Gamma.hh

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// $Id: Gamma.hh 68057 2013-03-13 14:46:00Z gcosmo $
//
//
//---------------------------------------------------------------
//  GEANT 4 class header file
//
//  Gamma
//
//  Class description:
//
//  Gamma function.

//---------------------------------------------------------------
#ifndef MYGAMMA_H
#define MYGAMMA_H

#include <cmath>

class MyGamma
{
  public:

    MyGamma ();
    ~MyGamma();
  
    double Gamma(double z);
    double Gamma(double a,double x);

  private:

    double GamCf(double a,double x);
    double GamSer(double a,double x);
  
    // Abs
    static short  Abs(short d)  { return (d > 0) ? d : -d; }
    static int    Abs(int d)    { return (d > 0) ? d : -d; }
    static long   Abs(long d)   { return (d > 0) ? d : -d; }
    static float  Abs(float d)  { return (d > 0) ? d : -d; }
    static double Abs(double d) { return (d > 0) ? d : -d; }
    static double LnGamma(double z); 
    static double Log(double x) { return std::log(x); }
    static double Exp(double x) { return std::exp(x); }
};

#endif