]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - HMPID/AliHMPIDRecon.cxx
Bug in area evaluation for reconstruction of ring. Important for PbPb events (high...
[u/mrichter/AliRoot.git] / HMPID / AliHMPIDRecon.cxx
index 41a820de0d04d6f260384f71f78202f225c6a59b..d9b40bd90d3719e58366d1dbc256936fa5b0f2fa 100644 (file)
@@ -53,9 +53,17 @@ AliHMPIDRecon::AliHMPIDRecon():TTask("RichRec","RichPat"),
     fPhotPhi [i] = -1;
     fPhotWei [i] =  0;
   }
+//hidden algorithm
+  fMipX=fMipY=fThTrkFit=fPhTrkFit=fCkovFit=fMipQ=fRadX=fRadY=-999;
+  fIdxMip=fNClu=0;
+  fCkovSig2=0;
+  for (Int_t i=0; i<100; i++) {
+    fXClu[i] = fYClu[i] = 0;
+    fClCk[i] = kTRUE;
+  }
 }
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::CkovAngle(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean)
+void AliHMPIDRecon::CkovAngle(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean,Double_t qthre)
 {
 // Pattern recognition method based on Hough transform
 // Arguments:   pTrk     - track for which Ckov angle is to be found
@@ -67,10 +75,10 @@ void AliHMPIDRecon::CkovAngle(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t n
   if(pCluLst->GetEntries()>pParam->MultCut()) fIsWEIGHT = kTRUE; // offset to take into account bkg in reconstruction
   else                                        fIsWEIGHT = kFALSE;
 
-  Float_t xRa,yRa,th,ph;       
+  Float_t xRa,yRa,th,ph;
   pTrk->GetHMPIDtrk(xRa,yRa,th,ph);        //initialize this track: th and ph angles at middle of RAD 
   SetTrack(xRa,yRa,th,ph);
-  
+
   fRadNmean=nmean;
 
   Float_t dMin=999,mipX=-1,mipY=-1;Int_t chId=-1,mipId=-1,mipQ=-1;                                                                           
@@ -78,7 +86,7 @@ void AliHMPIDRecon::CkovAngle(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t n
   for (Int_t iClu=0; iClu<pCluLst->GetEntriesFast();iClu++){//clusters loop
     AliHMPIDCluster *pClu=(AliHMPIDCluster*)pCluLst->UncheckedAt(iClu);                       //get pointer to current cluster    
     chId=pClu->Ch();
-    if(pClu->Q()>pParam->QCut()){                                                             //charge compartible with MIP clusters      
+    if(pClu->Q()>qthre){                                                                      //charge compartible with MIP clusters      
       Float_t dX=fPc.X()-pClu->X(),dY=fPc.Y()-pClu->Y(),d =TMath::Sqrt(dX*dX+dY*dY);          //distance between current cluster and intersection point
       if( d < dMin) {mipId=iClu; dMin=d;mipX=pClu->X();mipY=pClu->Y();mipQ=(Int_t)pClu->Q();} //current cluster is closer, overwrite data for min cluster
     }else{                                                                                    //charge compatible with photon cluster
@@ -86,20 +94,26 @@ void AliHMPIDRecon::CkovAngle(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t n
       if(FindPhotCkov(pClu->X(),pClu->Y(),thetaCer,phiCer)){                                  //find ckov angle for this  photon candidate
         fPhotCkov[fPhotCnt]=thetaCer;                                                         //actual theta Cerenkov (in TRS)
         fPhotPhi [fPhotCnt]=phiCer;                                                           //actual phi   Cerenkov (in TRS): -pi to come back to "unusual" ref system (X,Y,-Z)
+       //PH        Printf("photon n. %i reconstructed theta = %f",fPhotCnt,fPhotCkov[fPhotCnt]);
         fPhotCnt++;                                                                           //increment counter of photon candidates
       }
     }
   }//clusters loop
+  fMipPos.Set(mipX,mipY);
+  if(fPhotCnt<=3) pTrk->SetHMPIDsignal(kNoPhotAccept);                                        //no reconstruction with <=3 photon candidates
   Int_t iNacc=FlagPhot(HoughResponse());                                                      //flag photons according to individual theta ckov with respect to most probable
   pTrk->SetHMPIDmip(mipX,mipY,mipQ,iNacc);                                                    //store mip info 
 
