HepMC3 event record library
class_example_write.cc
1 // -*- C++ -*-
2 //
3 // This file is part of HepMC
4 // Copyright (C) 2014-2019 The HepMC collaboration (see AUTHORS for details)
5 //
6 /**
7  * @example class_example_write.cc
8  * @brief Basic example of use of root I/O: writing events to file
9  *
10  * @author Witold Pokorski
11  * @date 16/10/14
12  */
13 #include "HepMC3/GenEvent.h"
14 #include "HepMC3/GenRunInfo.h"
15 #include "HepMC3/ReaderAscii.h"
16 #include "HepMC3/Print.h"
17 
18 #include "TFile.h"
19 
20 #include <iostream>
21 #include <sstream>
22 
23 using namespace HepMC3;
24 using std::cout;
25 using std::endl;
26 
27 #include "MyClass.h"
28 #include "MyRunClass.h"
29 
30 /** Main */
31 int main(int argc, char **argv) {
32 
33  if( argc<3 ) {
34  cout << "Usage: " << argv[0] << " <input_hepmc3_file> <output_root_file>" << endl;
35  exit(-1);
36  }
37 
38  ReaderAscii text_input(argv[1]);
39 
40  TFile* fFile = new TFile(argv[2],"RECREATE");
41 
42  int events_parsed = 0;
43 
44  bool is_gen_run_info_written = false;
45 
46  while( !text_input.failed() ) {
47 
48  GenEvent evt(Units::GEV,Units::MM);
49 
50  text_input.read_event(evt);
51 
52  if( text_input.failed() ) break;
53 
54  if( events_parsed == 0 ) {
55  cout << "First event: " << endl;
56  Print::listing(evt);
57  }
58 
59  if(!is_gen_run_info_written) {
60  if(evt.run_info()) {
61  GenRunInfo run_info(*evt.run_info());
62 
63  MyRunClass *my_run = new MyRunClass();
64 
65  my_run->SetRunInfo(&run_info);
66 
67  fFile->WriteObject(my_run,"MyRunClass");
68 
69  is_gen_run_info_written = true;
70  }
71  }
72 
73  MyClass* myclass = new MyClass();
74 
75  myclass->SetEvent(&evt);
76  //
77  std::ostringstream os;
78  os << events_parsed;
79  std::string stevt = "Event_" + os.str();
80  const char* chevt = stevt.c_str();
81 
82  cout << "writing " << stevt << endl;
83 
84  fFile->WriteObject(myclass, chevt);
85 
86  ++events_parsed;
87 
88  if( events_parsed%100 == 0 ) {
89  cout << "Event: " << events_parsed << endl;
90  }
91  }
92 
93  text_input.close();
94  fFile->Close();
95  std::cout << "Events parsed and written: " << events_parsed << std::endl;
96 
97  return 0;
98 }
Definition of class GenRunInfo.
HepMC3 main namespace.
Definition: ReaderGZ.h:28
Sample class for root I/O test.
Definition: MyClass.h:9
GenEvent I/O parsing for structured text files.
Definition: ReaderAscii.h:29
Stores run-related information.
Definition: GenRunInfo.h:32
static void listing(std::ostream &os, const GenEvent &event, unsigned short precision=2)
Print event in listing (HepMC2) format.
Definition: Print.cc:51
Sample class for root I/O test.
Definition: MyRunClass.h:9
Stores event-related information.
Definition: GenEvent.h:42
Definition of class ReaderAscii.
int main(int argc, char **argv)
void SetEvent(GenEvent *)
Set HepMC event.
Definition: MyClass.cc:5
Definition of class GenEvent.