integration_cuba.cpp

This example shows how to use the wrapper for CUBA multidimensiona integration functions

// ===============================================================================================
// Example code: how to integrate a multidimensional function using wrappers to the CUBA libraries
// ===============================================================================================
 
#include "Func.h"
 
int main () {
 
  try {
 
    // dimension of the integrand function
    const int ndim = 2;
 
    // function to be integrated
    auto integrand = [] (const std::vector<double> x)
      {
    double sum = 0.;
    for (size_t i=0; i<x.size(); i++)
      sum += x[i];
    return sum;
      };
    
    // limits of the integral
    std::vector<std::vector<double>> integration_limits(2);
    integration_limits[0] = {0., 2.};
    integration_limits[1] = {0., 2.};
 
    // wrapper to CUBA libraries
    cbl::wrapper::cuba::CUBAwrapper CW(integrand, ndim);
 
    // write the outputs
    std::cout << "The integral computed with Vegas is: " << CW.IntegrateVegas(integration_limits) << std::endl;
    std::cout << "The integral computed with Suave is: " << CW.IntegrateSuave(integration_limits) << std::endl;
    std::cout << "The integral computed with Divonne is: " << CW.IntegrateDivonne(integration_limits) << std::endl;
    std::cout << "The integral computed with Cuhre is: " << CW.IntegrateCuhre(integration_limits) << std::endl;
  
  }
 
  catch(cbl::glob::Exception &exc) { std::cerr << exc.what() << std::endl; exit(1); }
 
  return 0;
}