   if(mipId==-1)              {pTrk->SetHMPIDsignal(kMipQdcCut);  return;}                     //no clusters with QDC more the threshold at all
   if(dMin>pParam->DistCut()) {pTrk->SetHMPIDsignal(kMipDistCut); return;}                     //closest cluster with enough charge is still too far from intersection
   pTrk->SetHMPIDcluIdx(chId,mipId);                                                           //set index of cluster
-  if(iNacc<1)    pTrk->SetHMPIDsignal(kNoPhotAccept);                                         //no photon candidates is accepted
-  else           pTrk->SetHMPIDsignal(FindRingCkov(pCluLst->GetEntries()));                   //find best Theta ckov for ring i.e. track
-  
-  pTrk->SetHMPIDchi2(fCkovSigma2);                                                            //errors squared 
+  if(iNacc<1){
+    pTrk->SetHMPIDsignal(kNoPhotAccept);                                                      //no photon candidates is accepted
+  }
+  else {
+    pTrk->SetHMPIDsignal(FindRingCkov(pCluLst->GetEntries()));                                //find best Theta ckov for ring i.e. track
+    pTrk->SetHMPIDchi2(fCkovSigma2);                                                          //errors squared
+  }
 
 }//CkovAngle()
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -178,20 +192,78 @@ void AliHMPIDRecon::RecPhot(TVector3 dirCkov,Double_t &thetaCer,Double_t &phiCer
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 Double_t AliHMPIDRecon::FindRingArea(Double_t ckovAng)const
 {
-// Find area inside the cerenkov ring which lays inside PCs
-// Arguments: ckovAng - cerenkov angle    
+// Find area covered in the PC acceptance
+// Arguments: ckovAng - cerenkov angle     
 //   Returns: area of the ring in cm^2 for given theta ckov
    
