HMPID/AliHMPIDReconHTA.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
   5  * Contributors are mentioned in the code where appropriate.              *
   6  *                                                                        *
   7  * Permission to use, copy, modify and distribute this software and its   *
   8  * documentation strictly for non-commercial purposes is hereby granted   *
   9  * without fee, provided that the above copyright notice appears in all   *
  10  * copies and that both the copyright notice and this permission notice   *
  11  * appear in the supporting documentation. The authors make no claims     *
  12  * about the suitability of this software for any purpose. It is          *
  13  * provided "as is" without express or implied warranty.                  *
  14  **************************************************************************/
  15
  16 //////////////////////////////////////////////////////////////////////////
  17 //                                                                      //
  18 // AliHMPIDReconHTA                                                         //
  19 //                                                                      //
  20 // HMPID class to perfom pattern recognition based on Hough transfrom    //
  21 // for single chamber                                                   //
  22 //////////////////////////////////////////////////////////////////////////
  23
  24 #include "AliHMPIDReconHTA.h"//class header
  25 #include "AliHMPIDCluster.h" //CkovHiddenTrk()
  26 #include "AliHMPIDRecon.h"   //FunMinPhot()
  27 #include <TMinuit.h>         //FitFree()
  28 #include <TClonesArray.h>    //CkovHiddenTrk()
  29 #include <AliESDtrack.h>     //CkovHiddenTrk()
  30 #include <TH2I.h>            //InitDatabase()
  31 #include <TGraph.h>          //ShapeModel()
  32 #include <TSpline.h>         //ShapeModel()
  33 #include "TStopwatch.h"      //
  34
  35 TH2I* AliHMPIDReconHTA::fgDatabase = 0x0;
  36
  37 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  38 AliHMPIDReconHTA::AliHMPIDReconHTA():
  39   TTask("RichRec","RichPat"),
  40   fMipX(-999),
  41   fMipY(-999),
  42   fMipQ(-999),
  43   fRadX(-999),
  44   fRadY(-999),
  45   fIdxMip(0),
  46   fNClu(0),
  47   fXClu(0),
  48   fYClu(0),
  49   fClCk(0),
  50   fThTrkFit(-999),
  51   fPhTrkFit(-999),
  52   fCkovFit(-999),
  53   fCkovSig2(0),
  54   fParam(AliHMPIDParam::Instance())
  55 {
  56 //..
  57 //hidden algorithm
  58 //..
  59   fParam->SetRefIdx(fParam->MeanIdxRad()); // initialization of ref index to a default one
  60   if(!fgDatabase) InitDatabase();
  61 }
  62 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  63 AliHMPIDReconHTA::~AliHMPIDReconHTA()
  64 {
  65   DeleteVars();
  66 }
  67 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  68 void AliHMPIDReconHTA::InitVars(Int_t n)
  69 {
  70 //..
  71 //Init some variables
  72 //..
  73   fXClu = new Double_t[n];
  74   fYClu = new Double_t[n];
  75   fClCk = new Bool_t[n];
  76   for(Int_t i=0;i<n;i++) fClCk[i] = kTRUE;
  77 //
  78 }
  79 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  80 void AliHMPIDReconHTA::DeleteVars()const
  81 {
  82 //..
  83 //Delete variables
  84 //..
  85   if(fXClu) delete fXClu;
  86   if(fYClu) delete fYClu;
  87   if(fClCk) delete fClCk;
  88 }
  89 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  90 Bool_t AliHMPIDReconHTA::CkovHiddenTrk(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean, Double_t qthre)
  91 {
  92 // Pattern recognition method without any infos from tracking:HTA (Hidden Track Algorithm)...
