#include <Vector_Resolution.h>

Public Member Functions
const Resolution &	eta_res () const
	Return a constant reference to the pseudorapidity resolution. More...

double	eta_sigma (const Fourvec &v) const
	Calculate the pseudorapidity resolution of a four-momentum. More...

const Resolution &	p_res () const
	Return a constant reference to the momentum resolution. More...

double	p_sigma (const Fourvec &v) const
	Calculate the momentum resolution of a four-momentum. More...

const Resolution &	phi_res () const
	Return a constant reference to the azimuthal angle resolution. More...

double	phi_sigma (const Fourvec &v) const
	Calculate the azimuthal angle resolution of a four-momentum. More...

void	smear (Fourvec &v, CLHEP::HepRandomEngine &engine, bool do_smear_dir=false) const
	Smear a four-momentum according to the resolutions. More...

bool	use_et () const
	Return the use_et flag. More...

	Vector_Resolution ()
	Constructor, instantiate an instance of Vector_Resolution with infinite precision. More...

	Vector_Resolution (const Resolution &p_res, const Resolution &eta_res, const Resolution &phi_res, bool use_et=false)
	Constructor, instantiate an instance of Vector_Resolution from three instances of Resolution objects. More...

	Vector_Resolution (std::string s)
	Constructor, instantiate an instance of Vector_Resolution from a string using format as described in the class description. More...

Private Member Functions
void	smear_dir (Fourvec &v, CLHEP::HepRandomEngine &engine) const
	Helper function to smear direction. More...

Private Attributes
Resolution	_eta_res

Resolution	_p_res

Resolution	_phi_res

bool	_use_et

Friends
std::ostream &	operator<< (std::ostream &s, const Vector_Resolution &r)
	Output stream operator, print the content of this Vector_Resolution object to an output stream. More...

Detailed Description

@class Vector_Resolution

@brief Calculate and represent resolution for a vector of
\f$p\f$, pseudorapidity \f$\eta\f$, and azimuthal angle \f$\phi\f$.
An instance of this class holds three Resolution objects, one each for
\f$p\f$, \f$\eta\f$, and \f$\phi\f$.  In addition, we have a flag
to indicate if the momentum resolution is in \f$p_{T}\f$ or \f$p\f$.
This flag is set by appending [/et] at the end of the string.

This class is initialized from a string with format

\verbatim

<p-resolution>/<eta-resolution>/<phi-resolution>[/et]

where the resolution formats are given in the documentation for the Resolution class.

Addendum by Haryo Sumowidagdo: When using the inverse flag, only the inverse flag in p-resolution will be used by the fitter to set that flag which says the error in 'p' is really the error on '1/p'. The inverse flag for $\eta$ in eta-resolution and $\phi$ in phi-resolution are not used by the fitter. As usually the angular resolution is of the form

$\sigma_{\eta,\phi} = \sqrt{\frac{C^{2}}{p^{2}} + \frac{R^{2}}{p} + N^2}$

where $ p $ can be the magnitude of the momentum ( $ p $ ) or or transverse momentum ( $p_{T}$ ), one then can (and should!) use the inverse flag for $\eta$ and $\phi$ resolution.

Definition at line 89 of file Vector_Resolution.h.

Constructor & Destructor Documentation

◆ Vector_Resolution() [1/3]

hitfit::Vector_Resolution::Vector_Resolution ( )

Constructor, instantiate an instance of Vector_Resolution with infinite precision.

Definition at line 91 of file Vector_Resolution.cc.

       : _p_res("0,0,0"),
         _eta_res("0,0,0"),
         _phi_res("0,0,0"),
         _use_et(false)
  
   {}

◆ Vector_Resolution() [2/3]

hitfit::Vector_Resolution::Vector_Resolution ( std::string s )

Constructor, instantiate an instance of Vector_Resolution from a string using format as described in the class description.

Parameters

s	String enconding the resolution parameters.

Definition at line 103 of file Vector_Resolution.cc.

111 : _p_res(field(s, 0)), _eta_res(field(s, 1)), _phi_res(field(s, 2)), _use_et(field(s, 3) == "et") {}

◆ Vector_Resolution() [3/3]

hitfit::Vector_Resolution::Vector_Resolution	(	const Resolution &	p_res,
		const Resolution &	eta_res,
		const Resolution &	phi_res,
		bool	use_et = `false`
	)

Constructor, instantiate an instance of Vector_Resolution from three instances of Resolution objects.

Parameters

p_res	The momentum resolution.
eta_res	The pseudorapidity resolution.
phi_res	The azimuthal angle resolution.
use_et	If TRUE then use $p_{T}$ instead of for momentum resolution.

Definition at line 113 of file Vector_Resolution.cc.

126 : _p_res(p_res), _eta_res(eta_res), _phi_res(phi_res), _use_et(use_et) {}

Member Function Documentation

◆ eta_res()

const Resolution & hitfit::Vector_Resolution::eta_res ( ) const

Return a constant reference to the pseudorapidity resolution.

Definition at line 139 of file Vector_Resolution.cc.

   {
     return _eta_res;
   }

References _eta_res.

◆ eta_sigma()

double hitfit::Vector_Resolution::eta_sigma ( const Fourvec & v ) const

Calculate the pseudorapidity resolution of a four-momentum.

