Computational Physics - Department of Physics

5.6 An Integration Class 145

#ifndefFUNCTION_H
#defineFUNCTION_H

#include"Array.h"

classFunction{
public:
//! Destructor
virtual~Function(){};// Not needed here.
/*
@brief Overload the function operator().

• *Used for evaluating functions with one independent variable.


• 
  

  /
  virtual double operator()(doublex){}
  /
  *@brief Overload the function operator().

  
  


• 
  

  *Used for evaluating functions with more than one independent variable.
  **/
  virtual double operator()(constArray& x){}
  };
  #endif

  
  

The header fileIntegral.hcontains, with an example on how to use it, the following state-
ments

http://folk.uio.no/mhjensen/compphys/programs/chapter05/cpp/Integral.h

#ifndefINTEGRAL_H
#defineINTEGRAL_H

#include"Array.h"
#include"Function.h"
#include

classIntegral{
protected: // Access in the subclasses.
doublea; // Lower limit of integration.
doubleb; // Upper limit of integration.
intnpts; // Number of integration points.
Function &f;// Function to be integrated.
public:
/*
@brief Constructor.

• @param lower_. Lower limit of integration.
  @param upper. Upper limit of integration.
  *@param npts. Number of points of integration.
  *@param f. Reference to a functor representing the function to be integrated.
  **/
  Integral(doublelower,doubleupper,intnpts, Function &f_);
  //! Destructor
  virtual~Integral(){}