HMPID/AliHMPIDReconHTA.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
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  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 <TFile.h>           //Database()
  28 #include <TMinuit.h>         //FitFree()
  29 #include <TClonesArray.h>    //CkovHiddenTrk()
  30 #include <AliESDtrack.h>     //CkovHiddenTrk()
  31 #include <TH2F.h>            //InitDatabase()
  32 #include <TGraph.h>          //ShapeModel()
  33 #include <TSpline.h>         //ShapeModel()
  34 #include "TStopwatch.h"      //
  35
  36 TH2F* AliHMPIDReconHTA::fgDatabase = new TH2F("deconv","database;d1;d2;thC+1000*thTrk",500,0,50,150,0,15);
  37
  38
  39 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  40 AliHMPIDReconHTA::AliHMPIDReconHTA():
  41   TTask("RichRec","RichPat"),
  42   fMipX(-999),
  43   fMipY(-999),
  44   fMipQ(-999),
  45   fRadX(-999),
  46   fRadY(-999),
  47   fIdxMip(0),
  48   fNClu(0),
  49   fXClu(0),
  50   fYClu(0),
  51   fClCk(0),
  52   fThTrkFit(-999),
  53   fPhTrkFit(-999),
  54   fCkovFit(-999),
  55   fCkovSig2(0),
  56   fParam(AliHMPIDParam::Instance())
  57 {
  58 //..
  59 //hidden algorithm
  60 //..
  61   fParam->SetRefIdx(fParam->MeanIdxRad()); // initialization of ref index to a default one
  62   if(fgDatabase->GetEntries()<1) InitDatabase();
  63 }
  64 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  65 AliHMPIDReconHTA::~AliHMPIDReconHTA()
  66 {
  67   DeleteVars();
  68 }
  69 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  70 void AliHMPIDReconHTA::InitVars(Int_t n)
  71 {
  72 //..
  73 //Init some variables
  74 //..
  75   fXClu = new Double_t[n];
  76   fYClu = new Double_t[n];
  77   fClCk = new Bool_t[n];
  78   for(Int_t i=0;i<n;i++) fClCk[i] = kTRUE;
  79 //
  80 }
  81 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  82 void AliHMPIDReconHTA::DeleteVars()const
  83 {
  84 //..
  85 //Delete variables
  86 //..
  87   if(fXClu) delete fXClu;
  88   if(fYClu) delete fYClu;
  89   if(fClCk) delete fClCk;
  90 }
  91 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  92 Bool_t AliHMPIDReconHTA::CkovHiddenTrk(AliESDtrack *pTrk,TClonesArray *pCluLst,Int_t index, Double_t nmean)
  93 {
  94 // Pattern recognition method without any infos from tracking:HTA (Hidden Track Algorithm)...
  95 // The method finds in the chmuber the cluster with the highest charge
  96 // compatibile with a MIP, then the strategy is applied
  97 // Arguments:  pTrk     - pointer to ESD track
  98 //             pCluLs   - list of clusters for a given chamber
  99 //             pNmean   - pointer to ref. index
 100 //             pQthre   - pointer to qthre
 101 //   Returns:           - 0=ok,1=not fitted
 102
 103   AliHMPIDParam *pParam = AliHMPIDParam::Instance();
 104
 105   if(!CluPreFilter(pCluLst)) return kFALSE;
 106
 107   Int_t nCh=0;
 108   Int_t sizeClu=0;
 109
 110   fNClu = pCluLst->GetEntriesFast();
 111
 112   for (Int_t iClu=0;iClu<fNClu;iClu++){                                                       //clusters loop
 113     AliHMPIDCluster *pClu=(AliHMPIDCluster*)pCluLst->UncheckedAt(iClu);                       //get pointer to current cluster
 114     fXClu[iClu] = pClu->X();fYClu[iClu] = pClu->Y();                                          //store x,y for fitting procedure
 115     fClCk[iClu] = kTRUE;                                                                      //all cluster are accepted at this stage to be reconstructed
 116
 117     if(iClu == index) {
 118
 119       fMipX = pClu->X();
 120       fMipY = pClu->Y();
 121       fMipQ = pClu->Q();
 122       sizeClu = pClu->Size();
