Class that helps perform filtering (Butterworth, Davison, Rubin and Salam, arXiv:0802.2470) and trimming (Krohn, Thaler and Wang, arXiv:0912.1342) on jets, optionally in conjunction with subtraction (Cacciari and Salam, arXiv:0707.1378).
More...
|
| | Filter () |
| | trivial ctor Note: this is just for derived classes a Filter initialised through this constructor will not work! More...
|
| |
| | Filter (JetDefinition subjet_def, Selector selector, double rho=0.0) |
| | define a filter that decomposes a jet into subjets using a generic JetDefinition and then keeps only a subset of these subjets according to a Selector. More...
|
| |
| | Filter (double Rfilt, Selector selector, double rho=0.0) |
| | Same as the full constructor (see above) but just specifying the radius By default, Cambridge-Aachen is used If the jet (or all its pieces) is obtained with a non-default recombiner, that one will be used. More...
|
| |
| | Filter (FunctionOfPseudoJet< double > *Rfilt_func, Selector selector, double rho=0.0) |
| | Same as the full constructor (see above) but just specifying a filtering radius that will depend on the jet being filtered As for the previous case, Cambridge-Aachen is used If the jet (or all its pieces) is obtained with a non-default recombiner, that one will be used. More...
|
| |
| virtual | ~Filter () |
| | default dtor More...
|
| |
| void | set_subtractor (const FunctionOfPseudoJet< PseudoJet > *subtractor_in) |
| | Set a subtractor that is applied to all individual subjets before deciding which ones to keep. More...
|
| |
| const FunctionOfPseudoJet< PseudoJet > * | subtractor () const |
| | Set a subtractor that is applied to all individual subjets before deciding which ones to keep. More...
|
| |
| virtual PseudoJet | result (const PseudoJet &jet) const |
| | runs the filtering and sets kept and rejected to be the jets of interest (with non-zero rho, they will have been subtracted). More...
|
| |
| virtual std::string | description () const |
| | class description More...
|
| |
| | Transformer () |
| | default ctor More...
|
| |
| virtual | ~Transformer () |
| | default dtor More...
|
| |
| virtual PseudoJet | result (const PseudoJet &original) const =0 |
| | the result of the Transformer acting on the PseudoJet. More...
|
| |
| virtual std::string | description () const =0 |
| | This should be overloaded to return a description of the Transformer. More...
|
| |
| | FunctionOfPseudoJet () |
| | default ctor More...
|
| |
| virtual | ~FunctionOfPseudoJet () |
| | default dtor (virtual to allow safe polymorphism) More...
|
| |
| virtual std::string | description () const |
| | returns a description of the function (an empty string by default) More...
|
| |
| virtual PseudoJet | result (const PseudoJet &pj) const=0 |
| | the action of the function this has to be overloaded in derived classes More...
|
| |
| PseudoJet | operator() (const PseudoJet &pj) const |
| | apply the function using the "traditional" () operator. More...
|
| |
| std::vector< PseudoJet > | operator() (const std::vector< PseudoJet > &pjs) const |
| | apply the function on a vector of PseudoJet, returning a vector of the results. More...
|
| |
Class that helps perform filtering (Butterworth, Davison, Rubin and Salam, arXiv:0802.2470) and trimming (Krohn, Thaler and Wang, arXiv:0912.1342) on jets, optionally in conjunction with subtraction (Cacciari and Salam, arXiv:0707.1378).
For example, to apply filtering that reclusters a jet's constituents with the Cambridge/Aachen jet algorithm with R=0.3 and then selects the 3 hardest subjets, one can use the following code:
PseudoJet filtered_jet = filter(original_jet);
Class that helps perform filtering (Butterworth, Davison, Rubin and Salam, arXiv:0802....
class that is intended to hold a full definition of the jet clusterer
Class to contain pseudojets, including minimal information of use to jet-clustering routines.
Selector SelectorNHardest(unsigned int n)
select the n hardest objects
@ cambridge_algorithm
the longitudinally invariant variant of the cambridge algorithm (aka Aachen algoithm).
To obtain trimming, involving for example the selection of all subjets carrying at least 3% of the original jet's pt, the selector would be replaced by SelectorPtFractionMin(0.03).
To additionally perform subtraction on the subjets prior to selection, either include a 3rd argument specifying the background density rho, or call the set_subtractor(...) member function. If subtraction is requested, the original jet must be the result of a clustering with active area with explicit ghosts support or a merging of such pieces.
The information on the subjets that were kept and rejected can be obtained using:
vector<PseudoJet> kept_subjets = filtered_jet.
pieces();
const TransformerType::StructureType & structure_of() const
this is a helper to access any structure created by a Transformer (that is, of type Transformer::Stru...
virtual std::vector< PseudoJet > pieces() const
retrieve the pieces that make up the jet.
Implementation Note
If the original jet was defined with the Cambridge/Aachen algorithm (or is made of pieces each of which comes from the C/A alg) and the filtering definition is C/A, then the filter does not rerun the C/A algorithm on the constituents, but instead makes use of the existent C/A cluster sequence in the original jet. This increases the speed of the filter.
See also 11 - use of filtering for a further usage example.
Support for areas, reuse of C/A cluster sequences, etc., considerably complicates the implementation of Filter. For an explanation of how a simpler filter might be coded, see the "User-defined transformers" appendix of the manual.
Definition at line 97 of file Filter.hh.
Public Types inherited from fastjet::Transformer