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Using Rcpp in Xcode

March 13, 2019
C++ R


In this tutorial, we’ll look at how you can configure Xcode to work with and debug Rcpp objects and methods.


I’m interested in building fast machine learning models with C++ and exposing those models to R, much like ranger and xgboost. Rcpp makes it easy to pass objects between R and C++. However, the only way to debug Rcpp code within RStudio that I’m aware of is to litter the code with print statements. On the other hand, Xcode is a fantastic IDE (for mac os) to build C++ applications. It comes equipped with a very handy debugging tool and I’d like to use it to step through and debug my Rcpp code.

Before we get started, let’s take a look at the end result in action.


Firstly, I’ll assume you have R, Rcpp, and Xcode installed and working.

  1. From R, install RInside with install.packages("RInside")
  2. Add necessary R header files to the Xcode Header Search Paths. For me, these paths are
    • /Library/Frameworks/R.framework/Headers/
    • /Library/Frameworks/R.framework/Versions/3.5/Resources/library/RInside/include/
    • /Library/Frameworks/R.framework/Versions/3.5/Resources/library/Rcpp/include/

  1. Add the R and RInside dynamic libraries to your Xcode project. For me, these are located in
    • /Library/Frameworks/R.framework/Versions/3.5/Resources/lib/libR.dylib
    • /Library/Frameworks/R.framework/Versions/3.5/Resources/library/RInside/lib/libRInside.dylib

  1. #include <Rcpp.h> and #include <RInside.h> somwhere in your C++ project
  2. Inside main, create and embedded R instance with RInside R(argc, argv);
  3. Give it a go!
#include <iostream>
#include <Rcpp.h>
#include <RInside.h>

int main(int argc, const char * argv[]) {
    // Create an embedded R instance
    RInside R(argc, argv);
    // Print Hello World to the console using Rcout
    Rcpp::Rcout << "Hello World!" << std::endl;
    // Make a numeric vector. Then calculate and print the mean
    Rcpp::NumericVector x = Rcpp::NumericVector::create(1, 2, 3);
    double y = Rcpp::mean(x);
    std::cout << "Mean: " << y << std::endl;
    return 0;

Special Thanks

I owe special thanks to Brian Hall for his article Linking Xcode, C++ and R to create plots. This article is basically a re-write of his. And of course thanks to Dirk Eddelbuettel for making Rcpp and RInside.

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