 123       nCh = pClu->Ch();
 124       fClCk[index] = kFALSE;
 125       fIdxMip = index;
 126  //    Printf(" n. %d x %f y %f Q %f",iClu,pClu->X(),pClu->Y(),pClu->Q());
 127     }
 128   }//clusters loop
 129
 130   pParam->SetRefIdx(nmean);
 131
 132   //
 133   Float_t xra,yra,th,ph; pTrk->GetHMPIDtrk(xra,yra,th,ph);
 134   Printf(" simulated phi %6.2f ",ph*TMath::RadToDeg());
 135   //
 136
 137   if(!DoRecHiddenTrk()) {
 138     pTrk->SetHMPIDsignal(pParam->kNoPhotAccept);
 139     return kFALSE;
 140   }                                                                           //Do track and ring reconstruction,if problems returns 1
 141   Printf("    fitted phi %6.2f ",fPhTrkFit*TMath::RadToDeg());
 142
 143   pTrk->SetHMPIDtrk(fRadX,fRadY,fThTrkFit,fPhTrkFit);                                        //store track intersection info
 144   pTrk->SetHMPIDmip(fMipX,fMipY,(Int_t)fMipQ,fNClu);                                         //store mip info
 145   pTrk->SetHMPIDcluIdx(nCh,fIdxMip+1000*sizeClu);                                            //set cham number, index of cluster + cluster size
 146   pTrk->SetHMPIDsignal(fCkovFit);                                                            //find best Theta ckov for ring i.e. track
 147   pTrk->SetHMPIDchi2(fCkovSig2);                                                             //errors squared
 148 //    Printf(" n clusters tot %i accepted %i",pCluLst->GetEntriesFast(),fNClu);
 149 //    Printf("CkovHiddenTrk: thetaC %f th %f ph %f",fCkovFit,fThTrkFit,fPhTrkFit);
 150
 151   return kTRUE;
 152
 153 }//CkovHiddenTrk()
 154 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 155 Bool_t AliHMPIDReconHTA::DoRecHiddenTrk()
 156 {
 157 // Pattern recognition method without any infos from tracking...
 158 // First a preclustering filter to avoid part of the noise
 159 // Then only ellipsed-rings are fitted (no possibility,
 160 // for the moment, to reconstruct very inclined tracks)
 161 // Finally a fitting with (th,ph) free, starting by very close values
 162 // previously evaluated.
 163 // Arguments:   none
 164 //   Returns:   none
 165   Double_t thTrkRec,phiTrkRec,thetaCRec;
 166
 167   if(!FindShape(thTrkRec,phiTrkRec,thetaCRec)) return kFALSE;
 168
 169   if(!FitFree(thTrkRec,phiTrkRec)) {return kFALSE;}
 170
 171   return kTRUE;
 172 }//DoRecHiddenTrk()
 173 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 174 Bool_t AliHMPIDReconHTA::CluPreFilter(TClonesArray *pCluLst)
 175 {
 176 // Pre-filter of bkg clusters
 177 // Arguments:    pSluLst  -  List of the clusters for a given chamber
 178 //   Returns:    status   -  TRUE if filtering leaves enough photons, FALSE if not
 179 //
 180   Int_t nClusTot = pCluLst->GetEntriesFast();
 181   if(nClusTot<4||nClusTot>100) {
 182     return kFALSE;
 183   } else {
 184     InitVars(nClusTot);
 185     return kTRUE;
 186   }
 187 }
 188 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 189 Bool_t AliHMPIDReconHTA::FindShape(Double_t &thTrkRec,Double_t &phiTrkRec,Double_t &thetaCRec)
 190 {
 191 // Finds the estimates for phi and theta of the track and the ThetaCerenkov
 192 // by using a database of the shapes of the rings
 193 // Arguments:   none
 194 //   Returns:   thTrkRec  - estimate of theta track
 195 //              phiTrkRec - estimate of phi   track
 196 //              thetaCRec - estimate of ThetaCerenkov
 197 //              status    - TRUE if a good solution is found, FALSE if not
 198
 199   Double_t *phiphot = new Double_t[fNClu];
 200   Double_t *dist    = new Double_t[fNClu];
 201   Int_t    *indphi  = new    Int_t[fNClu];
 202
 203   Bool_t status;
 204
 205 // Sort in phi angle...
