;
+ m[1][0]=-2/kk*x12*y12;
+ m[1][1]=2-2/kk*y12*y12;
+ m[1][2]=-2/kk*y12*z12;
+ m[2][0]=-2/kk*x12*z12;
+ m[2][1]=-2*y12*z12;
+ m[2][2]=2-2/kk*z12*z12;
+ d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
+ d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
+ d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
+
+}
+//--------------------------------------------------------------------------
+void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t (*m)[3],Double_t *d)
+{
+ //
+ Double_t x12=p1[0]-p0[0];
+ Double_t y12=p1[1]-p0[1];
+ Double_t z12=p1[2]-p0[2];
+
+ Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
+
+ Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
+
+ Double_t cc[3];
+ cc[0]=-x12/sigmasq[0];
+ cc[1]=-y12/sigmasq[1];
+ cc[2]=-z12/sigmasq[2];
+
+ 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;
+
+ Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
+
+ Double_t aa[3];
+ aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
+ aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
+ aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
+
+ m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
+ m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
+ m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
+
+ m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
+ m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
+ m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
+
+ m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
+ m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
+ m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
+
+ d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
+ d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
+ d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
+
+ }
+//--------------------------------------------------------------------------
+Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0)
+{
+ //
+ Double_t x12=p0[0]-p1[0];
+ Double_t y12=p0[1]-p1[1];
+ Double_t z12=p0[2]-p1[2];
+ Double_t x10=p0[0]-x0[0];
+ Double_t y10=p0[1]-x0[1];
+ Double_t z10=p0[2]-x0[2];
+ 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);
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::OneTrackVertFinder()
+{
+ // find vertex for events with 1 track, using DCA to nominal beam axis
+ if(fDebug) printf("Number of prepared tracks =%d - Call OneTrackVertFinder",fTrkArray.GetEntries());
+ AliESDtrack *track1;
+ track1 = (AliESDtrack*)fTrkArray.At(0);
+ Double_t field=GetField();
+ Double_t alpha=track1->GetAlpha();
+ Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
+ Double_t pos[3],dir[3];
+ track1->GetXYZAt(mindist,field,pos);
+ track1->GetPxPyPzAt(mindist,field,dir);
+ AliStrLine *line1 = new AliStrLine(pos,dir);
+ Double_t p1[3]={fNominalPos[0],fNominalPos[1],0.};
+ Double_t p2[3]={fNominalPos[0],fNominalPos[1],10.};
+ AliStrLine *zeta=new AliStrLine(p1,p2,kTRUE);
+ Double_t crosspoint[3]={0.,0.,0.};
+ Double_t sigma=999.;
+ Int_t nContrib=-1;
+ Int_t retcode = zeta->Cross(line1,crosspoint);
+ if(retcode>=0){
+ sigma=line1->GetDistFromPoint(crosspoint);
+ nContrib=1;
+ }
+ delete zeta;
+ delete line1;
+ fVert.SetXYZ(crosspoint);
+ fVert.SetDispersion(sigma);
+ fVert.SetNContributors(nContrib);
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::HelixVertexFinder()
+{
+ // Get estimate of vertex position in (x,y) from tracks DCA
+
+
+ Double_t initPos[3];
+ initPos[2] = 0.;
+ for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
+ Double_t field=GetField();
+
+ Int_t nacc = (Int_t)fTrkArray.GetEntriesFast();
+
+ Double_t aver[3]={0.,0.,0.};
+ Double_t averquad[3]={0.,0.,0.};
+ Double_t sigmaquad[3]={0.,0.,0.};
+ Double_t sigma=0;
+ Int_t ncombi = 0;
+ AliESDtrack *track1;
+ AliESDtrack *track2;
+ Double_t distCA;
+ Double_t x, par[5];
+ Double_t alpha, cs, sn;
+ Double_t crosspoint[3];
+ for(Int_t i=0; i<nacc; i++){
+ track1 = (AliESDtrack*)fTrkArray.At(i);
+
+
+ for(Int_t j=i+1; j<nacc; j++){
+ track2 = (AliESDtrack*)fTrkArray.At(j);
+
+ distCA=track2->PropagateToDCA(track1,field);
+ if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
+ track1->GetExternalParameters(x,par);
+ alpha=track1->GetAlpha();
+ cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
+ Double_t x1=x*cs - par[0]*sn;
+ Double_t y1=x*sn + par[0]*cs;
+ Double_t z1=par[1];
+ Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
+ track2->GetExternalParameters(x,par);
+ alpha=track2->GetAlpha();
+ cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
