Function.h

//
//    Class representing a correction function
//
//    first version: Hartmut Stadie 2008/12/14
//    $Id: Function.h,v 1.9 2010/11/24 09:50:21 stadie Exp $
//   
#ifndef FUNCTION_H
#define FUNCTION_H
 
class Measurement;
class Parametrization;


class Function {
 public:
  typedef double (Parametrization::*ParametrizationFunction)(const Measurement*, const double*) const; 

  Function(ParametrizationFunction func, ParametrizationFunction invfunc,
	   double *firstpar, int parindex, int npars, const Parametrization* p)
    : func_(func),invfunc_(invfunc),firstpar_(firstpar),parindex_(parindex),
    npars_(npars)
  {param_ = p; }
    
  virtual ~Function() {}
  virtual Function* clone() {
    return new Function(*this);
  }
  double* firstPar() const { return firstpar_;}
  int parIndex() const { return parindex_;}
  int nPars() const { return npars_;}
  double operator()(const Measurement* x) const { return (param_->*func_)(x,firstpar_);}
  void changeParBase(double* oldpar, double* newpar) { firstpar_ += newpar - oldpar;}
  
  bool hasInverse() const { return invfunc_;}
  double inverse(const Measurement* x) const { return invfunc_ ? (param_->*invfunc_)(x,firstpar_) : 0;}
  const ParametrizationFunction& parFunc() const { return func_;}
  const Parametrization* parametrization() const { return param_;}

 protected:
  ParametrizationFunction func_;
  ParametrizationFunction invfunc_;
  double *firstpar_;
  int parindex_;
  int npars_;
  static const Parametrization* param_;
};

#endif