  93 // The method finds in the chmuber the cluster with the highest charge
  94 // compatibile with a MIP, then the strategy is applied
  95 // Arguments:  pTrk     - pointer to ESD track
  96 //             pCluLs   - list of clusters for a given chamber
  97 //             nmean    - mean freon ref. index
  98 //   Returns:           - 0=ok,1=not fitted
  99
 100   AliHMPIDParam *pParam = AliHMPIDParam::Instance();
 101   pParam->SetRefIdx(nmean);
 102
 103   if(!CluPreFilter(pCluLst)) {return kFALSE;}
 104
 105   Float_t mipX=-1,mipY=-1;Int_t mipId=-1,mipQ=-1;
 106   Double_t qRef = 0;
 107   Int_t nCh=0;
 108   Int_t sizeClu=0;
 109   for (Int_t iClu=0;iClu<pCluLst->GetEntriesFast();iClu++){                                   //clusters loop
 110     AliHMPIDCluster *pClu=(AliHMPIDCluster*)pCluLst->UncheckedAt(iClu);                       //get pointer to current cluster
 111     nCh = pClu->Ch();
 112     fXClu[iClu] = pClu->X();fYClu[iClu] = pClu->Y();                                          //store x,y for fitting procedure
 113     fClCk[iClu] = kTRUE;                                                                      //all cluster are accepted at this stage to be reconstructed
 114     if(pClu->Q()>qthre) fClCk[iClu] = kFALSE;                                                 // not a good photon in any case (multiple MIPs)
 115     if(pClu->Q()>qRef){                                                                       //searching the highest charge to select a MIP
 116       qRef = pClu->Q();
 117       mipId=iClu; mipX=pClu->X();mipY=pClu->Y();mipQ=(Int_t)pClu->Q();
 118       sizeClu=pClu->Size();
 119     }
 120 //    Printf(" n. %d x %f y %f Q %f",iClu,pClu->X(),pClu->Y(),pClu->Q());
 121   }//clusters loop
 122
 123   fNClu = pCluLst->GetEntriesFast();
 124   if(qRef>qthre){                                                                     //charge compartible with MIP clusters
 125     fIdxMip = mipId;
 126     fClCk[mipId] = kFALSE;
 127     fMipX = mipX; fMipY=mipY; fMipQ = qRef;
 128 //    Printf(" mipId %d x %f y %f Q %f",fIdxMip,fMipX,fMipY,fMipQ);
 129     if(!DoRecHiddenTrk()) {
 130       pTrk->SetHMPIDsignal(pParam->kNoPhotAccept);
 131       return kFALSE;
 132     }                                                                           //Do track and ring reconstruction,if problems returns 1
 133     pTrk->SetHMPIDtrk(fRadX,fRadY,fThTrkFit,fPhTrkFit);                                        //store track intersection info
 134     pTrk->SetHMPIDmip(fMipX,fMipY,(Int_t)fMipQ,fNClu);                                         //store mip info
 135     pTrk->SetHMPIDcluIdx(nCh,fIdxMip+1000*sizeClu);                                            //set cham number, index of cluster + cluster size
 136     pTrk->SetHMPIDsignal(fCkovFit);                                                            //find best Theta ckov for ring i.e. track
 137     pTrk->SetHMPIDchi2(fCkovSig2);                                                             //errors squared
 138 //    Printf(" n clusters tot %i accepted %i",pCluLst->GetEntriesFast(),fNClu);
 139 //    Printf("CkovHiddenTrk: thetaC %f th %f ph %f",fCkovFit,fThTrkFit,fPhTrkFit);
 140     return kTRUE;
 141   }
 142
 143   return kFALSE;
 144 }//CkovHiddenTrk()
 145 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 146 Bool_t AliHMPIDReconHTA::DoRecHiddenTrk()
 147 {
 148 // Pattern recognition method without any infos from tracking...
 149 // First a preclustering filter to avoid part of the noise
 150 // Then only ellipsed-rings are fitted (no possibility,
 151 // for the moment, to reconstruct very inclined tracks)
 152 // Finally a fitting with (th,ph) free, starting by very close values
 153 // previously evaluated.