   const Int_t kN=100;
+  TVector2 pos1;
   Double_t area=0;
+  Bool_t first=kFALSE;
   for(Int_t i=0;i<kN;i++){
-    TVector2 pos1=TracePhot(ckovAng,Double_t(TMath::TwoPi()*i    /kN));//trace this photon 
-    TVector2 pos2=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN));//trace the next photon 
-    area+=(pos1-fTrkPos)*(pos2-fTrkPos);                               //add area of the triangle... 
+   if(!first) {
+     pos1=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN));                                     //find a good trace for the first photon
+     if(pos1.X()==-999) continue;                                                                   //no area: open ring                 
+     if(!AliHMPIDParam::IsInside(pos1.X(),pos1.Y(),0)) pos1 = IntWithEdge(fMipPos,pos1);            // ffind the very first intersection...
+     first=kTRUE;
+     continue;
+   }
+   TVector2 pos2=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN));                              //trace the next photon
+   if(pos2.X()==-999) continue;                                                                     //no area: open ring            
+   if(!AliHMPIDParam::IsInside(pos2.X(),pos2.Y(),0)) {
+     pos2 = IntWithEdge(fMipPos,pos2);
+   }
+   area+=TMath::Abs((pos1-fMipPos).X()*(pos2-fMipPos).Y()-(pos1-fMipPos).Y()*(pos2-fMipPos).X());   //add area of the triangle...           
+   pos1 = pos2;
   }
+//---  find points from ring
+  area*=0.5;
   return area;
 }//FindRingArea()
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+TVector2 AliHMPIDRecon::IntWithEdge(TVector2 p1,TVector2 p2)const
+{
+// It finds the intersection of the line for 2 points traced as photons
+// and the edge of a given PC
+// Arguments: 2 points obtained tracing the photons
+//   Returns: intersection point with detector (PC) edges
+
+  AliHMPIDParam *pParam = AliHMPIDParam::Instance();
+  
+  Double_t xmin = (p1.X()<p2.X())? p1.X():p2.X(); 
+  Double_t xmax = (p1.X()<p2.X())? p2.X():p1.X(); 
+  Double_t ymin = (p1.Y()<p2.Y())? p1.Y():p2.Y(); 
+  Double_t ymax = (p1.Y()<p2.Y())? p2.Y():p1.Y(); 
+  
+  Double_t m = TMath::Tan((p2-p1).Phi());
+  TVector2 pint;
+  //intersection with low  X
+  pint.Set((Double_t)(p1.X() + (0-p1.Y())/m),0.);
+  pint.Print();
+  if(pint.X()>=0 && pint.X()<=pParam->SizeAllX() &&
+     pint.X()>=xmin && pint.X()<=xmax            &&
+     pint.Y()>=ymin && pint.Y()<=ymax) return pint;
+  //intersection with high X  
+  pint.Set((Double_t)(p1.X() + (pParam->SizeAllY()-p1.Y())/m),(Double_t)(pParam->SizeAllY()));
+  pint.Print();
+  if(pint.X()>=0 && pint.X()<=pParam->SizeAllX() &&
+     pint.X()>=xmin && pint.X()<=xmax            &&
+     pint.Y()>=ymin && pint.Y()<=ymax) return pint;
+  //intersection with left Y  
+  pint.Set(0.,(Double_t)(p1.Y() + m*(0-p1.X())));
+  pint.Print();
+  if(pint.Y()>=0 && pint.Y()<=pParam->SizeAllY() &&
+     pint.Y()>=ymin && pint.Y()<=ymax            &&
+     pint.X()>=xmin && pint.X()<=xmax) return pint;
+  //intersection with righ Y  
+  pint.Set((Double_t)(pParam->SizeAllX()),(Double_t)(p1.Y() + m*(pParam->SizeAllX()-p1.X())));
+  pint.Print();
+  if(pint.Y()>=0 && pint.Y()<=pParam->SizeAllY() &&
+     pint.Y()>=ymin && pint.Y()<=ymax            &&
+     pint.X()>=xmin && pint.X()<=xmax) return pint;
+  return p1;
+}//IntWithEdge()
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 Double_t AliHMPIDRecon::FindRingCkov(Int_t)
 {
 // Loops on all Ckov candidates and estimates the best Theta Ckov for a ring formed by those candidates. Also estimates an error for that Theat Ckov
@@ -243,6 +315,7 @@ Int_t AliHMPIDRecon::FlagPhot(Double_t ckov)
 
   Int_t iInsideCnt = 0; //count photons which Theta ckov inside the window
   for(Int_t i=0;i<fPhotCnt;i++){//photon candidates loop
+    fPhotFlag[i] = 0;
     if(fPhotCkov[i] >= tmin && fPhotCkov[i] <= tmax)   { 
       fPhotFlag[i]=2;    
       iInsideCnt++;
@@ -290,14 +363,15 @@ void AliHMPIDRecon::Refract(TVector3 &dir,Double_t n1,Double_t n2)const
 //   Returns: none
 //   On exit: dir is new direction
   Double_t sinref=(n1/n2)*TMath::Sin(dir.Theta());
-  if(sinref>1.)    dir.SetXYZ(-999,-999,-999);
+  if(TMath::Abs(sinref)>1.) dir.SetXYZ(-999,-999,-999);
   else             dir.SetTheta(TMath::ASin(sinref));
 }//Refract()
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 Double_t AliHMPIDRecon::HoughResponse()
 {
 //
-//
+//    fIdxMip = mipId;
+
 //       
   Double_t kThetaMax=0.75;
   Int_t nChannels = (Int_t)(kThetaMax/fDTheta+0.5);
@@ -313,7 +387,7 @@ Double_t AliHMPIDRecon::HoughResponse()
     Int_t bin = (Int_t)(0.5+angle/(fDTheta));
     Double_t weight=1.;
     if(fIsWEIGHT){
-      Double_t lowerlimit = ((Double_t)bin)*fDTheta - 0.5*fDTheta;  Double_t upperlimit = ((Double_t)bin)*fDTheta + 0.5*fDTheta;   
+      Double_t lowerlimit = ((Double_t)bin)*fDTheta - 0.5*fDTheta;  Double_t upperlimit = ((Double_t)bin)*fDTheta + 0.5*fDTheta;
       Double_t diffArea = FindRingArea(upperlimit)-FindRingArea(lowerlimit);
       if(diffArea>0) weight = 1./diffArea;
     }
@@ -334,7 +408,7 @@ Double_t AliHMPIDRecon::HoughResponse()
 // evaluate the "BEST" theta ckov as the maximum value of histogramm
   Double_t *pVec = resultw->GetArray();
   Int_t locMax = TMath::LocMax(nBin,pVec);
-  phots->Delete();photsw->Delete();resultw->Delete(); // Reset and delete objects
+  delete phots;delete photsw;delete resultw; // Reset and delete objects
   