+ Double_t x2=x*cs - par[0]*sn;
+ Double_t y2=x*sn + par[0]*cs;
+ Double_t z2=par[1];
+ Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
+ Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
+ Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
+ Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
+ Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
+ crosspoint[0]=wx1*x1 + wx2*x2;
+ crosspoint[1]=wy1*y1 + wy2*y2;
+ crosspoint[2]=wz1*z1 + wz2*z2;
+
+ ncombi++;
+ for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
+ for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
+ }
+ }
+
+ }
+ if(ncombi>0){
+ for(Int_t jj=0;jj<3;jj++){
+ initPos[jj] = aver[jj]/ncombi;
+ averquad[jj]/=ncombi;
+ sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
+ sigma+=sigmaquad[jj];
+ }
+ sigma=TMath::Sqrt(TMath::Abs(sigma));
+ }
+ else {
+ Warning("HelixVertexFinder","Finder did not succed");
+ sigma=999;
+ }
+ fVert.SetXYZ(initPos);
+ fVert.SetDispersion(sigma);
+ fVert.SetNContributors(ncombi);
}
//----------------------------------------------------------------------------
-Int_t AliVertexerTracks::PrepareTracks(TTree &trkTree) {
+Int_t AliVertexerTracks::PrepareTracks(TTree &trkTree,Int_t optImpParCut)
+{
//
// Propagate tracks to initial vertex position and store them in a TObjArray
//
- Double_t alpha,xlStart;
+ Double_t maxd0rphi;
+ Double_t maxd0z0 = fMaxd0z0; // default is 5 mm
Int_t nTrks = 0;
+ Double_t sigmaCurr[3];
+ Double_t normdistx,normdisty;
+ Float_t d0z0[2],covd0z0[3];
+ Double_t sigma;
+ Double_t field=GetField();
+
+ AliESDVertex *initVertex = new AliESDVertex(fNominalPos,fNominalCov,1,1);
Int_t nEntries = (Int_t)trkTree.GetEntries();
- if(!fTrkArray.IsEmpty()) fTrkArray.Clear();
- fTrkArray.Expand(nEntries);
+ if(!fTrkArray.IsEmpty()) fTrkArray.Delete();
+
+ if(fDebug) {
+ printf(" PrepareTracks()\n");
+ }
for(Int_t i=0; i<nEntries; i++) {
AliESDtrack *track = new AliESDtrack;
trkTree.SetBranchAddress("tracks",&track);
trkTree.GetEvent(i);
- // propagate track to vtxSeed
- alpha = track->GetAlpha();
- xlStart = fNominalPos[0]*TMath::Cos(alpha)+fNominalPos[1]*TMath::Sin(alpha);
- track->PropagateTo(xlStart,GetField()); // to vtxSeed
+ // propagate track to vertex
+ if(optImpParCut<=1 || fOnlyFitter) { // optImpParCut==1 or 0
+ track->RelateToVertex(initVertex,field,100.);
+ } else { // optImpParCut==2
+ fCurrentVertex->GetSigmaXYZ(sigmaCurr);
+ normdistx = TMath::Abs(fCurrentVertex->GetXv()-fNominalPos[0])/TMath::Sqrt(sigmaCurr[0]*sigmaCurr[0]+fNominalCov[0]);
+ normdisty = TMath::Abs(fCurrentVertex->GetYv()-fNominalPos[1])/TMath::Sqrt(sigmaCurr[1]*sigmaCurr[1]+fNominalCov[2]);
+ if(normdistx < 3. && normdisty < 3. &&
+ (sigmaCurr[0]+sigmaCurr[1])<(TMath::Sqrt(fNominalCov[0])+TMath::Sqrt(fNominalCov[2]))) {
+ track->RelateToVertex(fCurrentVertex,field,100.);
+ } else {
+ track->RelateToVertex(initVertex,field,100.);
+ }
+ }
+
+ track->GetImpactParameters(d0z0,covd0z0);
+ sigma = TMath::Sqrt(covd0z0[0]);
+ maxd0rphi = fNSigma*sigma;
+ if(optImpParCut==1) maxd0rphi *= 5.;
+
+
+
+ if(fDebug) printf("trk %d; lab %d; |d0| = %f; d0 cut = %f; |z0| = %f; |d0|oplus|z0| = %f; d0z0 cut = %f\n",i,track->GetLabel(),TMath::Abs(d0z0[0]),maxd0rphi,TMath::Abs(d0z0[1]),TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]),maxd0z0);
+
+ // during iterations 1 and 2, if fConstraint=kFALSE,
+ // select tracks with d0oplusz0 < maxd0z0
+ if(optImpParCut>=1 && !fConstraint && nEntries>=3 &&
+ fVert.GetNContributors()>0) {
+ if(TMath::Sqrt(d0z0[0]*d0z0[0]+d0z0[1]*d0z0[1]) > maxd0z0) {
+ if(fDebug) printf(" rejected\n");
+ delete track; continue;
+ }
+ }
+
+ // select tracks with d0rphi < maxd0rphi
+ if(optImpParCut>0 && TMath::Abs(d0z0[0]) > maxd0rphi) {
+ if(fDebug) printf(" rejected\n");
+ delete track; continue;
+ }
+
fTrkArray.AddLast(track);
nTrks++;
}
+
+ delete initVertex;
+
return nTrks;
}
-//----------------------------------------------------------------------------
-AliVertex* AliVertexerTracks::VertexForSelectedTracks(TTree *trkTree) {
+//---------------------------------------------------------------------------
+AliESDVertex* AliVertexerTracks::RemoveTracksFromVertex(AliESDVertex *inVtx,
+ TTree *trksTree,
+ Float_t *diamondxy)
+{
//
-// Return vertex from tracks in trkTree
+// Removes tracks in trksTree from fit of inVtx
//
- // get tracks and propagate them to initial vertex position
- Int_t nTrks = PrepareTracks(*trkTree);
- if(nTrks < fMinTracks) {
- printf("TooFewTracks\n");
