[u/mrichter/AliRoot.git] / TEvtGen / HepMC / Polarization.h

//--------------------------------------------------------------------------
#ifndef HEPMC_POLARIZATION_H
#define HEPMC_POLARIZATION_H

//////////////////////////////////////////////////////////////////////////
// Matt.Dobbs@Cern.CH, September 1999, refer to:
// M. Dobbs and J.B. Hansen, "The HepMC C++ Monte Carlo Event Record for
// High Energy Physics", Computer Physics Communications (to be published).
//
// Polarization object for a particle. All angles are in radians.
//////////////////////////////////////////////////////////////////////////

#include "HepMC/SimpleVector.h"
#include <iostream>
#include <cmath>

namespace HepMC {

    static const double HepMC_pi = 3.14159265358979323846;  // copy of pi from CLHEP
    
    //! The Polarization class stores theta and phi for a GenParticle

    ///
    /// \class  Polarization
    /// HepMC::Polarization stores a particle's theta and phi in radians.
    /// Use of this information is optional. 
    /// By default, the polarization is set to zero.
    ///
    class Polarization {

        /// print polarization information
	friend std::ostream& operator<<( std::ostream&, const Polarization& );

    public:
        /// default constructor
	Polarization( );
	/// constructor requiring at least one value
	Polarization( double theta, double phi = 0 );
	/// construct from another polarization object
	Polarization( const Polarization& inpolar );
	/// construct using the polar and azimuthal angles from a ThreeVector
	Polarization( const ThreeVector& vec3in );
	virtual       ~Polarization() {}

        /// swap
        void swap( Polarization & other);
	/// make a copy
	Polarization& operator=( const Polarization& inpolar );
	/// equality requires that theta and phi are equal
	bool          operator==( const Polarization& ) const;
	/// inequality results if either theta or phi differ
	bool          operator!=( const Polarization& ) const;

        /// print theta and phi
	void          print( std::ostream& ostr = std::cout ) const;
    
	////////////////////
	// access methods //
	////////////////////
	double        theta() const;    //!< returns polar angle in radians
	double        phi() const;      //!< returns azimuthal angle in radians
	ThreeVector   normal3d() const; //!< unit 3 vector for easy manipulation
	bool          is_defined() const;   //!< returns true if the Polarization has been defined

        /// set polar angle in radians 
	double        set_theta( double theta );
        /// set azimuthal angle in radians 
	double        set_phi( double phi );
	/// set both polar and azimuthal angles in radians
	void          set_theta_phi( double theta, double phi );
	/// sets polarization according to direction of 3 vec
	ThreeVector   set_normal3d( const ThreeVector& vec3in ); 
	/// declares the Polarization as undefined and zeros the values
	void          set_undefined();

    private:
    	/// private method to return a polar angle in the correct range
	double valid_theta( double theta );
    	/// private method to return an azimuthal angle in the correct range
	double valid_phi( double phi );

    private:
	double m_theta; //polar angle of polarization in radians 0< theta <pi
	double m_phi;   //azimuthal angle of polarization in rad. 0< phi <2pi
	bool   m_defined; //used to flag if the Polarization has been defined
    };

    ///////////////////////////
    // INLINE Access Methods //
    ///////////////////////////

    inline double Polarization::theta() const { return m_theta; }
    inline double Polarization::phi() const { return m_phi; }

    ///////////////////////////
    // INLINE Operators      //
    ///////////////////////////

    inline bool Polarization::operator==( const Polarization& a ) const 
    {
	return ( a.theta() == this->theta() && a.phi() == this->phi() && a.is_defined() == this->is_defined() );
    }

    inline bool Polarization::operator!=(const Polarization& a ) const 
    {
	return !( a == *this );
    }

