fastjet.ClusterSequence

class fastjet.ClusterSequence(data, jetdef)

The base class for all clustering.

Parameters:

data (awkward.highlevel.Array) – The data for clustering.
jetdef (fastjet._swig.JetDefinition) – The JetDefinition for clustering specification.

Q() → Array | float

Returns the sum of all energies in the event (relevant mainly for e+e-)

Parameters:: None –
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

Q2() → Array | float

Return Q()^2

Parameters:: None –
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

childless_pseudojets() → Array

Return the list of pseudojets in the ClusterSequence that do not have children (and are not among the inclusive jets).

Parameters:: None –
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

constituent_index(min_pt: float = 0) → Array

Returns the index of the constituent of each Jet.

Parameters:: min_pt (float) – The minimum value of the pt for the inclusive jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

constituents(min_p: float = 0) → Array

Returns the particles that make up each Jet.

Parameters:: min_pt (float) – The minimum value of the pt for the inclusive jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_dmerge(njets: int = 10) → Array | float

Returns the dmin corresponding to the recombination that went from n+1 to n jets.

Parameters:: n_jets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_dmerge_max(njets: int = 10) → Array | float

Returns the maximum of the dmin encountered during all recombinations up to the one that led to an n-jet final state.

Parameters:: n_jets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_jets(n_jets: int = -1, dcut: float = -1) → Array

Returns the exclusive jets after clustering in the same format as the input awkward array. Either takes njets or dcut as argument.

Parameters:

n_jets (int) – The number of jets it was clustered to.
dcut (float) – The dcut for the result.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

exclusive_jets_constituents(njets: int = 10) → Array

Returns the particles that make up each exclusive jet.

Parameters:: njets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_jets_constituents_index(njets: int = 10) → Array

Returns the index of the constituent of each exclusive jet.

Parameters:: njets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_jets_energy_correlator(njets: int = 1, beta: int = 1, npoint: int = 0, angles: int = -1, alpha=0, func='generalized', normalized=True) → Array

Returns the energy correlator of each exclusive jet.

Parameters:

njets (int) – The number of jets it was clustered to.
n_point (int) – The number of points in the correlator.
angle – The number of angles to be used in the correlator (if angle != n_point, ECFG is used).
beta – The beta value for the correlator.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

exclusive_jets_lund_declusterings(njets: int = 10) → Array

Returns the Lund declustering Delta and k_T parameters from exclusive n_jets.

Parameters:: njets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_jets_softdrop_grooming(njets: int = 1, beta: int = 0, symmetry_cut: float = 0.1, symmetry_measure='scalar_z', R0: float = 0.8, recursion_choice='larger_pt', mu_cut: float = inf) → Array

Performs softdrop pruning on jets. :param n_jets: number of exclusive subjets. :param beta: softdrop beta parameter. :param symmetry_cut: softdrop symmetry cut value. :param symmetry_measure: Which symmetry measure to use, found in RecursiveSymmetryCutBase.hh :param R0: softdrop R0 parameter. :param recursion_choice: Which recursion choice to use, found in RecursiveSymmetryCutBase.hh :param subtractor: an optional pointer to a pileup subtractor (ignored if zero)

Returns:: Returns an array of values from the jet after it has been groomed by softdrop.

exclusive_jets_ycut(ycut: float = -1) → Array

Returns the exclusive jets after clustering in the same format as the input awkward array.

Parameters:: ycut (float) – The dcut for the result.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_subdmerge(data: Array, nsub: int = 0) → Array | float

Returns the dij that was present in the merging nsub+1 -> nsub subjets inside this jet.

Parameters:

data (awkward.highlevel.Array) – An Awkward Array containing the Jets.
n_sub (int) – The number of subjets.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

exclusive_subdmerge_max(data: Array, nsub: int = 0) → Array | float

Returns the maximum dij that occurred in the whole event at the stage that the nsub+1 -> nsub merge of subjets occurred inside this jet.

