-Double_t AliHMPIDRecon::Sigma2(Double_t ckovTh, Double_t ckovPh)const
-{
-// Analithical calculation of total error (as a sum of localization, geometrical and chromatic errors) on Cerenkov angle for a given Cerenkov photon
-// created by a given MIP. Fromulae according to CERN-EP-2000-058
-// Arguments: Cerenkov and azimuthal angles for Cerenkov photon, [radians]
-// dip and azimuthal angles for MIP taken at the entrance to radiator, [radians]
-// MIP beta
-// Returns: absolute error on Cerenkov angle, [radians]
-
- TVector3 v(-999,-999,-999);
- Double_t trkBeta = 1./(TMath::Cos(ckovTh)*fRadNmean);
-
- if(trkBeta > 1) trkBeta = 1; //protection against bad measured thetaCer
- if(trkBeta < 0) trkBeta = 0.0001; //
-
- v.SetX(SigLoc (ckovTh,ckovPh,trkBeta));
- v.SetY(SigGeom(ckovTh,ckovPh,trkBeta));
- v.SetZ(SigCrom(ckovTh,ckovPh,trkBeta));
-
- return v.Mag2();
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Double_t AliHMPIDRecon::SigLoc(Double_t thetaC, Double_t phiC,Double_t betaM)const
-{
-// Analithical calculation of localization error (due to finite segmentation of PC) on Cerenkov angle for a given Cerenkov photon
-// created by a given MIP. Fromulae according to CERN-EP-2000-058
-// Arguments: Cerenkov and azimuthal angles for Cerenkov photon, [radians]
-// dip and azimuthal angles for MIP taken at the entrance to radiator, [radians]
-// MIP beta
-// Returns: absolute error on Cerenkov angle, [radians]
-
- Double_t phiDelta = phiC - fTrkDir.Phi();
-
- Double_t sint = TMath::Sin(fTrkDir.Theta());
- Double_t cost = TMath::Cos(fTrkDir.Theta());
- Double_t sinf = TMath::Sin(fTrkDir.Phi());
- Double_t cosf = TMath::Cos(fTrkDir.Phi());
- Double_t sinfd = TMath::Sin(phiDelta);
- Double_t cosfd = TMath::Cos(phiDelta);
- Double_t tantheta = TMath::Tan(thetaC);
-
- Double_t alpha =cost-tantheta*cosfd*sint; // formula (11)
- Double_t k = 1.-fRadNmean*fRadNmean+alpha*alpha/(betaM*betaM); // formula (after 8 in the text)
- if (k<0) return 1e10;
- Double_t mu =sint*sinf+tantheta*(cost*cosfd*sinf+sinfd*cosf); // formula (10)
- Double_t e =sint*cosf+tantheta*(cost*cosfd*cosf-sinfd*sinf); // formula (9)
-
- Double_t kk = betaM*TMath::Sqrt(k)/(fgkGapThick*alpha); // formula (6) and (7)
- Double_t dtdxc = kk*(k*(cosfd*cosf-cost*sinfd*sinf)-(alpha*mu/(betaM*betaM))*sint*sinfd); // formula (6)
- Double_t dtdyc = kk*(k*(cosfd*sinf+cost*sinfd*cosf)+(alpha* e/(betaM*betaM))*sint*sinfd); // formula (7) pag.4
-
- Double_t errX = 0.2,errY=0.25; //end of page 7
- return TMath::Sqrt(errX*errX*dtdxc*dtdxc + errY*errY*dtdyc*dtdyc);
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Double_t AliHMPIDRecon::SigCrom(Double_t thetaC, Double_t phiC,Double_t betaM)const
-{
-// Analithical calculation of chromatic error (due to lack of knowledge of Cerenkov photon energy) on Cerenkov angle for a given Cerenkov photon
-// created by a given MIP. Fromulae according to CERN-EP-2000-058
-// Arguments: Cerenkov and azimuthal angles for Cerenkov photon, [radians]
-// dip and azimuthal angles for MIP taken at the entrance to radiator, [radians]
