Reference¶

pyhepmc¶

pyhepmc is a pythonic and Jupyter-friendly Python API for HepMC3.

Differences between HepMC3 C++ and pyhepmc¶

The pyhepmc API uses properties where the C++ API uses setters/getters (where possible).
Sequences with matching types and lengths are implicitly convertible to FourVector und ToolInfo.
In addition to the C++ Reader/Writer classes, we offer an easy to use open(). It can read and write any supported HepMC3 format, including compressed files (gzip, bzip2, lzma are supported).
Attributes for GenRunInfo, GenEvent, GenParticle, GenVertex can be accessed via a dict-like view returned by the attributes property. The view automatically converts between native C++ types to native Python types.
The Print class is missing, but listing() and content() are present as free functions.
The member functions delta_X of FourVector are free functions with two arguments.
HEPEVT_Wrapper and friends are missing, use GenEvent.from_hepevt() instead.
ReaderGZ and WriterGZ are missing, since open() offers this functionality.
API marked as deprecated in HepMC3 is not available in Python.
pyhepmc offers event visualization and renders in Jupyter notebooks if all required extra packages are installed, see pyhepmc.view.to_dot().

Missing functionality¶

ReaderMT will not be implemented. If you want to use multi-threaded IO, it is better to use the high-level threading API of Python to achieve this. You can read the next GenEvent in a child thread from a file while you are processing the current event in the main thread.

class pyhepmc.FourVector¶

Generic 4-vector.

Interpretation of its content depends on accessors used: it’s much simpler to do this than to distinguish between space and momentum vectors via the type system (especially given the need for backward compatibility with HepMC2). Be sensible and don’t call energy functions on spatial vectors! To avoid duplication, most definitions are only implemented on the spatial function names, with the energy-momentum functions as aliases.

This is not intended to be a fully featured 4-vector, but does contain the majority of common non-boosting functionality, as well as a few support operations on 4-vectors.

The implementations in this class are fully inlined.

abs_eta(self: pyhepmc._core.FourVector) → float¶: Absolute pseudorapidity.

abs_rap(self: pyhepmc._core.FourVector) → float¶: Absolute rapidity.

eta(self: pyhepmc._core.FourVector) → float¶: Pseudorapidity.

interval(self: pyhepmc._core.FourVector) → float¶: Spacetime invariant interval s^2 = t^2 - x^2 - y^2 - z^2.

is_zero(self: pyhepmc._core.FourVector) → bool¶: Check if the length of this vertex is zero.

length(self: pyhepmc._core.FourVector) → float¶: Magnitude of spatial (x, y, z) 3-vector.

length2(self: pyhepmc._core.FourVector) → float¶: Squared magnitude of (x, y, z) 3-vector.

m(self: pyhepmc._core.FourVector) → float¶: Invariant mass. Returns -sqrt(-m) if e^2 - P^2 is negative.

m2(self: pyhepmc._core.FourVector) → float¶: Squared invariant mass m^2 = E^2 - px^2 - py^2 - pz^2.

p3mod(self: pyhepmc._core.FourVector) → float¶: Magnitude of p3 = (px, py, pz) vector.

p3mod2(self: pyhepmc._core.FourVector) → float¶: Squared magnitude of p3 = (px, py, pz) vector.

perp(self: pyhepmc._core.FourVector) → float¶: Magnitude of (x, y) vector.

perp2(self: pyhepmc._core.FourVector) → float¶: Squared magnitude of (x, y) vector.

phi(self: pyhepmc._core.FourVector) → float¶: Azimuthal angle.

pt(self: pyhepmc._core.FourVector) → float¶: Transverse momentum.

pt2(self: pyhepmc._core.FourVector) → float¶: Squared transverse momentum px^2 + py^2.

rap(self: pyhepmc._core.FourVector) → float¶: Rapidity.

rho(self: pyhepmc._core.FourVector) → float¶: Magnitude of spatial (x, y, z) 3-vector, for HepMC2 compatibility.

theta(self: pyhepmc._core.FourVector) → float¶: Polar angle w.r.t. z direction.

property e¶: Energy component of momentum.

property px¶: x-component of momentum.

property py¶: y-component of momentum.

property pz¶: z-component of momentum.

property t¶: Time component of position/displacement.

property x¶: x-component of position/displacement.

property y¶: y-component of position/displacement.

property z¶: z-component of position/displacement.

class pyhepmc.GenCrossSection¶

Stores additional information about cross-section.

