# Installing RCall.jl

RCall.jl can simply be installed with

Pkg.add("RCall")

## Customizing the R installation

The RCall build script (run by Pkg.add) will check for an existing R installation by looking in the following locations, in order.

• The R_HOME environment variable, if set, should be the location of the R home directory. You could run R.home() in R to determine its location.
• Otherwise, it runs the R RHOME command, assuming R is located in your PATH.
• Otherwise, on Windows, it looks in the Windows registry.

To change which R installation is used for RCall, set the R_HOME environment variable and run Pkg.build("RCall"). Once this is configured, RCall remembers the location of R in future updates, so you don't need to set R_HOME permanently.

ENV["R_HOME"] = "....directory of R home...."
Pkg.build("RCall")

When R_HOME is set to "*", RCall.jl will automatically install R for you using Conda.

Should you experience problems with any of these methods, please open an issue.

## Standard installations

If you want to install R yourself, rather than relying on the automatic Conda installation, you can use one of the following options:

### Windows

The current Windows binary from CRAN.

### OS X

The CRAN .pkg or the homebrew/science tap.

### Linux

Most Linux distributions allow installation of R from their package manager, however these are often out of date, and may not work with RCall.jl. We recommend that you use the updated repositories from CRAN.

#### Ubuntu

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E084DAB9

### Other methods

If you have installed R by some other method (e.g. building from scratch, or files copied but not installed in the usual manner), which often happens on cluster installations, then you may need to set R_HOME or your PATH as described above before running Pkg.build("RCall") in order for the build script to find your R installation. RCall requries R to be installed with its shared library. It could be done with the flag --enable-R-shlib, consult your server administrator to see if it was the case.

For some environments, you might also need to specify LD_LIBRARY_PATH

export LD_LIBRARY_PATH="\$LD_LIBRARY_PATH:R RHOME/lib"

## Updating R

If you have updated your R installation, you may need to re-run Pkg.build("RCall") as described above, possibly changing the R_HOME` environment variable first.