 206 //  Printf(" mipX %f mipy %f",fMipX,fMipY);
 207   for(Int_t i=0;i<fNClu;i++) {
 208     if(!fClCk[i]) {
 209       phiphot[i] = 999.;
 210       dist[i] = 999.;
 211       continue;
 212     }
 213     phiphot[i] = (TMath::ATan2(fMipY-fYClu[i],fMipX-fXClu[i])+TMath::Pi())*TMath::RadToDeg();
 214     dist[i]=TMath::Sqrt((fMipX-fXClu[i])*(fMipX-fXClu[i])+(fMipY-fYClu[i])*(fMipY-fYClu[i]));
 215 //    Printf(" n.%3i  phiphot %f dist %f check %i",i,phiphot[i],dist[i],fClCk[i]);
 216   }
 217
 218   TMath::Sort(fNClu,phiphot,indphi,kFALSE);
 219
 220 // Purify with a truncated mean;
 221   Int_t np=0;
 222   Double_t dMean  = 0;
 223   Double_t dMean2 = 0;
 224   for(Int_t i=0;i<fNClu;i++) {
 225     if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
 226     dMean +=dist[indphi[i]];
 227     dMean2+=dist[indphi[i]]*dist[indphi[i]];
 228     np++;
 229   }
 230
 231   dMean  /=(Double_t)np;
 232   dMean2 /=(Double_t)np;
 233   Double_t rms = TMath::Sqrt(dMean2 - dMean*dMean);
 234
 235   for(Int_t i=0;i<fNClu;i++) {
 236     if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
 237     if(TMath::Abs(dMean-dist[indphi[i]]) > 2*rms) {
 238       fClCk[indphi[i]] = kFALSE;
 239       continue;
 240     }
 241   }
 242
 243 //
 244 //  purify vectors for good photon candidates
 245 //
 246   Int_t npeff=0;
 247   Double_t *phiphotP = new Double_t[fNClu+1];
 248   Double_t *distP    = new Double_t[fNClu+1];
 249   for(Int_t i=0;i<fNClu;i++) {
 250     if(!fClCk[indphi[i]]) continue;                                                  // Check if a good photon candidate or not
 251     phiphotP[npeff] = phiphot[indphi[i]];
 252     distP[npeff]    = dist[indphi[i]];
 253 //    Printf("n. %2i phi %f dist %f",npeff,phiphotP[npeff],distP[npeff]);
 254     npeff++;
 255   }
 256
 257   delete [] phiphot;
 258   delete [] dist;
 259   delete [] indphi;
 260
 261   if(npeff<3) {
 262     delete [] phiphotP;
 263     delete [] distP;
 264     return kFALSE;
 265   }
 266
 267 //  for(Int_t i=0;i<npeff;i++) {Printf(" n. %d phiphot %f dist %f",i,phiphotP[i],distP[i]);}
 268
 269   Double_t xA,xB;
 270   status = kFALSE;
 271   if(ShapeModel(npeff,phiphotP,distP,xA,xB,phiTrkRec)) {
 272
 273 //    Printf("FindShape: phi start %f xA %f yA %f",phiTrkRec*TMath::RadToDeg(),xA,xB);
 274     if(xA < 50 && xB < 15) {                     // limits of the Database. See TH2F in InitDatabase()
 275
 276       Int_t bin = fgDatabase->FindBin(xA,xB);
 277       if(bin>0) {
 278         Int_t compact = (Int_t)fgDatabase->GetBinContent(bin);
 279         thetaCRec =  (Double_t)(compact%1000);
 280         thTrkRec  =  (Double_t)(compact/1000);
 281
 282         thTrkRec *= TMath::DegToRad();
 283         thetaCRec *= TMath::DegToRad();
 284
 285     //    Printf("FindShape: xA %f xB %f compact %d thTrk %f thC %f",xA,xB,compact,thTrkRec*TMath::RadToDeg(),thetaCRec*TMath::RadToDeg());
 286
 287         status = kTRUE;
 288       }
 289     }
 290   }
 291
 292   delete [] phiphotP;
 293   delete [] distP;
 294
 295   return status;
 296 }
 297 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 298 Bool_t AliHMPIDReconHTA::ShapeModel(Int_t np,Double_t *phiphot,Double_t *dist,Double_t &xA,Double_t &xB,Double_t &phiStart)
 299 {
 300 // Find a Spline curve to define dist. vs. phi angle
 301 // in order to estimate the phi of the track
