# Introduction

Compiled code in R is the zeitgeist echoing throughout all corridors of user styles. The advent of Rcpp and the afforded seamless transition between R objects and C++ objects has yielded countless accolades. However, there is a gatekeeper to enabling Rcpp outside of the R environment: A compiler. Enter into the picture Rtools, which provides a toolchain to compile code with R for Windows.

## Prerequisite

In order to follow this installation guide, you must:

1. Be on Windows 7 or greater.
2. Have R version 3.3.0 or greater.
• Rtools radically changed before then
3. Be able to launch an application via “Run as Administrator” prompt.

## R Compilers for Other Platforms

This installation guide is specific to Windows operating systems >= Windows 7.

If you are on MacOS, please see: http://thecoatlessprofessor.com/programming/r-compiler-tools-for-rcpp-on-os-x/

For those of you on Linux, you can either use:

# RHEL/CentOS
sudo yum update
sudo yum install R

# Ubuntu
sudo apt-get update
sudo apt-get install r-base r-base-dev


# Install Guide

The steps below will guide you through setting up the Rtools toolchain on Windows. The version these steps are done for is Rtools 3.4. Generally, each R point release (x.y.0) yields an equivalent Rtools release.

## Installation Steps

• Step 3: Open the folder location where Rtools can be found.
• Step 4: Right click on the “Rtools34.exe” and select “Run as administrator”

• Step 4: Accept the UAC prompt that appears

• Step 5: Select the appropriate language and press “OK”

• Step 6: Press “Next” to begin the install process

• Step 7: Agree to the terms of the licenses used by the toolchain by pressing “Next”.

• Step 8: Select the install directory for Rtools and press “Next”.
• I strongly recommend against switching away from the default.
• Default directory: c:\Rtools

• Step 9: Ensure only the installer is following the “Package authoring installation” guidelines and press “Next”.

• Step 10: Elect to modify the Windows PATH variable to contain a reference to where the Rtools install directorys are by pressing “Next”.

• Step 11: Ensure that the PATH variable in the following order before pressing “Next”.
• c:\Rtools\bin;
• c:\Rtools\mingw_32\bin;

• Step 12: Note the changes to the installer will make before pressing “Next” to begin installing each component.

• Step 13: Wait patiently as Rtools installs on your system….

• Step 14: Rejoice as Rtools is now installed on your system!

If you are unsure of manually downloading the program, please use the installr package to download and install Rtools.

# install.packages("installr")
library("installr")
install.Rtools()


This will automatically download Rtools and give you the previous installer prompts.

## Verifying Install

Open your IDE of choice and type:

install.packages("Rcpp")
Rcpp::evalCpp("2+2")


If the output is not a number (psst 4), then there is an issue with the Rtools install. Please google the error and let us know about it!

## Common Issues

Failure to install Rcpp prior to calling Rcpp::evalCpp("2+2") yields:

Error in if (grepl(” “, path, fixed = TRUE)) path <- utils::shortPathName(path) :

argument is of length zero