HMPID/AliHMPIDCluster.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 #include "AliHMPIDCluster.h"  //class header
  17 #include <TMinuit.h>         //Solve()
  18 #include <TClonesArray.h>    //Solve()
  19 #include <TMarker.h>         //Draw()
  20
  21 Bool_t AliHMPIDCluster::fgDoCorrSin=kTRUE;
  22
  23 ClassImp(AliHMPIDCluster)
  24 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  25 void AliHMPIDCluster::CoG()
  26 {
  27 // Calculates naive cluster position as a center of gravity of its digits.
  28 // Arguments: none
  29 //   Returns: none
  30   Int_t minPadX=999,minPadY=999,maxPadX=-1,maxPadY=-1;      //for box finding
  31   if(fDigs==0) return;                                      //no digits in this cluster
  32   fX=fY=fQRaw=0;                                            //init summable parameters
  33   Int_t maxQpad=-1,maxQ=-1;                                 //to calculate the pad with the highest charge
  34   AliHMPIDDigit *pDig;
  35   for(Int_t iDig=0;iDig<fDigs->GetEntriesFast();iDig++){    //digits loop
  36     pDig=(AliHMPIDDigit*)fDigs->At(iDig);                   //get pointer to next digit
  37
  38     if(pDig->PadPcX() > maxPadX) maxPadX = pDig->PadPcX();  // find the minimum box that contain the cluster  MaxX
  39     if(pDig->PadPcY() > maxPadY) maxPadY = pDig->PadPcY();  //                                                MaxY
  40     if(pDig->PadPcX() < minPadX) minPadX = pDig->PadPcX();  //                                                MinX
  41     if(pDig->PadPcY() < minPadY) minPadY = pDig->PadPcY();  //                                                MinY
  42
  43     Float_t q=pDig->Q();                                    //get QDC
  44     fX += pDig->LorsX()*q;fY +=pDig->LorsY()*q;             //add digit center weighted by QDC
  45     fQRaw+=q;                                               //increment total charge
  46     if(q>maxQ) {maxQpad = pDig->Pad();maxQ=(Int_t)q;}       // to find pad with highest charge
  47   }//digits loop
  48
  49   fBox=(maxPadX-minPadX+1)*100+maxPadY-minPadY+1;           // dimension of the box: format Xdim*100+Ydim
  50
  51   if ( fQRaw != 0 )   fX/=fQRaw;fY/=fQRaw;                  //final center of gravity
  52
  53   if(fDigs->GetEntriesFast()>1&&fgDoCorrSin)CorrSin();       //correct it by sinoid
  54
  55   fQ  = fQRaw;                                              // Before starting fit procedure, Q and QRaw must be equal
  56   fCh=pDig->Ch();                                           //initialize chamber number
  57   fMaxQpad = maxQpad; fMaxQ=maxQ;                           //store max charge pad to the field
  58   fChi2=0;                                                  // no Chi2 to find
  59   fNlocMax=0;                                               // proper status from this method
  60   fSt=kCoG;
  61 }//CoG()
  62 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  63 void AliHMPIDCluster::CorrSin()
  64 {
  65 // Correction of cluster x position due to sinoid, see HMPID TDR  page 30
  66 // Arguments: none
  67 //   Returns: none
  68   Int_t pc,px,py;
  69   AliHMPIDDigit::Lors2Pad(fX,fY,pc,px,py);             //tmp digit to get it center
  70   Float_t x=fX-AliHMPIDDigit::LorsX(pc,px);                    //diff between cluster x and center of the pad contaning this cluster
  71   fX+=3.31267e-2*TMath::Sin(2*TMath::Pi()/0.8*x)-2.66575e-3*TMath::Sin(4*TMath::Pi()/0.8*x)+2.80553e-3*TMath::Sin(6*TMath::Pi()/0.8*x)+0.0070;
  72 }
  73 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  74 void AliHMPIDCluster::Draw(Option_t*)
  75 {
  76   TMarker *pMark=new TMarker(X(),Y(),5); pMark->SetUniqueID(fSt);pMark->SetMarkerColor(kBlue); pMark->Draw();
  77 }
  78 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  79 void AliHMPIDCluster::FitFunc(Int_t &iNpars, Double_t* /*deriv*/, Double_t &chi2, Double_t *par, Int_t /* */)
  80 {
  81 // Cluster fit function
  82 // par[0]=x par[1]=y par[2]=q for the first Mathieson shape
  83 // par[3]=x par[4]=y par[5]=q for the second Mathieson shape and so on up to iNpars/3 Mathieson shapes
  84 // For each pad of the cluster calculates the difference between actual pad charge and the charge induced to this pad by all Mathieson distributions
  85 // Then the chi2 is calculated as the sum of this value squared for all pad in the cluster.