 302 // Arguments:   np     - # points corresponding to # photon candidates
 303 //             dist    - distance of each photon from MIP
 304 //             phiphot - phi of the photon in the DRS
 305 //   Returns:  xA      - min. distance from MIP
 306 //             xB      - dist. from mip perpedicular to the major axis
 307 //             phiStart- estimate of the track phi
 308
 309   TGraph *phigr = new TGraph(np,phiphot,dist);
 310   TSpline3 *sphi = new TSpline3("sphi",phigr);
 311   if(!sphi) {Printf("Spline not created!Bye.");return kFALSE;}
 312
 313   Int_t locMin = TMath::LocMin(np,dist);
 314   Int_t locMax = TMath::LocMax(np,dist);
 315
 316   Double_t minX = phiphot[locMin];
 317 //  Double_t minY =    dist[locMin];
 318   Double_t maxX = phiphot[locMax];
 319 //  Double_t maxY =    dist[locMax];
 320
 321   Int_t ip[3] = {-1,0,1};
 322   if(locMin==0   ) {ip[0]= 0;ip[1]= 1;ip[2]= 2;}
 323   if(locMin==np-1) {ip[0]=-2;ip[1]=-1;ip[2]= 0;}
 324
 325   Double_t minXf = VertParab(phiphot[locMin+ip[0]],dist[locMin+ip[0]],
 326                              phiphot[locMin+ip[1]],dist[locMin+ip[1]],
 327                              phiphot[locMin+ip[2]],dist[locMin+ip[2]]);
 328   if(minXf< phiphot[locMin+ip[0]] || minXf > phiphot[locMin+ip[2]]) minXf = minX;
 329
 330   ip[0]=-1;ip[1]=0;ip[2]=1;
 331   if(locMax==0   ) {ip[0]= 0;ip[1]= 1;ip[2]= 2;}
 332   if(locMax==np-1) {ip[0]=-2;ip[1]=-1;ip[2]= 0;}
 333
 334   Double_t maxXf = VertParab(phiphot[locMax+ip[0]],dist[locMax+ip[0]],
 335                              phiphot[locMax+ip[1]],dist[locMax+ip[1]],
 336                              phiphot[locMax+ip[2]],dist[locMax+ip[2]]);
 337   if(maxXf< phiphot[locMax+ip[0]] || maxXf > phiphot[locMax+ip[2]]) maxXf = maxX;
 338
 339 //
 340   if(TMath::Abs(maxXf-minXf)>30) {
 341     xA = sphi->Eval(minXf);
 342     if(xA < 0) xA = dist[sphi->FindX(xA)];
 343     xB = sphi->Eval(minXf-90);
 344     if(xB < 0) xB = dist[sphi->FindX(xB)];
 345     phiStart = minXf-180;  //open ring or acceptance effect...so believe to min phi angle!
 346   } else {
 347     phiStart = 0.5*(maxXf-180+minXf);
 348     xA = sphi->Eval(phiStart+180);
 349     if(xA < 0) xA = dist[sphi->FindX(xA)];
 350     xB = sphi->Eval(phiStart+90);
 351     if(xB < 0) xB = dist[sphi->FindX(xB)];
 352   }
 353   //
 354 //  Printf("ShapeModel: phiStart %f xA %f xB %f",phiStart,xA,xB);
 355
 356
 357   phiStart*=TMath::DegToRad();
 358   Double_t phitest = FindSimmPhi();
 359     //Double_t phiStart = phitest;
 360   phiStart = phitest;
 361   Printf("   started phi %6.2f ",phiStart*TMath::RadToDeg());
 362
 363 //  Printf("phiStart %f phiTest %f",phiStart*TMath::RadToDeg(),phitest*TMath::RadToDeg());
 364
 365   return kTRUE;
 366 }
 367 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 368 Double_t AliHMPIDReconHTA::VertParab(Double_t x1,Double_t y1,Double_t x2, Double_t y2, Double_t x3, Double_t y3)const
 369 {
 370 // It uses parabola from 3 points to evaluate the x-coord of the parab
 371 // Arguments:    xi,yi - points
 372 //   Returns:    x-coord of the vertex
 373
 374   Double_t a = ((x1-x3)*(y1-y2)-(x1-x2)*(y1-y3))/((x1*x1-x2*x2)*(x1-x3)-(x1*x1-x3*x3)*(x1-x2));
 375   Double_t b = (y1-y2 - a*(x1*x1-x2*x2))/(x1-x2);
 376 //  Double_t c = y1 - a*x1*x1-b*x1;
 377   return -0.5*b/a;
 378 }
 379 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 380 Bool_t AliHMPIDReconHTA::FitFree(Double_t thTrkRec,Double_t phiTrkRec)
