text: /// functions to infect an agent and spread disease
  #pragma once
  
  #include <iostream>
  #include <fstream>
  #include <vector>
  #include <cmath>
  #include <algorithm> 
  #include <cassert>
  
  #include <Rcpp.h>
  #include <boost/geometry.hpp>
  #include <boost/geometry/geometries/point.hpp>
  #include <boost/geometry/index/rtree.hpp>
  
  #include "agent.hpp"
  
  /// function to infect n individual
  void popIntroPathogen(std::vector<Agent> &pop, const int nInfected);
  /// function to spread pathogen
  void popPathogenSpread(std::vector<Agent> &pop, const float perception,
                         const float pTransmit, const int t_);
  /// function for pathogen cost
  void popPathogenCost(std::vector<Agent> &pop, const float costInfection, const int t_);
  