  86 // Arguments: iNpars - number of parameters which is number of local maxima of cluster * 3
  87 //            chi2   - function result to be minimised
  88 //            par   - parameters array of size iNpars
  89 //   Returns: none
  90   AliHMPIDCluster *pClu=(AliHMPIDCluster*)gMinuit->GetObjectFit();
  91   Int_t iNshape = iNpars/3;
  92
  93   chi2 = 0;
  94   for(Int_t i=0;i<pClu->Size();i++){                                                   //loop on all pads of the cluster
  95     Double_t dQpadMath = 0;                                                            //pad charge collector
  96     for(Int_t j=0;j<iNshape;j++){                                                      //Mathiesons loop as all of them may contribute to this pad
  97       dQpadMath+=par[3*j+2]*pClu->Dig(i)->IntMathieson(par[3*j],par[3*j+1]);           // par[3*j+2] is charge par[3*j] is x par[3*j+1] is y of current Mathieson
  98     }
  99 //    if(dQpadMath>0)chi2 +=TMath::Power((pClu->Dig(i)->Q()-dQpadMath),2)/dQpadMath;   //
 100     if(dQpadMath>0 && pClu->Dig(i)->Q())
 101       chi2 +=TMath::Power((pClu->Dig(i)->Q()-dQpadMath),2)/pClu->Dig(i)->Q(); //
 102   }                                                                                    //loop on all pads of the cluster
 103 }//FitFunction()
 104 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 105 void AliHMPIDCluster::Print(Option_t* opt)const
 106 {
 107 //Print current cluster
 108   const char *status=0;
 109   switch(fSt){
 110     case        kFrm  : status="formed        "   ;break;
 111     case        kUnf  : status="unfolded (fit)"   ;break;
 112     case        kCoG  : status="coged         "   ;break;
 113     case        kLo1  : status="locmax 1 (fit)"   ;break;
 114     case        kMax  : status="exceeded (cog)"   ;break;
 115     case        kNot  : status="not done (cog)"   ;break;
 116     case        kEmp  : status="empty         "   ;break;
 117     case        kEdg  : status="edge     (fit)"   ;break;
 118     case        kSi1  : status="size 1   (cog)"   ;break;
 119     case        kNoLoc: status="no LocMax(fit)"   ;break;
 120     case        kAbn  : status="Abnormal fit  "   ;break;
 121
 122     default:            status="??????"          ;break;
 123   }
 124   Double_t ratio=0;
 125   if(Q()>0&&QRaw()>0) ratio = Q()/QRaw()*100;
 126   Printf("%sCLU: ch=%i                 (%7.3f,%7.3f) Q=%8.3f Qraw=%8.3f(%3.0f%%) Size=%2i DimBox=%i LocMax=%i Chi2=%7.3f   %s",
 127          opt,Ch(),X(),Y(),Q(),QRaw(),ratio,Size(),fBox,fNlocMax,fChi2,status);
 128   if(fDigs) fDigs->Print();
 129 }//Print()
 130 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 131 Int_t AliHMPIDCluster::Solve(TClonesArray *pCluLst,Bool_t isTryUnfold)
 132 {
 133 //This methode is invoked when the cluster is formed to solve it. Solve the cluster means to try to unfold the cluster
 134 //into the local maxima number of clusters. This methode is invoked by AliHMPIDRconstructor::Dig2Clu() on cluster by cluster basis.
