func.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 <cmath>
 
namespace Belle2 {
  namespace TOP {
 
    namespace func {
 
      inline double unfold(double x, int nx, double A)
      {
        if (nx % 2 == 0) return (nx * A + x);
        else return (nx * A - x);
      }
 
 
      inline double unfold(double kx, int nx)
      {
        if (nx % 2 == 0) return kx;
        else return -kx;
      }
 
 
      inline void fold(double xu, double A, double& x, double& kx, int& nx)
      {
        nx = lround(xu / A);
        x = xu - nx * A;
        if (nx % 2 != 0) {
          x = -x;
          kx = -kx;
        }
      }
 
      inline double clip(double x, int Nx, double A, double xmi, double xma)
      {
        x = unfold(x, Nx, A);
        x = std::max(std::min(x, xma), xmi) - Nx * A;
        if (Nx % 2 != 0) x = -x;
        return x;
      }
 
      inline int getNumOfEven(int j1, int j2)
      {
        return (j2 - j1 + 1 - abs(j1) % 2) / 2;
      }
 
      inline double within2PI(double angle)
      {
        angle = fmod(angle, 2 * M_PI);
        if (angle < 0) angle += 2 * M_PI;
        return angle;
      }
 
    } // func
  } // TOP
} // Belle2