Jetscape

class Jetscape.Jetscape(JETSCAPE_FILE, **kwargs)[source]

Defines a Jetscape object.

The Jetscape class contains a single Jetscape hadron output file including all or only chosen events. It’s methods allow to directly act on all contained events as applying acceptance filters (e.g. un/charged particles) to keep/romove particles by their PDG codes or to apply cuts (e.g. multiplicity, pseudo/rapidity, pT). Once these filters are applied, the new data set can be saved 1) as a nested list containing all quantities of the Jetscape format 2) as a list containing Particle objects from the Particle or it can be printed to a file complying with the input format.

Note

If filters are applied, be aware that not all cuts commute.

Parameters:

JETSCAPE_FILEstr: Path to Jetscape file

Other Parameters:

**kwargsproperties, optional

kwargs are used to specify optional properties like a chunk reading and must be used like 'property'='value' where the possible properties are specified below.

Property	Description
`events` (int)	From the input Jetscape file load only a single event by specifying `events=i` where i is event number i.
`events` (tuple)	From the input Jetscape file load only a range of events given by the tuple `(first_event, last_event)` by specifying `events=(first_event, last_event)` where last_event is included.
`filters` (dict)	Apply filters on an event-by-event basis to directly filter the particles after the read in of one event. This method saves memory. The names of the filters are the same as the names of the filter methods. All filters are applied in the order in which they appear in the dictionary.
`particletype` (str)	This parameter allows to switch from the standard hadron file to the parton output of JETSCAPE. The parameter can be set to `particletype='hadron'` (default) or `particletype='parton'`. Quark charges are multiplied by 3 to make them integer values.

Notes

All filters with the keyword argument filters need the usual parameters for the filter functions in the dictionary. All filter functions without arguments need a True in the dictionary.

Examples

1. Initialization

To create a Jetscape object, the path to the Jetscape file has to be passed. By default the Jetscape object will contain all events of the input file. If the Jetscape object should only contain certain events, the keyword argument “events” must be used.

>>> from sparkx.Jetscape import Jetscape
>>>
>>> JETSCAPE_FILE_PATH = [Jetscape_directory]/particle_lists.dat
>>>
>>> # Jetscape object containing all events
>>> jetscape1 = Jetscape(JETSCAPE_FILE_PATH)
>>>
>>> # Jetscape object containing only the first event
>>> jetscape2 = Jetscape(JETSCAPE_FILE_PATH, events=0)
>>>
>>> # Jetscape object containing only events 2, 3, 4 and 5
>>> jetscape3 = Jetscape(JETSCAPE_FILE_PATH, events=(2,5))

2. Method Usage

All methods that apply filters to the Jetscape data return self. This means that methods can be concatenated. To access the Jetscape data as list to store it into a variable, the method particle_list() or particle_objects_list must be called in the end. Let’s assume we only want to keep participant pions in events with a multiplicity > 500:

>>> jetscape = Jetscape(JETSCAPE_FILE_PATH)
>>>
>>> pions = jetscape.multiplicity_cut(500).participants().particle_species((211, -211, 111))
>>>
>>> # save the pions of all events as nested list
>>> pions_list = pions.particle_list()
>>>
>>> # save the pions as list of Particle objects
>>> pions_particle_objects = pions.particle_objects_list()
>>>
>>> # print the pions to an Jetscape file
>>> pions.print_particle_lists_to_file('./particle_lists.dat')

3. Constructor cuts

Cuts can be performed directly in the constructor by passing a dictionary. This has the advantage that memory is saved because the cuts are applied after reading each single event. This is achieved by the keyword argument filters, which contains the filter dictionary. Filters are applied in the order in which they appear. Let’s assume we only want to keep pions in events with a multiplicity > 500:

>>> jetscape = Jetscape(JETSCAPE_FILE_PATH, filters={'multiplicity_cut':500, 'particle_species':(211, -211, 111)}})
>>>
>>> # print the pions to a jetscape file
>>> jetscape.print_particle_lists_to_file('./particle_lists.dat')

Attributes:

PATH_JETSCAPE_str: Path to the Jetscape file
num_output_per_event_numpy.array: Array containing the event number and the number of particles in this event as num_output_per_event_[event i][num_output in event i] (updated when filters are applied)
num_events_int: Number of events contained in the Jetscape object (updated when filters are applied)

Methods

particle_list:	Returns current Jetscape data as nested list
particle_objects_list:	Returns current Jetscape data as nested list of Particle objects
num_events:	Get number of events
num_output_per_event:	Get number of particles in each event
get_sigmaGen:	Retrieves the sigmaGen values with error
particle_species:	Keep only particles with given PDG ids
remove_particle_species:	Remove particles with given PDG ids
charged_particles:	Keep charged particles only
uncharged_particles:	Keep uncharged particles only
strange_particles:	Keep strange particles only
particle_status:	Keep only particles with a given status flag
pt_cut:	Apply pT cut to all particles
rapidity_cut:	Apply rapidity cut to all particles
pseudorapidity_cut:	Apply pseudorapidity cut to all particles
multiplicity_cut:	Apply multiplicity cut to all particles
lower_event_energy_cut:	Filters out events with total energy lower than a threshold.
print_particle_lists_to_file:	Print current particle data to file with same format

Jetscape.particle_list()[source]

Returns a nested python list containing all quantities from the current Jetscape data as numerical values with the following shape:

Single Event: [event][output_line][particle_quantity]

Multiple Events: [event][output_line][particle_quantity]

Returns:

list: Nested list containing the current Jetscape data

Jetscape.particle_objects_list()[source]

Returns a nested python list containing all quantities from the current Jetscape data as numerical values with the following shape:

Single Event: [output_line][particle_quantity]

Multiple Events: [event][output_line][particle_quantity]

Returns:

list: Nested list containing the current Jetscape data

Jetscape.num_events()[source]

Returns the number of events in particle_list

num_events is updated with every manipulation e.g. after applying cuts.

