FastJet  3.3.0
Public Member Functions | List of all members
fastjet::NNH< BJ, I > Class Template Reference

Help solve closest pair problems with generic interparticle and beam distance (generic case) More...

#include <fastjet/NNH.hh>

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Public Member Functions

 NNH (const std::vector< PseudoJet > &jets)
 constructor with an initial set of jets (which will be assigned indices 0 ... More...
 
 NNH (const std::vector< PseudoJet > &jets, I *info)
 
void start (const std::vector< PseudoJet > &jets)
 initialisation from a given list of particles
 
double dij_min (int &iA, int &iB)
 return the dij_min and indices iA, iB, for the corresponding jets. More...
 
void remove_jet (int iA)
 remove the jet pointed to by index iA
 
void merge_jets (int iA, int iB, const PseudoJet &jet, int jet_index)
 merge the jets pointed to by indices A and B and replace them with jet, assigning it an index jet_index. More...
 
 ~NNH ()
 a destructor
 
- Public Member Functions inherited from fastjet::NNBase< I >
 NNBase ()
 Default constructor.
 
 NNBase (I *info)
 Constuctor with additional Info.
 
- Public Member Functions inherited from fastjet::NNInfo< I >
 NNInfo (I *info)
 
template<class BJ >
void init_jet (BJ *briefjet, const fastjet::PseudoJet &jet, int index)
 

Detailed Description

template<class BJ, class I = _NoInfo>
class fastjet::NNH< BJ, I >

Help solve closest pair problems with generic interparticle and beam distance (generic case)

(see NNBase.hh for an introductory description)

This variant provides an implementation for any distance measure. It is templated with a BJ (brief jet) classand can be used with or without an extra "Information" template, i.e. NNH<BJ> or NNH<BJ,I>

For the NNH<BJ> version of the class to function, BJ must provide three member functions

For the NNH<BJ,I> version to function, the BJ::init(...) member must accept an extra argument

NOTE: THE DISTANCE MUST BE SYMMETRIC I.E. SATISFY a.distance(b) == b.distance(a)

For an example of how the NNH<BJ> class is used, see the Jade (and EECambridge) plugins

NB: the NNH algorithm is expected N^2, but has a worst case of N^3. Many QCD problems tend to place one closer to the N^3 end of the spectrum than one would like. There is scope for further progress (cf Eppstein, Cardinal & Eppstein), nevertheless the current class is already significantly faster than standard N^3 implementations.

Definition at line 75 of file NNH.hh.

Constructor & Destructor Documentation

◆ NNH()

template<class BJ, class I = _NoInfo>
fastjet::NNH< BJ, I >::NNH ( const std::vector< PseudoJet > &  jets)
inline

constructor with an initial set of jets (which will be assigned indices 0 ...

jets.size()-1

Definition at line 80 of file NNH.hh.

Member Function Documentation

◆ dij_min()

template<class BJ , class I >
double fastjet::NNH< BJ, I >::dij_min ( int &  iA,
int &  iB 
)
virtual

return the dij_min and indices iA, iB, for the corresponding jets.

If iB < 0 then iA recombines with the beam

Implements fastjet::NNBase< I >.

Definition at line 187 of file NNH.hh.

◆ merge_jets()

template<class BJ , class I >
void fastjet::NNH< BJ, I >::merge_jets ( int  iA,
int  iB,
const PseudoJet jet,
int  jet_index 
)
virtual

merge the jets pointed to by indices A and B and replace them with jet, assigning it an index jet_index.

Implements fastjet::NNBase< I >.

Definition at line 230 of file NNH.hh.


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