This is an example of event attribute used to store cross-section information.

This class is meant to be used to pass, on an event by event basis, the current best guess of the total cross section. it is expected that the final cross section will be stored elsewhere.

Several cross sections and related info can be included in case of runs with multiple weights.

The units of cross-sections are expected to be pb.

set_cross_section(self: pyhepmc._core.GenCrossSection, cross_section: float, cross_section_error: float, accepted_events: int = -1, attempted_events: int = -1) → None¶: Set all fields.

set_xsec(self: pyhepmc._core.GenCrossSection, index_or_name: object, value: float) → None¶

set_xsec_err(self: pyhepmc._core.GenCrossSection, index_or_name: object, value: float) → None¶

xsec(self: pyhepmc._core.GenCrossSection, index_or_name: object = 0) → float¶

Access the cross section corresponding to the weight named wName.

Access the cross section corresponding to the weight with index indx.

Access the cross section corresponding to the weight named wName.

Access the cross section corresponding to the weight with index indx.

xsec_err(self: pyhepmc._core.GenCrossSection, index_or_name: object = 0) → float¶

Access the cross section error corresponding to the weight named wName.

Access the cross section error corresponding to the weight with index indx.

Access the cross section error corresponding to the weight named wName.

Access the cross section error corresponding to the weight with index indx.

property accepted_events¶: Access the number of accepted events.

property attempted_events¶: Access the number of attempted events.

property is_valid¶: Verify that the instance contains non-zero information.

class pyhepmc.GenEvent¶

Stores event-related information.

Manages event-related information. Contains lists of GenParticle and GenVertex objects.

add_particle(self: pyhepmc._core.GenEvent, arg0: HepMC3::GenParticle) → None¶: Add particle.

add_vertex(self: pyhepmc._core.GenEvent, arg0: HepMC3::GenVertex) → None¶: Add vertex.

clear(self: pyhepmc._core.GenEvent) → None¶: Remove contents of this event.

event_pos(self: pyhepmc._core.GenEvent) → pyhepmc._core.FourVector¶: Vertex representing the overall event position.

from_hepevt(self: pyhepmc._core.GenEvent, event_number: int, px: numpy.ndarray[numpy.float64], py: numpy.ndarray[numpy.float64], pz: numpy.ndarray[numpy.float64], en: numpy.ndarray[numpy.float64], m: numpy.ndarray[numpy.float64], pid: numpy.ndarray[numpy.int32], status: numpy.ndarray[numpy.int32], parents: object = None, children: object = None, vx: object = None, vy: object = None, vz: object = None, vt: object = None, fortran: bool = True) → None¶

Convert HEPEVT record to GenEvent.

GenEvent is cleared and then filled with the information provided in the argument arrays. Recovering the particle history only requires either parents or children. If both are not None, parents are used.

All particle arrays must have equal length.

Parameters:

