Coding rule violations

[u/mrichter/AliRoot.git] / HMPID / AliHMPIDReconHTA.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// AliHMPIDReconHTA                                                         //
//                                                                      //
// HMPID class to perfom pattern recognition based on Hough transfrom    //
// for single chamber                                                   //
//////////////////////////////////////////////////////////////////////////

#include "AliHMPIDReconHTA.h"//class header
#include "AliHMPIDCluster.h" //CkovHiddenTrk()
#include "AliHMPIDRecon.h"   //FunMinPhot()
#include <TMinuit.h>         //FitFree()
#include <TClonesArray.h>    //CkovHiddenTrk()
#include <AliESDtrack.h>     //CkovHiddenTrk()
#include <TH2I.h>            //InitDatabase()
#include <TGraph.h>          //ShapeModel()
#include <TFile.h>           //ShapeModel()
#include <TSpline.h>         //ShapeModel()
#include "TStopwatch.h"      //

TH2I* AliHMPIDReconHTA::fDatabase = 0x0;

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AliHMPIDReconHTA::AliHMPIDReconHTA():TTask("RichRec","RichPat")
{
//..
//hidden algorithm
//..
  fMipX=fMipY=fThTrkFit=fPhTrkFit=fCkovFit=fMipQ=fRadX=fRadY=-999;
  fIdxMip=fNClu=0;
  fCkovSig2=0;
  fXClu = 0x0;
  fYClu = 0x0;
  fClCk = 0x0;
  
  fParam=AliHMPIDParam::Instance();
  
  fParam->SetRefIdx(fParam->MeanIdxRad()); // initialization of ref index to a default one
  if(!fDatabase) InitDatabase();
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AliHMPIDReconHTA::~AliHMPIDReconHTA()
{
  DeleteVars();
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
void AliHMPIDReconHTA::InitVars(Int_t n)
{
//..
//Init some variables
//..
  fXClu = new Double_t[n];
  fYClu = new Double_t[n];
  fClCk = new Bool_t[n];
  for(Int_t i=0;i<n;i++) fClCk[i] = kTRUE;
//
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
void AliHMPIDReconHTA::DeleteVars()
{
//..
//Delete variables
//..
  if(fXClu) delete fXClu;
  if(fYClu) delete fYClu;
  if(fClCk) delete fClCk;
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::CkovHiddenTrk(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean, Double_t qthre)
{
// Pattern recognition method without any infos from tracking:HTA (Hidden Track Algorithm)...
// The method finds in the chmuber 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(); 
  pParam->SetRefIdx(nmean);

  if(!CluPreFilter(pCluLst)) {return kFALSE;}
  
  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()>qthre) fClCk[iClu] = kFALSE;                                                 // not a good photon in any case (multiple MIPs)
    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();
    }                                                                                    
//    Printf(" n. %d x %f y %f Q %f",iClu,pClu->X(),pClu->Y(),pClu->Q());
  }//clusters loop

  fNClu = pCluLst->GetEntriesFast();
  if(qRef>qthre){                                                                     //charge compartible with MIP clusters
    fIdxMip = mipId;
    fClCk[mipId] = kFALSE;
    fMipX = mipX; fMipY=mipY; fMipQ = qRef;
//    Printf(" mipId %d x %f y %f Q %f",fIdxMip,fMipX,fMipY,fMipQ);
    if(!DoRecHiddenTrk()) {
      pTrk->SetHMPIDsignal(pParam->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);
//    Printf("CkovHiddenTrk: thetaC %f th %f ph %f",fCkovFit,fThTrkFit,fPhTrkFit);
    return kTRUE;
  }
  
  return kFALSE;
}//CkovHiddenTrk()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::DoRecHiddenTrk()
{
// 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 thTrkRec,phiTrkRec,thetaCRec;
  
  if(!FindShape(thTrkRec,phiTrkRec,thetaCRec)) return kFALSE;

  if(!FitFree(thTrkRec,phiTrkRec)) {return kFALSE;}
  
  return kTRUE;
}//DoRecHiddenTrk()
/*
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::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 thTrkRec,phiTrkRec,thetaCRec;
  
  if(!FindShape(thTrkRec,phiTrkRec,thetaCRec)) return kFALSE;

