RangeDefinition.hh

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// $Id: RangeDefinition.hh 1761 2010-09-16 10:43:18Z soyez $
//
// Copyright (c) 2005-2007, Matteo Cacciari and Gavin Salam
//
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// This file is part of FastJet.
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#ifndef __FASTJET_RANGEDEFINITION_HH__
#define __FASTJET_RANGEDEFINITION_HH__

#include "fastjet/PseudoJet.hh"
#include "fastjet/Error.hh"
#include<sstream>
#include<iostream>
#include<string>

FASTJET_BEGIN_NAMESPACE      // defined in fastjet/internal/base.hh

//----------------------------------------------------------------------
//
class RangeDefinition {
public:
  RangeDefinition() {}

  RangeDefinition(double rapmax) {
                     assert ( rapmax > 0.0 );
                     _rapmax = rapmax;
                     _rapmin = -rapmax;
                     _phimin = 0.0;
                     _phimax = twopi;
                     _total_area = 2.0*rapmax*twopi;
                     _phispan = _phimax-_phimin; }
  
  virtual ~RangeDefinition() {}
     
  RangeDefinition(double rapmin, double rapmax, 
                  double phimin = 0.0, double phimax = twopi) {
                     assert ( rapmin < rapmax);
                     assert ( phimin < phimax);
                     assert ( phimin > -twopi );
                     assert ( phimax < 2*twopi);
                     _rapmax = rapmax;
                     _rapmin = rapmin;
                     _phimin = phimin;
                     _phimax = phimax;
                     if (_phimax-_phimin > twopi)
                       _total_area = (_rapmax - _rapmin)*twopi;
                     else
                       _total_area = (_rapmax - _rapmin)*(_phimax - _phimin);
                     _phispan = _phimax-_phimin; }

  virtual inline bool is_localizable() const { return false; }


  inline void set_position(const double & rap, const double & phi) {
     if (! is_localizable() ) {
       std::ostringstream err;
       err << description() << 
         "\nThis range is not localizable. set_position() should not be used on it.";         
       throw fastjet::Error(err.str()); 
     } else {
       _rapjet = rap;
       _phijet = phi;
     }
  }

  inline void set_position(const PseudoJet & jet) {
     set_position(jet.rap(),jet.phi());
  }

  inline bool is_in_range(const PseudoJet & jet) const {
    double rap = jet.rap();
    double phi = jet.phi();
    return is_in_range(rap,phi);
  }
  
  virtual inline bool is_in_range(double rap, double phi) const {
    double dphi=phi-_phimin;
    if (dphi >= twopi) dphi -= twopi;
    if (dphi < 0)      dphi += twopi;
    return  ( rap  >= _rapmin && 
              rap  <= _rapmax &&
              dphi <= _phispan );
  }

  virtual inline void get_rap_limits(double & rapmin, double & rapmax) const {
    rapmin = _rapmin;
    rapmax = _rapmax;
  }
  
  virtual inline double area() const { return _total_area; }
  
  virtual inline std::string description() const {
    std::ostringstream ostr;
    ostr << "Range: " << _rapmin << " <= y <= "   << _rapmax << ", "
                      << _phimin << " <= phi <= " << _phimax ;
    return ostr.str();
}

protected:
  double _total_area;  // total area of specified range

  void _numerical_total_area(double rapmax, int npoints) ;
  double _rapjet,_phijet; // jet position. only used in localizable derived classes
  
private:
  double _rapmin,_rapmax,_phimin,_phimax,_phispan;

};

FASTJET_END_NAMESPACE        // defined in fastjet/internal/base.hh

#endif // __FASTJET_RANGEDEFINITION_HH__