event_number (int) – Event number, starting with zero.
px (array-like) – X-component of momentum of particles in GeV.
py (array-like) – Y-component of momentum of particles in GeV.
pz (array-like) – Z-component of momentum of particles in GeV.
en (array-like) – Energy of particles in GeV.
m (array-like) – Generated mass of particles in GeV.
pid (array-like) – PDG IDs of particles.
status (array-like) – Status codes of particles.
parents (array-like or None, optional) – Array of int with shape (N, 2). Start and stop index (inclusive) in the record for the parents of each particle. Indices must be zero-based (C) or one-based (Fortran). In the latter case, keyword subtract_one must be set to true. No parents for a particle are indicated by the pair (-1, -1). Single parents are indicated either by (N, -1) or (N, N) with N > 0.
children (array-like or None, optional) – Like parents but for the children of this particle.
vx (array-like or None, optional) – X-component of location of production vertex of particles in mm.
vy (array-like or None, optional) – Y-component of location of production vertex of particles in mm.
vz (array-like or None, optional) – Z-component of location of production vertex of particles in mm.
vt (array-like or None, optional) – Time (ct) of production vertex of particles in mm.
fortran (bool, optional) – If True (default), the source indices are 1-based (Fortran, Pythia8). Set this to False, if the indices are 0-based (C-style).

read_data(self: pyhepmc._core.GenEvent, data: pyhepmc._core.GenEventData) → None¶: Fill GenEvent based on GenEventData.

remove_particle(self: pyhepmc._core.GenEvent, arg0: HepMC3::GenParticle) → None¶

Remove particle from the event.

This function will remove whole sub-tree starting from this particle if it is the only incoming particle of this vertex. It will also production vertex of this particle if this vertex has no more outgoing particles.

remove_vertex(self: pyhepmc._core.GenEvent, arg0: HepMC3::GenVertex) → None¶

Remove vertex from the event.

This will remove all sub-trees of all outgoing particles of this vertex.

reserve(self: pyhepmc._core.GenEvent, particles: int, vertices: int = 0) → None¶

Reserve memory for particles and vertices.

Helps optimize event creation when size of the event is known beforehand.

set_beam_particles(self: pyhepmc._core.GenEvent, arg0: HepMC3::GenParticle, arg1: HepMC3::GenParticle) → None¶

set_units(self: pyhepmc._core.GenEvent, arg0: pyhepmc._core.Units.MomentumUnit, arg1: pyhepmc._core.Units.LengthUnit) → None¶: Change event units Converts event from current units to new ones.

set_weight(self: pyhepmc._core.GenEvent, name: str, value: float) → None¶: Set event weight accessed by index (or the canonical/first one if there is no argument) or name.

Access by weight name requires a GenRunInfo attached to the event, otherwise this will throw an exception.

It’s the user’s responsibility to ensure that the index or name exists!

weight(self: pyhepmc._core.GenEvent, index_or_name: object = 0) → float¶: Get event weight accessed by index (or the canonical/first one if there is no argument) or name.

Access by weight name requires a GenRunInfo attached to the event, otherwise this will throw an exception.

It’s the user’s responsibility to ensure that the index or name exists!

write_data(self: pyhepmc._core.GenEvent, data: pyhepmc._core.GenEventData) → None¶: Fill GenEventData object.

property attributes¶

Access attributes with a dict-like view.

It is possible to read and write attributes. Primitive C++ types (and vectors therefore) are converted from/to native Python types.

property beams¶

Access beam particles as a sequence.

HepMC3 considers every particle as a beam particles, which does not have another ancestor particle. Therefore, this is a read-only property.

property cross_section¶

Access to the GenCrossSection.

If this attribute is not set, returns None.

property event_number¶: Access event number.

property heavy_ion¶

Access to the GenHeavyIon.

If this attribute is not set, returns None.

property length_unit¶: Get length unit.

property momentum_unit¶: Get momentum unit.

property numpy¶

property particles¶: Access list of particles.

property pdf_info¶

Access to the GenPdfInfo.

If this attribute is not set, returns None.

property run_info¶

Access to the GenRunInfo.

If this attribute is not set, returns None.

property vertices¶: Access list of vertices.

property weight_names¶

Get event weight names.

Access requires a GenRunInfo attached to the event, otherwise this will throw an exception.

property weights¶

Access event weight values as a sequence.