//  Printf("thTrkRec %f phiTrkRec %f ThetaCRec %f",thTrkRec*TMath::RadToDeg(),phiTrkRec*TMath::RadToDeg(),thetaCRec*TMath::RadToDeg());  
  Int_t nClTmp1 = pCluLst->GetEntriesFast()-1;  //minus MIP...
  Int_t nClTmp2 = 0;
  
  while(nClTmp1 != nClTmp2){
    SetNClu(pCluLst->GetEntriesFast());
    if(!FitFree(thTrkRec,phiTrkRec)) {return kFALSE;}
    nClTmp2 = NClu();
    if(nClTmp2!=nClTmp1) {nClTmp1=nClTmp2;nClTmp2=0;}
  }
  
  fNClu = nClTmp2;
  return kTRUE;
}//DoRecHiddenTrk()
*/
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::CluPreFilter(TClonesArray *pCluLst)
{
// Filter of bkg clusters
// based on elliptical-shapes...
//
  Int_t nClusTot = pCluLst->GetEntriesFast();
  if(nClusTot<4||nClusTot>100) {
    return kFALSE; 
  } else { 
    InitVars(nClusTot);
    return kTRUE;
  }
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::FindShape(Double_t &thTrkRec,Double_t &phiTrkRec,Double_t &thetaCRec)
{
  Double_t *phiphot = new Double_t[fNClu];  
  Double_t *dist    = new Double_t[fNClu];  
  Int_t    *indphi  = new    Int_t[fNClu];  

  Bool_t status;
    
// Sort in phi angle...  
  for(Int_t i=0;i<fNClu;i++) {
    phiphot[i] = (TMath::ATan2(fMipY-fYClu[i],fMipX-fXClu[i])+TMath::Pi())*TMath::RadToDeg();
    dist[i]=TMath::Sqrt((fMipX-fXClu[i])*(fMipX-fXClu[i])+(fMipY-fYClu[i])*(fMipY-fYClu[i]));
  }
  
  TMath::Sort(fNClu,phiphot,indphi,kFALSE);
  
// Purify with a truncated mean;
  Int_t np=0;
  Double_t dMean  = 0;
  Double_t dMean2 = 0;
  for(Int_t i=0;i<fNClu;i++) {
    if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
    dMean +=dist[indphi[i]];
    dMean2+=dist[indphi[i]]*dist[indphi[i]];
    np++;
  }
  
  dMean  /=(Double_t)np;
  dMean2 /=(Double_t)np;
  Double_t rms = TMath::Sqrt(dMean2 - dMean*dMean);
  
  for(Int_t i=0;i<fNClu;i++) {
    if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
    if(TMath::Abs(dMean-dist[indphi[i]]) > 2*rms) {
      fClCk[indphi[i]] = kFALSE;
      continue;
    }
  }

//
//  purify vectors for good photon candidates
//
  Int_t npeff=0;
  Double_t *phiphotP = new Double_t[fNClu+1];  
  Double_t *distP    = new Double_t[fNClu+1];  
  for(Int_t i=0;i<fNClu;i++) {
    if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
    phiphotP[npeff] = phiphot[indphi[i]];
    distP[npeff]    = dist[indphi[i]];
    npeff++;
  }
  
  delete [] phiphot;
  delete [] dist;
  delete [] indphi;

  if(npeff<3) {
    delete [] phiphotP;
    delete [] distP;
    return kFALSE;
  }

//  for(Int_t i=0;i<npeff;i++) {Printf(" n. %d phiphot %f dist %f",i,phiphotP[i],distP[i]);}
  
  Double_t xA,xB;
  if(ShapeModel(npeff,phiphotP,distP,xA,xB,phiTrkRec)) {
    
//    Printf("FindShape: phi start %f",phiTrkRec*TMath::RadToDeg());

    Int_t bin = fDatabase->FindBin(xA,xB);
    Int_t compact = (Int_t)fDatabase->GetBinContent(bin);
    thetaCRec =  (Double_t)(compact%1000);
    thTrkRec  =  (Double_t)(compact/1000);

    thTrkRec *= TMath::DegToRad(); 
    thetaCRec *= TMath::DegToRad();

//    Printf("FindShape: xA %f xB %f compact %d thTrk %f thC %f",xA,xB,compact,thTrkRec*TMath::RadToDeg(),thetaCRec*TMath::RadToDeg());
        
    status = kTRUE;
    
