HepMC3 event record library
GenEvent.h
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1 // -*- C++ -*-
2 //
3 // This file is part of HepMC
4 // Copyright (C) 2014-2021 The HepMC collaboration (see AUTHORS for details)
5 //
6 ///
7 /// @file GenEvent.h
8 /// @brief Definition of \b class GenEvent
9 ///
10 #ifndef HEPMC3_GENEVENT_H
11 #define HEPMC3_GENEVENT_H
12 
13 #include "HepMC3/Units.h"
14 #include "HepMC3/GenParticle_fwd.h"
15 #include "HepMC3/GenVertex_fwd.h"
16 #include "HepMC3/GenPdfInfo_fwd.h"
17 #include "HepMC3/GenHeavyIon_fwd.h"
18 #include "HepMC3/GenCrossSection_fwd.h"
19 
20 #if !defined(__CINT__)
21 #include "HepMC3/GenHeavyIon.h"
22 #include "HepMC3/GenPdfInfo.h"
23 #include "HepMC3/GenCrossSection.h"
24 #include "HepMC3/GenRunInfo.h"
25 #include <mutex>
26 #endif // __CINT__
27 
28 #ifdef HEPMC3_ROOTIO
29 class TBuffer;
30 #endif
31 
32 
33 namespace HepMC3 {
34 
35 struct GenEventData;
36 
37 /// @brief Stores event-related information
38 ///
39 /// Manages event-related information.
40 /// Contains lists of GenParticle and GenVertex objects
41 class GenEvent {
42 
43 public:
44 
45  /// @brief Event constructor without a run
47  Units::LengthUnit length_unit = Units::MM);
48 
49 #if !defined(__CINT__)
50 
51  /// @brief Constructor with associated run
52  GenEvent(std::shared_ptr<GenRunInfo> run,
54  Units::LengthUnit length_unit = Units::MM);
55 
56  /// @brief Copy constructor
57  GenEvent(const GenEvent&);
58 
59  /// @brief Destructor
60  ~GenEvent();
61 
62  /// @brief Assignment operator
63  GenEvent& operator=(const GenEvent&);
64 
65  /// @name Particle and vertex access
66  /// @{
67 
68  /// @brief Get list of particles (const)
69  const std::vector<ConstGenParticlePtr>& particles() const;
70  /// @brief Get list of vertices (const)
71  const std::vector<ConstGenVertexPtr>& vertices() const;
72 
73 
74  /// @brief Get/set list of particles (non-const)
75  const std::vector<GenParticlePtr>& particles() { return m_particles; }
76  /// @brief Get/set list of vertices (non-const)
77  const std::vector<GenVertexPtr>& vertices() { return m_vertices; }
78 
79  /// @}
80 
81 
82  /// @name Particle and vertex access
83  //@{
84  ///Particles size, HepMC2 compatiility
85  inline int particles_size() const { return m_particles.size(); }
86  ///Particles empty, HepMC2 compatiility
87  inline bool particles_empty() const { return m_particles.empty(); }
88  ///Vertices size, HepMC2 compatiility
89  inline int vertices_size() const { return m_vertices.size(); }
90  ///Vertices empty, HepMC2 compatiility
91  inline bool vertices_empty() const { return m_vertices.empty(); }
92  //@}
93 
94  /// @name Event weights
95  /// @{
96 
97  /// Get event weight values as a vector
98  const std::vector<double>& weights() const { return m_weights; }
99  /// Get event weights as a vector (non-const)
100  std::vector<double>& weights() { return m_weights; }
101  /// Get event weight accessed by index (or the canonical/first one if there is no argument)
102  /// @note It's the user's responsibility to ensure that the given index exists!
103  double weight(const unsigned long& index=0) const { if ( index < weights().size() ) return weights().at(index); else throw std::runtime_error("GenEvent::weight(const unsigned long&): weight index outside of range"); return 0.0; }
104  /// Get event weight accessed by weight name
105  /// @note Requires there to be an attached GenRunInfo, otherwise will throw an exception
106  /// @note It's the user's responsibility to ensure that the given name exists!
107  double weight(const std::string& name) const {
108  if (!run_info()) throw std::runtime_error("GenEvent::weight(const std::string&): named access to event weights requires the event to have a GenRunInfo");
109  return weight(run_info()->weight_index(name));
110  }
111  /// Get event weight accessed by weight name
112  /// @note Requires there to be an attached GenRunInfo, otherwise will throw an exception
113  /// @note It's the user's responsibility to ensure that the given name exists!
