Class to hold the prediction of resolution depending dE/dx, nhit, and cos(theta) More...

#include <CDCDedxSigmaPred.h>

Public Member Functions
std::vector< double >	getSigmaVector () const
	Return the resolution vector from payload.

double	sigmaCurve (double x, const double par, int version) const
	resolution functions depending on dE/dx, nhit, and cos(theta)

double	getSigma (double dedx, double nhit, double cos, double timereso)
	Return the predicted resolution depending on dE/dx, nhit, and cos(theta)

double	nhitPrediction (double nhit)
	Return sigma from the nhit parameterization.

double	ionzPrediction (double dedx)
	Return sigma from the ionization parameterization.

double	cosPrediction (double cos)
	Return sigma from the cos parameterization.

Private Attributes
std::vector< double >	m_sigmapars
	dE/dx resolution parameters

const DBObjPtr< CDCDedxSigmaPars >	m_DBSigmaPars
	db object for dE/dx resolution parameters

Detailed Description

Class to hold the prediction of resolution depending dE/dx, nhit, and cos(theta)

Definition at line 31 of file CDCDedxSigmaPred.h.

Member Function Documentation

◆ cosPrediction()

double cosPrediction ( double cos )

Return sigma from the cos parameterization.

Definition at line 92 of file CDCDedxSigmaPred.cc.

{
 
  m_sigmapars = getSigmaVector();
  double x[1];
  double corCos;
 
  if (m_sigmapars.size() == 17) {
    double cospar[11];
    cospar[0] = 3;
    for (int i = 0; i < 10; ++i) {
      cospar[i + 1] = m_sigmapars[i + 7];
    }
    x[0] = cos;
    corCos = sigmaCurve(x, cospar, 0);
  }
 
  else {
    double sinpar[6];
 
    sinpar[0] = 2;
    for (int i = 0; i < 5; ++i) {
      sinpar[i + 1] = m_sigmapars[i + 7];
    }
 
    double sin = sqrt(1 - cos * cos);
    if (sin > 0.99) sin = 0.99;
    x[0] = sin;
 
    corCos = sigmaCurve(x, sinpar, 0);
  }
 
  return corCos;
}

◆ getSigma()

double getSigma	(	double	dedx,
		double	nhit,
		double	cos,
		double	timereso
	)

Return the predicted resolution depending on dE/dx, nhit, and cos(theta)

Definition at line 35 of file CDCDedxSigmaPred.cc.

{
  double correction  = cosPrediction(cos) * nhitPrediction(nhit) * ionzPrediction(dedx) * timereso;
  return correction;
}

◆ getSigmaVector()

std::vector< double > getSigmaVector ( ) const

inline

Return the resolution vector from payload.

Definition at line 38 of file CDCDedxSigmaPred.h.

    {
 
      // make sure the resolution parameters are reasonable
      if (!m_DBSigmaPars || m_DBSigmaPars->getSize() == 0) {
        B2WARNING("No dE/dx sigma parameters!");
        std::vector<double> sigmapar;
        for (int i = 0; i < 12; ++i)
          sigmapar.push_back(1.0);
        return sigmapar;
      } else return m_DBSigmaPars->getSigmaPars();
    }

◆ ionzPrediction()

double ionzPrediction ( double dedx )

Return sigma from the ionization parameterization.

Definition at line 72 of file CDCDedxSigmaPred.cc.

{
 
  m_sigmapars = getSigmaVector();
  double x[1];
  double dedxpar[3];
 
  dedxpar[0] = 1;
 
  for (int i = 0; i < 2; ++i) {
    dedxpar[i + 1] = m_sigmapars[i];
 
  }
  // determine sigma from the parameterization
  x[0] = dedx;
  double corDedx = sigmaCurve(x, dedxpar, 0);
 
  return corDedx;
}

◆ nhitPrediction()

double nhitPrediction ( double nhit )

Return sigma from the nhit parameterization.

Definition at line 42 of file CDCDedxSigmaPred.cc.

{
 
  m_sigmapars = getSigmaVector();
  double x[1];
  double nhitpar[6];
 
  nhitpar[0] = 2;
  for (int i = 0; i < 5; ++i) {
    nhitpar[i + 1] = m_sigmapars[i + 2];
  }
 
  // determine sigma from the nhit parameterization
  x[0] = nhit;
 
  double corNHit;
  int nhit_min = 8, nhit_max = 37;
 
  if (nhit <  nhit_min) {
    x[0] = nhit_min;
    corNHit = sigmaCurve(x, nhitpar, 0) * sqrt(nhit_min / nhit);
  } else if (nhit > nhit_max) {
    x[0] = nhit_max;
    corNHit = sigmaCurve(x, nhitpar, 0) * sqrt(nhit_max / nhit);
  } else corNHit = sigmaCurve(x, nhitpar, 0);
 
 
  return corNHit;
}

◆ sigmaCurve()

double sigmaCurve	(	double *	x,
		const double *	par,
		int	version
	)		const

resolution functions depending on dE/dx, nhit, and cos(theta)

Definition at line 13 of file CDCDedxSigmaPred.cc.

{
  // calculate the predicted mean value as a function of beta-gamma (bg)
  // this is done with a different function depending dE/dx, nhit, and cos(theta)
  double f = 0;
 
  if (version == 0) {
    if (par[0] == 1) { // return dedx parameterization
      f = par[1] + par[2] * x[0];
    } else if (par[0] == 2) { // return nhit or sin(theta) parameterization
      f = par[1] * std::pow(x[0], 4) + par[2] * std::pow(x[0], 3) +
          par[3] * x[0] * x[0] + par[4] * x[0] + par[5];
    } else if (par[0] == 3) { // return cos(theta) parameterization
      f = par[1] * exp(-0.5 * pow(((x[0] - par[2]) / par[3]), 2)) +
          par[4] * pow(x[0], 6) + par[5] * pow(x[0], 5) + par[6] * pow(x[0], 4) +
          par[7] * pow(x[0], 3) + par[8] * x[0] * x[0] + par[9] * x[0] + par[10];
    }
  }
 
  return f;
}

Member Data Documentation

◆ m_DBSigmaPars

const DBObjPtr<CDCDedxSigmaPars> m_DBSigmaPars

private

db object for dE/dx resolution parameters

Definition at line 80 of file CDCDedxSigmaPred.h.

◆ m_sigmapars

std::vector<double> m_sigmapars