-// MIP beta
-// Returns: absolute error on Cerenkov angle, [radians]
-
- Double_t phiDelta = phiC - fTrkDir.Phi();
-
- Double_t sint = TMath::Sin(fTrkDir.Theta());
- Double_t cost = TMath::Cos(fTrkDir.Theta());
- Double_t cosfd = TMath::Cos(phiDelta);
- Double_t tantheta = TMath::Tan(thetaC);
-
- Double_t alpha =cost-tantheta*cosfd*sint; // formula (11)
- Double_t dtdn = cost*fRadNmean*betaM*betaM/(alpha*tantheta); // formula (12)
-
-// Double_t f = 0.00928*(7.75-5.635)/TMath::Sqrt(12.);
- Double_t f = 0.0172*(7.75-5.635)/TMath::Sqrt(24.);
-
- return f*dtdn;
-}//SigCrom()
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Double_t AliHMPIDRecon::SigGeom(Double_t thetaC, Double_t phiC,Double_t betaM)const
-{
-// Analithical calculation of geometric error (due to lack of knowledge of creation point in radiator) on Cerenkov angle for a given Cerenkov photon
-// created by a given MIP. Formulae according to CERN-EP-2000-058
-// Arguments: Cerenkov and azimuthal angles for Cerenkov photon, [radians]
-// dip and azimuthal angles for MIP taken at the entrance to radiator, [radians]
-// MIP beta
-// Returns: absolute error on Cerenkov angle, [radians]
-
- Double_t phiDelta = phiC - fTrkDir.Phi();
-
- Double_t sint = TMath::Sin(fTrkDir.Theta());
- Double_t cost = TMath::Cos(fTrkDir.Theta());
- Double_t sinf = TMath::Sin(fTrkDir.Phi());
- Double_t cosfd = TMath::Cos(phiDelta);
- Double_t costheta = TMath::Cos(thetaC);
- Double_t tantheta = TMath::Tan(thetaC);
-
- Double_t alpha =cost-tantheta*cosfd*sint; // formula (11)
-
- Double_t k = 1.-fRadNmean*fRadNmean+alpha*alpha/(betaM*betaM); // formula (after 8 in the text)
- if (k<0) return 1e10;
-
- Double_t eTr = 0.5*fgkRadThick*betaM*TMath::Sqrt(k)/(fgkGapThick*alpha); // formula (14)
- Double_t lambda = 1.-sint*sint*sinf*sinf; // formula (15)
-
- Double_t c1 = 1./(1.+ eTr*k/(alpha*alpha*costheta*costheta)); // formula (13.a)
- Double_t c2 = betaM*TMath::Power(k,1.5)*tantheta*lambda/(fgkGapThick*alpha*alpha); // formula (13.b)
- Double_t c3 = (1.+eTr*k*betaM*betaM)/((1+eTr)*alpha*alpha); // formula (13.c)
- Double_t c4 = TMath::Sqrt(k)*tantheta*(1-lambda)/(fgkGapThick*betaM); // formula (13.d)
- Double_t dtdT = c1 * (c2+c3*c4);
- Double_t trErr = fgkRadThick/(TMath::Sqrt(12.)*cost);
-
- return trErr*dtdT;
-}//SigGeom()
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-//
-// From here HTA....
-//
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Bool_t AliHMPIDRecon::CkovHiddenTrk(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean)
-{
-// Pattern recognition method without any infos from tracking:HTA (Hidden Track Algorithm)...
-// The method finds in the chmber the cluster with the highest charge
-// compatibile with a MIP, then the strategy is applied
-// Arguments: pTrk - pointer to ESD track
-// pCluLs - list of clusters for a given chamber
-// nmean - mean freon ref. index
-// Returns: - 0=ok,1=not fitted
-
- AliHMPIDParam *pParam=AliHMPIDParam::Instance();
-
- fRadNmean=nmean;
-
- if(pCluLst->GetEntriesFast()>100) return kFALSE; //boundary check for CluX,CluY...