114  double& weight(const std::string& name) {
115  if (!run_info()) throw std::runtime_error("GenEvent::weight(const std::string&): named access to event weights requires the event to have a GenRunInfo");
116  int pos = run_info()->weight_index(name);
117  if ( pos < 0 ) throw std::runtime_error("GenEvent::weight(const std::string&): no weight with given name in this run");
118  if ( pos >= int(m_weights.size())) throw std::runtime_error("GenEvent::weight(const std::string&): weight index outside of range");
119  return m_weights[pos];
120  }
121  /// Get event weight names, if there are some
122  /// @note Requires there to be an attached GenRunInfo with registered weight names, otherwise will throw an exception
123  const std::vector<std::string>& weight_names() const {
124  if (!run_info()) throw std::runtime_error("GenEvent::weight_names(): access to event weight names requires the event to have a GenRunInfo");
125  const std::vector<std::string>& weightnames = run_info()->weight_names();
126  if (weightnames.empty()) throw std::runtime_error("GenEvent::weight_names(): no event weight names are registered for this run");
127  return weightnames;
128  }
129 
130  /// @}
131 
132 
133  /// @name Auxiliary info and event metadata
134  /// @{
135 
136  /// @brief Get a pointer to the the GenRunInfo object.
137  std::shared_ptr<GenRunInfo> run_info() const {
138  return m_run_info;
139  }
140  /// @brief Set the GenRunInfo object by smart pointer.
141  void set_run_info(std::shared_ptr<GenRunInfo> run) {
142  m_run_info = run;
143  if ( run && !run->weight_names().empty() )
144  m_weights.resize(run->weight_names().size(), 1.0);
145  }
146 
147  /// @brief Get event number
148  int event_number() const { return m_event_number; }
149  /// @brief Set event number
150  void set_event_number(const int& num) { m_event_number = num; }
151 
152  /// @brief Get momentum unit
154  /// @brief Get length unit
155  const Units::LengthUnit& length_unit() const { return m_length_unit; }
156  /// @brief Change event units
157  /// Converts event from current units to new ones
158  void set_units( Units::MomentumUnit new_momentum_unit, Units::LengthUnit new_length_unit);
159 
160  /// @brief Get heavy ion generator additional information
161  GenHeavyIonPtr heavy_ion() { return attribute<GenHeavyIon>("GenHeavyIon"); }
162  /// @brief Get heavy ion generator additional information (const version)
163  ConstGenHeavyIonPtr heavy_ion() const { return attribute<GenHeavyIon>("GenHeavyIon"); }
164  /// @brief Set heavy ion generator additional information
165  void set_heavy_ion(GenHeavyIonPtr hi) { add_attribute("GenHeavyIon",hi); }
166 
167  /// @brief Get PDF information
168  GenPdfInfoPtr pdf_info() { return attribute<GenPdfInfo>("GenPdfInfo"); }
169  /// @brief Get PDF information (const version)
170  ConstGenPdfInfoPtr pdf_info() const { return attribute<GenPdfInfo>("GenPdfInfo"); }
171  /// @brief Set PDF information
172  void set_pdf_info(GenPdfInfoPtr pi) { add_attribute("GenPdfInfo",pi); }
173 
174  /// @brief Get cross-section information
175  GenCrossSectionPtr cross_section() { return attribute<GenCrossSection>("GenCrossSection"); }
176  /// @brief Get cross-section information (const version)
177  ConstGenCrossSectionPtr cross_section() const { return attribute<GenCrossSection>("GenCrossSection"); }
178  /// @brief Set cross-section information
179  void set_cross_section(GenCrossSectionPtr cs) { add_attribute("GenCrossSection",cs); }
180 
181  /// @}
182 
183 
184  /// @name Event position
185  /// @{
186 
187  /// Vertex representing the overall event position
188  const FourVector& event_pos() const;
189 
190  /// @brief Vector of beam particles
191  std::vector<ConstGenParticlePtr> beams() const;
192 
193  /// @brief Vector of beam particles
194  const std::vector<GenParticlePtr> & beams();
195 
196  /// @brief Shift position of all vertices in the event by @a delta
197  void shift_position_by( const FourVector & delta );
198 
199  /// @brief Shift position of all vertices in the event to @a op