 154 // Arguments:   none
 155 //   Returns:   none
 156   Double_t thTrkRec,phiTrkRec,thetaCRec;
 157
 158   if(!FindShape(thTrkRec,phiTrkRec,thetaCRec)) return kFALSE;
 159
 160   if(!FitFree(thTrkRec,phiTrkRec)) {return kFALSE;}
 161
 162   return kTRUE;
 163 }//DoRecHiddenTrk()
 164 /*
 165 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 166 Bool_t AliHMPIDReconHTA::DoRecHiddenTrk(TClonesArray *pCluLst)
 167 {
 168 // Pattern recognition method without any infos from tracking...
 169 // First a preclustering filter to avoid part of the noise
 170 // Then only ellipsed-rings are fitted (no possibility,
 171 // for the moment, to reconstruct very inclined tracks)
 172 // Finally a fitting with (th,ph) free, starting by very close values
 173 // previously evaluated.
 174 // Arguments:   none
 175 //   Returns:   none
 176   Double_t thTrkRec,phiTrkRec,thetaCRec;
 177
 178   if(!FindShape(thTrkRec,phiTrkRec,thetaCRec)) return kFALSE;
 179
 180 //  Printf("thTrkRec %f phiTrkRec %f ThetaCRec %f",thTrkRec*TMath::RadToDeg(),phiTrkRec*TMath::RadToDeg(),thetaCRec*TMath::RadToDeg());
 181   Int_t nClTmp1 = pCluLst->GetEntriesFast()-1;  //minus MIP...
 182   Int_t nClTmp2 = 0;
 183
 184   while(nClTmp1 != nClTmp2){
 185     SetNClu(pCluLst->GetEntriesFast());
 186     if(!FitFree(thTrkRec,phiTrkRec)) {return kFALSE;}
 187     nClTmp2 = NClu();
 188     if(nClTmp2!=nClTmp1) {nClTmp1=nClTmp2;nClTmp2=0;}
 189   }
 190
 191   fNClu = nClTmp2;
 192   return kTRUE;
 193 }//DoRecHiddenTrk()
 194 */
 195 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 196 Bool_t AliHMPIDReconHTA::CluPreFilter(TClonesArray *pCluLst)
 197 {
 198 // Pre-filter of bkg clusters
 199 // Arguments:    pSluLst  -  List of the clusters for a given chamber
 200 //   Returns:    status   -  TRUE if filtering leaves enough photons, FALSE if not
 201 //
 202   Int_t nClusTot = pCluLst->GetEntriesFast();
 203   if(nClusTot<4||nClusTot>100) {
 204     return kFALSE;
 205   } else {
 206     InitVars(nClusTot);
 207     return kTRUE;
 208   }
 209 }
 210 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 211 Bool_t AliHMPIDReconHTA::FindShape(Double_t &thTrkRec,Double_t &phiTrkRec,Double_t &thetaCRec)
 212 {
 213 // Finds the estimates for phi and theta of the track and the ThetaCerenkov
 214 // by using a database of the shapes of the rings
 215 // Arguments:   none
 216 //   Returns:   thTrkRec  - estimate of theta track
 217 //              phiTrkRec - estimate of phi   track
 218 //              thetaCRec - estimate of ThetaCerenkov
 219 //              status    - TRUE if a good solution is found, FALSE if not
 220
 221   Double_t *phiphot = new Double_t[fNClu];
 222   Double_t *dist    = new Double_t[fNClu];
 223   Int_t    *indphi  = new    Int_t[fNClu];
 224
 225   Bool_t status;
 226
 227 // Sort in phi angle...