 381 {
 382 // Fit performed by minimizing RMS/sqrt(n) of the
 383 // photons reconstructed. First phi is fixed and theta
 384 // is fouond, then (th,ph) of the track
 385 // as free parameters
 386 // Arguments:    PhiRec phi of the track
 387 //   Returns:    none
 388
 389   TMinuit *pMinuit = new TMinuit(2);
 390   pMinuit->mncler();
 391   gMinuit->SetObjectFit((TObject*)this);  gMinuit->SetFCN(AliHMPIDReconHTA::FunMinPhot);  //set fit function
 392   Double_t aArg=-1,parStep,parLow,parHigh;     Int_t iErrFlg;                 //tmp vars for TMinuit
 393   Double_t d1,d2,d3;
 394   TString sName;
 395   Double_t th,ph;
 396
 397   pMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg);                                          //suspend all printout from TMinuit
 398   pMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg);
 399
 400   if(thTrkRec==0) thTrkRec = 3.*TMath::DegToRad();    // not to start from the edge...
 401
 402   pMinuit->mnparm(0," thTrk  ",thTrkRec ,parStep=0.01,parLow=0,parHigh=TMath::PiOver4(),iErrFlg);
 403   pMinuit->mnparm(1," phiTrk ",phiTrkRec,parStep=0.01,parLow=0,parHigh=TMath::TwoPi(),iErrFlg);
 404
 405   pMinuit->FixParameter(1);
 406   pMinuit->mnexcm("SIMPLEX" ,&aArg,0,iErrFlg);
 407   pMinuit->mnexcm("MIGRAD"  ,&aArg,0,iErrFlg);
 408   pMinuit->Release(1);
 409   pMinuit->mnexcm("MIGRAD"  ,&aArg,0,iErrFlg);
 410
 411   pMinuit->mnpout(0,sName,th,d1,d2,d3,iErrFlg);
 412   pMinuit->mnpout(1,sName,ph,d1,d2,d3,iErrFlg);
 413
 414   Double_t f,par[2];
 415   Double_t *grad=0x0;
 416   par[0] = th;par[1] = ph;
 417   pMinuit->Eval(2,grad,f,par,3);
 418
 419 //  Printf("FitFree: theta %f phi %f",th,ph);
 420
 421   SetTrkFit(th,ph);
 422   return kTRUE;
 423 }
 424 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 425 void AliHMPIDReconHTA::FunMinPhot(Int_t &/* */,Double_t* /* */,Double_t &f,Double_t *par,Int_t iflag)
 426 {
 427 // Minimization function to find best track and thetaC parameters
 428 // Arguments:    f = function value to minimize
 429 //             par = list of parameter to find
 430 //           iflag = flag status. See Minuit instructions
 431 //   Returns:    none
 432 //
 433 // Note: it is necessary to call an instance of AlihMPIDParam. Not possible to use fParam
 434 // because of the static instantiation of the function in Minuit
 435
 436   AliHMPIDParam *pParam=AliHMPIDParam::Instance();
 437   AliHMPIDReconHTA *pRecHTA=(AliHMPIDReconHTA*)gMinuit->GetObjectFit();
 438   AliHMPIDRecon pRec;
 439   Double_t sizeCh = 0.5*pParam->RadThick()+pParam->WinThick()+pParam->GapThick();
 440   Double_t thTrk = par[0];
 441   Double_t phTrk = par[1];
 442   Double_t xrad = pRecHTA->MipX() - sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
 443   Double_t yrad = pRecHTA->MipY() - sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);
 444   pRecHTA->SetRadXY(xrad,yrad);
 445   pRec.SetTrack(xrad,yrad,thTrk,phTrk);
 446
 447   Double_t meanCkov =0;
 448   Double_t meanCkov2=0;
 449   Double_t thetaCer,phiCer;
 450   Int_t nClAcc = 0;
 451   Int_t nClTot=pRecHTA->NClu();
 452
 453   for(Int_t i=0;i<nClTot;i++) {
 454     if(!(pRecHTA->ClCk(i))) continue;
 455     pRec.FindPhotCkov(pRecHTA->XClu(i),pRecHTA->YClu(i),thetaCer,phiCer);
 456     meanCkov  += thetaCer;
 457     meanCkov2 += thetaCer*thetaCer;
