CDCDedxWidgetCurve.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
#pragma once
 
#include <math.h>
 
namespace Belle2 {
  class CDCDedxWidgetCurve {
 
  public:
 
    CDCDedxWidgetCurve() {};
 
    virtual ~CDCDedxWidgetCurve() {};
 
 
    double meanCurve(double* x, const std::vector<double>& par) const
    {
      double f = 0;
 
      if (par[0] == 1) {
        if (par.size() == 8)
          f = par[1] * std::pow(std::sqrt(x[0] * x[0] + 1), par[3]) / std::pow(x[0], par[3]) *
              (par[2] - par[5] * std::log(1 / x[0])) - par[4] + std::exp(par[6] + par[7] * x[0]);
      } else if (par[0] == 2) {
        if (par.size() == 5)
          f = par[1] * std::pow(x[0], 3) + par[2] * x[0] * x[0] + par[3] * x[0] + par[4];
      } else if (par[0] == 3) {
        if (par.size() == 5)
          f = -1.0 * par[1] * std::log(par[4] + std::pow(1 / x[0], par[2])) + par[3];
      }
      return f;
    }
 
  };
} // Belle2 namespace