 228   for(Int_t i=0;i<fNClu;i++) {
 229     phiphot[i] = (TMath::ATan2(fMipY-fYClu[i],fMipX-fXClu[i])+TMath::Pi())*TMath::RadToDeg();
 230     dist[i]=TMath::Sqrt((fMipX-fXClu[i])*(fMipX-fXClu[i])+(fMipY-fYClu[i])*(fMipY-fYClu[i]));
 231   }
 232
 233   TMath::Sort(fNClu,phiphot,indphi,kFALSE);
 234
 235 // Purify with a truncated mean;
 236   Int_t np=0;
 237   Double_t dMean  = 0;
 238   Double_t dMean2 = 0;
 239   for(Int_t i=0;i<fNClu;i++) {
 240     if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
 241     dMean +=dist[indphi[i]];
 242     dMean2+=dist[indphi[i]]*dist[indphi[i]];
 243     np++;
 244   }
 245
 246   dMean  /=(Double_t)np;
 247   dMean2 /=(Double_t)np;
 248   Double_t rms = TMath::Sqrt(dMean2 - dMean*dMean);
 249
 250   for(Int_t i=0;i<fNClu;i++) {
 251     if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
 252     if(TMath::Abs(dMean-dist[indphi[i]]) > 2*rms) {
 253       fClCk[indphi[i]] = kFALSE;
 254       continue;
 255     }
 256   }
 257
 258 //
 259 //  purify vectors for good photon candidates
 260 //
 261   Int_t npeff=0;
 262   Double_t *phiphotP = new Double_t[fNClu+1];
 263   Double_t *distP    = new Double_t[fNClu+1];
 264   for(Int_t i=0;i<fNClu;i++) {
 265     if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
 266     phiphotP[npeff] = phiphot[indphi[i]];
 267     distP[npeff]    = dist[indphi[i]];
 268     npeff++;
 269   }
 270
 271   delete [] phiphot;
 272   delete [] dist;
 273   delete [] indphi;
 274
 275   if(npeff<3) {
 276     delete [] phiphotP;
 277     delete [] distP;
 278     return kFALSE;
 279   }
 280
 281 //  for(Int_t i=0;i<npeff;i++) {Printf(" n. %d phiphot %f dist %f",i,phiphotP[i],distP[i]);}
 282
 283   Double_t xA,xB;
 284   if(ShapeModel(npeff,phiphotP,distP,xA,xB,phiTrkRec)) {
 285
 286 //    Printf("FindShape: phi start %f",phiTrkRec*TMath::RadToDeg());
 287
 288     Int_t bin = fgDatabase->FindBin(xA,xB);
 289     Int_t compact = (Int_t)fgDatabase->GetBinContent(bin);
 290     thetaCRec =  (Double_t)(compact%1000);
 291     thTrkRec  =  (Double_t)(compact/1000);
 292
 293     thTrkRec *= TMath::DegToRad();
 294     thetaCRec *= TMath::DegToRad();
 295
 296 //    Printf("FindShape: xA %f xB %f compact %d thTrk %f thC %f",xA,xB,compact,thTrkRec*TMath::RadToDeg(),thetaCRec*TMath::RadToDeg());
 297
 298     status = kTRUE;
 299
 300   } else {
 301
 302     status = kFALSE;
 303
 304   }
 305
 306   delete [] phiphotP;
 307   delete [] distP;
 308
 309   return status;
 310 }
 311 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 312 Bool_t AliHMPIDReconHTA::ShapeModel(Int_t np,Double_t *phiphot,Double_t *dist,Double_t &xA,Double_t &xB,Double_t &phiStart)
 313 {
 314 // Find a Spline curve to define dist. vs. phi angle
 315 // in order to estimate the phi of the track
 316 // Arguments:   np     - # points corresponding to # photon candidates
 317 //             dist    - distance of each photon from MIP
 318 //             phiphot - phi of the photon in the DRS
 319 //   Returns:  xA      - min. distance from MIP
 320 //             xB      - dist. from mip perpedicular to the major axis
 321 //             phiStart- estimate of the track phi
 322
 323   TGraph *phigr = new TGraph(np,phiphot,dist);
 324   TSpline3 *sphi = new TSpline3("sphi",phigr);
 325   if(!sphi) {Printf("Spline not created!Bye.");return kFALSE;}
 326
 327   Int_t locMin = TMath::LocMin(np,dist);
 328   Int_t locMax = TMath::LocMax(np,dist);
 329
 330   Double_t minX = phiphot[locMin];