 135 //At this point, cluster contains a list of digits, cluster charge and size is precalculated in AddDigit(), position is preset to (-1,-1) in ctor,
 136 //status is preset to kFormed in AddDigit(), chamber-sector info is preseted to actual values in AddDigit()
 137 //Method first finds number of local maxima and if it's more then one tries to unfold this cluster into local maxima number of clusters
 138 //Arguments: pCluLst     - cluster list pointer where to add new cluster(s)
 139 //           isTryUnfold - flag to switch on/off unfolding
 140 //  Returns: number of local maxima of original cluster
 141   CoG();
 142   Int_t iCluCnt=pCluLst->GetEntriesFast();                                               //get current number of clusters already stored in the list by previous operations
 143   if(isTryUnfold==kFALSE || Size()==1) {                                                 //if cluster contains single pad there is no way to improve the knowledge
 144     (isTryUnfold)?fSt=kSi1:fSt=kNot;
 145     new ((*pCluLst)[iCluCnt++]) AliHMPIDCluster(*this);  //add this raw cluster
 146     return 1;
 147   }
 148 //Phase 0. Initialise TMinuit
 149   const Int_t kMaxLocMax=6;                                                              //max allowed number of loc max for fitting
 150   if(!gMinuit) gMinuit = new TMinuit(100);                                               //init MINUIT with this number of parameters (3 params per mathieson)
 151   gMinuit->mncler();                                                                     // reset Minuit list of paramters
 152   gMinuit->SetObjectFit((TObject*)this);  gMinuit->SetFCN(AliHMPIDCluster::FitFunc);     //set fit function
 153   Double_t aArg=-1;                                                                    //tmp vars for TMinuit
 154   Int_t iErrFlg;
 155   gMinuit->mnexcm("SET PRI",&aArg,1,iErrFlg);                                          //suspend all printout from TMinuit
 156   gMinuit->mnexcm("SET NOW",&aArg,0,iErrFlg);                                          //suspend all warning printout from TMinuit
 157 //Phase 1. Find number of local maxima. Strategy is to check if the current pad has QDC more then all neigbours. Also find the box contaning the cluster
 158   fNlocMax=0;
 159
 160  for(Int_t iDig1=0;iDig1<Size();iDig1++) {                                               //first digits loop
 161     AliHMPIDDigit *pDig1 = Dig(iDig1);                                                   //take next digit
 162     Int_t iCnt = 0;                                                                      //counts how many neighbouring pads has QDC more then current one
 163     for(Int_t iDig2=0;iDig2<Size();iDig2++) {                                            //loop on all digits again
 164       if(iDig1==iDig2) continue;                                                         //the same digit, no need to compare
 165       AliHMPIDDigit *pDig2 = Dig(iDig2);                                                 //take second digit to compare with the first one
 166       Int_t dist = TMath::Sign(Int_t(pDig1->PadChX()-pDig2->PadChX()),1)+TMath::Sign(Int_t(pDig1->PadChY()-pDig2->PadChY()),1);//distance between pads
 167       if(dist==1)                                                                        //means dig2 is a neighbour of dig1
 168          if(pDig2->Q()>=pDig1->Q()) iCnt++;                                              //count number of pads with Q more then Q of current pad
 169     }//second digits loop
 170     if(iCnt==0&&fNlocMax<kMaxLocMax){                                                    //this pad has Q more then any neighbour so it's local maximum
 171       Double_t xStart=pDig1->LorsX();Double_t yStart=pDig1->LorsY();
 172       Double_t xMin=xStart-AliHMPIDDigit::SizePadX();
 173       Double_t xMax=xStart+AliHMPIDDigit::SizePadX();
 174       Double_t yMin=yStart-AliHMPIDDigit::SizePadY();
 175       Double_t yMax=yStart+AliHMPIDDigit::SizePadY();
 176       gMinuit->mnparm(3*fNlocMax  ,Form("x%i",fNlocMax),xStart,0.1,xMin,xMax,iErrFlg);   // X,Y,Q initial values of the loc max pad
 177       gMinuit->mnparm(3*fNlocMax+1,Form("y%i",fNlocMax),yStart,0.1,yMin,yMax,iErrFlg);   // X, Y constrained to be near the loc max
 178       gMinuit->mnparm(3*fNlocMax+2,Form("q%i",fNlocMax),pDig1->Q(),0.1,0,100000,iErrFlg);// Q constrained to be positive
 179       fNlocMax++;
 180     }//if this pad is local maximum
 181   }//first digits loop
 182
 183 //Phase 2. Fit loc max number of Mathiesons or add this current cluster to the list
 184 // case 1 -> no loc max found
 185  if ( fNlocMax == 0) {                                                                   // case of no local maxima found: pads with same charge...