200  void shift_position_to( const FourVector & newpos ) {
201  const FourVector delta = newpos - event_pos();
202  shift_position_by(delta);
203  }
204 
205  /// @brief Boost event using x,y,z components of @a v as velocities
206  bool boost( const FourVector& v );
207  /// @brief Rotate event using x,y,z components of @a v as rotation angles
208  bool rotate( const FourVector& v );
209  /// @brief Change sign of @a axis
210  bool reflect(const int axis);
211 
212  /// @}
213 
214 
215  /// @name Additional attributes
216  /// @{
217  /// @brief Add event attribute to event
218  ///
219  /// This will overwrite existing attribute if an attribute
220  /// with the same name is present
221  void add_attribute(const std::string &name, const std::shared_ptr<Attribute> &att, const int& id = 0);
222 
223  /// @brief Add multiple attributes to event
224  ///
225  /// This will overwrite existing attributes if attributes
226  /// with the same names are present
227  void add_attributes(const std::vector<std::string> &names, const std::vector<std::shared_ptr<Attribute> > &atts, const std::vector<int>& ids);
228 
229  /// @brief Add multiple attributes to event
230  ///
231  /// This will overwrite existing attributes if attributes
232  /// with the same names are present
233  void add_attributes(const std::string& name, const std::vector<std::shared_ptr<Attribute> > &atts, const std::vector<int>& ids);
234 
235  /// @brief Add multiple attributes to event
236  ///
237  /// This will overwrite existing attributes if attributes
238  /// with the same names are present
239  void add_attributes(const std::string& name, const std::vector<std::pair<int, std::shared_ptr<Attribute> > > &atts);
240 
241 
242  /// @brief Remove attribute
243  void remove_attribute(const std::string &name, const int& id = 0);
244 
245  /// @brief Get attribute of type T
246  template<class T>
247  std::shared_ptr<T> attribute(const std::string &name, const int& id = 0) const;
248 
249  /// @brief Get attribute of any type as string
250  std::string attribute_as_string(const std::string &name, const int& id = 0) const;
251 
252  /// @brief Get list of attribute names
253  std::vector<std::string> attribute_names( const int& id = 0) const;
254 
255  /// @brief Get a copy of the list of attributes
256  /// @note To avoid thread issues, this is returns a copy. Better solution may be needed.
257  std::map< std::string, std::map<int, std::shared_ptr<Attribute> > > attributes() const {
258  std::lock_guard<std::recursive_mutex> lock(m_lock_attributes);
259  return m_attributes;
260  }
261 
262  /// @}
263 
264 
265  /// @name Particle and vertex modification
266  /// @{
267 
268  /// @brief Add particle
269  void add_particle( GenParticlePtr p );
270 
271  /// @brief Add vertex
272  void add_vertex( GenVertexPtr v );
273 
274  /// @brief Remove particle from the event
275  ///
276  /// This function will remove whole sub-tree starting from this particle
277  /// if it is the only incoming particle of this vertex.
278  /// It will also production vertex of this particle if this vertex
279  /// has no more outgoing particles
280  void remove_particle( GenParticlePtr v );
281 
282  /// @brief Remove a set of particles
283  ///
284  /// This function follows rules of GenEvent::remove_particle to remove
285  /// a list of particles from the event.
286  void remove_particles( std::vector<GenParticlePtr> v );
287 
288  /// @brief Remove vertex from the event
289  ///
290  /// This will remove all sub-trees of all outgoing particles of this vertex
291  void remove_vertex( GenVertexPtr v );
292 
293  /// @brief Add whole tree in topological order
294  ///
295  /// This function will find the beam particles (particles
296  /// that have no production vertices or their production vertices
297  /// have no particles) and will add the whole decay tree starting from
298  /// these particles.
299  ///
300  /// @note Any particles on this list that do not belong to the tree
301  /// will be ignored.