 331 //  Double_t minY =    dist[locMin];
 332   Double_t maxX = phiphot[locMax];
 333 //  Double_t maxY =    dist[locMax];
 334
 335   Int_t ip[3] = {-1,0,1};
 336   if(locMin==0   ) {ip[0]= 0;ip[1]= 1;ip[2]= 2;}
 337   if(locMin==np-1) {ip[0]=-2;ip[1]=-1;ip[2]= 0;}
 338
 339   Double_t minXf = VertParab(phiphot[locMin+ip[0]],dist[locMin+ip[0]],
 340                              phiphot[locMin+ip[1]],dist[locMin+ip[1]],
 341                              phiphot[locMin+ip[2]],dist[locMin+ip[2]]);
 342   if(minXf< phiphot[locMin+ip[0]] || minXf > phiphot[locMin+ip[2]]) minXf = minX;
 343
 344   ip[0]=-1;ip[1]=0;ip[2]=1;
 345   if(locMax==0   ) {ip[0]= 0;ip[1]= 1;ip[2]= 2;}
 346   if(locMax==np-1) {ip[0]=-2;ip[1]=-1;ip[2]= 0;}
 347
 348   Double_t maxXf = VertParab(phiphot[locMax+ip[0]],dist[locMax+ip[0]],
 349                              phiphot[locMax+ip[1]],dist[locMax+ip[1]],
 350                              phiphot[locMax+ip[2]],dist[locMax+ip[2]]);
 351   if(maxXf< phiphot[locMax+ip[0]] || maxXf > phiphot[locMax+ip[2]]) maxXf = maxX;
 352
 353 //  Printf(" phi at mindist %f and found %f",minX,minXf);
 354 //  Printf(" phi at maxdist %f and found %f",maxX,maxXf);
 355 //
 356   if(TMath::Abs(maxXf-minXf)>30) {
 357     xA = sphi->Eval(minXf);
 358     if(xA < 0) xA = dist[sphi->FindX(xA)];
 359     xB = sphi->Eval(minXf-90);
 360     if(xB < 0) xB = dist[sphi->FindX(xB)];
 361     phiStart = minXf-180;  //open ring or acceptance effect...so believe to min phi angle!
 362   } else {
 363     phiStart = 0.5*(maxXf-180+minXf);
 364     xA = sphi->Eval(phiStart+180);
 365     if(xA < 0) xA = dist[sphi->FindX(xA)];
 366     xB = sphi->Eval(phiStart+90);
 367     if(xB < 0) xB = dist[sphi->FindX(xB)];
 368   }
 369   //
 370 //  Printf("ShapeModel: phiStart %f xA %f xB %f",phiStart,xA,xB);
 371
 372   phiStart*=TMath::DegToRad();
 373   return kTRUE;
 374 }
 375 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 376 Double_t AliHMPIDReconHTA::VertParab(Double_t x1,Double_t y1,Double_t x2, Double_t y2, Double_t x3, Double_t y3)const
 377 {
 378 // It uses parabola from 3 points to evaluate the x-coord of the parab
 379 // Arguments:    xi,yi - points
 380 //   Returns:    x-coord of the vertex
 381
 382   Double_t a = ((x1-x3)*(y1-y2)-(x1-x2)*(y1-y3))/((x1*x1-x2*x2)*(x1-x3)-(x1*x1-x3*x3)*(x1-x2));
 383   Double_t b = (y1-y2 - a*(x1*x1-x2*x2))/(x1-x2);
 384 //  Double_t c = y1 - a*x1*x1-b*x1;
 385   return -0.5*b/a;
 386 }
 387 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 388 Bool_t AliHMPIDReconHTA::FitFree(Double_t thTrkRec,Double_t phiTrkRec)
 389 {
 390 // Fit performed by minimizing RMS/sqrt(n) of the
 391 // photons reconstructed. First phi is fixed and theta
 392 // is fouond, then (th,ph) of the track
 393 // as free parameters
 394 // Arguments:    PhiRec phi of the track
 395 //   Returns:    none
 396
 397   TMinuit *pMinuit = new TMinuit(2);
 398   pMinuit->mncler();
 399   gMinuit->SetObjectFit((TObject*)this);  gMinuit->SetFCN(AliHMPIDReconHTA::FunMinPhot);  //set fit function
 400   Double_t aArg=-1,parStep,parLow,parHigh;     Int_t iErrFlg;                 //tmp vars for TMinuit
 401   Double_t d1,d2,d3;
 402   TString sName;
 403   Double_t th,ph;
 404
 405   pMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg);                                          //suspend all printout from TMinuit
 406   pMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg);
 407
 408   if(thTrkRec==0) thTrkRec = 3.*TMath::DegToRad();    // not to start from the edge...
