catalogue.cpp

This example shows how to construct a catalogue of extragalactic objects

// ===================================================================
// Example code: how to construct a catalogue of extragalactic objects
// ===================================================================
 
#include "Catalogue.h"
 
int main () {
 
  try {
 
  
    std::string file_catalogue = "cat.dat";
  
  
    // -----------------------------------------------------------------------------------------
    // ------- method I : construct a galaxy catalogue directly by reading an input file ------- 
    // -----------------------------------------------------------------------------------------
  
    cbl::catalogue::Catalogue catalogue1 {cbl::catalogue::ObjectType::_Galaxy_, cbl::CoordinateType::_comoving_, {file_catalogue}};
 
    // standard
    std::cout << "The coordinates of the first galaxy in the catalogue are: " <<
      catalogue1.xx(0) << ", " << catalogue1.yy(0) << ", " << catalogue1.zz(0) << std::endl;
 
    // with vector syntax
    std::cout << "The coordinates of the first galaxy in the catalogue are: " <<
      catalogue1[0]->xx() << ", " << catalogue1[0]->yy() << ", " << catalogue1[0]->zz() << std::endl;
    
    
    // -----------------------------------------------------------------------------------------------------------------------
    // ------- method II : construct a galaxy catalogue directly from a file, choosing which quantity has to be read ---------
    // -----------------------------------------------------------------------------------------------------------------------
 
    // std::vector containing the quantities to be read
    std::vector<cbl::catalogue::Var> attribute = {cbl::catalogue::Var::_X_, cbl::catalogue::Var::_Y_, cbl::catalogue::Var::_Z_};
 
    // std::vector containing the columns corresponding to each quantity
    std::vector<int> column = {1, 2, 3};
    
    cbl::catalogue::Catalogue catalogue2 {cbl::catalogue::ObjectType::_Galaxy_, cbl::CoordinateType::_comoving_, attribute, column, {file_catalogue}};
 
    
    // -----------------------------------------------------------------------------------------------------------------
    // --------- method III : construct a galaxy catalogue using std::vectors to specify the galaxy properties ---------
    // -----------------------------------------------------------------------------------------------------------------
 
    std::ifstream fin; fin.open(file_catalogue.c_str()); cbl::checkIO(fin, file_catalogue);
  
    double X, Y, Z;
    std::vector<double> x, y, z;
  
    while (fin >> X >> Y >> Z) {
      x.emplace_back(X);
      y.emplace_back(Y);
      z.emplace_back(Z);
    }
  
    fin.clear();
  
    cbl::catalogue::Catalogue catalogue3 {cbl::catalogue::ObjectType::_Galaxy_, cbl::CoordinateType::_comoving_, x, y, z};
 
  
    // ------------------------------------------------------------------------------------------------------
    // -------- method IV : construct a std::vector of galaxies and add them into an empty catalogue --------
    // ------------------------------------------------------------------------------------------------------
 
    std::vector<std::shared_ptr<cbl::catalogue::Object>> object;
  
    fin.seekg(std::ios::beg);
  
    while (fin >> X >> Y >> Z) {
      cbl::comovingCoordinates coord = {X, Y, Z};
      auto galaxy = std::make_shared<cbl::catalogue::Galaxy>(coord);
      object.emplace_back(galaxy);
    }
  
    fin.clear(); fin.close();
 
    cbl::catalogue::Catalogue catalogue4; catalogue4.add_objects(object);
 
    
    // --------------------------------------------------------------
    // -------- method V : subsample a catalogue with a mask --------
    // --------------------------------------------------------------
 
    cbl::catalogue::mask_function mask = [&] (const std::shared_ptr<cbl::catalogue::Object> obj)
    {
      if (obj->xx()>-70 && obj->xx()<10)
        return true;
      return false;
    };
 
    cbl::catalogue::Catalogue catalogue5 = catalogue1.sub_catalogue(mask);
  
    std::cout << "The number of galaxy in catalogue1 is " << catalogue1.nObjects() << std::endl;
    std::cout << "The number of galaxy in catalogue2 is " << catalogue2.nObjects() << std::endl;
    std::cout << "The number of galaxy in catalogue3 is " << catalogue3.nObjects() << std::endl;
    std::cout << "The number of galaxy in catalogue4 is " << catalogue4.nObjects() << std::endl;
    std::cout << "The number of galaxy in catalogue5 is " << catalogue5.nObjects() << std::endl;
 
  }
 
  catch(cbl::glob::Exception &exc) { std::cerr << exc.what() << std::endl; exit(1); }
  
  return 0;
}