fits.cpp

This example shows how to read/write a fits file

// ===========================================
// Example code: how to read/write a fits file
// ===========================================
 
#include "FITSwrapper.h"
 
int main () {
 
  try {
 
    // input file to read
    const std::string input_file = "catalogue.fits";
 
    // number of the table extension in the FITS file; a FITS can
    // contain more the one extension; the extension 0 is the primary
    // header
    const int next = 1;
 
    // the value used to fill non-existing columns, if
    // fill_value==par::defaultDouble, an error is raised when a
    // column is not found
    const double fill_value = 1.;
 
    // name of the columns in the Table
    const std::vector<std::string> column_names = {"XX", "YY", "ZZ", "Weight"};
   
    // read the columns from the table searching by names
    std::vector<std::vector<double>> table = cbl::wrapper::ccfits::read_table_fits(input_file, column_names, next, fill_value);
    std::cout << table[0][0] << " " <<table[1][0] << " " << table[2][0] << " " << table[3][0] << std::endl;
    
    // the unit of the columns, optional
    const std::vector<std::string> column_units = {"Mpc/h", "Mpc/h", "Mpc/h", ""};
 
    // write the output on a new fits file, adding the weight column
    cbl::wrapper::ccfits::write_table_fits("./", "catalogue_with_weights.fits", column_names, table, column_units);
  }
  
  catch(cbl::glob::Exception &exc) { std::cerr << exc.what() << std::endl; exit(1); }
  
  return 0;
}