HepMC3 event record library
AnalysisExample.cc
1 #include "AnalysisExample.h"
2 #include <limits>
3 namespace HepMC3
4 {
5 HEPMC3_DECLARE_WRITER_FILE(AnalysisExample)
6 HEPMC3_DECLARE_WRITER_STREAM(AnalysisExample)
7 
8 AnalysisExample::AnalysisExample(const std::string &filename,std::shared_ptr<GenRunInfo> run): m_file(filename),
9  m_stream(&m_file)
10 {
11  if ( !m_file.is_open() ) {
12  HEPMC3_ERROR( "AnalysisExample: could not open output file: "<<filename )
13  }
14  m_sum_of_weights=0;
15  m_sum_of_weights2=0;
16  m_bins["rapidity"]=std::vector<double> {-std::numeric_limits<double>::infinity(), -5.0,-4.5,-4.0,-3.5,-3.0,-2.5,-2.0,-1.5,-1.0,-0.5,0.0,0.5,1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5,5.0,std::numeric_limits<double>::infinity()};
17  m_vals["rapidity"]=std::vector<double>(m_bins.at("rapidity").size()-1,0.0);
18  m_errs["rapidity"]=std::vector<double>(m_bins.at("rapidity").size()-1,0.0);
19 }
20 
21 AnalysisExample::AnalysisExample(std::ostream &stream, std::shared_ptr<GenRunInfo> run)
22  : m_file(),
23  m_stream(&stream)
24 {
27  m_bins["rapidity"]=std::vector<double> {-std::numeric_limits<double>::infinity(), -5.0,-4.5,-4.0,-3.5,-3.0,-2.5,-2.0,-1.5,-1.0,-0.5,0.0,0.5,1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5,5.0,std::numeric_limits<double>::infinity()};
28  m_vals["rapidity"]=std::vector<double>(m_bins.at("rapidity").size()-1,0.0);
29  m_errs["rapidity"]=std::vector<double>(m_bins.at("rapidity").size()-1,0.0);
30 
31 }
32 
34 {
35  double w=evt.weight();
37  m_sum_of_weights2+=w*w;
38  for(auto p: evt.particles() )
39  {
40  if (p->status()!=1) continue;
41  double eta=p->momentum().eta();
42  int bin=std::distance(m_bins["rapidity"].begin(), lower_bound(m_bins["rapidity"].begin(),m_bins["rapidity"].end(),eta))-1;
43  if (bin<0) bin=0;
44  m_vals["rapidity"][bin]+=w;
45  m_errs["rapidity"][bin]+=w*w;
46  }
47 }
48 
50  if (!m_stream) return;
51  std::ofstream* ofs = dynamic_cast<std::ofstream*>(m_stream);
52  for (size_t i=1; i<m_vals["rapidity"].size()-1; i++)
53  {
54  double val=m_vals["rapidity"][i]/m_sum_of_weights/(m_bins["rapidity"][i+1]-m_bins["rapidity"][i]);
55  double err=sqrt(m_errs["rapidity"][i])/m_sum_of_weights/(m_bins["rapidity"][i+1]-m_bins["rapidity"][i]);
56  (*ofs)<< std::fixed << std::setprecision( 6 )<<m_bins["rapidity"][i]<<" "<<m_bins["rapidity"][i+1]<<" "<<val<<" "<<err<<std::endl;
57  }
58  if (ofs && !ofs->is_open()) return;
59  if (ofs) ofs->close();
60 
61 }
62 
63 } // namespace HepMC3
std::map< std::string, std::vector< double > > m_bins
Binings.
Example analysis. Produces a rapidity distribution of final state particles.
Stores run-related information.
Definition: GenRunInfo.h:33
std::map< std::string, std::vector< double > > m_errs
Uncertainties.
std::map< std::string, std::vector< double > > m_vals
Values.
void write_event(const GenEvent &evt) override
Write event to file.
AnalysisExample(const std::string &filename, std::shared_ptr< GenRunInfo > run)
Constructor.
Stores event-related information.
Definition: GenEvent.h:41
double m_sum_of_weights
Sum of event weights.
std::ostream * m_stream
Output stream.
#define HEPMC3_ERROR(MESSAGE)
Macro for printing error messages.
Definition: Errors.h:23
double weight(const unsigned long &index=0) const
Definition: GenEvent.h:91
const std::vector< ConstGenParticlePtr > & particles() const
Get list of particles (const)
Definition: GenEvent.cc:39
double m_sum_of_weights2
Sum of event weights**2.
void close() override
Close file stream.
Definition of class AnalysisExample.