 186    gMinuit->mnparm(3*fNlocMax  ,Form("x%i",fNlocMax),fX,0.1,0,0,iErrFlg);                // Init values taken from CoG() -> fX,fY,fQRaw
 187    gMinuit->mnparm(3*fNlocMax+1,Form("y%i",fNlocMax),fY,0.1,0,0,iErrFlg);                //
 188    gMinuit->mnparm(3*fNlocMax+2,Form("q%i",fNlocMax),fQRaw,0.1,0,100000,iErrFlg);        //
 189    fNlocMax = 1;
 190    fSt=kNoLoc;
 191  }
 192
 193 // case 2 -> loc max found. Check # of loc maxima
 194  if ( fNlocMax >= kMaxLocMax)                                                            // if # of local maxima exceeds kMaxLocMax...
 195    {
 196      fSt = kMax;   new ((*pCluLst)[iCluCnt++]) AliHMPIDCluster(*this);                   //...add this raw cluster
 197    }                                                                                     //or...
 198  else{                                                                                   //...resonable number of local maxima to fit and user requested it
 199    Double_t arglist[10];arglist[0] = 10000;arglist[1] = 1.;                              //number of steps and sigma on pads charges
 200    gMinuit->mnexcm("SIMPLEX" ,arglist,2,iErrFlg);                                        //start fitting with Simplex
 201    gMinuit->mnexcm("MIGRAD" ,arglist,2,iErrFlg);                                         //fitting improved by Migrad
 202    if(iErrFlg) {
 203      Double_t strategy=2;
 204      gMinuit->mnexcm("SET STR",&strategy,1,iErrFlg);                                     //change level of strategy
 205      if(!iErrFlg) {
 206        gMinuit->mnexcm("SIMPLEX" ,arglist,2,iErrFlg);
 207        gMinuit->mnexcm("MIGRAD" ,arglist,2,iErrFlg);                                     //fitting improved by Migrad
 208 //       Printf("Try to improve fit --> err %d",iErrFlg);
 209      }
 210    }
 211    if(iErrFlg) fSt=kAbn;                                                                 //no convergence of the fit...
 212    Double_t dummy; TString sName;                                                        //vars to get results from Minuit
 213    for(Int_t i=0;i<fNlocMax;i++){                                                        //store the local maxima parameters
 214       gMinuit->mnpout(3*i   ,sName,  fX, fErrX , dummy, dummy, iErrFlg);                 // X
 215       gMinuit->mnpout(3*i+1 ,sName,  fY, fErrY , dummy, dummy, iErrFlg);                 // Y
 216       gMinuit->mnpout(3*i+2 ,sName,  fQ, fErrQ , dummy, dummy, iErrFlg);                 // Q
 217       gMinuit->mnstat(fChi2,dummy,dummy,iErrFlg,iErrFlg,iErrFlg);                        // Chi2 of the fit
 218       if(fSt!=kAbn) {
 219         if(fNlocMax!=1)fSt=kUnf;                                                           // if unfolded
 220         if(fNlocMax==1&&fSt!=kNoLoc) fSt=kLo1;                                             // if only 1 loc max
 221         if ( !IsInPc()) fSt = kEdg;                                                        // if Out of Pc
 222         if(fSt==kNoLoc) fNlocMax=0;                                                        // if with no loc max (pads with same charge..)
 223       }
 224       new ((*pCluLst)[iCluCnt++]) AliHMPIDCluster(*this);                                //add new unfolded cluster
 225    }
 226  }
 227
 228  return fNlocMax;
 229
 230 }//Solve()
 231 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++