302  void add_tree( const std::vector<GenParticlePtr> &particles );
303 
304  /// @brief Reserve memory for particles and vertices
305  ///
306  /// Helps optimize event creation when size of the event is known beforehand
307  void reserve(const size_t& particles, const size_t& vertices = 0);
308 
309  /// @brief Remove contents of this event
310  void clear();
311 
312  /// @}
313 
314  /// @name Deprecated functionality
315  /// @{
316 
317  /// @brief Add particle by raw pointer
318  /// @deprecated Use GenEvent::add_particle( const GenParticlePtr& ) instead
319  void add_particle( GenParticle *p );
320 
321  /// @brief Add vertex by raw pointer
322  /// @deprecated Use GenEvent::add_vertex( const GenVertexPtr& ) instead
323  void add_vertex ( GenVertex *v );
324 
325 
326  /// @brief Set incoming beam particles
327  /// @deprecated Backward compatibility
328  void set_beam_particles(GenParticlePtr p1, GenParticlePtr p2);
329 
330 
331  /// @brief Add particle to root vertex
332 
333  void add_beam_particle(GenParticlePtr p1);
334 
335 
336  /// @}
337 
338 #endif // __CINT__
339 
340 
341  /// @name Methods to fill GenEventData and to read it back
342  /// @{
343 
344  /// @brief Fill GenEventData object
345  void write_data(GenEventData &data) const;
346 
347  /// @brief Fill GenEvent based on GenEventData
348  void read_data(const GenEventData &data);
349 
350 #ifdef HEPMC3_ROOTIO
351  /// @brief ROOT I/O streamer
352  void Streamer(TBuffer &b);
353  /// @}
354 #endif
355 
356 private:
357 
358  /// @name Fields
359  /// @{
360 
361 #if !defined(__CINT__)
362 
363  /// List of particles
364  std::vector<GenParticlePtr> m_particles;
365  /// List of vertices
366  std::vector<GenVertexPtr> m_vertices;
367 
368  /// Event number
370 
371  /// Event weights
372  std::vector<double> m_weights;
373 
374  /// Momentum unit
376  /// Length unit
378 
379  /// The root vertex is stored outside the normal vertices list to block user access to it
380  GenVertexPtr m_rootvertex;
381 
382  /// Global run information.
383  std::shared_ptr<GenRunInfo> m_run_info;
384 
385  /// @brief Map of event, particle and vertex attributes
386  ///
387  /// Keys are name and ID (0 = event, <0 = vertex, >0 = particle)
388  mutable std::map< std::string, std::map<int, std::shared_ptr<Attribute> > > m_attributes;
389 
390  /// @brief Attribute map key type
391  typedef std::map< std::string, std::map<int, std::shared_ptr<Attribute> > >::value_type att_key_t;
392 
393  /// @brief Attribute map value type
394  typedef std::map<int, std::shared_ptr<Attribute> >::value_type att_val_t;
395 
396  /// @brief Mutex lock for the m_attibutes map.
397  mutable std::recursive_mutex m_lock_attributes;
398 #endif // __CINT__
399 
400  /// @}
401 
402 };
403 
404 #if !defined(__CINT__)
405 //
406 // Template methods
407 //
408 template<class T>
409 std::shared_ptr<T> GenEvent::attribute(const std::string &name, const int& id) const {
410  std::lock_guard<std::recursive_mutex> lock(m_lock_attributes);
411  std::map< std::string, std::map<int, std::shared_ptr<Attribute> > >::iterator i1 =
412  m_attributes.find(name);
413  if ( i1 == m_attributes.end() ) {
414  if ( id == 0 && run_info() ) {
415  return run_info()->attribute<T>(name);
416  }
417  return std::shared_ptr<T>();
418  }
419 
420  std::map<int, std::shared_ptr<Attribute> >::iterator i2 = i1->second.find(id);
421  if (i2 == i1->second.end() ) return std::shared_ptr<T>();
422 
423  if (!i2->second->is_parsed() ) {
424 
425  std::shared_ptr<T> att = std::make_shared<T>();
426  att->m_event = this;
427 
428  if ( id > 0 && id <= int(particles().size()) )
429  att->m_particle = m_particles[id - 1];
430  if ( id < 0 && -id <= int(vertices().size()) )
431  att->m_vertex = m_vertices[-id - 1];
432  if ( att->from_string(i2->second->unparsed_string()) &&
433  att->init() ) {
434  // update map with new pointer
435  i2->second = att;
436  return att;
437  } else {
438  return std::shared_ptr<T>();
439  }
440  }
441  else return std::dynamic_pointer_cast<T>(i2->second);
442 }
443 #endif // __CINT__
444 
445 } // namespace HepMC3
446 #endif
Definition of attribute class GenCrossSection.
Definition of attribute class GenHeavyIon.
Definition of event attribute class GenPdfInfo.
Definition of class GenRunInfo.