Can be used to set multiple weights by assigning a sequence.

class pyhepmc.GenEventData¶

Stores serializable event information.

property attribute_id¶: Attribute owner id.

property attribute_name¶: Attribute name.

property attribute_string¶: Attribute serialized as string.

property event_number¶: Event number.

property event_pos¶: Event position.

property length_unit¶: Length unit.

property links1¶

First id of the vertex links.

If this id is positive - it is the incoming particle id of a vertex which id is written in GenEventData::links2.

If this id is negative - it’s the id of a vertex which outgoing particle id is written in GenEventData::links2.

The links1[i] points to links2[i]. In case links1[i] is particle, links2[i] is end vertex. In case links2[i] is vertex, links2[i] is outgoing particle. An example of usage is given in documentation.

property links2¶: Second id of the vertex links.

property momentum_unit¶: Momentum unit.

property particles¶: Particles.

property vertices¶: Vertices.

property weights¶: Weights.

class pyhepmc.GenHeavyIon¶

Stores additional information about Heavy Ion generator.

This is an example of event attribute used to store Heavy Ion information.

property N_Nwounded_collisions¶

Collisions with a diffractively excited target nucleon.

The number of single diffractive nucleon-nucleon collisions where the target nucleon is excited. A negative value means that the information is not available.

property Ncoll¶

the number of inelastic nucleon-nucleon collisions.

Note that a one participating nucleon can be involved in many inelastic collisions, and that inelastic also includes diffractive excitation. A negative value means that the information is not available.

property Ncoll_hard¶

the number of hard nucleon-nucleon collisions.

Model-dependent. Usually the number of nucleon-nucleon collisions containing a special signal process. A negative value means that the information is not available.

property Npart_proj¶

the number of participating nucleons in the projectile.

The number of nucleons in the projectile participating in an inelastic collision (see Ncoll). A negative value means that the information is not available.

property Npart_targ¶

the number of participating nucleons in the target.

The number of nucleons in the target participating in an inelastic collision (see Ncoll). A negative value means that the information is not available.

property Nspec_proj_n¶

The number of spectator neutrons in the projectile.

ie. those that thave not participated in any inelastic nucleon-nucleon collision. A negative value indicatess that the information is not available.

property Nspec_proj_p¶

The number of spectator protons in the projectile.

ie. those that thave not participated in any inelastic nucleon-nucleon collision. A negative value indicatess that the information is not available.

property Nspec_targ_n¶

The number of spectator neutrons in the target.

ie. those that thave not participated in any inelastic nucleon-nucleon collision. A negative value indicatess that the information is not available.

property Nspec_targ_p¶

The number of spectator protons in the target.

ie. those that thave not participated in any inelastic nucleon-nucleon collision. A negative value indicatess that the information is not available.

property Nwounded_N_collisions¶

Collisions with a diffractively excited projectile nucleon.

The number of single diffractive nucleon-nucleon collisions where the projectile nucleon is excited. A negative value means that the information is not available.

property Nwounded_Nwounded_collisions¶

Non-diffractive or doubly diffractive collisions.

The number of nucleon-nucleon collisions where both projectile and target nucleons are wounded. A negative value means that the information is not available.

property centrality¶

The centrality.

The generated centrality in percentiles, where 0 is the maximally central and 100 is the minimally central. A negative value means that the information is not available.

property eccentricities¶

Eccentricities.

Calculated to different orders. The key of the map specifies the order, and the value gives the corresponding eccentricity.

property event_plane_angle¶

The event plane angle.

The angle wrt. the x-axix of the impact parameter vector (pointing frm the target to the projectile). A positive number between 0 and two pi. A negative value means that the information is not available.

property impact_parameter¶

The impact parameter.

The impact parameter given in units of femtometer. A negative value means that the information is not available.

property participant_plane_angles¶

Participant plane angles.

calculated to different orders. The key of the map specifies the order, and the value gives to the angle wrt. the event plane.

property sigma_inel_NN¶

The assumed inelastic nucleon-nucleon cross section.

in units of millibarn. As used in a Glauber calculation to simulate the distribution in Ncoll. A negative value means that the information is not available.

property user_cent_estimate¶

A user defined centrality estimator.