Parameters

v	The four-momentum.

Definition at line 226 of file Vector_Resolution.cc.

   {
     return find_sigma(v, _eta_res, _use_et);
   }

References findQualityFiles::v.

Referenced by hitfit::Lepjets_Event_Lep::eta_sigma().

◆ p_res()

const Resolution & hitfit::Vector_Resolution::p_res ( ) const

Return a constant reference to the momentum resolution.

Definition at line 128 of file Vector_Resolution.cc.

   {
     return _p_res;
   }

References _p_res.

◆ p_sigma()

double hitfit::Vector_Resolution::p_sigma ( const Fourvec & v ) const

Calculate the momentum resolution of a four-momentum.

Parameters

v	The four-momentum.

Definition at line 204 of file Vector_Resolution.cc.

   {
     double sig = find_sigma(v, _p_res, _use_et);
     if (_use_et) {
       if (_p_res.inverse()) {
         sig *= v.perp() / v.e();
       } else {
         sig *= v.e() / v.perp();
       }
     }
     return sig;
   }

References findQualityFiles::v.

Referenced by hitfit::Lepjets_Event_Lep::p_sigma().

◆ phi_res()

const Resolution & hitfit::Vector_Resolution::phi_res ( ) const

Return a constant reference to the azimuthal angle resolution.

Definition at line 150 of file Vector_Resolution.cc.

   {
     return _phi_res;
   }

References _phi_res.

◆ phi_sigma()

double hitfit::Vector_Resolution::phi_sigma ( const Fourvec & v ) const

Calculate the azimuthal angle resolution of a four-momentum.

Parameters

v	The four-momentum.

Definition at line 240 of file Vector_Resolution.cc.

   {
     return find_sigma(v, _phi_res, _use_et);
   }

References findQualityFiles::v.

Referenced by hitfit::Lepjets_Event_Lep::phi_sigma().

◆ smear()

void hitfit::Vector_Resolution::smear	(	Fourvec &	v,
		CLHEP::HepRandomEngine &	engine,
		bool	do_smear_dir = `false`
	)		const

Smear a four-momentum according to the resolutions.

Parameters

v	The four-momentum to smear.
engine	The underlying random number generator.
do_smear_dir	If FALSE, only smear the energy. If TRUE, also smear the direction.

Definition at line 316 of file Vector_Resolution.cc.

   {
     double ee = _use_et ? v.perp() : v.e();  // ??? is perp() correct?
     v *= _p_res.pick(ee, ee, engine) / ee;
  
     if (do_smear_dir) {
       smear_eta(v, ee, _eta_res, engine);
       smear_phi(v, ee, _phi_res, engine);
     }
   }

References findQualityFiles::v.

Referenced by hitfit::Lepjets_Event_Lep::smear().

◆ smear_dir()

void hitfit::Vector_Resolution::smear_dir	(	Fourvec &	v,
		CLHEP::HepRandomEngine &	engine
	)		const

private

Helper function to smear direction.

Parameters

v	The four-momentum to smear.
engine	The underlying random number generator.

◆ use_et()

bool hitfit::Vector_Resolution::use_et ( ) const

Return the use_et flag.

Definition at line 161 of file Vector_Resolution.cc.

   {
     return _use_et;
   }

References _use_et.

Friends And Related Function Documentation

◆ operator<<

std::ostream& operator<<	(	std::ostream &	s,
		const Vector_Resolution &	r
	)

friend

Output stream operator, print the content of this Vector_Resolution object to an output stream.

Parameters

s	The stream to which to write.
r	The instance of Vector_Resolution to be printed.

Definition at line 346 of file Vector_Resolution.cc.

   {
     s << r._p_res << "/ " << r._eta_res << "/ " << r._phi_res;
     if (r._use_et)
       s << "/et";
     s << "\n";
     return s;
   }

Member Data Documentation

◆ _eta_res

Resolution hitfit::Vector_Resolution::_eta_res

private

The pseudorapidity resolution.

Definition at line 201 of file Vector_Resolution.h.

Referenced by eta_res().

◆ _p_res

Resolution hitfit::Vector_Resolution::_p_res

private

The momentum resolution.

Definition at line 196 of file Vector_Resolution.h.

Referenced by p_res().

◆ _phi_res

Resolution hitfit::Vector_Resolution::_phi_res

private

The phi resolution.

Definition at line 206 of file Vector_Resolution.h.

Referenced by phi_res().

◆ _use_et

bool hitfit::Vector_Resolution::_use_et

private

The momentum resolution.

Definition at line 211 of file Vector_Resolution.h.

Referenced by use_et().

Public Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Vector_Resolution() [1/3]

◆ Vector_Resolution() [2/3]

◆ Vector_Resolution() [3/3]

Member Function Documentation

◆ eta_res()

◆ eta_sigma()

◆ p_res()

◆ p_sigma()

◆ phi_res()

◆ phi_sigma()

◆ smear()

◆ smear_dir()

◆ use_et()

Friends And Related Function Documentation

◆ operator<<

Member Data Documentation

◆ _eta_res

◆ _p_res

◆ _phi_res

◆ _use_et