- Double_t vtx[3]={0,0,0};
- fVert.SetXYZ(vtx);
- fVert.SetDispersion(999);
- fVert.SetNContributors(-5);
- return &fVert;
+ if(!strstr(inVtx->GetTitle(),"VertexerTracksWithConstraintOnlyFitter"))
+ printf("WARNING: result of tracks' removal will be only approximately correct\n");
+
+ TMatrixD rv(3,1);
+ rv(0,0) = inVtx->GetXv();
+ rv(1,0) = inVtx->GetYv();
+ rv(2,0) = inVtx->GetZv();
+ TMatrixD vV(3,3);
+ Double_t cov[6];
+ inVtx->GetCovMatrix(cov);
+ vV(0,0) = cov[0];
+ vV(0,1) = cov[1]; vV(1,0) = cov[1];
+ vV(1,1) = cov[2];
+ vV(0,2) = cov[3]; vV(2,0) = cov[3];
+ vV(1,2) = cov[4]; vV(2,1) = cov[4];
+ vV(2,2) = cov[5];
+
+ TMatrixD sumWi(TMatrixD::kInverted,vV);
+ TMatrixD sumWiri(sumWi,TMatrixD::kMult,rv);
+
+ Int_t nUsedTrks = inVtx->GetNContributors();
+ Double_t chi2 = inVtx->GetChi2();
+
+ AliESDtrack *track = 0;
+ trksTree->SetBranchAddress("tracks",&track);
+ Int_t ntrks = trksTree->GetEntries();
+ for(Int_t i=0;i<ntrks;i++) {
+ trksTree->GetEvent(i);
+ if(!inVtx->UsesTrack(track->GetID())) {
+ printf("track %d was not used in vertex fit\n",track->GetID());
+ continue;
+ }
+ Double_t alpha = track->GetAlpha();
+ Double_t xl = diamondxy[0]*TMath::Cos(alpha)+diamondxy[1]*TMath::Sin(alpha);
+ track->AliExternalTrackParam::PropagateTo(xl,AliTracker::GetBz());
+ // vector of track global coordinates
+ TMatrixD ri(3,1);
+ // covariance matrix of ri
+ TMatrixD wWi(3,3);
+
+ // get space point from track
+ if(!TrackToPoint(track,ri,wWi)) continue;
+
+ TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
+
+ sumWi -= wWi;
+ sumWiri -= wWiri;
+
+ // track chi2
+ TMatrixD deltar = rv; deltar -= ri;
+ TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
+ Double_t chi2i = deltar(0,0)*wWideltar(0,0)+
+ deltar(1,0)*wWideltar(1,0)+
+ deltar(2,0)*wWideltar(2,0);
+ // remove from total chi2
+ chi2 -= chi2i;
+
+ nUsedTrks--;
+ if(nUsedTrks<2) {
+ printf("Trying to remove too many tracks!\n");
+ return 0x0;
+ }
}
-
- // Set initial vertex position from ESD
- if(fAlgo==1) StrLinVertexFinderMinDist(1);
- if(fAlgo==2) StrLinVertexFinderMinDist(0);
- if(fAlgo==3) HelixVertexFinder();
- if(fAlgo==4) VertexFinder(1);
- if(fAlgo==5) VertexFinder(0);
- return &fVert;
+
+ TMatrixD rvnew(3,1);
+ TMatrixD vVnew(3,3);
+
+ // new inverted of weights matrix
+ TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
+ vVnew = invsumWi;
+ // new position of primary vertex
+ rvnew.Mult(vVnew,sumWiri);
+
+ Double_t position[3];
+ position[0] = rvnew(0,0);
+ position[1] = rvnew(1,0);
+ position[2] = rvnew(2,0);
+ cov[0] = vVnew(0,0);
+ cov[1] = vVnew(0,1);
+ cov[2] = vVnew(1,1);
+ cov[3] = vVnew(0,2);
+ cov[4] = vVnew(1,2);
+ cov[5] = vVnew(2,2);
+
+ // store data in the vertex object
+ AliESDVertex *outVtx = new AliESDVertex(position,cov,chi2,nUsedTrks);
+ outVtx->SetTitle(inVtx->GetTitle());
+ Double_t tp[3];
+ inVtx->GetTruePos(tp);
+ outVtx->SetTruePos(tp);
+ UShort_t *inindices = inVtx->GetIndices();
+ UShort_t *outindices = new UShort_t[outVtx->GetNContributors()];
+ Int_t j=0;
+ Bool_t copyindex;
+ for(Int_t k=0; k<inVtx->GetNIndices(); k++) {
+ copyindex=kTRUE;
+ for(Int_t l=0; l<ntrks; l++) {
+ trksTree->GetEvent(l);
+ if(inindices[k]==track->GetID()) copyindex=kFALSE;
+ }
+ if(copyindex) {
+ outindices[j] = inindices[k]; j++;
+ }
+ }
+ outVtx->SetIndices(outVtx->GetNContributors(),outindices);
+ delete [] outindices;
+
+ if(fDebug) {
+ printf("Vertex before removing tracks:\n");
+ inVtx->PrintStatus();
+ inVtx->PrintIndices();
+ printf("Vertex after removing tracks:\n");
+ outVtx->PrintStatus();
+ outVtx->PrintIndices();
+ }
+
+ return outVtx;
}
-//----------------------------------------------------------------------------
-AliVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray) {
+//---------------------------------------------------------------------------
+void AliVertexerTracks::SetSkipTracks(Int_t n,Int_t *skipped)
+{
+//
+// Mark the tracks not to be used in the vertex reconstruction.
+// Tracks are identified by AliESDtrack::GetID()
+//
+ fNTrksToSkip = n; fTrksToSkip = new Int_t[n];
+ for(Int_t i=0;i<n;i++) fTrksToSkip[i] = skipped[i];
+ return;
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::SetVtxStart(AliESDVertex *vtx)
+{
+//
+// Set initial vertex knowledge
+//
+ vtx->GetXYZ(fNominalPos);
+ vtx->GetCovMatrix(fNominalCov);
+ SetConstraintOn();
+ return;
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights)
+{
+ // Calculate the point at minimum distance to prepared tracks
+