Returns:

num_events_int: Number of events in particle_list

Jetscape.num_output_per_event()[source]

Returns a numpy array containing the event number (starting with 1) and the corresponding number of particles created in this event as

num_output_per_event[event_n, number_of_particles_in_event_n]

num_output_per_event is updated with every manipulation e.g. after applying cuts.

Returns:

num_output_per_event_numpy.ndarray: Array containing the event number and the corresponding number of particles

Jetscape.get_sigmaGen()[source]

Retrieves the sigmaGen values with error from the last line of a file.

Returns:

tuple: A tuple containing the first and second sigmaGen values as floats.

Jetscape.particle_species(pdg_list)[source]

Keep only particle species given by their PDG ID in every event

Parameters:

pdg_listint: To keep a single particle species only, pass a single PDG ID
pdg_listtuple/list/array: To keep multiple particle species, pass a tuple or list or array of PDG IDs

Returns:

selfJetscape object: Containing only particle species specified by pdg_list for every event

Jetscape.remove_particle_species(pdg_list)[source]

Remove particle species from particle_list by their PDG ID in every event

Parameters:

pdg_listint: To remove a single particle species only, pass a single PDG ID
pdg_listtuple/list/array: To remove multiple particle species, pass a tuple or list or array of PDG IDs

Returns:

selfJetscape object: Containing all but the specified particle species in every event

Jetscape.lower_event_energy_cut(minimum_event_energy)[source]

Filters out events with total energy lower than a threshold.

Parameters:

minimum_event_energyint or float: The minimum event energy threshold. Should be a positive integer or float.

Returns:

self: Jetscape object: The updated instance of the class contains only events above the energy threshold.

Raises:

TypeError: If the minimum_event_energy parameter is not an integer or float.
ValueError: If the minimum_event_energy parameter is less than or equal to 0.

Jetscape.charged_particles()[source]

Keep only charged particles in particle_list

Returns:

selfJetscape object: Containing charged particles in every event only

Jetscape.uncharged_particles()[source]

Keep only uncharged particles in particle_list

Returns:

selfJetscape object: Containing uncharged particles in every event only

Jetscape.strange_particles()[source]

Keep only strange particles in particle_list

Returns:

selfJetscape object: Containing strange particles in every event only

Jetscape.pt_cut(cut_value_tuple)[source]

Apply transverse momentum cut to all events by passing an acceptance range by ::code`cut_value_tuple`. All particles outside this range will be removed.

Parameters:

cut_value_tupletuple: Tuple with the upper and lower limits of the pT acceptance range (cut_min, cut_max). If one of the limits is not required, set it to None, i.e. (None, cut_max) or (cut_min, None).

Returns:

selfJetscape object: Containing only particles complying with the transverse momentum cut for all events

Jetscape.rapidity_cut(cut_value)[source]

Apply rapidity cut to all events and remove all particles with rapidity not complying with cut_value

Parameters:

cut_valuefloat: If a single value is passed, the cut is applied symmetrically around 0. For example, if cut_value = 1, only particles with rapidity in [-1.0, 1.0] are kept.
cut_valuetuple: To specify an asymmetric acceptance range for the rapidity of particles, pass a tuple (cut_min, cut_max)

Returns:

selfJetscape object: Containing only particles complying with the rapidity cut for all events

Jetscape.pseudorapidity_cut(cut_value)[source]

Apply pseudo-rapidity cut to all events and remove all particles with pseudo-rapidity not complying with cut_value

Parameters:

cut_valuefloat: If a single value is passed, the cut is applied symmetrically around 0. For example, if cut_value = 1, only particles with pseudo-rapidity in [-1.0, 1.0] are kept.
cut_valuetuple: To specify an asymmetric acceptance range for the pseudo-rapidity of particles, pass a tuple (cut_min, cut_max)

Returns:

selfJetscape object: Containing only particles complying with the pseudo-rapidity cut for all events

Jetscape.multiplicity_cut(min_multiplicity)[source]

Apply multiplicity cut. Remove all events with a multiplicity lower than min_multiplicity

Parameters:

min_multiplicityint: Lower bound for multiplicity. If the multiplicity of an event is lower than min_multiplicity, this event is discarded.

Returns:

selfJetscape object: Containing only events with a multiplicity >= min_multiplicity

Jetscape.particle_status(status_list)[source]

Keep only particles with a given particle status

Parameters:

status_listint: To keep a particles with a single status only, pass a single status
status_listtuple/list/array: To keep hadrons with different hadron status, pass a tuple or list or array

Returns:

selfJetscape object: Containing only hadrons with status specified by status_list for every event

Jetscape.print_particle_lists_to_file(output_file)[source]

Prints the current Jetscape data to an output file specified by output_file with the same format as the input file

Parameters:

output_filestr: Path to the output file like [output_directory]/particle_lists.dat