HepMC3 event record library
rootIOTree_example_write.cc
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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  * @file rootIOTree_example_write.cc
8  * @brief Basic example of use of root I/O: writing events to file
9  *
10  * @author Witold Pokorski/Andrii Verbytskyi
11  * @date 29/10/15
12  */
13 #include "HepMC3/GenEvent.h"
14 #include "HepMC3/ReaderAscii.h"
15 #include "HepMC3/WriterRootTree.h"
16 #include "HepMC3/Print.h"
17 
18 #include <iostream>
19 
20 using namespace HepMC3;
21 
22 /** Main */
23 int main(int argc, char **argv) {
24 
25  if( argc<3 ) {
26  std::cout << "Usage: " << argv[0] << " <input_hepmc3_file> <output_root_file>" << std::endl;
27  exit(-1);
28  }
29 
30  ReaderAscii text_input (argv[1]);
31  WriterRootTree root_output(argv[2]);
32 
33  int events_parsed = 0;
34 
35  while( !text_input.failed() ) {
36 
37  GenEvent evt(Units::GEV,Units::MM);
38 
39  text_input.read_event(evt);
40 
41  if( text_input.failed() ) break;
42 
43  if( events_parsed == 0 ) {
44  std::cout << "First event: " << std::endl;
45  Print::listing(evt);
46  }
47 
48  root_output.write_event(evt);
49  ++events_parsed;
50 
51  if( events_parsed%1000 == 0 ) {
52  std::cout << "Event: " << events_parsed << std::endl;
53  }
54  }
55 
56  text_input.close();
57  root_output.close();
58 
59  std::cout << "Events parsed and written: " << events_parsed << std::endl;
60 
61  return 0;
62 }
GenEvent I/O parsing for structured text files.
Definition: ReaderAscii.h:29
bool read_event(GenEvent &evt) override
Load event from file.
Definition: ReaderAscii.cc:63
Definition of class WriterRootTree.
static void listing(std::ostream &os, const GenEvent &event, unsigned short precision=2)
Print event in listing (HepMC2) format.
Definition: Print.cc:50
void write_event(const GenEvent &evt) override
Write event to file.
Stores event-related information.
Definition: GenEvent.h:41
bool failed() override
Return status of the stream.
Definition: ReaderAscii.cc:553
GenEvent I/O serialization for root files based on root TTree.
Definition of class ReaderAscii.
void close() override
Close file stream.
int main(int argc, char **argv)
Definition of class GenEvent.
void close() override
Close file stream.
Definition: ReaderAscii.cc:555