integration.h

/***************************************************************************
                          integration.h  -  description
                             -------------------
    begin                : Fri Apr 6 2001
    copyright            : (C) 2000-2021 by Thies Jochimsen
    email                : thies@jochimsen.de
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef INTEGRATION_H
#define INTEGRATION_H
 
#include <odindata/data.h>
 
 
class Integrand {
 
 public:
 
  virtual double evaluate(double x) const = 0;
 
  double get_integral(double xmin, double xmax, unsigned int max_subintervals=1000, double error_limit=1e-7) const;
 
 
 protected:
   Integrand() {}
   virtual ~Integrand() {}
};
 
 
class GslData4Integr; // forward declaration
 
class FunctionIntegral {
 
 public:
 
  FunctionIntegral(const Integrand& func, unsigned int max_subintervals=1000, double error_limit=1e-7);
 
  ~FunctionIntegral();
 
  double get_integral(double xmin, double xmax) const;
  
 
 private:
  static double integrand(double x, void *params);
  
  const Integrand& f;
  unsigned int n_intervals;
  double errlimit;
  GslData4Integr* gsldata;
 
};
 
#endif