This variable may contain anything a generator feels is reasonable for estimating centrality. The value should be non-negative, and a low value corresponds to a low centrality. A negative value indicatess that the information is not available.

class pyhepmc.GenParticle¶

Stores particle-related information.

is_generated_mass_set(self: pyhepmc._core.GenParticle) → bool¶: See generated_mass.

unset_generated_mass(self: pyhepmc._core.GenParticle) → None¶: Declare that generated mass is not set. See generated_mass.

property abs_pid¶: Equivalent to abs(genparticle.pid)

property attributes¶

Access attributes with a dict-like view.

It is possible to read and write attributes. Primitive C++ types (and vectors therefore) are converted from/to native Python types.

property children¶

Convenience access to immediate outgoing particles via end vertex.

Less efficient than via the vertex since return must be by value (in case there is no vertex).

property end_vertex¶: Access end vertex.

property generated_mass¶

Get or set generated mass.

This function will return mass as set by a generator/tool. If not set, it will return momentum().m().

property id¶: Number which uniquely identifies this particle in the current event. This is not a particle ID, see pid for the PDG ID. The id is a persistent pointer to this particle.

property in_event¶: Check if this particle belongs to an event.

property momentum¶: Access momentum.

property parent_event¶: Access parent event.

property parents¶

Convenience access to immediate incoming particles via production vertex.

Less efficient than via the vertex since return must be by value (in case there is no vertex).

property pid¶: PDG ID of particle

property production_vertex¶: Access production vertex.

property status¶: Access status code.

class pyhepmc.GenPdfInfo¶

Stores additional information about PDFs.

This is an example of event attribute used to store PDF-related information.

Input parton flavour codes id1 & id2 are expected to obey the PDG code conventions, especially g = 21.

The contents of pdf1 and pdf2 are expected to be x*f(x). The LHAPDF set ids are the entries in the first column of http:///projects.hepforge.org/lhapdf/PDFsets.index.

property parton_id1¶: Parton PDG ID.

property parton_id2¶: Parton PDG ID.

property pdf_id1¶: LHAPDF ID code.

property pdf_id2¶: LHAPDF ID code.

property scale¶: Factorisation scale (in GEV).

property x1¶: Parton momentum fraction.

property x2¶: Parton momentum fraction.

property xf1¶: PDF value.

property xf2¶: PDF value.

class pyhepmc.GenRunInfo¶

Stores run-related information.

Manages run-related information. Contains run-wide attributes.

class ToolInfo¶

Interrnal struct for keeping track of tools.

property description¶

property name¶

property version¶

property attributes¶

Access attributes with a dict-like view.

It is possible to read and write attributes. Primitive C++ types (and vectors therefore) are converted from/to native Python types.

property tools¶

property weight_names¶

Access the vector of weight names.

Access the names of the weights in this run.

For consistency, the length of the vector should be the same as the number of weights in the events in the run.

class pyhepmc.GenVertex¶

Stores vertex-related information.

add_particle_in(self: pyhepmc._core.GenVertex, arg0: pyhepmc._core.GenParticle) → None¶: Add incoming particle.

add_particle_out(self: pyhepmc._core.GenVertex, arg0: pyhepmc._core.GenParticle) → None¶: Add outgoing particle.

has_set_position(self: pyhepmc._core.GenVertex) → bool¶: Check if position of this vertex is set.

remove_particle_in(self: pyhepmc._core.GenVertex, arg0: pyhepmc._core.GenParticle) → None¶: Remove incoming particle.

remove_particle_out(self: pyhepmc._core.GenVertex, arg0: pyhepmc._core.GenParticle) → None¶: Remove outgoing particle.

property attributes¶

property id¶: Number which uniquely identifies this vertex in the current event. The id is a persistent pointer to this vertex.

property in_event¶: Check if this vertex belongs to an event.

property parent_event¶: Access parent event.

property particles_in¶: Access list of incoming particles.

property particles_out¶: Access list of outgoing particles.

property position¶

Access vertex position.

