An exaple of calling R function in RcppArmadillo

rpgcall.cpp

#include <RcppArmadillo.h>
// [[Rcpp::depends(RcppArmadillo)]]
using namespace Rcpp;

// [[Rcpp::export]]
arma::vec rpg_call(const arma::vec & h, const arma::vec & z){
  Environment pkg = Environment::namespace_env("BayesLogit");
  Function f = pkg["rpg"];
  NumericVector out = f(Rcpp::Named("num", h.n_elem),
                        Rcpp::Named("h",h),
                        Rcpp::Named("z",z));
  return as<arma::vec>(out);
}