iguana_ex_cpp_00_run_functions.cc

Go to the documentation of this file.

 
#include <hipo4/reader.h>
#include <iguana/algorithms/AlgorithmSequence.h>

int main(int argc, char** argv)
{
 
  // parse arguments
  char const* inFileName = argc > 1 ? argv[1] : "data.hipo";
  int const numEvents    = argc > 2 ? std::stoi(argv[2]) : 3;
 
  // read input file
  hipo::reader reader(inFileName, {0});
 
  // set list of banks to be read
  hipo::banklist banks = reader.getBanks({"RUN::config",
                                          "REC::Particle",
                                          "REC::Calorimeter",
                                          "REC::Track",
                                          "REC::Scintillator"});
 
  // iguana algorithm sequence
  // NOTE: the order that they are added to the sequence here will be the same order in which they will be run
  iguana::AlgorithmSequence seq;
  seq.Add("clas12::EventBuilderFilter"); // filter by Event Builder PID (a filter algorithm)
  seq.Add("clas12::SectorFinder"); // get the sector for each particle (a creator algorithm)
  seq.Add("clas12::rga::MomentumCorrection"); // momentum corrections (a transformer algorithm)
  // seq.PrintSequence();
 
  // configure algorithms with a custom YAML file
  // - in practice, specify the path(s) to your preferred configuration file(s); see documentation
  //   on 'How to Configure Algorithms' for details, and alternative methods for algorithm configuration
  // - in this example, the file is from the source-code path `./config/examples/`, which was copied to
  //   the installation subdirectory `etc/iguana/`, within the default configuration-file search path
  seq.SetConfigFileForEachAlgorithm("examples/config_for_examples.yaml");
  // alternatively: use this configuration for the algorithm that needs it
  // seq.Get("clas12::EventBuilderFilter")->SetConfigFile("examples/config_for_examples.yaml");
 
  // start the algorithms
  seq.Start(banks);
 
  // get bank index, for each bank we want to use after Iguana algorithms run
  // NOTE: new banks from creator algorithms are initialized by `Start`
  auto b_config   = iguana::tools::GetBankIndex(banks, "RUN::config");
  auto b_particle = iguana::tools::GetBankIndex(banks, "REC::Particle");
  auto b_sector   = seq.GetCreatedBankIndex(banks, "clas12::SectorFinder"); // newly created bank; string parameter is algorithm name, not bank name
 
  // run the algorithm sequence on each event
  int iEvent = 0;
  while(reader.next(banks) && (numEvents == 0 || iEvent++ < numEvents)) {
 
    // references to this event's banks
    auto& bank_config   = banks.at(b_config);
    auto& bank_particle = banks.at(b_particle);
    auto& bank_sector   = banks.at(b_sector);
 
    // print the event number
    fmt::println("===== EVENT {} =====", bank_config.getInt("event", 0));
 
    // print the particle bank before Iguana algorithms
    fmt::println("----- BEFORE IGUANA -----");
    bank_particle.show(); // the original particle bank
 
    // run the sequence of Iguana algorithms
    seq.Run(banks);
 
    // print the banks after Iguana algorithms
    fmt::println("----- AFTER IGUANA -----");
    bank_particle.show(); // the filtered particle bank, with corrected momenta
    bank_sector.show(); // the new sector bank
 
    // print a table; first the header
    fmt::print("----- Analysis Particles -----\n");
    fmt::print("  {:<20} {:<20} {:<20} {:<20}\n", "row == pindex", "PDG", "|p|", "sector");
    // then print a row for each particle
    // - use the `hipo::bank::getRowList()` method to loop over the bank rows that PASS the filter
    // - if you'd rather loop over ALL bank rows, iterate from `i=0` up to `i < hipo::bank::getRows()` instead
    for(auto const& row : bank_particle.getRowList()) {
      auto p = std::hypot(
          bank_particle.getFloat("px", row),
          bank_particle.getFloat("py", row),
          bank_particle.getFloat("pz", row));
      auto pdg    = bank_particle.getInt("pid", row);
      auto sector = bank_sector.getInt("sector", row);
      fmt::print("  {:<20} {:<20} {:<20.3f} {:<20}\n", row, pdg, p, sector);
    }
    fmt::print("\n");
  }
 
  // stop algorithms
  seq.Stop();
  return 0;
}