/afs/cern.ch/work/a/aaltunda/public/www/CMSSW_5_3_14/src/RecoLocalCalo/EcalRecAlgos/interface/EcalUncalibRecHitRecChi2Algo.h

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#ifndef RecoLocalCalo_EcalRecAlgos_EcalUncalibRecHitRecChi2Algo_HH
#define RecoLocalCalo_EcalRecAlgos_EcalUncalibRecHitRecChi2Algo_HH

#include "Math/SVector.h"
#include "Math/SMatrix.h"
#include "RecoLocalCalo/EcalRecAlgos/interface/EcalUncalibRecHitRecAbsAlgo.h"
#include "CondFormats/EcalObjects/interface/EcalWeightSet.h"
#include "SimCalorimetry/EcalSimAlgos/interface/EcalShapeBase.h"
#include "CondFormats/EcalObjects/interface/EcalTimeCalibConstants.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"


#include <vector>

template<class C> class EcalUncalibRecHitRecChi2Algo 
{
  public:

  // destructor
  virtual ~EcalUncalibRecHitRecChi2Algo<C>() { };

  EcalUncalibRecHitRecChi2Algo<C>() { };
  EcalUncalibRecHitRecChi2Algo<C>(
                                  const C& dataFrame,
                                  const double amplitude,
                                  const EcalTimeCalibConstant& timeIC,
                                  const double amplitudeOutOfTime,
                                  const double jitter,
                                  const double* pedestals,
                                  const double* pedestalsRMS,
                                  const double* gainRatios,
                                  const EcalShapeBase & testbeamPulseShape,
                                  const std::vector<double>& chi2Parameters
  );


  virtual double chi2(){return chi2_;}
  virtual double chi2OutOfTime(){return chi2OutOfTime_;}


  private:
    double chi2_;
    double chi2OutOfTime_;
};


template <class C>
EcalUncalibRecHitRecChi2Algo<C>::EcalUncalibRecHitRecChi2Algo(
                        const C& dataFrame, 
                        const double amplitude, 
                        const EcalTimeCalibConstant& timeIC, 
                        const double amplitudeOutOfTime, 
                        const double jitter, 
                        const double* pedestals, 
                        const double* pedestalsRMS,
                        const double* gainRatios,
                        const EcalShapeBase & testbeamPulseShape,
                        const std::vector<double>& chi2Parameters
) 
{

    double noise_A = chi2Parameters[0]; // noise term for in-time chi2
    double const_A = chi2Parameters[1]; // constant term for in-time chi2
    double noise_B = chi2Parameters[2]; // noise term for out-of-time chi2
    double const_B = chi2Parameters[3]; // constant term for out-of-time chi2


    chi2_=0;
    chi2OutOfTime_=0;
    double S_0=0;  // will store the first mgpa sample
    double ped_ave=0;  // will store the average pedestal

    int gainId0 = 1;
    int iGainSwitch = 0;
    bool isSaturated = 0;
    for(int iSample = 0; iSample < C::MAXSAMPLES; iSample++) // if gain switch use later the pedestal RMS, otherwise we use the pedestal from the DB
    {
      int gainId = dataFrame.sample(iSample).gainId();
      if(gainId == 0)
      {
        gainId = 3; // if saturated, treat it as G1
        isSaturated = 1;
      }
      if(gainId != gainId0)iGainSwitch = 1;

      if(gainId==1 && iSample==0)S_0 = dataFrame.sample(iSample).adc(); // take only first presample to estimate the pedestal
      if(gainId==1 && iSample<3)ped_ave += (1/3.0)*dataFrame.sample(iSample).adc(); // take first 3 presamples to estimate the pedestal
    }


    // compute testbeamPulseShape shape parameters
    double ADC_clock = 25; // 25 ns
    double risingTime = testbeamPulseShape.timeToRise();
    double tzero = risingTime  - 5*ADC_clock;  // 5 samples before the peak

    double shiftTime = + timeIC; // we put positive here
    double shiftTimeOutOfTime = -jitter*ADC_clock; // we put negative here
    

    bool readoutError = false;

    for(int iSample = 0; iSample < C::MAXSAMPLES; iSample++)
    {
        int gainId = dataFrame.sample(iSample).gainId();
        if(dataFrame.sample(iSample).adc()==0)readoutError=true;
        if(gainId==0)continue; // skip saturated samples


        double ped = !iGainSwitch ? ped_ave:pedestals[gainId-1];  // use dynamic pedestal for G12 and average pedestal for G6,G1
        //double pedRMS = pedestalsRMS[gainId-1];
        double S_i = double(dataFrame.sample(iSample).adc());

        // --- calculate in-time chi2


        double f_i = (testbeamPulseShape)(tzero + shiftTime + iSample*ADC_clock);
        double R_i = (S_i- ped)*gainRatios[gainId-1] - f_i*amplitude;
        double R_iErrorSquare = noise_A*noise_A + const_A*const_A*amplitude*amplitude;

        chi2_ += R_i*R_i/R_iErrorSquare;

        // --- calculate out-of-time chi2

        double g_i = (testbeamPulseShape)(tzero + shiftTimeOutOfTime + iSample*ADC_clock); // calculate out of time chi2

        double R_iOutOfTime = (S_i- S_0)*gainRatios[gainId-1] - g_i*amplitudeOutOfTime;
        double R_iOutOfTimeErrorSquare = noise_B*noise_B + const_B*const_B*amplitudeOutOfTime*amplitudeOutOfTime;

 
        chi2OutOfTime_ += R_iOutOfTime*R_iOutOfTime/R_iOutOfTimeErrorSquare;
    }


    if(!isSaturated && !iGainSwitch && chi2_>0 && chi2OutOfTime_>0)     
    {   
        chi2_ = 7*(3+log(chi2_)); chi2_ = chi2_<0 ? 0:chi2_; // this is just a convinient mapping for storing in the calibRecHit bit map 
        chi2OutOfTime_ = 7*(3+log(chi2OutOfTime_)); chi2OutOfTime_ = chi2OutOfTime_<0 ? 0:chi2OutOfTime_; 
    }else
    {
        chi2_=0;
        chi2OutOfTime_=0;
    }

    if(readoutError) // rare situation
    {
        chi2_=99.0;  // chi2 is very large in these cases, put a code value to discriminate against normal noise
        chi2OutOfTime_=99.0;
    }
}

#endif