ProtonReconstructionAlgorithm::ChiSquareCalculator Class Reference

class for calculation of chi^2 More...

Public Member Functions
	ChiSquareCalculator ()=default
double	operator() (const double *parameters) const

Public Attributes
const std::map< unsigned int, RPOpticsData > *	m_rp_optics
const CTPPSLocalTrackLiteRefVector *	tracks

Detailed Description

class for calculation of chi^2

Definition at line 66 of file ProtonReconstructionAlgorithm.h.

Constructor & Destructor Documentation

ProtonReconstructionAlgorithm::ChiSquareCalculator::ChiSquareCalculator ( )

default

Member Function Documentation

double ProtonReconstructionAlgorithm::ChiSquareCalculator::operator()

(

const double *

parameters

)

const

Definition at line 112 of file ProtonReconstructionAlgorithm.cc.

References indexGen::s2, HLT_2018_cff::track, PDWG_EXOHSCP_cff::tracks, x, LHCInterpolatedOpticalFunctionsSet::Kinematics::x, y, and LHCInterpolatedOpticalFunctionsSet::Kinematics::y.

                                                                                                  {
  // extract proton parameters
  const LHCInterpolatedOpticalFunctionsSet::Kinematics k_in = {
      0., parameters[1], parameters[3], parameters[2], parameters[0]};

  // calculate chi^2 by looping over hits
  double s2 = 0.;

  for (const auto &track : *tracks) {
    const CTPPSDetId rpId(track->rpId());

    // transport proton to the RP
    auto oit = m_rp_optics->find(rpId);
    LHCInterpolatedOpticalFunctionsSet::Kinematics k_out;
    oit->second.optics->transport(k_in, k_out);

    // proton position wrt. beam
    const double x = k_out.x - oit->second.x0;
    const double y = k_out.y - oit->second.y0;

    // calculate chi^2 contributions, convert track data mm --> cm
    const double x_diff_norm = (x - track->x() * 1E-1) / (track->xUnc() * 1E-1);
    const double y_diff_norm = (y - track->y() * 1E-1) / (track->yUnc() * 1E-1);

    // increase chi^2
    s2 += x_diff_norm * x_diff_norm + y_diff_norm * y_diff_norm;
  }

  return s2;
}

Member Data Documentation

const std::map<unsigned int, RPOpticsData>* ProtonReconstructionAlgorithm::ChiSquareCalculator::m_rp_optics

Definition at line 73 of file ProtonReconstructionAlgorithm.h.

const CTPPSLocalTrackLiteRefVector* ProtonReconstructionAlgorithm::ChiSquareCalculator::tracks

Definition at line 72 of file ProtonReconstructionAlgorithm.h.