Definition of class Units.
Generic 4-vector.
Definition: FourVector.h:36
Stores event-related information.
Definition: GenEvent.h:41
std::shared_ptr< T > attribute(const std::string &name, const int &id=0) const
Get attribute of type T.
Definition: GenEvent.h:409
void add_tree(const std::vector< GenParticlePtr > &particles)
Add whole tree in topological order.
Definition: GenEvent.cc:265
std::recursive_mutex m_lock_attributes
Mutex lock for the m_attibutes map.
Definition: GenEvent.h:397
void add_vertex(GenVertexPtr v)
Add vertex.
Definition: GenEvent.cc:96
void shift_position_to(const FourVector &newpos)
Shift position of all vertices in the event to op.
Definition: GenEvent.h:200
int vertices_size() const
Vertices size, HepMC2 compatiility.
Definition: GenEvent.h:89
bool vertices_empty() const
Vertices empty, HepMC2 compatiility.
Definition: GenEvent.h:91
int event_number() const
Get event number.
Definition: GenEvent.h:148
const std::vector< std::string > & weight_names() const
Definition: GenEvent.h:123
std::vector< std::string > attribute_names(const int &id=0) const
Get list of attribute names.
Definition: GenEvent.cc:621
void write_data(GenEventData &data) const
Fill GenEventData object.
Definition: GenEvent.cc:633
void remove_particle(GenParticlePtr v)
Remove particle from the event.
Definition: GenEvent.cc:116
ConstGenCrossSectionPtr cross_section() const
Get cross-section information (const version)
Definition: GenEvent.h:177
void remove_particles(std::vector< GenParticlePtr > v)
Remove a set of particles.
Definition: GenEvent.cc:184
std::map< std::string, std::map< int, std::shared_ptr< Attribute > > >::value_type att_key_t
Attribute map key type.
Definition: GenEvent.h:391
void add_particle(GenParticlePtr p)
Add particle.
Definition: GenEvent.cc:48
void set_units(Units::MomentumUnit new_momentum_unit, Units::LengthUnit new_length_unit)
Change event units Converts event from current units to new ones.
Definition: GenEvent.cc:391
std::vector< double > m_weights
Event weights.
Definition: GenEvent.h:372
ConstGenHeavyIonPtr heavy_ion() const
Get heavy ion generator additional information (const version)
Definition: GenEvent.h:163
void shift_position_by(const FourVector &delta)
Shift position of all vertices in the event by delta.
Definition: GenEvent.cc:424
void remove_vertex(GenVertexPtr v)
Remove vertex from the event.
Definition: GenEvent.cc:192
void set_event_number(const int &num)
Set event number.
Definition: GenEvent.h:150
std::map< std::string, std::map< int, std::shared_ptr< Attribute > > > attributes() const
Get a copy of the list of attributes.
Definition: GenEvent.h:257
const std::vector< GenVertexPtr > & vertices()
Get/set list of vertices (non-const)
Definition: GenEvent.h:77
std::vector< ConstGenParticlePtr > beams() const
Vector of beam particles.
Definition: GenEvent.cc:416
int m_event_number
Event number.
Definition: GenEvent.h:369
void set_run_info(std::shared_ptr< GenRunInfo > run)
Set the GenRunInfo object by smart pointer.
Definition: GenEvent.h:141
ConstGenPdfInfoPtr pdf_info() const
Get PDF information (const version)
Definition: GenEvent.h:170
const std::vector< ConstGenVertexPtr > & vertices() const
Get list of vertices (const)
Definition: GenEvent.cc:43
~GenEvent()
Destructor.
Definition: GenEvent.cc:74
std::vector< double > & weights()
Get event weights as a vector (non-const)
Definition: GenEvent.h:100
bool reflect(const int axis)
Change sign of axis.
Definition: GenEvent.cc:521
GenEvent(Units::MomentumUnit momentum_unit=Units::GEV, Units::LengthUnit length_unit=Units::MM)
Event constructor without a run.
Definition: GenEvent.cc:21
double weight(const unsigned long &index=0) const
Definition: GenEvent.h:103
void set_cross_section(GenCrossSectionPtr cs)
Set cross-section information.
Definition: GenEvent.h:179
const FourVector & event_pos() const
Vertex representing the overall event position.
Definition: GenEvent.cc:412
void set_heavy_ion(GenHeavyIonPtr hi)
Set heavy ion generator additional information.
