Multiple versions of R installed - terminal launching wrong / different R from RStudio

Question

I am attempting to compile my R package, and realized that I have multiple versions of R installed on my mac, which is giving me difficulty. When I run 'which R' from terminal, I receive this:

Home$ which R
/Users/Home/anaconda2/bin/R

Home$ R
R version 3.2.2 (2015-08-14) -- "Fire Safety"

However, when I launch RStudio from my applications folder, and type 'version' in the console, I get this:

> version
               _                           
platform       x86_64-apple-darwin13.4.0   
arch           x86_64                      
os             darwin13.4.0                
system         x86_64, darwin13.4.0        
status                                     
major          3                           
minor          3.2                         
year           2016                        
month          10                          
day            31                          
svn rev        71607                       
language       R                           
version.string R version 3.3.2 (2016-10-31)
nickname       Sincere Pumpkin Patch      

So I have 3.3.2 on RStudio (the version I want for compiling my package), and 3.2.2 from anaconda being launched in terminal when I type R in terminal.

How can I fix this? Do I have to change my path to find the correct version of R when I launch from terminal? How do I find the correct path?

Thanks!

Answer 1

I bet anaconda has just inserted its path at the front of your PATH variable and is overriding your newer 3.3.2 version at the terminal. If you want your 'RStudio' version to be the default version that pops up at your terminal when you type 'R', then you gotta modify your PATH. No biggie.

First, figure out which R version RStudio points to. Type the following into your RStudio console:

Sys.which("R")

I bet you'll see something like /usr/local/bin/R. So that's what you have to add to the front of your PATH (minus the '/R').

To confirm that anaconda has messed you up, open up your terminal and check out your PATH:

echo $PATH

You'll probably see /Users/YOURNAME/anaconda2/bin as the first entry in your PATH, and further down you'll see /usr/local/bin. We have to flip this order. There are a million ways to fix this. Here's the quick and dirty solution -- add the following to the bottom of your .bash_profile

export PATH="/usr/local/bin:$PATH"

And type R --version in your terminal to confirm that your default R has changed.

You might get fancy later with sed or awk if having two /usr/local/bin entries in your PATH annoys you (as it would me).