 458     nClAcc++;
 459   }
 460   if(nClAcc==0) {f=999;return;}
 461   meanCkov  /=(Double_t)nClAcc;
 462   meanCkov2 /=(Double_t)nClAcc;
 463   Double_t rms = TMath::Sqrt(TMath::Abs(meanCkov2 - meanCkov*meanCkov));
 464   f = rms/TMath::Sqrt((Double_t)nClAcc);
 465
 466   if(iflag==3) {
 467 /*
 468     Printf("FunMinPhot before: photons candidates %i used %i",nClTot,nClAcc);
 469     nClAcc = 0;
 470     Double_t meanCkov1=0;
 471     Double_t meanCkov2=0;
 472     for(Int_t i=0;i<nClTot;i++) {
 473       if(!(pRec->ClCk(i))) continue;
 474       pRec->FindPhotCkov(pRec->XClu(i),pRec->YClu(i),thetaCer,phiCer);
 475       if(TMath::Abs(thetaCer-meanCkov)<2*rms) {
 476         meanCkov1 += thetaCer;
 477         meanCkov2 += thetaCer*thetaCer;
 478         nClAcc++;
 479       } else pRec->SetClCk(i,kFALSE);
 480     }
 481     meanCkov1/=nClAcc;
 482     Double_t rms2 = (meanCkov2 - meanCkov*meanCkov*nClAcc)/nClAcc;
 483     Printf("FunMinPhot after: photons candidates %i used %i thetaCer %f",nClTot,nClAcc,meanCkov1);
 484     pRec->SetCkovFit(meanCkov1);
 485     pRec->SetCkovSig2(rms2);
 486     pRec->SetNClu(nClAcc);
 487 */
 488 //    Printf("FunMinPhot: reconstructed theta Cerenkov %f with %d photons",meanCkov,nClAcc);
 489     pRecHTA->SetCkovFit(meanCkov);
 490     pRecHTA->SetCkovSig2(rms*rms);
 491     pRecHTA->SetNClu(nClAcc);
 492   }
 493 }//FunMinPhot()
 494 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 495 void AliHMPIDReconHTA::InitDatabase()
 496 {
 497 // Construction a database of ring shapes on fly
 498 //   Arguments: none
 499 //   Returns  : none
 500 //  N.B. fgDatabase points to a TH2I with x-min dist from MIP
 501 //                                        y-dist from the ring of the MIP perpendicular to major axis
 502 //        The content is the packed info of track theta and thetaC in degrees
 503 //                        thetaC+1000*thTrk
 504 //
 505 //  TFile *pout = new TFile("./database.root","recreate");
 506
 507   TStopwatch timer;
 508   timer.Start();
 509
 510   AliInfo(Form("database HTA is being built.Please, wait..."));
 511 //
 512   Double_t x[3]={0,0,0},y[3];
 513
 514   AliHMPIDRecon rec;
 515
 516   if(!fParam) fParam=AliHMPIDParam::Instance();
 517   Double_t thetaMax = TMath::ACos(1./fParam->MeanIdxRad());
 518   Double_t thTrkMax = 1./TMath::ASin(fParam->MeanIdxRad());
 519
 520   Int_t nstepx = 1000;
 521   Int_t nstepy = 1000;
 522
 523 //  TH2F *fgDatabase = new TH2F("deconv","database;d1;d2;thC+1000*thTrk",500,0,50,150,0,15);
 524   //
 525   Double_t xrad = 0;
 526   Double_t yrad = 0;
 527   Double_t phTrk = 0;
 528
 529   for(Int_t i=0;i<nstepx;i++) {     //loop on thetaC
 530     for(Int_t j=0;j<nstepy;j++) {   //loop on theta particle
 531       Double_t thetaC = thetaMax/nstepx*((Double_t)i+0.5);
 532       Double_t thTrk  = thTrkMax/nstepy*((Double_t)j+0.5);
 533       //
 534       //mip position
 535       //
 536       Double_t sizeCh = 0.5*fParam->RadThick()+fParam->WinThick()+fParam->GapThick();
 537       Double_t xmip = xrad + sizeCh*TMath::Tan(thTrk)*TMath::Cos(phTrk);
 538       Double_t ymip = yrad + sizeCh*TMath::Tan(thTrk)*TMath::Sin(phTrk);
 539
 540       Double_t dist1,dist2;
 541       //
 542       //first point at phi=0
 543       //
 544       rec.SetTrack(xrad,yrad,thTrk,phTrk);
 545       TVector2 pos;
 546       pos=rec.TracePhot(thetaC,0);