+ Double_t initPos[3];
+ initPos[2] = 0.;
+ Double_t sigma=0;
+ for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
+ const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast();
+ Double_t field=GetField();
+
+ AliESDtrack *track1;
+ Double_t (*vectP0)[3]=new Double_t [knacc][3];
+ Double_t (*vectP1)[3]=new Double_t [knacc][3];
+
+ Double_t sum[3][3];
+ Double_t dsum[3]={0,0,0};
+ for(Int_t i=0;i<3;i++)
+ for(Int_t j=0;j<3;j++)sum[i][j]=0;
+ for(Int_t i=0; i<knacc; i++){
+ track1 = (AliESDtrack*)fTrkArray.At(i);
+ Double_t alpha=track1->GetAlpha();
+ Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
+ Double_t pos[3],dir[3];
+ track1->GetXYZAt(mindist,field,pos);
+ track1->GetPxPyPzAt(mindist,field,dir);
+ AliStrLine *line1 = new AliStrLine(pos,dir);
+ // AliStrLine *line1 = new AliStrLine();
+ // track1->ApproximateHelixWithLine(mindist,field,line1);
+
+ Double_t p0[3],cd[3];
+ line1->GetP0(p0);
+ line1->GetCd(cd);
+ Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
+ vectP0[i][0]=p0[0];
+ vectP0[i][1]=p0[1];
+ vectP0[i][2]=p0[2];
+ vectP1[i][0]=p1[0];
+ vectP1[i][1]=p1[1];
+ vectP1[i][2]=p1[2];
+
+ Double_t matr[3][3];
+ Double_t dknow[3];
+ if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
+ if(optUseWeights==1){
+ Double_t sigmasq[3];
+ sigmasq[0]=track1->GetSigmaY2();
+ sigmasq[1]=track1->GetSigmaY2();
+ sigmasq[2]=track1->GetSigmaZ2();
+ GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
+ }
+
+ for(Int_t iii=0;iii<3;iii++){
+ dsum[iii]+=dknow[iii];
+ for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
+ }
+ delete line1;
+ }
+
+ Double_t vett[3][3];
+ Double_t det=GetDeterminant3X3(sum);
+
+ if(det!=0){
+ for(Int_t zz=0;zz<3;zz++){
+ for(Int_t ww=0;ww<3;ww++){
+ for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
+ }
+ for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
+ initPos[zz]=GetDeterminant3X3(vett)/det;
+ }
+
+
+ for(Int_t i=0; i<knacc; i++){
+ Double_t p0[3]={0,0,0},p1[3]={0,0,0};
+ for(Int_t ii=0;ii<3;ii++){
+ p0[ii]=vectP0[i][ii];
+ p1[ii]=vectP1[i][ii];
+ }
+ sigma+=GetStrLinMinDist(p0,p1,initPos);
+ }
+
+ sigma=TMath::Sqrt(sigma);
+ }else{
+ Warning("StrLinVertexFinderMinDist","Finder did not succed");
+ sigma=999;
+ }
+ delete vectP0;
+ delete vectP1;
+ fVert.SetXYZ(initPos);
+ fVert.SetDispersion(sigma);
+ fVert.SetNContributors(knacc);
+}
+//---------------------------------------------------------------------------
+Bool_t AliVertexerTracks::TrackToPoint(AliESDtrack *t,
+ TMatrixD &ri,TMatrixD &wWi) const
+{
+//
+// Extract from the AliESDtrack the global coordinates ri and covariance matrix
+// wWi of the space point that it represents (to be used in VertexFitter())
+//
+
+
+ Double_t rotAngle = t->GetAlpha();
+ if(rotAngle<0.) rotAngle += 2.*TMath::Pi();
+ Double_t cosRot = TMath::Cos(rotAngle);
+ Double_t sinRot = TMath::Sin(rotAngle);
+
+ ri(0,0) = t->GetX()*cosRot-t->GetY()*sinRot;
+ ri(1,0) = t->GetX()*sinRot+t->GetY()*cosRot;
+ ri(2,0) = t->GetZ();
+
+ // matrix to go from global (x,y,z) to local (y,z);
+ TMatrixD qQi(2,3);
+ qQi(0,0) = -sinRot;
+ qQi(0,1) = cosRot;
+ qQi(0,2) = 0.;
+ qQi(1,0) = 0.;
+ qQi(1,1) = 0.;
+ qQi(1,2) = 1.;
+
+ // covariance matrix of local (y,z) - inverted
+ TMatrixD uUi(2,2);
+ Double_t cc[15];
+ t->GetExternalCovariance(cc);
+ uUi(0,0) = cc[0];
+ uUi(0,1) = cc[1];
+ uUi(1,0) = cc[1];
+ uUi(1,1) = cc[2];
+ if(uUi.Determinant() <= 0.) return kFALSE;
+ TMatrixD uUiInv(TMatrixD::kInverted,uUi);
+
+ // weights matrix: wWi = qQiT * uUiInv * qQi
+ TMatrixD uUiInvQi(uUiInv,TMatrixD::kMult,qQi);
+ TMatrixD m(qQi,TMatrixD::kTransposeMult,uUiInvQi);
+ wWi = m;
+
+ return kTRUE;
+}
+//---------------------------------------------------------------------------
+void AliVertexerTracks::TooFewTracks(const AliESD* esdEvent)
+{
//
-// Return vertex from array of tracks
+// When the number of tracks is < fMinTracks
//
- // get tracks and propagate them to initial vertex position
- Int_t nTrks = trkArray->GetEntriesFast();
- if(nTrks < fMinTracks) {
- printf("TooFewTracks\n");
- Double_t vtx[3]={0,0,0};
- fVert.SetXYZ(vtx);
- fVert.SetDispersion(999);
- fVert.SetNContributors(-5);
- return &fVert;
- }
- TTree *trkTree = new TTree("TreeT","tracks");
- AliESDtrack *esdTrack = 0;
- trkTree->Branch("tracks","AliESDtrack",&esdTrack);
- for(Int_t i=0; i<nTrks; i++){
- esdTrack = (AliESDtrack*)trkArray->At(i);
- trkTree->Fill();
+ // deal with vertices not found
+ Double_t pos[3],err[3];
+ Int_t ncontr=0;
+ pos[0] = fNominalPos[0];