- Float_t mipX=-1,mipY=-1;Int_t mipId=-1,mipQ=-1;
- Double_t qRef = 0;
- Int_t nCh=0;
- for (Int_t iClu=0;iClu<pCluLst->GetEntriesFast();iClu++){ //clusters loop
- AliHMPIDCluster *pClu=(AliHMPIDCluster*)pCluLst->UncheckedAt(iClu); //get pointer to current cluster
- nCh = pClu->Ch();
- fXClu[iClu] = pClu->X();fYClu[iClu] = pClu->Y(); //store x,y for fitting procedure
- fClCk[iClu] = kTRUE; //all cluster are accepted at this stage to be reconstructed
- if(pClu->Q()>qRef){ //searching the highest charge to select a MIP
- qRef = pClu->Q();
- mipId=iClu; mipX=pClu->X();mipY=pClu->Y();mipQ=(Int_t)pClu->Q();
- }
- }//clusters loop
-
- fNClu = pCluLst->GetEntriesFast();
- if(qRef>pParam->QCut()){ //charge compartible with MIP clusters
- fIdxMip = mipId;
- fClCk[mipId] = kFALSE;
- fMipX = mipX; fMipY=mipY; fMipQ = qRef;
- if(!DoRecHiddenTrk(pCluLst)) {
- pTrk->SetHMPIDsignal(kNoPhotAccept);
- return kFALSE;
- } //Do track and ring reconstruction,if problems returns 1
- pTrk->SetHMPIDtrk(fRadX,fRadY,fThTrkFit,fPhTrkFit); //store track intersection info
- pTrk->SetHMPIDmip(fMipX,fMipY,(Int_t)fMipQ,fNClu); //store mip info
- pTrk->SetHMPIDcluIdx(nCh,fIdxMip); //set cham number and index of cluster
- pTrk->SetHMPIDsignal(fCkovFit); //find best Theta ckov for ring i.e. track
- pTrk->SetHMPIDchi2(fCkovSig2); //errors squared
-// Printf(" n clusters tot %i accepted %i",pCluLst->GetEntriesFast(),fNClu);
- return kTRUE;
- }
-
- return kFALSE;
-}//CkovHiddenTrk()
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Bool_t AliHMPIDRecon::DoRecHiddenTrk(TClonesArray *pCluLst)
-{
-// Pattern recognition method without any infos from tracking...
-// First a preclustering filter to avoid part of the noise
-// Then only ellipsed-rings are fitted (no possibility,
-// for the moment, to reconstruct very inclined tracks)
-// Finally a fitting with (th,ph) free, starting by very close values
-// previously evaluated.
-// Arguments: none
-// Returns: none
- Double_t phiRec;
- if(!CluPreFilter(pCluLst)) {return kFALSE;}
- if(!FitEllipse(phiRec)) {return kFALSE;}
- Int_t nClTmp1 = pCluLst->GetEntriesFast()-1; //minus MIP...
- Int_t nClTmp2 = 0;
- while(nClTmp1 != nClTmp2){
- SetNClu(pCluLst->GetEntriesFast());
- if(!FitFree(phiRec)) {return kFALSE;}
- nClTmp2 = NClu();
- if(nClTmp2!=nClTmp1) {nClTmp1=nClTmp2;nClTmp2=0;}
- }
- fNClu = nClTmp2;
- return kTRUE;
-}//DoRecHiddenTrk()
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Bool_t AliHMPIDRecon::CluPreFilter(TClonesArray *pCluLst)
-{
-// Filter of bkg clusters
-// based on elliptical-shapes...