   return (Double_t)(locMax*fDTheta+0.5*fDTheta); //final most probable track theta ckov   
 }//HoughResponse()
@@ -350,6 +424,9 @@ Double_t AliHMPIDRecon::Sigma2(Double_t ckovTh, Double_t ckovPh)const
   
   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));
@@ -366,20 +443,29 @@ Double_t AliHMPIDRecon::SigLoc(Double_t thetaC, Double_t phiC,Double_t betaM)con
 //            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 alpha =TMath::Cos(fTrkDir.Theta())-TMath::Tan(thetaC)*TMath::Cos(phiDelta)*TMath::Sin(fTrkDir.Theta());
-  Double_t k = 1.-fRadNmean*fRadNmean+alpha*alpha/(betaM*betaM);
+  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 mu =TMath::Sin(fTrkDir.Theta())*TMath::Sin(fTrkDir.Phi())+TMath::Tan(thetaC)*(TMath::Cos(fTrkDir.Theta())*TMath::Cos(phiDelta)*TMath::Sin(fTrkDir.Phi())+TMath::Sin(phiDelta)*TMath::Cos(fTrkDir.Phi()));
-  Double_t e  =TMath::Sin(fTrkDir.Theta())*TMath::Cos(fTrkDir.Phi())+TMath::Tan(thetaC)*(TMath::Cos(fTrkDir.Theta())*TMath::Cos(phiDelta)*TMath::Cos(fTrkDir.Phi())-TMath::Sin(phiDelta)*TMath::Sin(fTrkDir.Phi()));
-
-  Double_t kk = betaM*TMath::Sqrt(k)/(8*alpha);
-  Double_t dtdxc = kk*(k*(TMath::Cos(phiDelta)*TMath::Cos(fTrkDir.Phi())-TMath::Cos(fTrkDir.Theta())*TMath::Sin(phiDelta)*TMath::Sin(fTrkDir.Phi()))-(alpha*mu/(betaM*betaM))*TMath::Sin(fTrkDir.Theta())*TMath::Sin(phiDelta));
-  Double_t dtdyc = kk*(k*(TMath::Cos(phiDelta)*TMath::Sin(fTrkDir.Phi())+TMath::Cos(fTrkDir.Theta())*TMath::Sin(phiDelta)*TMath::Cos(fTrkDir.Phi()))+(alpha* e/(betaM*betaM))*TMath::Sin(fTrkDir.Theta())*TMath::Sin(phiDelta));
+  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
 
-  return  TMath::Sqrt(0.2*0.2*dtdxc*dtdxc + 0.25*0.25*dtdyc*dtdyc);
+  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
@@ -390,12 +476,19 @@ Double_t AliHMPIDRecon::SigCrom(Double_t thetaC, Double_t phiC,Double_t betaM)co
 //            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 alpha =TMath::Cos(fTrkDir.Theta())-TMath::Tan(thetaC)*TMath::Cos(phiDelta)*TMath::Sin(fTrkDir.Theta());
 
-  Double_t dtdn = TMath::Cos(fTrkDir.Theta())*fRadNmean*betaM*betaM/(alpha*TMath::Tan(thetaC));
+  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 = 0.00928*(7.75-5.635)/TMath::Sqrt(12.);
+  Double_t f = 0.0172*(7.75-5.635)/TMath::Sqrt(24.);
 
   return f*dtdn;
 }//SigCrom()
@@ -410,96 +503,116 @@ Double_t AliHMPIDRecon::SigGeom(Double_t thetaC, Double_t phiC,Double_t betaM)co
 //   Returns: absolute error on Cerenkov angle, [radians]    
 