+ err[0] = TMath::Sqrt(fNominalCov[0]);
+ pos[1] = fNominalPos[1];
+ err[1] = TMath::Sqrt(fNominalCov[2]);
+ pos[2] = esdEvent->GetVertex()->GetZv();
+ err[2] = esdEvent->GetVertex()->GetZRes();
+ if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()<=0)
+ ncontr = -1; // (x,y,z) = (0,0,0)
+ if(err[0]>1. && esdEvent->GetVertex()->GetNContributors()>0)
+ ncontr = -2; // (x,y,z) = (0,0,z_fromSPD)
+ if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()<=0)
+ ncontr = -3; // (x,y,z) = (x_mean,y_mean,0)
+ if(err[0]<1. && esdEvent->GetVertex()->GetNContributors()>0)
+ ncontr = -4; // (x,y,z) = (x_mean,y_mean,z_fromSPD)
+ fCurrentVertex = 0;
+ fCurrentVertex = new AliESDVertex(pos,err);
+ fCurrentVertex->SetNContributors(ncontr);
+
+ Double_t tp[3];
+ esdEvent->GetVertex()->GetTruePos(tp);
+ fCurrentVertex->SetTruePos(tp);
+ if(fConstraint) {
+ fCurrentVertex->SetTitle("VertexerTracksWithConstraint");
+ } else {
+ fCurrentVertex->SetTitle("VertexerTracksNoConstraint");
}
-
- return VertexForSelectedTracks(trkTree);
-}
+ return;
+}
//---------------------------------------------------------------------------
-void AliVertexerTracks::VertexFinder(Int_t optUseWeights) {
+void AliVertexerTracks::VertexFinder(Int_t optUseWeights)
+{
// Get estimate of vertex position in (x,y) from tracks DCA
Int_t ncombi = 0;
AliESDtrack *track1;
AliESDtrack *track2;
+ Double_t pos[3],dir[3];
Double_t alpha,mindist;
Double_t field=GetField();
track1 = (AliESDtrack*)fTrkArray.At(i);
alpha=track1->GetAlpha();
mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
- AliStrLine *line1 = new AliStrLine();
- track1->ApproximateHelixWithLine(mindist,field,line1);
+ track1->GetXYZAt(mindist,field,pos);
+ track1->GetPxPyPzAt(mindist,field,dir);
+ AliStrLine *line1 = new AliStrLine(pos,dir);
+
+ // AliStrLine *line1 = new AliStrLine();
+ // track1->ApproximateHelixWithLine(mindist,field,line1);
for(Int_t j=i+1; j<nacc; j++){
track2 = (AliESDtrack*)fTrkArray.At(j);
alpha=track2->GetAlpha();
mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
- AliStrLine *line2 = new AliStrLine();
- track2->ApproximateHelixWithLine(mindist,field,line2);
+ track2->GetXYZAt(mindist,field,pos);
+ track2->GetPxPyPzAt(mindist,field,dir);
+ AliStrLine *line2 = new AliStrLine(pos,dir);
+ // AliStrLine *line2 = new AliStrLine();
+ // track2->ApproximateHelixWithLine(mindist,field,line2);
Double_t distCA=line2->GetDCA(line1);
- if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
+ //printf("%d %d %f\n",i,j,distCA);
+ if(fDCAcut<=0 || (fDCAcut>0&&distCA<fDCAcut)){
Double_t pnt1[3],pnt2[3],crosspoint[3];
if(optUseWeights<=0){
if(optUseWeights>0){
Int_t retcode = line1->CrossPoints(line2,pnt1,pnt2);
if(retcode>=0){
- Double_t alpha, cs, sn;
+ Double_t cs, sn;
alpha=track1->GetAlpha();
cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
if(ncombi>0){
for(Int_t jj=0;jj<3;jj++){
initPos[jj] = aver[jj]/ncombi;
+ //printf("%f\n",initPos[jj]);
aversq[jj]/=ncombi;
sigmasq[jj]=aversq[jj]-initPos[jj]*initPos[jj];
sigma+=sigmasq[jj];
fVert.SetNContributors(ncombi);
}
//---------------------------------------------------------------------------
-void AliVertexerTracks::HelixVertexFinder() {
-
- // Get estimate of vertex position in (x,y) from tracks DCA
-
-
+void AliVertexerTracks::VertexFitter(Bool_t useConstraint)
+{
+//
+// The optimal estimate of the vertex position is given by a "weighted
+// average of tracks positions"
+// Original method: V. Karimaki, CMS Note 97/0051
+//
Double_t initPos[3];
- initPos[2] = 0.;
- for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
- Double_t field=GetField();
+ fVert.GetXYZ(initPos);
+ Int_t arrEntries = (Int_t)fTrkArray.GetEntries();
+ if(arrEntries==1) useConstraint=kTRUE;
+ if(fDebug) {
+ printf(" VertexFitter(): start\n");
+ printf(" Number of tracks in array: %d\n",(Int_t)fTrkArray.GetEntriesFast());
+ printf(" Minimum # tracks required in fit: %d\n",fMinTracks);
+ printf("Vertex position after finder: %f,%f,%f\n",initPos[0],initPos[1],initPos[2]);
+ if(useConstraint) printf(" This vertex will be used in fit: (%f+-%f,%f+-%f)\n",fNominalPos[0],TMath::Sqrt(fNominalCov[0]),fNominalPos[1],TMath::Sqrt(fNominalCov[2]));
+ }
- Int_t nacc = (Int_t)fTrkArray.GetEntriesFast();
+ Int_t i,j,k,step=0;
+ TMatrixD rv(3,1);
+ TMatrixD vV(3,3);
+ rv(0,0) = initPos[0];
+ rv(1,0) = initPos[1];
+ rv(2,0) = 0.;
+ Double_t xlStart,alpha;
+ Int_t nUsedTrks;
+ Double_t chi2,chi2i,chi2b;
+ AliESDtrack *t = 0;
+ Int_t failed = 0;
