GSLIntegrator.h

// -*- C++ -*-
//
// GSLIntegrator.h is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef HERWIG_GSLIntegrator_H
#define HERWIG_GSLIntegrator_H
//
// This is the declaration of the GSLIntegrator class.
//
 
#include "ThePEG/Pointer/ReferenceCounted.h"
#include "ThePEG/Repository/CurrentGenerator.h"
#include "gsl/gsl_integration.h"
#include "gsl/gsl_errno.h"
 
namespace Herwig {
 
using namespace ThePEG;
 
class GSLIntegrator : public Pointer::ReferenceCounted {
 
public:
 
  GSLIntegrator() : _abserr(1.0E-35), _relerr(1.0E-3), _nbins(1000) {}
  
  GSLIntegrator(double abserr, double relerr, int nbins) :
    _abserr(abserr), _relerr(relerr), _nbins(nbins) {}
 
  template <class T>
  using ValT = decltype(std::declval<typename T::ValType>() 
                      * std::declval<typename T::ArgType>());
 
  template <class T>
  inline ValT<T>
  value(const T & function, 
        const typename T::ArgType lower,
        const typename T::ArgType upper) const;
 
  template <class T>
  inline ValT<T>
  value(const T & function, 
        const typename T::ArgType lower,
        const typename T::ArgType upper,
        ValT<T> & error) const;
 
private:
 
  GSLIntegrator & operator=(const GSLIntegrator &) = delete;
 
private:
 
  double _abserr;
 
  double _relerr;
 
  int _nbins;
};
 
}
 
#include "GSLIntegrator.tcc"
 
#endif /* HERWIG_GSLIntegrator_H */