   Double_t phiDelta = phiC - fTrkDir.Phi();
-  Double_t alpha =TMath::Cos(fTrkDir.Theta())-TMath::Tan(thetaC)*TMath::Cos(phiDelta)*TMath::Sin(fTrkDir.Theta());
 
-  Double_t k = 1.-fRadNmean*fRadNmean+alpha*alpha/(betaM*betaM);
+  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*1.5*betaM*TMath::Sqrt(k)/(8*alpha);
-  Double_t lambda = 1.-TMath::Sin(fTrkDir.Theta())*TMath::Sin(fTrkDir.Theta())*TMath::Sin(phiC)*TMath::Sin(phiC);
+  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 c = 1./(1.+ eTr*k/(alpha*alpha*TMath::Cos(thetaC)*TMath::Cos(thetaC)));
-  Double_t i = betaM*TMath::Tan(thetaC)*lambda*TMath::Power(k,1.5);
-  Double_t ii = 1.+eTr*betaM*i;
+  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);
 
-  Double_t err = c * (i/(alpha*alpha*8) +  ii*(1.-lambda) / ( alpha*alpha*8*betaM*(1.+eTr)) );
-  Double_t trErr = 1.5/(TMath::Sqrt(12.)*TMath::Cos(fTrkDir.Theta()));
-
-  return trErr*err;
+  return trErr*dtdT;
 }//SigGeom()
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 //
-//
-//
-//
-//
-//
-//
-//
-//
-//
-//
-// From here Hidden track algorithm....
-//
-//
-//
-//
-//
-//
+// From here HTA....
 //
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::CkovHiddenTrk(TClonesArray *pCluLst,Double_t nmean)
+Bool_t AliHMPIDRecon::CkovHiddenTrk(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean, Double_t qthre)
 {
-// Pattern recognition method without any infos from tracking...
+// 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:  pCluLst  - list of clusters for this chamber   
-//   Returns:           - track ckov angle, [rad], 
-    
+// 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 
+  
   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;                                                                           
-  fPhotCnt=0;                                                      
   Double_t qRef = 0;
-  fNClu = pCluLst->GetEntriesFast();
-  for (Int_t iClu=0;iClu<fNClu;iClu++){                                                       //clusters loop
+  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
-  
-  fIdxMip = mipId;
-  fMipX = mipX; fMipY=mipY;
-  DoRecHiddenTrk();  
 
+  fNClu = pCluLst->GetEntriesFast();
+  if(qRef>qthre){                                                                     //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()
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::DoRecHiddenTrk()
+Bool_t AliHMPIDRecon::DoRecHiddenTrk(TClonesArray *pCluLst)
 {
 // Pattern recognition method without any infos from tracking...
-// Before a preclustering filter to avoid part of the noise
+// 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
+// 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;
-  CluPreFilter();
-  if(!FitEllipse(phiRec)) {Printf("Not an ellipse, bye!");return;}
-  Printf("--->now it starts the free fit with phi = %f",phiRec*TMath::RadToDeg());
-  return FitFree(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()
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::CluPreFilter()
+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)
@@ -525,11 +638,10 @@ Bool_t AliHMPIDRecon::FitEllipse(Double_t &phiRec)
   //       HG - AF
   //  b = --------
   //       AB - H^2
-  
   Double_t cA,cB,cF,cG,cH;
-  Double_t aArg=-1,parStep,parLow,parHigh;      Int_t iErrFlg;                         //tmp vars for TMinuit
+  Double_t aArg=-1;      Int_t iErrFlg;                                                //tmp vars for TMinuit
 
-  if(!gMinuit) gMinuit = new TMinuit(100);                                             //init MINUIT with this number of parameters (5 params)
+  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 
@@ -538,13 +650,13 @@ Bool_t AliHMPIDRecon::FitEllipse(Double_t &phiRec)
   Double_t d1,d2,d3;
   TString sName;
 