- Double_t aver[3]={0.,0.,0.};
- Double_t averquad[3]={0.,0.,0.};
- Double_t sigmaquad[3]={0.,0.,0.};
- Double_t sigma=0;
- Int_t ncombi = 0;
- AliESDtrack *track1;
- AliESDtrack *track2;
- Double_t distCA;
- Double_t x, par[5];
- Double_t alpha, cs, sn;
- Double_t crosspoint[3];
- for(Int_t i=0; i<nacc; i++){
- track1 = (AliESDtrack*)fTrkArray.At(i);
-
+ // initial vertex covariance matrix
+ TMatrixD vVb(3,3);
+ vVb(0,0) = fNominalCov[0];
+ vVb(0,1) = fNominalCov[1];
+ vVb(0,2) = 0.;
+ vVb(1,0) = fNominalCov[1];
+ vVb(1,1) = fNominalCov[2];
+ vVb(1,2) = 0.;
+ vVb(2,0) = 0.;
+ vVb(2,1) = 0.;
+ vVb(2,2) = fNominalCov[5];
+ TMatrixD vVbInv(TMatrixD::kInverted,vVb);
+ TMatrixD rb(3,1);
+ rb(0,0) = fNominalPos[0];
+ rb(1,0) = fNominalPos[1];
+ rb(2,0) = fNominalPos[2];
+ TMatrixD vVbInvrb(vVbInv,TMatrixD::kMult,rb);
- for(Int_t j=i+1; j<nacc; j++){
- track2 = (AliESDtrack*)fTrkArray.At(j);
- distCA=track2->PropagateToDCA(track1,field);
+ // 2 steps:
+ // 1st - estimate of vtx using all tracks
+ // 2nd - estimate of global chi2
+ for(step=0; step<2; step++) {
+ if(fDebug) printf(" step = %d\n",step);
+ chi2 = 0.;
+ nUsedTrks = 0;
- if(fDCAcut<=0 ||(fDCAcut>0&&distCA<fDCAcut)){
- track1->GetExternalParameters(x,par);
- alpha=track1->GetAlpha();
- cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
- Double_t x1=x*cs - par[0]*sn;
- Double_t y1=x*sn + par[0]*cs;
- Double_t z1=par[1];
- Double_t sx1=sn*sn*track1->GetSigmaY2(), sy1=cs*cs*track1->GetSigmaY2();
- track2->GetExternalParameters(x,par);
- alpha=track2->GetAlpha();
- cs=TMath::Cos(alpha); sn=TMath::Sin(alpha);
- Double_t x2=x*cs - par[0]*sn;
- Double_t y2=x*sn + par[0]*cs;
- Double_t z2=par[1];
- Double_t sx2=sn*sn*track2->GetSigmaY2(), sy2=cs*cs*track2->GetSigmaY2();
- Double_t sz1=track1->GetSigmaZ2(), sz2=track2->GetSigmaZ2();
- Double_t wx1=sx2/(sx1+sx2), wx2=1.- wx1;
- Double_t wy1=sy2/(sy1+sy2), wy2=1.- wy1;
- Double_t wz1=sz2/(sz1+sz2), wz2=1.- wz1;
- crosspoint[0]=wx1*x1 + wx2*x2;
- crosspoint[1]=wy1*y1 + wy2*y2;
- crosspoint[2]=wz1*z1 + wz2*z2;
+ TMatrixD sumWiri(3,1);
+ TMatrixD sumWi(3,3);
+ for(i=0; i<3; i++) {
+ sumWiri(i,0) = 0.;
+ for(j=0; j<3; j++) sumWi(j,i) = 0.;
+ }
- ncombi++;
- for(Int_t jj=0;jj<3;jj++)aver[jj]+=crosspoint[jj];
- for(Int_t jj=0;jj<3;jj++)averquad[jj]+=(crosspoint[jj]*crosspoint[jj]);
+ // mean vertex constraint
+ if(useConstraint) {
+ for(i=0;i<3;i++) {
+ sumWiri(i,0) += vVbInvrb(i,0);
+ for(k=0;k<3;k++) sumWi(i,k) += vVbInv(i,k);
}
+ // chi2
+ TMatrixD deltar = rv; deltar -= rb;
+ TMatrixD vVbInvdeltar(vVbInv,TMatrixD::kMult,deltar);
+ chi2b = deltar(0,0)*vVbInvdeltar(0,0)+
+ deltar(1,0)*vVbInvdeltar(1,0)+
+ deltar(2,0)*vVbInvdeltar(2,0);
+ chi2 += chi2b;
}
-
- }
- if(ncombi>0){
- for(Int_t jj=0;jj<3;jj++){
- initPos[jj] = aver[jj]/ncombi;
- averquad[jj]/=ncombi;
- sigmaquad[jj]=averquad[jj]-initPos[jj]*initPos[jj];
- sigma+=sigmaquad[jj];
- }
- sigma=TMath::Sqrt(TMath::Abs(sigma));
- }
- else {
- Warning("HelixVertexFinder","Finder did not succed");
- sigma=999;
- }
- fVert.SetXYZ(initPos);
- fVert.SetDispersion(sigma);
- fVert.SetNContributors(ncombi);
-}
-//---------------------------------------------------------------------------
-void AliVertexerTracks::StrLinVertexFinderMinDist(Int_t optUseWeights){
- // Calculate the point at minimum distance to prepared tracks
-
- Double_t initPos[3];
- initPos[2] = 0.;
- Double_t sigma=0;
- for(Int_t i=0;i<2;i++)initPos[i]=fNominalPos[i];
- const Int_t knacc = (Int_t)fTrkArray.GetEntriesFast();
- Double_t field=GetField();
- AliESDtrack *track1;
- Double_t (*vectP0)[3]=new Double_t [knacc][3];
- Double_t (*vectP1)[3]=new Double_t [knacc][3];
-
- Double_t sum[3][3];
- Double_t dsum[3]={0,0,0};
- for(Int_t i=0;i<3;i++)
- for(Int_t j=0;j<3;j++)sum[i][j]=0;
- for(Int_t i=0; i<knacc; i++){
- track1 = (AliESDtrack*)fTrkArray.At(i);
- Double_t alpha=track1->GetAlpha();
- Double_t mindist = TMath::Cos(alpha)*fNominalPos[0]+TMath::Sin(alpha)*fNominalPos[1];
- AliStrLine *line1 = new AliStrLine();
- track1->ApproximateHelixWithLine(mindist,field,line1);
+ // loop on tracks
+ for(k=0; k<arrEntries; k++) {
+ // get track from track array
+ t = (AliESDtrack*)fTrkArray.At(k);
+ alpha = t->GetAlpha();
+ xlStart = initPos[0]*TMath::Cos(alpha)+initPos[1]*TMath::Sin(alpha);
+ // to vtxSeed (from finder)
+ t->AliExternalTrackParam::PropagateTo(xlStart,AliTracker::GetBz());
+
- Double_t p0[3],cd[3];
- line1->GetP0(p0);
- line1->GetCd(cd);
- Double_t p1[3]={p0[0]+cd[0],p0[1]+cd[1],p0[2]+cd[2]};
