ITS/AliITSCorrMapSDD.cxx

   1 /**************************************************************************
   2  * Copyright(c) 2007-2009, 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 /* $Id$ */
  17
  18 ///////////////////////////////////////////////////////////////////
  19 //                                                               //
  20 // Implementation of the base class for SDD map corrections      //
  21 // Origin: F.Prino, Torino, prino@to.infn.it                     //
  22 //                                                               //
  23 ///////////////////////////////////////////////////////////////////
  24
  25 #include "TH1F.h"
  26 #include "TH2F.h"
  27 #include "AliITSCorrMapSDD.h"
  28
  29 const Int_t AliITSCorrMapSDD::fgkNAnodePtsDefault = 1;
  30 const Int_t AliITSCorrMapSDD::fgkNDriftPtsDefault = 72;
  31
  32 ClassImp(AliITSCorrMapSDD)
  33 //______________________________________________________________________
  34 AliITSCorrMapSDD::AliITSCorrMapSDD():TNamed("defaultmap",""),
  35   fNAnodePts(fgkNAnodePtsDefault),
  36   fNDriftPts(fgkNDriftPtsDefault),
  37   fXt1(0.),
  38   fXt2(0.),
  39   fXm1(0.),
  40   fXm2(0.),
  41   fDrLen(0.)
  42 {
  43   // default constructor
  44 }
  45 //______________________________________________________________________
  46 AliITSCorrMapSDD::AliITSCorrMapSDD(Char_t *mapname):
  47   TNamed(mapname,""),
  48   fNAnodePts(fgkNAnodePtsDefault),
  49   fNDriftPts(fgkNDriftPtsDefault),
  50   fXt1(0.),
  51   fXt2(0.),
  52   fXm1(0.),
  53   fXm2(0.),
  54   fDrLen(0.)
  55 {
  56   // standard constructor
  57 }
  58 //______________________________________________________________________
  59 void AliITSCorrMapSDD::ComputeGridPoints(Float_t z, Float_t x, AliITSsegmentationSDD *seg, Bool_t isReco){
  60   // extracts points from the discrete grid with the correction map
  61
  62   const Double_t kMicronTocm = 1.0e-4;
  63   Int_t nAnodes=seg->Npz();
  64   Int_t nAnodesHybrid=seg->NpzHalf();
  65   Int_t bina =(Int_t) seg->GetAnodeFromLocal(x,z);
  66   if(bina>nAnodes)  AliError("Wrong anode anumber!");
  67   if(bina>=nAnodesHybrid) bina-=nAnodesHybrid;
  68   Float_t stept = seg->Dx()*kMicronTocm/(Float_t)fNDriftPts;
  69   fDrLen= seg->Dx()*kMicronTocm-TMath::Abs(x);
  70   Int_t bint = TMath::Abs((Int_t)(fDrLen/stept));
  71   if(bint==fNDriftPts) bint-=1;
  72   if(bint>=fNDriftPts){
  73     AliError("Wrong bin number along drift direction!");
  74     bint=fNDriftPts-1;
  75   }
  76   fXt1=stept*bint;
  77   fXm1=fXt1-GetCellContent(bina,bint)*kMicronTocm;
  78   if((bint+1)<fNDriftPts){
  79     fXt2=stept*(bint+1);
  80     fXm2=fXt2-GetCellContent(bina,bint+1)*kMicronTocm;
  81   }else{
  82     fXt2=stept*(bint-1);
  83     fXm2=fXt2-GetCellContent(bina,bint-1)*kMicronTocm;
  84   }
  85   if(isReco){
  86     if(fXm1<fDrLen && fXm2>fDrLen) return;
  87     if(bint==0 || bint==(fNDriftPts-1)) return;
  88     if(fXm1>fDrLen){
  89       for(Int_t itry=1; itry<=10; itry++){
  90         Float_t xmtest=(bint-itry)*stept-GetCellContent(bina,bint-itry)*kMicronTocm;
  91         if(xmtest<fDrLen){
  92           fXt1=stept*(bint-itry);
  93           fXt2=fXt1+stept;
  94           fXm1=fXt1-GetCellContent(bina,bint-itry)*kMicronTocm;
  95           fXm2=fXt2-GetCellContent(bina,bint+1-itry)*kMicronTocm;