-  gMinuit->mnparm(0," A ",1,parStep=0.01,parLow=0,parHigh=0,iErrFlg);
-  gMinuit->mnparm(1," B ",1,parStep=0.01,parLow=0,parHigh=0,iErrFlg);
-  gMinuit->mnparm(2," H ",1,parStep=0.01,parLow=0,parHigh=0,iErrFlg);
-  gMinuit->mnparm(3," G ",1,parStep=0.01,parLow=0,parHigh=0,iErrFlg);
-  gMinuit->mnparm(4," F ",1,parStep=0.01,parLow=0,parHigh=0,iErrFlg);
+  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("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);
@@ -554,28 +666,30 @@ Bool_t AliHMPIDRecon::FitEllipse(Double_t &phiRec)
   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 comapring it
-  if(phiref<0) phiref+=TMath::TwoPi();                             //with the vector that poinst to the centre from the mip 
+//  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;  
+//  if(TMath::Abs(alfa1-phiref)<TMath::Abs(alfa2-phiref)) phiRec = alfa1; else phiRec = alfa2;  
   
-//  cout << " phi reconstructed " << phiRec*TMath::RadToDeg() << endl;
-  return (i2>0);
+//  Printf("FitEllipse: phi reconstructed %f",phiRec*TMath::RadToDeg());
+  phiRec=phiref;
+  return kTRUE;
 //
 }
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::FitFree(Double_t phiRec)
+Bool_t AliHMPIDRecon::FitFree(Double_t phiRec)
 {
 // Fit performed by minimizing RMS/sqrt(n) of the
 // photons reconstructed. First phi is fixed and theta
@@ -583,8 +697,8 @@ void AliHMPIDRecon::FitFree(Double_t phiRec)
 // as free parameters
 // Arguments:    PhiRec phi of the track
 //   Returns:    none
-  Double_t aArg=-1,parStep,parLow,parHigh;              Int_t iErrFlg;                 //tmp vars for TMinuit
-  if(!gMinuit) gMinuit = new TMinuit(100);                                             //init MINUIT with this number of parameters (5 params)
+  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 
@@ -594,11 +708,8 @@ void AliHMPIDRecon::FitFree(Double_t phiRec)
   TString sName;
   Double_t th,ph;
   
-  gMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg);                                          //suspend all printout from TMinuit
-  gMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg);
-
-  gMinuit->mnparm(0," theta ",0.01,parStep=0.01,parLow=0,parHigh=TMath::PiOver2(),iErrFlg);
-  gMinuit->mnparm(1," phi   ",phiRec,parStep=0.01,parLow=0,parHigh=TMath::TwoPi(),iErrFlg);
+  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);   
@@ -608,8 +719,13 @@ void AliHMPIDRecon::FitFree(Double_t phiRec)
   
   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);
   
-  Printf(" reconstr. theta %f  phi %f",th*TMath::RadToDeg(),ph*TMath::RadToDeg());
+  return kTRUE;
 }
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 Double_t AliHMPIDRecon::FunConSect(Double_t *c,Double_t x,Double_t y)
@@ -630,29 +746,62 @@ void AliHMPIDRecon::FunMinEl(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *
   f = minFun;
 }
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-void AliHMPIDRecon::FunMinPhot(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t /* */)
+void AliHMPIDRecon::FunMinPhot(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t iflag)
 {
   AliHMPIDRecon *pRec=(AliHMPIDRecon*)gMinuit->GetObjectFit();
-  
-  Double_t sizeCh = fgkRadThick+fgkWinThick+fgkGapThick;
+  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 meanCkov =0;
   Double_t meanCkov2=0;
   Double_t thetaCer,phiCer;
-  for(Int_t i=0;i<pRec->NClu();i++) {
+  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);
   }
-  meanCkov/=pRec->NClu();
-  Double_t rms = TMath::Sqrt(meanCkov2/pRec->NClu() - meanCkov*meanCkov);
-  f = rms/TMath::Sqrt(pRec->NClu());
-  pRec->SetCkovFit(meanCkov);
 }//FunMinPhot()
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+//
+// ended Hidden track algorithm....
+//
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++