 409
 410   pMinuit->mnparm(0," thTrk  ",thTrkRec ,parStep=0.01,parLow=0,parHigh=TMath::PiOver4(),iErrFlg);
 411   pMinuit->mnparm(1," phiTrk ",phiTrkRec,parStep=0.01,parLow=0,parHigh=TMath::TwoPi(),iErrFlg);
 412
 413   pMinuit->FixParameter(1);
 414   pMinuit->mnexcm("SIMPLEX" ,&aArg,0,iErrFlg);
 415   pMinuit->mnexcm("MIGRAD"  ,&aArg,0,iErrFlg);
 416   pMinuit->Release(1);
 417   pMinuit->mnexcm("MIGRAD"  ,&aArg,0,iErrFlg);
 418
 419   pMinuit->mnpout(0,sName,th,d1,d2,d3,iErrFlg);
 420   pMinuit->mnpout(1,sName,ph,d1,d2,d3,iErrFlg);
 421
 422   Double_t f,par[2];
 423   Double_t *grad=0x0;
 424   par[0] = th;par[1] = ph;
 425   pMinuit->Eval(2,grad,f,par,3);
 426
 427 //  Printf("FitFree: theta %f phi %f",th,ph);
 428
 429   SetTrkFit(th,ph);
 430   return kTRUE;
 431 }
 432 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 433 void AliHMPIDReconHTA::FunMinPhot(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t iflag)
 434 {
 435 // Minimization function to find best track and thetaC parameters
 436 // Arguments:    f = function value to minimize
 437 //             par = list of parameter to find
 438 //           iflag = flag status. See Minuit instructions
 439 //   Returns:    none
 440 //
 441 // Note: it is necessary to call an instance of AlihMPIDParam. Not possible to use fParam
 442 // because of the static instantiation of the function in Minuit
 443
 444   AliHMPIDParam *pParam=AliHMPIDParam::Instance();
 445   AliHMPIDReconHTA *pRecHTA=(AliHMPIDReconHTA*)gMinuit->GetObjectFit();
 446   AliHMPIDRecon pRec;
 447   Double_t sizeCh = 0.5*pParam->RadThick()+pParam->WinThick()+pParam->GapThick();
 448   Double_t thTrk = par[0];
 449   Double_t phTrk = par[1];
 450   Double_t xrad = pRecHTA->MipX() - sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
 451   Double_t yrad = pRecHTA->MipY() - sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);
 452   pRecHTA->SetRadXY(xrad,yrad);
 453   pRec.SetTrack(xrad,yrad,thTrk,phTrk);
 454
 455   Double_t meanCkov =0;
 456   Double_t meanCkov2=0;
 457   Double_t thetaCer,phiCer;
 458   Int_t nClAcc = 0;
 459   Int_t nClTot=pRecHTA->NClu();
 460
 461   for(Int_t i=0;i<nClTot;i++) {
 462     if(!(pRecHTA->ClCk(i))) continue;
 463     pRec.FindPhotCkov(pRecHTA->XClu(i),pRecHTA->YClu(i),thetaCer,phiCer);
 464     meanCkov  += thetaCer;
 465     meanCkov2 += thetaCer*thetaCer;
 466     nClAcc++;
 467   }
 468   if(nClAcc==0) {f=999;return;}
 469   meanCkov  /=(Double_t)nClAcc;
 470   meanCkov2 /=(Double_t)nClAcc;
 471   Double_t rms = TMath::Sqrt(TMath::Abs(meanCkov2 - meanCkov*meanCkov));
 472   f = rms/TMath::Sqrt((Double_t)nClAcc);
 473
 474   if(iflag==3) {
 475 /*
 476     Printf("FunMinPhot before: photons candidates %i used %i",nClTot,nClAcc);
 477     nClAcc = 0;
 478     Double_t meanCkov1=0;
 479     Double_t meanCkov2=0;
 480     for(Int_t i=0;i<nClTot;i++) {
 481       if(!(pRec->ClCk(i))) continue;
 482       pRec->FindPhotCkov(pRec->XClu(i),pRec->YClu(i),thetaCer,phiCer);