  96           return;
  97         }
  98       }
  99     }
 100     if(fXm2<fDrLen){
 101       for(Int_t itry=1; itry<=10; itry++){
 102         Float_t xmtest=(bint+1+itry)*stept-GetCellContent(bina,bint+1+itry)*kMicronTocm;
 103         if(xmtest>fDrLen){
 104           fXt1=stept*(bint+itry);
 105           fXt2=fXt1+stept;
 106           fXm1=fXt1-GetCellContent(bina,bint+itry)*kMicronTocm;
 107           fXm2=fXt2-GetCellContent(bina,bint+1+itry)*kMicronTocm;
 108           return;
 109         }
 110       }
 111     }
 112   }
 113 }
 114 //______________________________________________________________________
 115 Float_t AliITSCorrMapSDD::GetCorrection(Float_t z, Float_t x, AliITSsegmentationSDD *seg){
 116   // returns correction in cm starting from local coordinates on the module
 117   ComputeGridPoints(z,x,seg,kTRUE);
 118   Float_t m=(fXt2-fXt1)/(fXm2-fXm1);
 119   Float_t q=fXt1-m*fXm1;
 120   Float_t xcorr=m*fDrLen+q;
 121   // fDrLen is the measured drift distance, xcorr is the corresponding true
 122   return (xcorr-fDrLen);
 123 }
 124 //______________________________________________________________________
 125 Float_t AliITSCorrMapSDD::GetShiftForSimulation(Float_t z, Float_t x, AliITSsegmentationSDD *seg){
 126   // returns shift to be appiled in digitizarion (in cm) starting from local coordinates on the module
 127   ComputeGridPoints(z,x,seg,kFALSE);
 128   Float_t m=(fXm2-fXm1)/(fXt2-fXt1);
 129   Float_t q=fXm1-m*fXt1;
 130   Float_t xshifted=m*fDrLen+q;
 131   // fDrLen is the true drift distance, xshifted is the one with map shift
 132   return (fDrLen-xshifted);
 133 }
 134 //______________________________________________________________________
 135 TH2F* AliITSCorrMapSDD::GetMapHisto() const{
 136   // Returns a TH2F histogram with map of residuals
 137   TString hname;
 138   hname.Form("h%s",GetName());
 139   TH2F* hmap=new TH2F(hname.Data(),"",fNAnodePts,-0.5,255.5,fNDriftPts,0.,35.);
 140   for(Int_t iAn=0;iAn<fNAnodePts; iAn++){
 141     for(Int_t iDr=0;iDr<fNDriftPts; iDr++){
 142       hmap->SetBinContent(iAn+1,iDr+1,GetCellContent(iAn,iDr));
 143     }
 144   }
 145   return hmap;
 146 }
 147 //______________________________________________________________________
 148 TH1F* AliITSCorrMapSDD::GetMapProfile() const{
 149   // Returns a TH1F with the projection of the map along drift coordinate
 150   TString hname;
 151   hname.Form("p%s",GetName());
 152   TH1F* hprof=new TH1F(hname.Data(),"",fNDriftPts,0.,35.);
 153   for(Int_t iDr=0;iDr<fNDriftPts; iDr++){
 154     Float_t meanval=0.;
 155     for(Int_t iAn=0;iAn<fNAnodePts; iAn++){
 156       meanval+=GetCellContent(iAn,iDr);
 157     }
 158     hprof->SetBinContent(iDr+1,meanval/fNAnodePts);
 159   }
 160   return hprof;
 161
 162 }
 163 //______________________________________________________________________
 164 TH1F* AliITSCorrMapSDD::GetResidualDistr(Float_t dmin, Float_t dmax) const{
 165   // Returns a TH1F histogram with distribution of residual
 166   TString hname;
 167   hname.Form("hd%s",GetName());
 168   TH1F* hd=new TH1F(hname.Data(),"",100,dmin,dmax);
 169   for(Int_t iAn=0;iAn<fNAnodePts; iAn++){
 170     for(Int_t iDr=0;iDr<fNDriftPts; iDr++){
 171       hd->Fill(GetCellContent(iAn,iDr));
 172     }
 173   }
 174   return hd;
 175 }