ZDCFitWrapper.cxx File Reference

#include "ZdcAnalysis/ZDCFitWrapper.h"
#include <numeric>
#include <memory>

Include dependency graph for ZDCFitWrapper.cxx:

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Functions
double	ZDCFermiExpFit (const double *xvec, const double *pvec)
double	ZDCFermiExpFitRefl (const double *xvec, const double *pvec)

Function Documentation

ZDCFermiExpFit()

double ZDCFermiExpFit	(	const double *	xvec,
		const double *	pvec
	)

Definition at line 662 of file ZDCFitWrapper.cxx.

{
  static const float offsetScale = 0;
 
  double t = xvec[0];
 
  double amp = pvec[0];
  double t0 = pvec[1];
  double tau1 = pvec[2];
  double tau2 = pvec[3];
  double C = pvec[4];
 
  double tauRatio = tau2 / tau1;
  double tauRatioMinunsOne = tauRatio - 1;
 
  double norm = (  std::exp(-offsetScale / tauRatio) * std::pow(1. / tauRatioMinunsOne, 1. / (1 + tauRatio)) /
                  ( 1 + std::pow(1. / tauRatioMinunsOne, 1. / (1 + 1 / tauRatio)))                         );
 
  double deltaT = t - (t0 - offsetScale * tau1);
  if (deltaT < 0) deltaT = 0;
 
  double expTerm = std::exp(-deltaT / tau2);
  double fermiTerm = 1. / (1. + std::exp(-(t - t0) / tau1));
 
  return amp * expTerm * fermiTerm / norm + C; 
}

ZDCFermiExpFitRefl()

double ZDCFermiExpFitRefl	(	const double *	xvec,
		const double *	pvec
	)

Definition at line 689 of file ZDCFitWrapper.cxx.

{
  static const float offsetScale = 0;
 
  double t = xvec[0];
 
  double amp = pvec[0];
  double t0 = pvec[1];
  double tau1 = pvec[2];
  double tau2 = pvec[3];
  double C = pvec[4];
  
  double refldelay = pvec[5];
  double reflFrac = pvec[6];
  double reflwidth = pvec[7];
  double delta = pvec[8];
  
  double tauRatio = tau2 / tau1;
  double tauRatioMinunsOne = tauRatio - 1;
 
  double norm = (  std::exp(-offsetScale / tauRatio) * std::pow(1. / tauRatioMinunsOne, 1. / (1 + tauRatio)) /
           ( 1 + std::pow(1. / tauRatioMinunsOne, 1. / (1 + 1 / tauRatio)))                        ) / (1 + delta);
 
  double deltaT = t - (t0 - offsetScale * tau1);
  if (deltaT < 0) deltaT = 0;
 
  // Note: the small constant added here accounts for the very long tail on the pulse 
  //   which doesn't go to zero over the time range that we sample
  //
  double expTerm = delta + std::exp(-deltaT / tau2);
  double fermiTerm = 1. / (1. + std::exp(-(t - t0) / tau1));
 
  double deltaTRefl = deltaT - refldelay;
  double reflTerm =  -reflFrac*amp*std::exp(-0.5*deltaTRefl*deltaTRefl/reflwidth/reflwidth);
 
  return amp * expTerm * fermiTerm / norm + C + reflTerm; 
}