Parameters:

data (awkward.highlevel.Array) – An Awkward Array containing the Jets.
n_sub (int) – The number of subjets.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

exclusive_subjets(data: Array, dcut: float = -1, nsub: int = -1) → Array

Returns an Awkward Array of all subjets of the current jet (in the sense of the exclusive algorithm) that would be obtained when running the algorithm with the given dcut.

Parameters:

data (awkward.highlevel.Array) – An Array containing the Jets.
dcut (float) – The dcut for the result.
n_sub (int) – The number of subjets.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

exclusive_subjets_up_to(data: Array, nsub: int = 0) → Array

Returns the list of subjets obtained by unclustering the supplied jet down to nsub subjets (or all constituents if there are fewer than nsub).

Parameters:

data (awkward.highlevel.Array) – An Awkward Array containing the Jets.
n_sub (int) – The number of subjets.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

exclusive_ymerge(njets: int = 10) → Array | float

Returns the ymin corresponding to the recombination that went from n+1 to n jets.

Parameters:: n_jets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

exclusive_ymerge_max(njets: int = 10) → Array | float

Same as exclusive_dmerge_max, but normalised to squared total energy.

Parameters:: n_jets (int) – The number of jets it was clustered to.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

get_child(data: Array) → Array

If the jet has parents in the clustering, it returns them.

Parameters:: data (awkward.highlevel.Array) – An Array containing the Jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

get_parents(data: Array) → Array

If the jet has parents in the clustering, it returns them.

Parameters:: data (awkward.highlevel.Array) – An Array containing the Jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

has_child(data: Array) → Array | bool

If the jet has children in the clustering, it returns true.

Parameters:: data (awkward.highlevel.Array) – An Array containing the Jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

has_parents(data: Array) → Array | bool

if the jet has parents in the clustering, it returns true.

Parameters:: data (awkward.highlevel.Array) – An Array containing the Jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

inclusive_jets(min_pt: float = 0) → Array

Returns the inclusive jets after clustering in the same format as the input awkward array

Parameters:: min_pt (float) – The minimum value of the pt for the inclusive jets.
Returns:: Returns an Awkward Array of the same type as the input containting inclusive jets.
Return type:: awkward.highlevel.Array

jet_def() → JetDefinition

Returns the Jet Definition Object associated with the instance

Parameters:: None –
Returns:: Returns the jetdefinition stored as an attribute.
Return type:: JetDefinition

jet_scale_for_algorithm(data: Array) → Array | float

Returns the scale associated with a jet as required for this clustering algorithm (kt^2 for the kt-algorithm, 1 for the Cambridge algorithm).

Parameters:: data (awkward.highlevel.Array) – An Array containing the Jets.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

jets() → Array

Allows the user to access the internally stored _jets() array, which contains both the initial particles and the various intermediate and final stages of recombination.

Parameters:: none –
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

n_exclusive_jets(dcut: float = 0) → Array | int

Returns the number of jets (in the sense of the exclusive algorithm) that would be obtained when running the algorithm with the given dcut.

Parameters:: dcut (float) – The dcut for the result.
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

n_exclusive_subjets(data: Array, dcut: float = 0) → Array | int

Returns the size of exclusive_subjets(…); still n ln n with same coefficient, but marginally more efficient than manually taking len(exclusive_subjets)

Parameters:

data (awkward.highlevel.Array) – An Array containing the Jets.
dcut (float) – The dcut for the result.

Returns:

Returns an Awkward Array of the same type as the input.

Return type:

awkward.highlevel.Array

n_particles() → Array | int

Returns the number of particles that were provided to the clustering algorithm.

Parameters:: None –
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array

unclustered_particles() → Array

Returns the unclustered particles after clustering in the same format as the input awkward array

Parameters:: None –
Returns:: Returns an Awkward Array of the same type as the input contating the unclustered particles.
Return type:: awkward.highlevel.Array

unique_history_order() → Array

Routine that returns an order in which to read the history such that clusterings that lead to identical jet compositions but different histories (because of degeneracies in the clustering order) will have matching constituents for each matching entry in the unique_history_order.

Parameters:: None –
Returns:: Returns an Awkward Array of the same type as the input.
Return type:: awkward.highlevel.Array