  } else {
    
    status = kFALSE;
    
  }

  delete [] phiphotP;
  delete [] distP;
  
  return status;
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::ShapeModel(Int_t np,Double_t *phiphot,Double_t *dist,Double_t &xA,Double_t &xB,Double_t &phiStart)
{
  TGraph *phigr = new TGraph(np,phiphot,dist);
  TSpline3 *sphi = new TSpline3("sphi",phigr);
  if(!sphi) {Printf("Spline not created!Bye.");return kFALSE;}

  Int_t locMin = TMath::LocMin(np,dist);
  Int_t locMax = TMath::LocMax(np,dist);
  
  Double_t minX = phiphot[locMin];
//  Double_t minY =    dist[locMin];
  Double_t maxX = phiphot[locMax];
//  Double_t maxY =    dist[locMax];
  
  Int_t ip[3] = {-1,0,1};
  if(locMin==0   ) {ip[0]= 0;ip[1]= 1;ip[2]= 2;}
  if(locMin==np-1) {ip[0]=-2;ip[1]=-1;ip[2]= 0;}
  
  Double_t minXf = VertParab(phiphot[locMin+ip[0]],dist[locMin+ip[0]], 
                             phiphot[locMin+ip[1]],dist[locMin+ip[1]],
                             phiphot[locMin+ip[2]],dist[locMin+ip[2]]);
  if(minXf< phiphot[locMin+ip[0]] || minXf > phiphot[locMin+ip[2]]) minXf = minX;
  
  ip[0]=-1;ip[1]=0;ip[2]=1;
  if(locMax==0   ) {ip[0]= 0;ip[1]= 1;ip[2]= 2;}
  if(locMax==np-1) {ip[0]=-2;ip[1]=-1;ip[2]= 0;}
  
  Double_t maxXf = VertParab(phiphot[locMax+ip[0]],dist[locMax+ip[0]], 
                             phiphot[locMax+ip[1]],dist[locMax+ip[1]],
                             phiphot[locMax+ip[2]],dist[locMax+ip[2]]);
  if(maxXf< phiphot[locMax+ip[0]] || maxXf > phiphot[locMax+ip[2]]) maxXf = maxX;
  
//  Printf(" phi at mindist %f and found %f",minX,minXf);
//  Printf(" phi at maxdist %f and found %f",maxX,maxXf);
//  
  if(TMath::Abs(maxXf-minXf)>30) {
    xA = sphi->Eval(minXf);
    if(xA < 0) xA = dist[sphi->FindX(xA)];
    xB = sphi->Eval(minXf-90);
    if(xB < 0) xB = dist[sphi->FindX(xB)];
    phiStart = minXf-180;  //open ring or acceptance effect...so believe to min phi angle!
  } else {
    phiStart = 0.5*(maxXf-180+minXf);
    xA = sphi->Eval(phiStart+180);
    if(xA < 0) xA = dist[sphi->FindX(xA)];
    xB = sphi->Eval(phiStart+90);
    if(xB < 0) xB = dist[sphi->FindX(xB)];
  }
  //
//  Printf("ShapeModel: phiStart %f xA %f xB %f",phiStart,xA,xB);
  
  phiStart*=TMath::DegToRad();
  return kTRUE;
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Double_t AliHMPIDReconHTA::VertParab(Double_t x1,Double_t y1,Double_t x2, Double_t y2, Double_t x3, Double_t y3)
{
  Double_t a = ((x1-x3)*(y1-y2)-(x1-x2)*(y1-y3))/((x1*x1-x2*x2)*(x1-x3)-(x1*x1-x3*x3)*(x1-x2));
  Double_t b = (y1-y2 - a*(x1*x1-x2*x2))/(x1-x2);
//  Double_t c = y1 - a*x1*x1-b*x1;
  return -0.5*b/a;
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bool_t AliHMPIDReconHTA::FitFree(Double_t thTrkRec,Double_t phiTrkRec)
{
// 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
  
  
  TMinuit *pMinuit = new TMinuit(2);
  pMinuit->mncler();
  gMinuit->SetObjectFit((TObject*)this);  gMinuit->SetFCN(AliHMPIDReconHTA::FunMinPhot);  //set fit function
  Double_t aArg=-1,parStep,parLow,parHigh;     Int_t iErrFlg;                 //tmp vars for TMinuit
  Double_t d1,d2,d3;
  TString sName;
  Double_t th,ph;
  
  pMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg);                                          //suspend all printout from TMinuit
  pMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg);

  if(thTrkRec==0) thTrkRec = 3.*TMath::DegToRad();    // not to start from the edge...
  
