#ifndef PARAMETER_HH_INCLUDED
#define PARAMETER_HH_INCLUDED

#include <string>
using std::string;
#include <iostream>
#include "TString.h"


/*! The Parameter class is part of the fitting tools. A parameter
    is a named, numerical value, with errors. A parameter can be
    fitted by the fitting framework. */

struct Parameter
{
  string component_name;
  string name;
  string description;

  double value;

  bool fit;               // set false for fixed parameter
  double fit_start;
  double fit_min;
  double fit_max;
  double fit_step;
  
  double fit_error;
  double fit_error_up; // depricated
  double fit_error_down;// depricated
  double true_value;
          

  Parameter( string description,
             double value,
             double fit_min = 0,
             double fit_max = 1e10,
             double fit_step = 1 ) :
    component_name(""), name(""),
    description(description), value(value), fit(true), 
    fit_start((fit_min +fit_max)/2), 
    fit_min(fit_min),fit_max(fit_max), fit_step(fit_step), fit_error_up(0), fit_error_down(0), true_value(0) {}

  Parameter() : component_name(""), name(""), description(""), value(0), fit (false),
    fit_start(0), fit_min(0), fit_max(0), fit_step(0), fit_error_up(0), 
    fit_error_down(0), true_value(0) {}


  // dangerous, but fun :)
  operator double()
  {
    return value ;
  }

  string fullname()
  {
    return component_name + "." + name ;
  }

  string __str__() const
  {
    return Form("Parameter %s -> value = %f", name.c_str(),value);
  }

  string str() const { return __str__(); }

  void print( std::ostream& out = std::cout )
  {
    out << str() ;
  }

  ClassDefNV(Parameter, 1);

};

#endif