R Statistics Cookbook

How it works...

The sourcecpp function loads the C++ or Rcpp code from an external script and compiles it. In this C++ file, we first include the Rcpp headers that will allow us to add R functionality to our C++ script. We use using namespace Rcpp to tell the compiler that we want to work with that namespace (so we avoid the need to type Rcpp:: when using Rcpp functionality). The Rcpp::export declaration tells the compiler that we want to export this function to R.

Our bring_element function will return an integer (so that is why we have an int in its declaration). The arguments will be NumericVector and NumericMatrix, which are not C++ native variable types but Rcpp ones. These allow us to use vectors and matrices that operate with numbers ...