 483       if(TMath::Abs(thetaCer-meanCkov)<2*rms) {
 484         meanCkov1 += thetaCer;
 485         meanCkov2 += thetaCer*thetaCer;
 486         nClAcc++;
 487       } else pRec->SetClCk(i,kFALSE);
 488     }
 489     meanCkov1/=nClAcc;
 490     Double_t rms2 = (meanCkov2 - meanCkov*meanCkov*nClAcc)/nClAcc;
 491     Printf("FunMinPhot after: photons candidates %i used %i thetaCer %f",nClTot,nClAcc,meanCkov1);
 492     pRec->SetCkovFit(meanCkov1);
 493     pRec->SetCkovSig2(rms2);
 494     pRec->SetNClu(nClAcc);
 495 */
 496 //    Printf("FunMinPhot: reconstructed theta Cerenkov %f with %d photons",meanCkov,nClAcc);
 497     pRecHTA->SetCkovFit(meanCkov);
 498     pRecHTA->SetCkovSig2(rms*rms);
 499     pRecHTA->SetNClu(nClAcc);
 500   }
 501 }//FunMinPhot()
 502 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 503 void AliHMPIDReconHTA::InitDatabase()
 504 {
 505 // Construction a database of ring shapes on fly
 506 //   Arguments: none
 507 //   Returns  : none
 508 //  N.B. fgDatabase points to a TH2I with x-min dist from MIP
 509 //                                        y-dist from the ring of the MIP perpendicular to major axis
 510 //        The content is the packed info of track theta and thetaC in degrees
 511 //                        thetaC+1000*thTrk
 512 //
 513   TStopwatch timer;
 514   timer.Start();
 515
 516   AliInfo(Form("database HTA is being built.Please, wait..."));
 517 //
 518   Double_t x[3]={0,0,0},y[3];
 519
 520   AliHMPIDRecon rec;
 521
 522   if(!fParam) fParam=AliHMPIDParam::Instance();
 523   Double_t thetaMax = TMath::ACos(1./fParam->MeanIdxRad());
 524   Double_t thTrkMax = 1./TMath::ASin(fParam->MeanIdxRad());
 525
 526   Int_t nstepx = 1000;
 527   Int_t nstepy = 1000;
 528
 529   TH2I *deconv = new TH2I("deconv","database;d1;d2;thC+1000*thTrk",500,0,50,150,0,15);
 530   //
 531   Double_t xrad = 0;
 532   Double_t yrad = 0;
 533   Double_t phTrk = 0;
 534
 535   for(Int_t i=0;i<nstepx;i++) {     //loop on thetaC
 536     for(Int_t j=0;j<nstepy;j++) {   //loop on theta particle
 537       Double_t thetaC = thetaMax/nstepx*((Double_t)i+0.5);
 538       Double_t thTrk  = thTrkMax/nstepy*((Double_t)j+0.5);
 539       //
 540       //mip position
 541       //
 542       Double_t sizeCh = 0.5*fParam->RadThick()+fParam->WinThick()+fParam->GapThick();
 543       Double_t xmip = xrad + sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
 544       Double_t ymip = yrad + sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);
 545
 546       Double_t dist1,dist2;
 547       //
 548       //first point at phi=0
 549       //
 550       rec.SetTrack(xrad,yrad,thTrk,phTrk);
 551       TVector2 pos;
 552       pos=rec.TracePhot(thetaC,0);
 553
 554       if(pos.X()==-999) {
 555         dist1 = 0;            //open ring...anly the distance btw mip and point at 180 will be considered
 556       } else {
 557         x[0] = pos.X(); y[0] = pos.Y();
