FastJet 3.0.2
Public Member Functions
fastjet::GhostedAreaSpec Class Reference

Parameters to configure the computation of jet areas using ghosts. More...

#include <fastjet/GhostedAreaSpec.hh>

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Public Member Functions

 GhostedAreaSpec ()
 default constructor
 GhostedAreaSpec (double ghost_maxrap_in, int repeat_in=gas::def_repeat, double ghost_area_in=gas::def_ghost_area, double grid_scatter_in=gas::def_grid_scatter, double pt_scatter_in=gas::def_pt_scatter, double mean_ghost_pt_in=gas::def_mean_ghost_pt)
 explicit constructor
 GhostedAreaSpec (double ghost_minrap_in, double ghost_maxrap_in, int repeat_in=gas::def_repeat, double ghost_area_in=gas::def_ghost_area, double grid_scatter_in=gas::def_grid_scatter, double pt_scatter_in=gas::def_pt_scatter, double mean_ghost_pt_in=gas::def_mean_ghost_pt)
 explicit constructor
 GhostedAreaSpec (const Selector &selector, int repeat_in=gas::def_repeat, double ghost_area_in=gas::def_ghost_area, double grid_scatter_in=gas::def_grid_scatter, double pt_scatter_in=gas::def_pt_scatter, double mean_ghost_pt_in=gas::def_mean_ghost_pt)
 constructor based on a Selector
void _initialize ()
 does the initialization of actual ghost parameters
double ghost_etamax () const
double ghost_maxrap () const
double ghost_area () const
double grid_scatter () const
double pt_scatter () const
double mean_ghost_pt () const
int repeat () const
bool fj2_placement () const
double kt_scatter () const
double mean_ghost_kt () const
double actual_ghost_area () const
int n_ghosts () const
void set_ghost_area (double val)
void set_ghost_etamax (double val)
void set_ghost_maxrap (double val)
void set_grid_scatter (double val)
void set_pt_scatter (double val)
void set_mean_ghost_pt (double val)
void set_repeat (int val)
void set_kt_scatter (double val)
void set_mean_ghost_kt (double val)
void set_fj2_placement (bool val)
 if val is true, set ghost placement as it was in FastJet 2.X.
int nphi () const
 return nphi (ghosts layed out (-nrap, 0..nphi-1), (-nrap+1,0..nphi-1), ...
int nrap () const
void get_random_status (std::vector< int > &__iseed) const
 get all relevant information about the status of the random number generator, so that it can be reset subsequently with set_random_status.
void set_random_status (const std::vector< int > &__iseed)
 set the status of the random number generator, as obtained previously with get_random_status.
void checkpoint_random ()
void restore_checkpoint_random ()
std::string description () const
 for a summary
void add_ghosts (std::vector< PseudoJet > &) const
 push a set of ghost 4-momenta onto the back of the vector of PseudoJets
double random_at_own_risk () const
 very deprecated public access to a random number from the internal generator
BasicRandom< double > & generator_at_own_risk () const
 very deprecated public access to the generator itself

Detailed Description

Parameters to configure the computation of jet areas using ghosts.

Class that defines the parameters that go into the measurement of active jet areas.

Definition at line 62 of file GhostedAreaSpec.hh.


Constructor & Destructor Documentation

fastjet::GhostedAreaSpec::GhostedAreaSpec ( const Selector selector,
int  repeat_in = gas::def_repeat,
double  ghost_area_in = gas::def_ghost_area,
double  grid_scatter_in = gas::def_grid_scatter,
double  pt_scatter_in = gas::def_pt_scatter,
double  mean_ghost_pt_in = gas::def_mean_ghost_pt 
) [explicit]

constructor based on a Selector

explicit constructor

Definition at line 42 of file GhostedAreaSpec.cc.


Member Function Documentation

void fastjet::GhostedAreaSpec::_initialize ( )

does the initialization of actual ghost parameters

sets the detailed parameters for the ghosts (which may not be quite the same as those requested -- this is in order for things to fit in nicely into 2pi etc...

Definition at line 85 of file GhostedAreaSpec.cc.

void fastjet::GhostedAreaSpec::set_fj2_placement ( bool  val)

if val is true, set ghost placement as it was in FastJet 2.X.

The main differences between FJ2 and FJ3 ghost placement are

  • in FJ2 the rapidity spacing was ceil((maxrap-minrap)/sqrt(area)), while in FJ3 it is int((maxrap-minrap)/sqrt(area) + 0.5) [similarly for phi]. The FJ3 option offers more stability when trying to specify a spacing that exactly fits the extent.
  • in FJ2, the ghosts are placed at the corners of grid cells (i.e. extending up to maxrap), while in FJ3 they are placed at the centres of grid cells (i.e. extending roughly up to maxrap-sqrt(area)). The FJ2 behaviour effectively skews the total area coverage when maxrap is small, by an amount sqrt(area)/(2*maxrap).

FJ2 placement is now deprecated.

Definition at line 76 of file GhostedAreaSpec.cc.

int fastjet::GhostedAreaSpec::nphi ( ) const [inline]

return nphi (ghosts layed out (-nrap, 0..nphi-1), (-nrap+1,0..nphi-1), ...

(nrap,0..nphi-1)

Definition at line 173 of file GhostedAreaSpec.hh.

void fastjet::GhostedAreaSpec::get_random_status ( std::vector< int > &  __iseed) const [inline]

get all relevant information about the status of the random number generator, so that it can be reset subsequently with set_random_status.

Definition at line 179 of file GhostedAreaSpec.hh.

void fastjet::GhostedAreaSpec::set_random_status ( const std::vector< int > &  __iseed) [inline]

set the status of the random number generator, as obtained previously with get_random_status.

Note that the random generator is a static member of the class, i.e. common to all instances of the class --- so if you modify the random for this instance, you modify it for all instances.

Definition at line 187 of file GhostedAreaSpec.hh.

void fastjet::GhostedAreaSpec::add_ghosts ( std::vector< PseudoJet > &  ) const

push a set of ghost 4-momenta onto the back of the vector of PseudoJets

adds the ghost 4-momenta to the vector of PseudoJet's

Definition at line 112 of file GhostedAreaSpec.cc.


The documentation for this class was generated from the following files:
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