Returns the position of this vertex. If a position is not set on this vertex, the production vertices of ancestors are searched to find the inherited position. FourVector(0,0,0,0) is returned if no position information is found.

Access vertex position.

property status¶: Access vertex status code.

class pyhepmc.HEPEUPAttribute¶

momentum(self: pyhepmc._core.HEPEUPAttribute, arg0: int) → pyhepmc._core.FourVector¶

property hepeup¶

class pyhepmc.HEPRUPAttribute¶

property heprup¶

class pyhepmc.Setup¶

Imitates the Setup namespace.

You can directly read and write to the attributes of this class without creating an instance. They manipulate the corresponding global values in the HepMC3 C++ library.

debug_level¶

print_errors¶

print_warnings¶

class pyhepmc.Units¶

Units in which HepMC3 stores momentum and position.

class LengthUnit¶

Members:

CM

MM

CM = <LengthUnit.CM: 1>¶

MM = <LengthUnit.MM: 0>¶

property name¶

property value¶

class MomentumUnit¶

Members:

MEV

GEV

GEV = <MomentumUnit.GEV: 1>¶

MEV = <MomentumUnit.MEV: 0>¶

property name¶

property value¶

CM = <LengthUnit.CM: 1>¶

GEV = <MomentumUnit.GEV: 1>¶

MEV = <MomentumUnit.MEV: 0>¶

MM = <LengthUnit.MM: 0>¶

pyhepmc.content(arg0: pyhepmc._core.GenEvent) → str¶: Print content of all GenEvent containers.

pyhepmc.delta_eta(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: Pseudorapidity separation.

pyhepmc.delta_phi(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: Signed azimuthal angle separation in [-pi, pi].

pyhepmc.delta_r2_eta(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: R_eta^2-distance separation dR^2 = dphi^2 + deta^2.

pyhepmc.delta_r2_rap(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: R_rap^2-distance separation dR^2 = dphi^2 + drap^2.

pyhepmc.delta_r_eta(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: R_eta-distance separation dR = sqrt(dphi^2 + deta^2).

pyhepmc.delta_r_rap(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: R-rap-distance separation dR = sqrt(dphi^2 + drap^2).

pyhepmc.delta_rap(arg0: pyhepmc._core.FourVector, arg1: pyhepmc._core.FourVector) → float¶: Rapidity separation.

pyhepmc.equal_particle_sets(arg0: List[pyhepmc._core.GenParticle], arg1: List[pyhepmc._core.GenParticle]) → bool¶: Whether two sets of particles are equal. Algorithm is analog to equal_vertex_sets().

pyhepmc.equal_vertex_sets(arg0: List[pyhepmc._core.GenVertex], arg1: List[pyhepmc._core.GenVertex]) → bool¶: Whether two sets of vertices are equal. The vertices can have arbitrary order and their id() is ignored in the comparison. The sets are considered equal, if each vertex in one set compares equal to another vertex in the other set.

pyhepmc.listing(arg0: pyhepmc._core.GenEvent, arg1: int) → str¶: Print event in listing (HepMC2) format.

pyhepmc.open(fileobj: str | PurePath, mode: str = 'r', precision: int | None = None, format: str | None = None) → Any¶

Open HepMC files for reading or writing.

See HepMCFile.

pyhepmc.io¶

HepMC3 IO classes.

This module contains various Reader and Writer classes, which have pythonic interfaces. They act as context managers and close the file automatically. The Readers can be iterated over and yield events.

The open() function is even easier to use. It can read any supported file and will auto-detect the format. It can be used for reading and writing.

class pyhepmc.io.ReaderAscii¶: Reader for HepMC3 ASCII files.

class pyhepmc.io.ReaderAsciiHepMC2¶: Reader for HepMC2 ASCII files.

class pyhepmc.io.ReaderHEPEVT¶: Reader for HEPEVT files.

class pyhepmc.io.ReaderLHEF¶

Reader for LHEF files.

read_event(self: pyhepmc._core.Reader, event: pyhepmc._core.GenEvent) → bool¶

class pyhepmc.io.UnparsedAttribute¶

Unparsed attribute after deserialization.