 547
 548       if(pos.X()==-999) {
 549         dist1 = 0;            //open ring...anly the distance btw mip and point at 180 will be considered
 550       } else {
 551         x[0] = pos.X(); y[0] = pos.Y();
 552         dist1   = TMath::Sqrt((x[0]-xmip)*(x[0]-xmip)+(y[0]-ymip)*(y[0]-ymip));
 553       }
 554       //
 555       //second point at phi=180
 556       //
 557       rec.SetTrack(xrad,yrad,thTrk,phTrk);
 558       pos=rec.TracePhot(thetaC,TMath::Pi());
 559
 560       if(pos.X()==-999) {Printf("it should not happens!Bye");return;}
 561       x[1] = pos.X(); y[1] = pos.Y();
 562       if((x[1]-xmip)*(x[0]-xmip)>0) continue; // to avoid circles out mips (for very low ThetaC)
 563       dist2   = TMath::Sqrt((x[1]-xmip)*(x[1]-xmip)+(y[1]-ymip)*(y[1]-ymip));
 564
 565 //      Double_t distA = dist1+dist2;
 566       Double_t distA = dist2;     // only the minimum: problem of acceptance
 567       //
 568       //second point at phi=90
 569       //
 570       rec.SetTrack(xrad,yrad,thTrk,phTrk);
 571       pos=rec.TracePhot(thetaC,TMath::PiOver2());
 572
 573       if(pos.X()==-999) continue;
 574       x[2] = pos.X(); y[2] = pos.Y();
 575       Double_t distB   = TMath::Sqrt((x[2]-xmip)*(x[2]-xmip)+(y[2]-ymip)*(y[2]-ymip));
 576 // compact the infos...
 577       Int_t compact = (Int_t)(thetaC*TMath::RadToDeg())+1000*(Int_t)(thTrk*TMath::RadToDeg());
 578       Int_t bin = fgDatabase->FindBin(distA,distB);
 579       if(fgDatabase->GetBinContent(bin)==0) fgDatabase->Fill(distA,distB,compact);
 580     }
 581   }
 582
 583   FillZeroChan();
 584 //  fgDatabase = deconv;
 585
 586   timer.Stop();
 587   Double_t nSecs = timer.CpuTime();
 588   AliInfo(Form("database HTA successfully open in %3.1f sec.(CPU). Reconstruction is started.",nSecs));
 589
 590 //  pout->Write();
 591 //  pout->Close();
 592
 593 }//InitDatabase()
 594 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 595 void AliHMPIDReconHTA::FillZeroChan()const
 596 {
 597   //If fills eventually channel without entries
 598   //inthe histo "database" jyst interpolating the neighboring cells
 599   // Arguments: histogram pointer of the database
 600   //   Returns: none
 601   //
 602   Int_t nbinx = fgDatabase->GetNbinsX();
 603   Int_t nbiny = fgDatabase->GetNbinsY();
 604   for(Int_t i = 0;i<nbinx;i++) {
 605     for(Int_t j = 0;j<nbiny;j++) {
 606       if(fgDatabase->GetBinContent(i,j) == 0) {
 607         Int_t nXmin = i-1; Int_t nXmax=i+1;
 608         Int_t nYmin = j-1; Int_t nYmax=j+1;
 609         Int_t nc = 0;
 610         Double_t meanC =0;
 611         Double_t meanTrk =0;
 612         for(Int_t ix=nXmin;ix<=nXmax;ix++) {
 613           if(ix<0||ix>nbinx) continue;
 614           for(Int_t iy=nYmin;iy<=nYmax;iy++) {
 615             if(iy<0||iy>nbiny) continue;
 616             meanC  +=  (Int_t)fgDatabase->GetBinContent(ix,iy)%1000;
 617             meanTrk+=  (Int_t)fgDatabase->GetBinContent(ix,iy)/1000;
 618             nc++;
 619           }
 620           meanC/=nc; meanTrk/=nc;
 621           Int_t compact = (Int_t)meanC+1000*(Int_t)meanTrk;
 622           if(compact>0)fgDatabase->SetCellContent(i,j,compact);
 623         }
 624       }
 625     }
 626   }
 627 }//FillZeroChan()
 628 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 629
 630 // stima gli angoli con il metodo dei minimi quadrati che sfrutta le distanze...