-//
- if(pCluLst->GetEntriesFast()>50||pCluLst->GetEntriesFast()<4) return kFALSE;
- else return kTRUE;
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Bool_t AliHMPIDRecon::FitEllipse(Double_t &phiRec)
-{
-//Fit a set of clusters with an analitical conical section function:
- //
- // Ax^2 + B*y^2 + 2Hxy + 2Gx + 2Fy + 1 = 0 ---> conical section
- //
- // H*H - A*B > 0 hyperbola
- // < 0 ellipse
- // = 0 parabola
- //
- // tan 2alfa = 2H/(A-B) alfa=angle of rotation
- //
- // coordinate of the centre of the conical section:
- // x = x' + a
- // y = y' + b
- //
- // HF - BG
- // a = ---------
- // AB - H^2
- //
- // HG - AF
- // b = --------
- // AB - H^2
- Double_t cA,cB,cF,cG,cH;
- Double_t aArg=-1; Int_t iErrFlg; //tmp vars for TMinuit
-
- if(!gMinuit) gMinuit = new TMinuit(5); //init MINUIT with this number of parameters (5 params)
- gMinuit->mncler(); // reset Minuit list of paramters
- gMinuit->SetObjectFit((TObject*)this); gMinuit->SetFCN(AliHMPIDRecon::FunMinEl); //set fit function
- gMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg); //suspend all printout from TMinuit
- gMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg); //suspend all warning printout from TMinuit
-
- Double_t d1,d2,d3;
- TString sName;
-
- gMinuit->mnparm(0," A ",1,0.01,0,0,iErrFlg);
- gMinuit->mnparm(1," B ",1,0.01,0,0,iErrFlg);
- gMinuit->mnparm(2," H ",1,0.01,0,0,iErrFlg);
- gMinuit->mnparm(3," G ",1,0.01,0,0,iErrFlg);
- gMinuit->mnparm(4," F ",1,0.01,0,0,iErrFlg);
-
- gMinuit->mnexcm("SIMPLEX",&aArg,0,iErrFlg);
- gMinuit->mnexcm("MIGRAD" ,&aArg,0,iErrFlg);
- gMinuit->mnpout(0,sName,cA,d1,d2,d3,iErrFlg);
- gMinuit->mnpout(1,sName,cB,d1,d2,d3,iErrFlg);
- gMinuit->mnpout(2,sName,cH,d1,d2,d3,iErrFlg);
- gMinuit->mnpout(3,sName,cG,d1,d2,d3,iErrFlg);
- gMinuit->mnpout(4,sName,cF,d1,d2,d3,iErrFlg);
- delete gMinuit;
-
- Double_t i2 = cA*cB-cH*cH; //quartic invariant : i2 > 0 ellipse, i2 < 0 hyperbola
- if(i2<=0) return kFALSE;
- Double_t aX = (cH*cF-cB*cG)/i2; //x centre of the canonical section
- Double_t bY = (cH*cG-cA*cF)/i2; //y centre of the canonical section
- Double_t alfa1 = TMath::ATan(2*cH/(cA-cB)); //alpha = angle of rotation of the conical section
- if(alfa1<0) alfa1+=TMath::Pi();
- alfa1*=0.5;
-// Double_t alfa2 = alfa1+TMath::Pi();
- Double_t phiref = TMath::ATan2(bY-fMipY,aX-fMipX); //evaluate in a unique way the angle of rotation comparing it
- if(phiref<0) phiref+=TMath::TwoPi(); //with the vector that points to the centre from the mip
- if(i2<0) phiref+=TMath::Pi();
- if(phiref>TMath::TwoPi()) phiref-=TMath::TwoPi();
-
-// Printf(" alfa1 %f",alfa1*TMath::RadToDeg());
-// Printf(" alfa2 %f",alfa2*TMath::RadToDeg());
-// Printf(" firef %f",phiref*TMath::RadToDeg());
-// if(TMath::Abs(alfa1-phiref)<TMath::Abs(alfa2-phiref)) phiRec = alfa1; else phiRec = alfa2;
-
-// Printf("FitEllipse: phi reconstructed %f",phiRec*TMath::RadToDeg());
- phiRec=phiref;
- return kTRUE;
-//
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Bool_t AliHMPIDRecon::FitFree(Double_t phiRec)
-{
-// Fit performed by minimizing RMS/sqrt(n) of the
-// photons reconstructed. First phi is fixed and theta
-// is fouond, then (th,ph) of the track
-// as free parameters
-// Arguments: PhiRec phi of the track
-// Returns: none
- Double_t aArg=-1; Int_t iErrFlg; //tmp vars for TMinuit
- if(!gMinuit) gMinuit = new TMinuit(2); //init MINUIT with this number of parameters (5 params)
- gMinuit->mncler(); // reset Minuit list of paramters