 558         dist1   = TMath::Sqrt((x[0]-xmip)*(x[0]-xmip)+(y[0]-ymip)*(y[0]-ymip));
 559       }
 560       //
 561       //second point at phi=180
 562       //
 563       rec.SetTrack(xrad,yrad,thTrk,phTrk);
 564       pos=rec.TracePhot(thetaC,TMath::Pi());
 565
 566       if(pos.X()==-999) {Printf("it should not happens!Bye");return;}
 567       x[1] = pos.X(); y[1] = pos.Y();
 568       if((x[1]-xmip)*(x[0]-xmip)>0) continue; // to avoid circles out mips (for very low ThetaC)
 569       dist2   = TMath::Sqrt((x[1]-xmip)*(x[1]-xmip)+(y[1]-ymip)*(y[1]-ymip));
 570
 571 //      Double_t distA = dist1+dist2;
 572       Double_t distA = dist2;     // only the minimum: problem of acceptance
 573       //
 574       //second point at phi=90
 575       //
 576       rec.SetTrack(xrad,yrad,thTrk,phTrk);
 577       pos=rec.TracePhot(thetaC,TMath::PiOver2());
 578
 579       if(pos.X()==-999) continue;
 580       x[2] = pos.X(); y[2] = pos.Y();
 581       Double_t distB   = TMath::Sqrt((x[2]-xmip)*(x[2]-xmip)+(y[2]-ymip)*(y[2]-ymip));
 582 // compact the infos...
 583       Int_t compact = (Int_t)(thetaC*TMath::RadToDeg())+1000*(Int_t)(thTrk*TMath::RadToDeg());
 584       Int_t bin = deconv->FindBin(distA,distB);
 585       if(deconv->GetBinContent(bin)==0) deconv->Fill(distA,distB,compact);
 586     }
 587   }
 588
 589   FillZeroChan(deconv);
 590   fgDatabase = deconv;
 591
 592   timer.Stop();
 593   Double_t nSecs = timer.CpuTime();
 594   AliInfo(Form("database HTA successfully open in %3.1f sec.(CPU). Reconstruction is started.",nSecs));
 595 }
 596 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 597 void AliHMPIDReconHTA::FillZeroChan(TH2I *deconv)const
 598 {
 599   //If fills eventually channel without entries
 600   //inthe histo "database" jyst interpolating the neighboring cells
 601   // Arguments: histogram pointer of the database
 602   //   Returns: none
 603   //
 604   Int_t nbinx = deconv->GetNbinsX();
 605   Int_t nbiny = deconv->GetNbinsY();
 606   for(Int_t i = 0;i<nbinx;i++) {
 607     for(Int_t j = 0;j<nbiny;j++) {
 608       if(deconv->GetBinContent(i,j) == 0) {
 609         Int_t nXmin = i-1; Int_t nXmax=i+1;
 610         Int_t nYmin = j-1; Int_t nYmax=j+1;
 611         Int_t nc = 0;
 612         Double_t meanC =0;
 613         Double_t meanTrk =0;
 614         for(Int_t ix=nXmin;ix<=nXmax;ix++) {
 615           if(ix<0||ix>nbinx) continue;
 616           for(Int_t iy=nYmin;iy<=nYmax;iy++) {
 617             if(iy<0||iy>nbiny) continue;
 618             meanC  +=  (Int_t)deconv->GetBinContent(ix,iy)%1000;
 619             meanTrk+=  (Int_t)deconv->GetBinContent(ix,iy)/1000;
 620             nc++;
 621           }
 622           meanC/=nc; meanTrk/=nc;
 623           Int_t compact = (Int_t)meanC+1000*(Int_t)meanTrk;
 624           if(compact>0)deconv->SetCellContent(i,j,compact);
 625         }
 626       }
 627     }
 628   }
 629 }
 630 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++