  pMinuit->mnparm(0," thTrk  ",thTrkRec ,parStep=0.01,parLow=0,parHigh=TMath::PiOver4(),iErrFlg);
  pMinuit->mnparm(1," phiTrk ",phiTrkRec,parStep=0.01,parLow=0,parHigh=TMath::TwoPi(),iErrFlg);
  
  pMinuit->FixParameter(1);
  pMinuit->mnexcm("SIMPLEX" ,&aArg,0,iErrFlg);   
  pMinuit->mnexcm("MIGRAD"  ,&aArg,0,iErrFlg);
  pMinuit->Release(1);  
  pMinuit->mnexcm("MIGRAD"  ,&aArg,0,iErrFlg);
  
  pMinuit->mnpout(0,sName,th,d1,d2,d3,iErrFlg);
  pMinuit->mnpout(1,sName,ph,d1,d2,d3,iErrFlg);   
  
  Double_t f,par[2];
  Double_t *grad=0x0;
  par[0] = th;par[1] = ph;
  pMinuit->Eval(2,grad,f,par,3);

//  Printf("FitFree: theta %f phi %f",th,ph);
  
  SetTrkFit(th,ph);
  return kTRUE;
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
void AliHMPIDReconHTA::FunMinPhot(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t iflag)
{
// Minimization function to find best track and thetaC parameters
// Arguments:    f = function value to minimize
//             par = list of parameter to find
//           iflag = flag status. See Minuit instructions
//   Returns:    none
//
// Note: it is necessary to call an instance of AlihMPIDParam. Not possible to use fParam
// because of the static instantiation of the function in Minuit
  
  AliHMPIDParam *pParam=AliHMPIDParam::Instance();
  AliHMPIDReconHTA *pRecHTA=(AliHMPIDReconHTA*)gMinuit->GetObjectFit();
  AliHMPIDRecon pRec;
  Double_t sizeCh = 0.5*pParam->RadThick()+pParam->WinThick()+pParam->GapThick();
  Double_t thTrk = par[0]; 
  Double_t phTrk = par[1];
  Double_t xrad = pRecHTA->MipX() - sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
  Double_t yrad = pRecHTA->MipY() - sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);
  pRecHTA->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=pRecHTA->NClu();
    
  for(Int_t i=0;i<nClTot;i++) {
    if(!(pRecHTA->ClCk(i))) continue;
    pRec.FindPhotCkov(pRecHTA->XClu(i),pRecHTA->YClu(i),thetaCer,phiCer);  
    meanCkov  += thetaCer;
    meanCkov2 += thetaCer*thetaCer;
    nClAcc++;
  }
  if(nClAcc==0) {f=999;return;}
  meanCkov  /=(Double_t)nClAcc;
  meanCkov2 /=(Double_t)nClAcc;
  Double_t rms = TMath::Sqrt(TMath::Abs(meanCkov2 - meanCkov*meanCkov));
  f = rms/TMath::Sqrt((Double_t)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);
*/
//    Printf("FunMinPhot: reconstructed theta Cerenkov %f with %d photons",meanCkov,nClAcc);
    pRecHTA->SetCkovFit(meanCkov);
    pRecHTA->SetCkovSig2(rms*rms);
    pRecHTA->SetNClu(nClAcc);
  }
}//FunMinPhot()
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
void AliHMPIDReconHTA::InitDatabase()
{
  TStopwatch timer;
  timer.Start();
  
  AliInfo(Form("database HTA is being built.Please, wait..."));
//  
  Double_t x[3],y[3];

  AliHMPIDRecon rec;

  if(!fParam) fParam=AliHMPIDParam::Instance();
  Double_t thetaMax = TMath::ACos(1./fParam->MeanIdxRad());
  Double_t thTrkMax = 1./TMath::ASin(fParam->MeanIdxRad());    

  Int_t nstepx = 1000;
  Int_t nstepy = 1000;