Definition: GenEvent.h:165
void add_attribute(const std::string &name, const std::shared_ptr< Attribute > &att, const int &id=0)
Definition: GenEvent.cc:806
void read_data(const GenEventData &data)
Fill GenEvent based on GenEventData.
Definition: GenEvent.cc:690
std::map< std::string, std::map< int, std::shared_ptr< Attribute > > > m_attributes
Map of event, particle and vertex attributes.
Definition: GenEvent.h:388
GenPdfInfoPtr pdf_info()
Get PDF information.
Definition: GenEvent.h:168
Units::MomentumUnit m_momentum_unit
Momentum unit.
Definition: GenEvent.h:375
bool particles_empty() const
Particles empty, HepMC2 compatiility.
Definition: GenEvent.h:87
double & weight(const std::string &name)
Definition: GenEvent.h:114
void remove_attribute(const std::string &name, const int &id=0)
Remove attribute.
Definition: GenEvent.cc:609
const std::vector< GenParticlePtr > & particles()
Get/set list of particles (non-const)
Definition: GenEvent.h:75
const Units::LengthUnit & length_unit() const
Get length unit.
Definition: GenEvent.h:155
std::vector< GenVertexPtr > m_vertices
List of vertices.
Definition: GenEvent.h:366
GenVertexPtr m_rootvertex
The root vertex is stored outside the normal vertices list to block user access to it.
Definition: GenEvent.h:380
std::string attribute_as_string(const std::string &name, const int &id=0) const
Get attribute of any type as string.
Definition: GenEvent.cc:784
double weight(const std::string &name) const
Definition: GenEvent.h:107
void clear()
Remove contents of this event.
Definition: GenEvent.cc:599
int particles_size() const
Particles size, HepMC2 compatiility.
Definition: GenEvent.h:85
Units::LengthUnit m_length_unit
Length unit.
Definition: GenEvent.h:377
bool boost(const FourVector &v)
Boost event using x,y,z components of v as velocities.
Definition: GenEvent.cc:553
GenHeavyIonPtr heavy_ion()
Get heavy ion generator additional information.
Definition: GenEvent.h:161
std::shared_ptr< GenRunInfo > m_run_info
Global run information.
Definition: GenEvent.h:383
std::vector< GenParticlePtr > m_particles
List of particles.
Definition: GenEvent.h:364
void add_beam_particle(GenParticlePtr p1)
Add particle to root vertex.
Definition: GenEvent.cc:765
const std::vector< double > & weights() const
Get event weight values as a vector.
Definition: GenEvent.h:98
void add_attributes(const std::vector< std::string > &names, const std::vector< std::shared_ptr< Attribute > > &atts, const std::vector< int > &ids)
Add multiple attributes to event.
Definition: GenEvent.cc:821
void set_beam_particles(GenParticlePtr p1, GenParticlePtr p2)
Set incoming beam particles.
Definition: GenEvent.cc:760
std::map< int, std::shared_ptr< Attribute > >::value_type att_val_t
Attribute map value type.
Definition: GenEvent.h:394
bool rotate(const FourVector &v)
Rotate event using x,y,z components of v as rotation angles.
Definition: GenEvent.cc:434
void set_pdf_info(GenPdfInfoPtr pi)
Set PDF information.
Definition: GenEvent.h:172
GenCrossSectionPtr cross_section()
Get cross-section information.
Definition: GenEvent.h:175
const std::vector< ConstGenParticlePtr > & particles() const
Get list of particles (const)
Definition: GenEvent.cc:39
GenEvent & operator=(const GenEvent &)
Assignment operator.
Definition: GenEvent.cc:82
const Units::MomentumUnit & momentum_unit() const
Get momentum unit.
Definition: GenEvent.h:153
std::shared_ptr< GenRunInfo > run_info() const
Get a pointer to the the GenRunInfo object.
Definition: GenEvent.h:137
void reserve(const size_t &particles, const size_t &vertices=0)
Reserve memory for particles and vertices.
Definition: GenEvent.cc:385
Stores particle-related information.
Definition: GenParticle.h:31
Stores vertex-related information.
Definition: GenVertex.h:26
LengthUnit
Position units.
Definition: Units.h:32
MomentumUnit
Momentum units.
Definition: Units.h:29
HepMC3 main namespace.
Stores serializable event information.
Definition: GenEventData.h:26