- gMinuit->SetObjectFit((TObject*)this); gMinuit->SetFCN(AliHMPIDRecon::FunMinPhot); //set fit function
- gMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg); //suspend all printout from TMinuit
- gMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg); //suspend all warning printout from TMinuit
-
- Double_t d1,d2,d3;
- TString sName;
- Double_t th,ph;
-
- gMinuit->mnparm(0," theta ", 0.01,0.01,0,TMath::PiOver2(),iErrFlg);
- gMinuit->mnparm(1," phi ",phiRec,0.01,0,TMath::TwoPi() ,iErrFlg);
-
- gMinuit->FixParameter(1);
- gMinuit->mnexcm("SIMPLEX" ,&aArg,0,iErrFlg);
- gMinuit->mnexcm("MIGRAD" ,&aArg,0,iErrFlg);
- gMinuit->Release(1);
- gMinuit->mnexcm("MIGRAD" ,&aArg,0,iErrFlg);
-
- gMinuit->mnpout(0,sName,th,d1,d2,d3,iErrFlg);
- gMinuit->mnpout(1,sName,ph,d1,d2,d3,iErrFlg);
-
- Double_t outPar[2] = {th,ph}; Double_t g; Double_t f;Int_t flag = 3;
- gMinuit->Eval(2, &g, f, outPar,flag);
-
- SetTrkFit(th,ph);
-
- return kTRUE;
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-Double_t AliHMPIDRecon::FunConSect(Double_t *c,Double_t x,Double_t y)
-{
- return c[0]*x*x+c[1]*y*y+2*c[2]*x*y+2*c[3]*x+2*c[4]*y+1;
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::FunMinEl(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t /* */)
-{
- AliHMPIDRecon *pRec=(AliHMPIDRecon*)gMinuit->GetObjectFit();
- Double_t minFun = 0;
- Int_t np = pRec->NClu();
- for(Int_t i=0;i<np;i++) {
- if(i==pRec->IdxMip()) continue;
- Double_t el = pRec->FunConSect(par,pRec->XClu(i),pRec->YClu(i));
- minFun +=el*el;
- }
- f = minFun;
-}
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::FunMinPhot(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t iflag)
-{
- AliHMPIDRecon *pRec=(AliHMPIDRecon*)gMinuit->GetObjectFit();
- Double_t sizeCh = 0.5*fgkRadThick+fgkWinThick+fgkGapThick;
- Double_t thTrk = par[0];
- Double_t phTrk = par[1];
- Double_t xrad = pRec->MipX() - sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
- Double_t yrad = pRec->MipY() - sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);
- pRec->SetRadXY(xrad,yrad);
- pRec->SetTrack(xrad,yrad,thTrk,phTrk);
-
- Double_t meanCkov =0;
- Double_t meanCkov2=0;
- Double_t thetaCer,phiCer;
- Int_t nClAcc = 0;
- Int_t nClTot=pRec->NClu();
-
- for(Int_t i=0;i<nClTot;i++) {
- if(!(pRec->ClCk(i))) continue;
- pRec->FindPhotCkov(pRec->XClu(i),pRec->YClu(i),thetaCer,phiCer);
- meanCkov += thetaCer;
- meanCkov2 += thetaCer*thetaCer;
- nClAcc++;
- }
- if(nClAcc==0) {f=999;return;}
- meanCkov/=nClAcc;
- Double_t rms = (meanCkov2 - meanCkov*meanCkov*nClAcc)/nClAcc;
- if(rms<0) Printf(" rms2 = %f, strange!!!",rms);
- rms = TMath::Sqrt(rms);
- f = rms/TMath::Sqrt(nClAcc);
-
-
- if(iflag==3) {
- Printf("FunMinPhot before: photons candidates %i used %i",nClTot,nClAcc);
- nClAcc = 0;
- Double_t meanCkov1=0;
- Double_t meanCkov2=0;
- for(Int_t i=0;i<nClTot;i++) {
- if(!(pRec->ClCk(i))) continue;
- pRec->FindPhotCkov(pRec->XClu(i),pRec->YClu(i),thetaCer,phiCer);
- if(TMath::Abs(thetaCer-meanCkov)<2*rms) {
- meanCkov1 += thetaCer;
- meanCkov2 += thetaCer*thetaCer;
- nClAcc++;
- } else pRec->SetClCk(i,kFALSE);
- }
- meanCkov1/=nClAcc;
- Double_t rms2 = (meanCkov2 - meanCkov*meanCkov*nClAcc)/nClAcc;
- Printf("FunMinPhot after: photons candidates %i used %i thetaCer %f",nClTot,nClAcc,meanCkov1);
- pRec->SetCkovFit(meanCkov1);
- pRec->SetCkovSig2(rms2);
- pRec->SetNClu(nClAcc);
- }
-}//FunMinPhot()
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-//
-// ended Hidden track algorithm....
-//
-//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++