- vectP0[i][0]=p0[0];
- vectP0[i][1]=p0[1];
- vectP0[i][2]=p0[2];
- vectP1[i][0]=p1[0];
- vectP1[i][1]=p1[1];
- vectP1[i][2]=p1[2];
-
- Double_t matr[3][3];
- Double_t dknow[3];
- if(optUseWeights==0)GetStrLinDerivMatrix(p0,p1,matr,dknow);
- if(optUseWeights==1){
- Double_t sigmasq[3];
- sigmasq[0]=track1->GetSigmaY2();
- sigmasq[1]=track1->GetSigmaY2();
- sigmasq[2]=track1->GetSigmaZ2();
- GetStrLinDerivMatrix(p0,p1,sigmasq,matr,dknow);
- }
+ // vector of track global coordinates
+ TMatrixD ri(3,1);
+ // covariance matrix of ri
+ TMatrixD wWi(3,3);
- for(Int_t iii=0;iii<3;iii++){
- dsum[iii]+=dknow[iii];
- for(Int_t lj=0;lj<3;lj++) sum[iii][lj]+=matr[iii][lj];
+ // get space point from track
+ if(!TrackToPoint(t,ri,wWi)) continue;
+
+ TMatrixD wWiri(wWi,TMatrixD::kMult,ri);
+
+ // track chi2
+ TMatrixD deltar = rv; deltar -= ri;
+ TMatrixD wWideltar(wWi,TMatrixD::kMult,deltar);
+ chi2i = deltar(0,0)*wWideltar(0,0)+
+ deltar(1,0)*wWideltar(1,0)+
+ deltar(2,0)*wWideltar(2,0);
+
+ // add to total chi2
+ chi2 += chi2i;
+
+ sumWiri += wWiri;
+ sumWi += wWi;
+
+ nUsedTrks++;
+ } // end loop on tracks
+
+ if(nUsedTrks < fMinTracks) {
+ failed=1;
+ continue;
}
- delete line1;
- }
-
- Double_t vett[3][3];
- Double_t det=GetDeterminant3X3(sum);
-
- if(det!=0){
- for(Int_t zz=0;zz<3;zz++){
- for(Int_t ww=0;ww<3;ww++){
- for(Int_t kk=0;kk<3;kk++) vett[ww][kk]=sum[ww][kk];
- }
- for(Int_t kk=0;kk<3;kk++) vett[kk][zz]=dsum[kk];
- initPos[zz]=GetDeterminant3X3(vett)/det;
- }
-
-
- for(Int_t i=0; i<knacc; i++){
- Double_t p0[3]={0,0,0},p1[3]={0,0,0};
- for(Int_t ii=0;ii<3;ii++){
- p0[ii]=vectP0[i][ii];
- p1[ii]=vectP1[i][ii];
- }
- sigma+=GetStrLinMinDist(p0,p1,initPos);
- }
-
- sigma=TMath::Sqrt(sigma);
- }else{
- Warning("StrLinVertexFinderMinDist","Finder did not succed");
- sigma=999;
- }
- delete vectP0;
- delete vectP1;
- fVert.SetXYZ(initPos);
- fVert.SetDispersion(sigma);
- fVert.SetNContributors(knacc);
-}
-//_______________________________________________________________________
-Double_t AliVertexerTracks::GetDeterminant3X3(Double_t matr[][3]){
- //
- 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];
- return det;
-}
-//____________________________________________________________________________
-void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t m[][3],Double_t *d){
- //
- Double_t x12=p0[0]-p1[0];
- Double_t y12=p0[1]-p1[1];
- Double_t z12=p0[2]-p1[2];
- Double_t kk=x12*x12+y12*y12+z12*z12;
- m[0][0]=2-2/kk*x12*x12;
- m[0][1]=-2/kk*x12*y12;
- m[0][2]=-2/kk*x12*z12;
- m[1][0]=-2/kk*x12*y12;
- m[1][1]=2-2/kk*y12*y12;
- m[1][2]=-2/kk*y12*z12;
- m[2][0]=-2/kk*x12*z12;
- m[2][1]=-2*y12*z12;
- m[2][2]=2-2/kk*z12*z12;
- d[0]=2*p0[0]-2/kk*p0[0]*x12*x12-2/kk*p0[2]*x12*z12-2/kk*p0[1]*x12*y12;
- d[1]=2*p0[1]-2/kk*p0[1]*y12*y12-2/kk*p0[0]*x12*y12-2/kk*p0[2]*z12*y12;
- d[2]=2*p0[2]-2/kk*p0[2]*z12*z12-2/kk*p0[0]*x12*z12-2/kk*p0[1]*z12*y12;
+ Double_t determinant = sumWi.Determinant();
+ //cerr<<" determinant: "<<determinant<<endl;
+ if(determinant < 100.) {
+ printf("det(V) = 0\n");
+ failed=1;
+ continue;
+ }
-}
-//____________________________________________________________________________
-void AliVertexerTracks::GetStrLinDerivMatrix(Double_t *p0,Double_t *p1,Double_t *sigmasq,Double_t m[][3],Double_t *d){
- //
- Double_t x12=p1[0]-p0[0];
- Double_t y12=p1[1]-p0[1];
- Double_t z12=p1[2]-p0[2];
+ // inverted of weights matrix
+ TMatrixD invsumWi(TMatrixD::kInverted,sumWi);
+ vV = invsumWi;
+
+ // position of primary vertex
+ rv.Mult(vV,sumWiri);
- Double_t den= x12*x12*sigmasq[1]*sigmasq[2]+y12*y12*sigmasq[0]*sigmasq[2]+z12*z12*sigmasq[0]*sigmasq[1];
+ } // end loop on the 2 steps
- Double_t kk= 2*(x12*x12/sigmasq[0]+y12*y12/sigmasq[1]+z12*z12/sigmasq[2]);
+ // delete t;
- Double_t cc[3];
- cc[0]=-x12/sigmasq[0];
- cc[1]=-y12/sigmasq[1];
- cc[2]=-z12/sigmasq[2];
+ if(failed) {
+ if(fDebug) printf("TooFewTracks\n");
+ fCurrentVertex = new AliESDVertex(0.,0.,-1);
+ return;
+ }
- 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;
+ Double_t position[3];
+ position[0] = rv(0,0);
+ position[1] = rv(1,0);
+ position[2] = rv(2,0);
+ Double_t covmatrix[6];
+ covmatrix[0] = vV(0,0);
+ covmatrix[1] = vV(0,1);
+ covmatrix[2] = vV(1,1);
+ covmatrix[3] = vV(0,2);
+ covmatrix[4] = vV(1,2);
+ covmatrix[5] = vV(2,2);
+
+ // store data in the vertex object
+ fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nUsedTrks);
- Double_t ss= -p0[0]*cc[0]-p0[1]*cc[1]-p0[2]*cc[2];
+ if(fDebug) {
+ printf(" VertexFitter(): finish\n");