HepMC3 does not serialize the type of attributes, therefore the correct type cannot be restored upon deserialization (this is a limition of the HepMC3 C++ library and its serialization format). Use the astype() method to parse the attribute into a concrete type; this has important side-effects, see method description.

astype(self: pyhepmc._core.UnparsedAttribute, pytype: object) → object¶

Convert unparsed attribute to concrete type.

If the conversion is successful, the unparsed attribute is replaced with the parsed attribute, so this method has to be called only once. If the conversion fails, a TypeError is raised.

Parameters:: pytype (type) – Type of the attribute. Allowed values: bool, int, float, str, GenParticle, GenPdfInfo, GenHeavyIon, GenCrossSection, HEPRUPAttribute, HEPEUPAttribute, typing.List[int], typing.List[float], typing.List[str]. In Python-3.9+, typing.List can be replaced by list.

class pyhepmc.io.WriterAscii¶

write()¶: write_event(self: pyhepmc._core.Writer, event: pyhepmc._core.GenEvent) -> None

property precision¶

Return output precision.

Access output precision.

So far available range is [2,24]. Default is 16.

class pyhepmc.io.WriterAsciiHepMC2¶

write()¶: write_event(self: pyhepmc._core.Writer, event: pyhepmc._core.GenEvent) -> None

property precision¶

Return output precision.

Access output precision.

Available range is [2,24]. Default is 16.

class pyhepmc.io.WriterHEPEVT¶

write()¶: write_event(self: pyhepmc._core.Writer, event: pyhepmc._core.GenEvent) -> None

pyhepmc.io.open(fileobj: str | PurePath, mode: str = 'r', precision: int | None = None, format: str | None = None) → Any¶

Open HepMC files for reading or writing.

See HepMCFile.

pyhepmc.view¶

Visualization for GenEvent.

pyhepmc.view.savefig(event: GenEvent | Digraph, fname: str | BinaryIO, *, format: str | None = None, **kwargs: Any) → None¶

Save event as an image.

The SVG format is recommended, because it contains tooltips with extra information.

Supported formats: .

Parameters:

event (GenEvent or Digraph) – The event to be saved.
fname (path-like or file-like) – Path or file-like handle to which the image is written.
format (str, optional) – Output format.
**kwargs – Other arguments are forwarded to pyhepmc.view.to_dot.

pyhepmc.view.to_dot(evt: GenEvent, *, size: Tuple[int, int] | None = None, color_hadron: str = 'black', color_lepton_or_boson: str = 'goldenrod', color_quark_or_gluon: str = 'darkred', color_internal: str = 'dodgerblue', color_invalid: str = 'gainsboro', color_special: str = 'green') → Digraph¶

Convert GenEvent to Digraph.

This converts the GenEvent into a graphviz Digraph in the DOT language, which in turn can be rendered in SVG format and displayed in Jupyter notebooks.

Parameters:

evt (GenEvent) – The event to convert.
size ((int, int) or None, optional) – Maximum size of the graph in inches.
color_hadron (str, optional) – Color (HTML color specification) for hadrons.
color_lepton_or_boson (str, optional) – Color (HTML color specification) for leptons or bosons (gamma, W+/-, Z, H).
color_quark_or_gluon (str, optional) – Color (HTML color specification) for quarks, diquarks, and gluons.
color_internal (str, optional) – Color (HTML color specification) for generator-internal particles (e.g. strings, clusters, …).
color_special (str, optional) – Color (HTML color specification) for any valid particle which does not fit into the other categories (e.g. BSM particles).
color_invalid (str, optional) – Color (HTML color specification) for invalid particles (e.g. PID==0).