linear_interpolator.h

// -*- C++ -*-
//
// linear_interpolator.h is part of ExSample -- A Library for Sampling Sudakov-Type Distributions
//
// Copyright (C) 2008-2019 Simon Platzer -- simon.plaetzer@desy.de, The Herwig Collaboration
//
// ExSample is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
#ifndef EXSAMPLE_linear_interpolator_h_included
#define EXSAMPLE_linear_interpolator_h_included
 
#include "utility.h"
 
namespace exsample {
 
  struct inversion_has_no_solution { };
 
  struct constant_interpolation {
 
    constant_interpolation(double xlow,
                           double xhigh,
                           double h)
      : range(xlow,xhigh), value(h) {}
 
    std::pair<double,double> range;
 
    double value;
 
  };
 
  class linear_interpolator {
 
  public:
 
    linear_interpolator();
 
    explicit linear_interpolator(const std::map<double,double>& points);
 
  public:
 
    double operator()(double x) const;
 
    std::pair<double,double> range() const { return range_; }
 
  public:
 
    bool invertible(double f) const {
      return (range_.first <= f &&
              range_.second >= f);
    }
 
    double unique_inverse(double f) const;
 
    std::map<double,double>& interpolation() {
      return interpolation_;
    }
 
    void set_interpolation(double point, double value);
 
    void reset();
 
  public:
 
    template<class OStream>
    void put(OStream& os) const;
 
    template<class IStream>
    void get(IStream& is);
 
  private:
 
    std::map<double, double> interpolation_;
 
    std::pair<double,double> range_;
 
  };
 
  template<class OStream>
  inline OStream& operator<<(OStream& os, const linear_interpolator& ip) {
    ip.put(os);
    return os;
  }
 
  template<class IStream>
  inline IStream& operator>>(IStream& is, linear_interpolator& ip) {
    ip.get(is);
    return is;
  }
 
}
 
#include "linear_interpolator.icc"
 
#endif // EXSAMPLE_linear_interpolator_h_included