 631
 632 Double_t AliHMPIDReconHTA::FindSimmPhi()
 633 {
 634   //It finds the phi of the ring
 635   //by using the min. dist. algorithm
 636   // Arguments: none
 637   //   Returns: phi
 638   //
 639
 640   Float_t xrotsumm =0;     Float_t yrotsumm =0;     Float_t xx =0;
 641   Float_t yy =0;           Float_t xy =0;
 642
 643   Int_t np=0;
 644
 645   for(Int_t i=0;i<fNClu;i++) {
 646     if(!fClCk[i]) continue;
 647     np++;
 648     xrotsumm+=fXClu[i];         // summ xi
 649     yrotsumm+=fYClu[i];         // summ yi
 650     xx+=fXClu[i]*fXClu[i];      // summ xixi
 651     yy+=fYClu[i]*fYClu[i];      // summ yiyi
 652     xy+=fXClu[i]*fYClu[i];      // summ yixi
 653   }
 654
 655   //_____calc. met min quadr using effective distance _________________________________________________
 656
 657   Double_t coeff[3];
 658   coeff[0]= xy-xrotsumm*yrotsumm/np;
 659   coeff[1]= yrotsumm*yrotsumm/np - xrotsumm*xrotsumm/np - yy + xx;
 660   coeff[2]= xrotsumm*yrotsumm/np-  xy;
 661
 662   //____________________________________________________________________________________________________
 663
 664   Double_t m1=0, m2=0;
 665   Double_t n1=0, n2=0;
 666
 667   r2(coeff,m1,m2);
 668
 669   n1=(yrotsumm-m1*xrotsumm)/np;
 670   n2=(yrotsumm-m2*xrotsumm)/np;
 671
 672   // le due soluzioni.................
 673
 674   Double_t d1 =(1/(m1*m1+1))*(yy+m1*m1*xx+np*n1*n1-2*m1*xy-2*n1*yrotsumm+2*m1*n1*xrotsumm);
 675   Double_t d2 =(1/(m2*m2+1))*(yy+m2*m2*xx+np*n2*n2-2*m2*xy-2*n2*yrotsumm+2*m2*n2*xrotsumm);
 676   Double_t mMin;
 677   if(d1 > d2) mMin = m2; else mMin = m1;
 678
 679   Double_t PhiTrk= TMath::ATan(mMin);
 680
 681   // positive angles...
 682   if(PhiTrk<0)    PhiTrk+=180*TMath::DegToRad();
 683
 684   return PhiTrk;
 685 }
 686
 687 //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 688 Int_t AliHMPIDReconHTA::r2(Double_t *coef, Double_t &x1, Double_t &x2)
 689 {
 690   //2nd deg. equation
 691   //solution
 692   // Arguments: coef 2 1 0: ax^2+bx+c=0
 693   //   Returns: n. of solutions
 694   //            x1= 1st sol
 695   //            x2= 2nd sol
 696   Double_t a,b,c;
 697   a = coef[2];
 698   b = coef[1];
 699   c = coef[0];
 700   Double_t delta = b*b-4*a*c;
 701   if(delta<0) {return 0;}
 702   if(delta==0) {
 703     x1=x2=-b/(2*a);
 704     return 1;
 705   }
 706   // delta>0
 707   x1 = (-b+TMath::Sqrt(delta))/(2*a);
 708   x2 = (-b-TMath::Sqrt(delta))/(2*a);
 709   return 2;
 710 }//r2()