+ printf(" rv = ( %f , %f , %f )\n\n",rv(0,0),rv(1,0),rv(2,0));
+ fCurrentVertex->PrintStatus();
+ }
- Double_t aa[3];
- aa[0]=x12*sigmasq[1]*sigmasq[2]/den;
- aa[1]=y12*sigmasq[0]*sigmasq[2]/den;
- aa[2]=z12*sigmasq[0]*sigmasq[1]/den;
+ return;
+}
+//----------------------------------------------------------------------------
+AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TTree *trkTree,Bool_t optUseFitter,Bool_t optPropagate)
+{
+//
+// Return vertex from tracks in trkTree
+//
- m[0][0]=aa[0]*(aa[0]*kk+2*cc[0])+2*cc[0]*aa[0]+2/sigmasq[0];
- m[0][1]=aa[1]*(aa[0]*kk+2*cc[0])+2*cc[1]*aa[0];
- m[0][2]=aa[2]*(aa[0]*kk+2*cc[0])+2*cc[2]*aa[0];
+ SetConstraintOff();
- m[1][0]=aa[0]*(aa[1]*kk+2*cc[1])+2*cc[0]*aa[1];
- m[1][1]=aa[1]*(aa[1]*kk+2*cc[1])+2*cc[1]*aa[1]+2/sigmasq[1];
- m[1][2]=aa[2]*(aa[1]*kk+2*cc[1])+2*cc[2]*aa[1];
+ // get tracks and propagate them to initial vertex position
+ Int_t nTrksPrep = PrepareTracks(*trkTree,0);
+ if(nTrksPrep < TMath::Max(2,fMinTracks) ) {
+ if(fDebug) printf("TooFewTracks\n");
+ fCurrentVertex = new AliESDVertex(0.,0.,-1);
+ return fCurrentVertex;
+ }
+
+ switch (fAlgo) {
+ case 1: StrLinVertexFinderMinDist(1); break;
+ case 2: StrLinVertexFinderMinDist(0); break;
+ case 3: HelixVertexFinder(); break;
+ case 4: VertexFinder(1); break;
+ case 5: VertexFinder(0); break;
+ default: printf("Wrong algorithm\n"); break;
+ }
+
+ if(fDebug) printf(" Vertex finding completed\n");
- m[2][0]=aa[0]*(aa[2]*kk+2*cc[2])+2*cc[0]*aa[2];
- m[2][1]=aa[1]*(aa[2]*kk+2*cc[2])+2*cc[1]*aa[2];
- m[2][2]=aa[2]*(aa[2]*kk+2*cc[2])+2*cc[2]*aa[2]+2/sigmasq[2];
+ // vertex fitter
+ if(optUseFitter){
+ VertexFitter(fConstraint);
+ if(fDebug) printf(" Vertex fit completed\n");
+ }else{
+ Double_t position[3]={fVert.GetXv(),fVert.GetYv(),fVert.GetZv()};
+ Double_t covmatrix[6]={0.,0.,0.,0.,0.,0.};
+ Double_t chi2=99999.;
+ Int_t nUsedTrks=fVert.GetNContributors();
+ fCurrentVertex = new AliESDVertex(position,covmatrix,chi2,nUsedTrks);
+ }
+ fCurrentVertex->SetDispersion(fVert.GetDispersion());
- d[0]=-ww*(aa[0]*kk+2*cc[0])-2*ss*aa[0]+2*p0[0]/sigmasq[0];
- d[1]=-ww*(aa[1]*kk+2*cc[1])-2*ss*aa[1]+2*p0[1]/sigmasq[1];
- d[2]=-ww*(aa[2]*kk+2*cc[2])-2*ss*aa[2]+2*p0[2]/sigmasq[2];
+ // set indices of used tracks and propagate track to found vertex
+ UShort_t *indices = 0;
+ AliESDtrack *eta = 0;
+ if(fCurrentVertex->GetNContributors()>0) {
+ indices = new UShort_t[fCurrentVertex->GetNContributors()];
+ for(Int_t jj=0;jj<(Int_t)fTrkArray.GetEntriesFast();jj++) {
+ eta = (AliESDtrack*)fTrkArray.At(jj);
+ indices[jj] = (UShort_t)eta->GetID();
+ if(optPropagate&&optUseFitter){
+ if(TMath::Sqrt(fCurrentVertex->GetXv()*fCurrentVertex->GetXv()+fCurrentVertex->GetYv()*fCurrentVertex->GetYv())<3.) {
+ eta->RelateToVertex(fCurrentVertex,GetField(),100.);
+ if(fDebug) printf("Track %d propagated to found vertex\n",jj);
+ }else{
+ AliWarning("Found vertex outside beam pipe!");
+ }
+ }
+ }
+ fCurrentVertex->SetIndices(fCurrentVertex->GetNContributors(),indices);
+ }
+ delete [] indices;
+ fTrkArray.Delete();
+
+ return fCurrentVertex;
}
-//_____________________________________________________________________________
-Double_t AliVertexerTracks::GetStrLinMinDist(Double_t *p0,Double_t *p1,Double_t *x0){
- //
- Double_t x12=p0[0]-p1[0];
- Double_t y12=p0[1]-p1[1];
- Double_t z12=p0[2]-p1[2];
- Double_t x10=p0[0]-x0[0];
- Double_t y10=p0[1]-x0[1];
- Double_t z10=p0[2]-x0[2];
- 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);
+//----------------------------------------------------------------------------
+AliESDVertex* AliVertexerTracks::VertexForSelectedTracks(TObjArray *trkArray,Bool_t optUseFitter, Bool_t optPropagate)
+{
+//
+// Return vertex from array of tracks
+//
+
+ // get tracks and propagate them to initial vertex position
+ Int_t nTrks = trkArray->GetEntriesFast();
+ if(nTrks < TMath::Max(2,fMinTracks) ) {
+ if(fDebug) printf("TooFewTracks\n");
+ fCurrentVertex = new AliESDVertex(0.,0.,-1);
+ return fCurrentVertex;
+ }
+ TTree *trkTree = new TTree("TreeT","tracks");
+ AliESDtrack *esdTrack = 0;
+ trkTree->Branch("tracks","AliESDtrack",&esdTrack);
+ for(Int_t i=0; i<nTrks; i++){
+ esdTrack = (AliESDtrack*)trkArray->At(i);
+ trkTree->Fill();
+ }
+
+ AliESDVertex *vtx = VertexForSelectedTracks(trkTree,optUseFitter,optPropagate);
+ delete trkTree;
+ return vtx;
}
+//--------------------------------------------------------------------------
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff