HepMC3 event record library
class_example_read.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_read.cc
8 * @brief Basic example of use of root I/O: reading events from 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/WriterAscii.h"
16#include "HepMC3/Print.h"
17
18#include "MyClass.h"
19#include "MyRunClass.h"
20
21#include "TFile.h"
22#include "TSystem.h"
23#include "TKey.h"
24
25#include <iostream>
26
27using namespace HepMC3;
28using std::cout;
29using std::endl;
30
31/** Main */
32int main(int argc, char **argv) {
33
34 if( argc<3 ) {
35 cout << "Usage: " << argv[0] << " <input_root_file> <output_hepmc3_file>" << endl;
36 exit(-1);
37 }
38
39
40 TFile fo(argv[1]);
41 WriterAscii text_output(argv[2]);
42
43 MyClass* myevent;
44 int events_parsed = 0;
45
46 // Get GenRunInfo, if available
47 MyRunClass *my_run = (MyRunClass*)fo.Get("MyRunClass");
48 shared_ptr<GenRunInfo> run_info;
49
50 if( my_run ) run_info.reset(my_run->GetRunInfo());
51
52
53 fo.GetListOfKeys()->Print();
54
55 TIter next(fo.GetListOfKeys());
56 TKey *key;
57
58 while ((key=(TKey*)next()))
59 {
60 const char *cl = key->GetClassName();
61
62 if( strncmp(cl,"MyClass",7) != 0 ) continue;
63
64 fo.GetObject(key->GetName(), myevent);
65
66 cout << "Event: " << key->GetName() << endl;
67
68 if( events_parsed == 0 ) {
69 cout << "First event: " << endl;
70 Print::listing(*(myevent->GetEvent()));
71 }
72
73 if( run_info ) {
74 cout << "Setting run info" << endl;
75 myevent->GetEvent()->set_run_info(run_info);
76 run_info.reset();
77 }
78
79 text_output.write_event(*(myevent->GetEvent()));
80 ++events_parsed;
81
82 if( events_parsed%100 == 0 ) {
83 cout << "Event: " << events_parsed << endl;
84 }
85
86 delete myevent->GetEvent();
87 delete myevent;
88 }
89
90 text_output.close();
91
92 std::cout << "Events parsed and written: " << events_parsed << std::endl;
93
94 return 0;
95}
Definition of class GenEvent.
Definition of class GenRunInfo.
Definition of static class Print.
Definition of class WriterAscii.
void set_run_info(shared_ptr< GenRunInfo > run)
Set the GenRunInfo object by smart pointer.
Definition GenEvent.h:129
static void listing(std::ostream &os, const GenEvent &event, unsigned short precision=2)
Print event in listing (HepMC2) format.
Definition Print.cc:51
GenEvent I/O serialization for structured text files.
Definition WriterAscii.h:25
Sample class for root I/O test.
Definition MyClass.h:9
GenEvent * GetEvent()
Get HepMC event.
Definition MyClass.cc:10
Sample class for root I/O test.
Definition MyRunClass.h:9
GenRunInfo * GetRunInfo()
Get HepMC event.
Definition MyRunClass.cc:10
HepMC3 main namespace.
Definition ReaderGZ.h:28