} // HepMC

#endif  // HEPMC_POLARIZATION_H
//--------------------------------------------------------------------------
Commit	Line	Data
0ca57c2f	1	//--------------------------------------------------------------------------
	2	#ifndef HEPMC_POLARIZATION_H
	3	#define HEPMC_POLARIZATION_H
	4
	5	//////////////////////////////////////////////////////////////////////////
	6	// Matt.Dobbs@Cern.CH, September 1999, refer to:
	7	// M. Dobbs and J.B. Hansen, "The HepMC C++ Monte Carlo Event Record for
	8	// High Energy Physics", Computer Physics Communications (to be published).
	9	//
	10	// Polarization object for a particle. All angles are in radians.
	11	//////////////////////////////////////////////////////////////////////////
	12
	13	#include "HepMC/SimpleVector.h"
	14	#include <iostream>
	15	#include <cmath>
	16
	17	namespace HepMC {
	18
	19	static const double HepMC_pi = 3.14159265358979323846; // copy of pi from CLHEP
	20
	21	//! The Polarization class stores theta and phi for a GenParticle
	22
	23	///
	24	/// \class Polarization
	25	/// HepMC::Polarization stores a particle's theta and phi in radians.
	26	/// Use of this information is optional.
	27	/// By default, the polarization is set to zero.
	28	///
	29	class Polarization {
	30
	31	/// print polarization information
	32	friend std::ostream& operator<<( std::ostream&, const Polarization& );
	33
	34	public:
	35	/// default constructor
	36	Polarization( );
	37	/// constructor requiring at least one value
	38	Polarization( double theta, double phi = 0 );
	39	/// construct from another polarization object
	40	Polarization( const Polarization& inpolar );
	41	/// construct using the polar and azimuthal angles from a ThreeVector
	42	Polarization( const ThreeVector& vec3in );
	43	virtual ~Polarization() {}
	44
	45	/// swap
	46	void swap( Polarization & other);
	47	/// make a copy
	48	Polarization& operator=( const Polarization& inpolar );
	49	/// equality requires that theta and phi are equal
	50	bool operator==( const Polarization& ) const;
	51	/// inequality results if either theta or phi differ
	52	bool operator!=( const Polarization& ) const;
	53
	54	/// print theta and phi
	55	void print( std::ostream& ostr = std::cout ) const;
	56
	57	////////////////////
	58	// access methods //
	59	////////////////////
	60	double theta() const; //!< returns polar angle in radians
	61	double phi() const; //!< returns azimuthal angle in radians
	62	ThreeVector normal3d() const; //!< unit 3 vector for easy manipulation
	63	bool is_defined() const; //!< returns true if the Polarization has been defined
	64
65	/// set polar angle in radians
66	double set_theta( double theta );
67	/// set azimuthal angle in radians
68	double set_phi( double phi );
69	/// set both polar and azimuthal angles in radians
70	void set_theta_phi( double theta, double phi );
71	/// sets polarization according to direction of 3 vec
72	ThreeVector set_normal3d( const ThreeVector& vec3in );
73	/// declares the Polarization as undefined and zeros the values
74	void set_undefined();
75
76	private:
77	/// private method to return a polar angle in the correct range
78	double valid_theta( double theta );
79	/// private method to return an azimuthal angle in the correct range
80	double valid_phi( double phi );
81
82	private:
83	double m_theta; //polar angle of polarization in radians 0< theta <pi
84	double m_phi; //azimuthal angle of polarization in rad. 0< phi <2pi
85	bool m_defined; //used to flag if the Polarization has been defined
86	};
87
88	///////////////////////////
89	// INLINE Access Methods //
90	///////////////////////////
91
92	inline double Polarization::theta() const { return m_theta; }
93	inline double Polarization::phi() const { return m_phi; }
94
95	///////////////////////////
96	// INLINE Operators //
97	///////////////////////////
98
99	inline bool Polarization::operator==( const Polarization& a ) const
100	{
101	return ( a.theta() == this->theta() && a.phi() == this->phi() && a.is_defined() == this->is_defined() );
102	}
103
104	inline bool Polarization::operator!=(const Polarization& a ) const
105	{
106	return !( a == *this );
107	}
108
109	} // HepMC
110
111	#endif // HEPMC_POLARIZATION_H
112	//--------------------------------------------------------------------------