  TH2I *deconv = new TH2I("deconv","database;d1;d2;thC+1000*thTrk",500,0,50,150,0,15);
  //
  Double_t xrad = 0;
  Double_t yrad = 0;
  Double_t phTrk = 0;

  for(Int_t i=0;i<nstepx;i++) {     //loop on thetaC
    for(Int_t j=0;j<nstepy;j++) {   //loop on theta particle
      Double_t thetaC = thetaMax/nstepx*((Double_t)i+0.5);
      Double_t thTrk  = thTrkMax/nstepy*((Double_t)j+0.5);
      //
      //mip position
      //
      Double_t sizeCh = fParam->RadThick()+fParam->WinThick()+fParam->GapThick();
      Double_t xmip = xrad + sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
      Double_t ymip = yrad + sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);

      Double_t dist1,dist2;
      //
      //first point at phi=0
      //
      rec.SetTrack(xrad,yrad,thTrk,phTrk);
      TVector2 pos;
      pos=rec.TracePhot(thetaC,0);

      if(pos.X()==-999) {
        dist1 = 0;            //open ring...anly the distance btw mip and point at 180 will be considered
      } else {
        x[0] = pos.X(); y[0] = pos.Y();
        dist1   = TMath::Sqrt((x[0]-xmip)*(x[0]-xmip)+(y[0]-ymip)*(y[0]-ymip));
      }
      //
      //second point at phi=180
      //
      rec.SetTrack(xrad,yrad,thTrk,phTrk);
      pos=rec.TracePhot(thetaC,TMath::Pi());

      if(pos.X()==-999) {Printf("it should not happens!Bye");return;}
      x[1] = pos.X(); y[1] = pos.Y();
      if((x[1]-xmip)*(x[0]-xmip)>0) continue; // to avoid circles out mips (for very low ThetaC)
      dist2   = TMath::Sqrt((x[1]-xmip)*(x[1]-xmip)+(y[1]-ymip)*(y[1]-ymip));

//      Double_t distA = dist1+dist2;
      Double_t distA = dist2;     // only the minimum: problem of acceptance
      //
      //second point at phi=90
      //
      rec.SetTrack(xrad,yrad,thTrk,phTrk);
      pos=rec.TracePhot(thetaC,TMath::PiOver2());

      if(pos.X()==-999) continue;
      x[2] = pos.X(); y[2] = pos.Y();
      Double_t distB   = TMath::Sqrt((x[2]-xmip)*(x[2]-xmip)+(y[2]-ymip)*(y[2]-ymip));
// compact the infos...      
      Int_t compact = (Int_t)(thetaC*TMath::RadToDeg())+1000*(Int_t)(thTrk*TMath::RadToDeg());
      Int_t bin = deconv->FindBin(distA,distB);
      if(deconv->GetBinContent(bin)==0) deconv->Fill(distA,distB,compact);
    }
  }

  FillZeroChan(deconv);
  fDatabase = deconv;

  timer.Stop();
  Double_t nSecs = timer.CpuTime();  
  AliInfo(Form("database HTA successfully open in %3.1f sec.(CPU). Reconstruction is started.",nSecs));
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
void AliHMPIDReconHTA::FillZeroChan(TH2I *deconv)
{
  Int_t nbinx = deconv->GetNbinsX();
  Int_t nbiny = deconv->GetNbinsY();
  for(Int_t i = 0;i<nbinx;i++) {
    for(Int_t j = 0;j<nbiny;j++) {
      if(deconv->GetBinContent(i,j) == 0) {
        Int_t nXmin = i-1; Int_t nXmax=i+1;
        Int_t nYmin = j-1; Int_t nYmax=j+1;
        Int_t nc = 0;
        Double_t meanC =0;
        Double_t meanTrk =0;
        for(Int_t ix=nXmin;ix<=nXmax;ix++) {
          if(ix<0||ix>nbinx) continue;
          for(Int_t iy=nYmin;iy<=nYmax;iy++) {
            if(iy<0||iy>nbiny) continue;
            meanC  +=  (Int_t)deconv->GetBinContent(ix,iy)%1000;
            meanTrk+=  (Int_t)deconv->GetBinContent(ix,iy)/1000;
            nc++;
          }
          meanC/=nc; meanTrk/=nc;
          Int_t compact = (Int_t)meanC+1000*(Int_t)meanTrk;
          if(compact>0)deconv->SetCellContent(i,j,compact);
        }
      }
    }
  }
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++