fastjet::ClusterSequencePassiveArea Class Reference

Class that behaves essentially like ClusterSequence except that it also provides access to the area of a jet (which will be a random quantity. More...

#include <ClusterSequencePassiveArea.hh>

Inheritance diagram for fastjet::ClusterSequencePassiveArea:

[legend]Collaboration diagram for fastjet::ClusterSequencePassiveArea:

[legend]List of all members.

Public Member Functions
template<class L>
	ClusterSequencePassiveArea (const std::vector< L > &pseudojets, const JetDefinition &jet_def, const GhostedAreaSpec &area_spec, const bool &writeout_combinations=false)
	constructor based on JetDefinition and PassiveAreaSpec
virtual double	empty_area (const RangeDefinition &range) const
	return an empty area that's appropriate to the passive area determination carried out
Private Member Functions
void	_initialise_and_run_PA (const JetDefinition &jet_def, const GhostedAreaSpec &area_spec, const bool &writeout_combinations=false)
	global routine for initialising and running a passive area that is correct in general, but that chooses an optimal approach for various special cases.

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Detailed Description

Class that behaves essentially like ClusterSequence except that it also provides access to the area of a jet (which will be a random quantity.

.. Figure out what to do about seeds later...)

Definition at line 48 of file ClusterSequencePassiveArea.hh.

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Constructor & Destructor Documentation

template<class L>

fastjet::ClusterSequencePassiveArea::ClusterSequencePassiveArea	(	const std::vector< L > &	pseudojets,
		const JetDefinition &	jet_def,
		const GhostedAreaSpec &	area_spec,
		const bool &	writeout_combinations = false
	)			[inline]

constructor based on JetDefinition and PassiveAreaSpec

Definition at line 76 of file ClusterSequencePassiveArea.hh.

                                     {

  // transfer the initial jets (type L) into our own array
  _transfer_input_jets(pseudojets);

  // run the clustering for passive areas
  _initialise_and_run_PA(jet_def, area_spec, writeout_combinations);

}

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Member Function Documentation

double fastjet::ClusterSequencePassiveArea::empty_area

(

const RangeDefinition &

range

)

const [virtual]

return an empty area that's appropriate to the passive area determination carried out

Reimplemented from fastjet::ClusterSequenceActiveArea.

Definition at line 97 of file ClusterSequencePassiveArea.cc.

References fastjet::ClusterSequenceActiveArea::empty_area(), fastjet::ClusterSequenceAreaBase::empty_area(), fastjet::ClusterSequence::jet_def(), and fastjet::kt_algorithm.

                                                                                  {
  if (jet_def().jet_algorithm() == kt_algorithm) {
    // run the naive algorithm
    return ClusterSequenceAreaBase::empty_area(range);
  } else {
    return ClusterSequence1GhostPassiveArea::empty_area(range);
  }
}

void fastjet::ClusterSequencePassiveArea::_initialise_and_run_PA	(	const JetDefinition &	jet_def,
		const GhostedAreaSpec &	area_spec,
		const bool &	writeout_combinations = false
	)			[private]

global routine for initialising and running a passive area that is correct in general, but that chooses an optimal approach for various special cases.

Definition at line 43 of file ClusterSequencePassiveArea.cc.

References fastjet::ClusterSequenceActiveArea::_average_area, fastjet::ClusterSequenceActiveArea::_average_area_4vector, fastjet::ClusterSequence::_history, fastjet::ClusterSequence1GhostPassiveArea::_initialise_and_run_1GPA(), fastjet::ClusterSequenceActiveArea::_initialise_and_run_AA(), fastjet::ClusterSequence::_jet_def, fastjet::ClusterSequence::_jets, fastjet::ClusterSequenceActiveArea::_resize_and_zero_AA(), fastjet::antikt_algorithm, fastjet::cambridge_algorithm, fastjet::cambridge_for_passive_algorithm, fastjet::ClusterSequence::Invalid, fastjet::JetDefinition::jet_algorithm(), fastjet::ClusterSequence::jet_def(), fastjet::kt_algorithm, fastjet::GhostedAreaSpec::mean_ghost_kt(), fastjet::JetDefinition::plugin(), fastjet::plugin_algorithm, fastjet::JetDefinition::set_jet_finder(), and fastjet::ClusterSequence::transfer_from_sequence().

                                                    {

  if (jet_def.jet_algorithm() == kt_algorithm) {
    // first run the passive area
    ClusterSequenceVoronoiArea csva(_jets,jet_def,VoronoiAreaSpec(1.0));
    // now set up and transfer relevant information    
    // first the clustering sequence
    transfer_from_sequence(csva);
    // then the areas
    _resize_and_zero_AA();
    for (unsigned i = 0; i < _history.size(); i++) {
      int ijetp = _history[i].jetp_index;
      if (ijetp != Invalid) {
        _average_area[i] = csva.area(_jets[ijetp]);
        _average_area_4vector[i] = csva.area_4vector(_jets[ijetp]);
      }
    }

  } else if (jet_def.jet_algorithm() == cambridge_algorithm) {
    // run a variant of the cambridge algorithm that has been hacked
    // to deal with passive areas
    JetDefinition tmp_jet_def = jet_def;
    tmp_jet_def.set_jet_finder(cambridge_for_passive_algorithm);
    tmp_jet_def.set_extra_param(sqrt(area_spec.mean_ghost_kt()));
    _initialise_and_run_AA(tmp_jet_def, area_spec, writeout_combinations);
    _jet_def = jet_def;

  } else if (jet_def.jet_algorithm() == antikt_algorithm) {
    // for the antikt algorithm, passive and active are identical
    _initialise_and_run_AA(jet_def, area_spec, writeout_combinations);

  } else if (jet_def.jet_algorithm() == plugin_algorithm &&
             jet_def.plugin()->supports_ghosted_passive_areas()) {
    // for some plugin algorithms, one can "prime" the algorithm with information
    // about the ghost scale, and then an "AA" run will actually give a passive
    // area
    double ghost_sep_scale_store = jet_def.plugin()->ghost_separation_scale();
    jet_def.plugin()->set_ghost_separation_scale(sqrt(area_spec.mean_ghost_kt()));
    _initialise_and_run_AA(jet_def, area_spec, writeout_combinations);

    // restore the original ghost_sep_scale
    jet_def.plugin()->set_ghost_separation_scale(ghost_sep_scale_store);

  } else {
    // for a generic algorithm, just run the 1GhostPassiveArea
    _initialise_and_run_1GPA(jet_def, area_spec, writeout_combinations);
  }
}

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

• include/fastjet/ClusterSequencePassiveArea.hh
• src/ClusterSequencePassiveArea.cc

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