Kevin's Blog

ROOT installation on OS X

In particle physics, when it comes to data analysis, CERN’s ROOT often is the tool of choice. It is a big and powerful framework that can do a lot of magical things. In this post, I don’t want to discuss its advantages or disadvantages but rather explain how I install it on Mac OS and why I do so.

There are always different ways to install ROOT. Although you might almost always want to work with the latest production version, be warned that new releases sometimes break compatibility with older code. You will have to decide for yourself whether you want to install via MacPorts and get to work quickly or compile from source and be able to maintain multiple versions on your system.

The easy way: MacPorts

If you don’t care about multiple versions and just want to get started, you can install ROOT via MacPorts with the following command. This will, however, install ROOT into your $PATH which might have unwanted side-effects.

sudo port install root

Additional features can be activated by adding +feature to the above line. The possible features are

clang30 clang31 clang32 clang33 clang34 clang35
gcc43 gcc44 gcc45 gcc46 gcc47 gcc48 gcc49

for manually choosing the compiler version,

python26 python27 python31 python32 python33 python34

for specifying a Python version,


for enabling support for Ruby,

mysql mysql51 mysql55
postgresql90 postgresql92

for adding database support, and a myriad of other options e.g for GUI frameworks or the TMVA framework for multivariate analysis:

avahi cocoa debug fftw3 fitsio graphviz gsl ldap minuit2
opengl percona pythia qt_mac roofit ruby soversion ssl
tmva x11 xml xrootd

Installation from Source

The following instructions are tested on OS X 10.9 and 10.8 and are most likely to also work in 10.7. Installation on 10.6 might be different but why would you be using such an old operating system, anyway?


You will have to install Apple’s XCode and the XCode Command Line Tools. XQuartz, the Mac OS implementation of the X11 framework, is mandatory.

From source

A more comprehensive documentation can be found on the official website.

The following lines will install a basic version of ROOT 5.34.18 to /opt/ROOT/5.34.18.

curl -O
tar xvzf root_v5.34.18.source.tar.gz
cd root
./configure --prefix=/opt/ROOT/5.34.18/
sudo make install

If you want to speed up the compilation, use make -jN where N should be 1.5 times the number of cores on your machine, e.g. make -j3 on my old dual-core MacBook Pro.

The configure step is where you can introduce additional options e.g. enable advanced packages or define custom paths. A comprehensive list of options can be obtained by running

./configure --help

My personal configuration looks something like this:

./configure macosx64 \
    --prefix=/opt/ROOT/5.34.18 \
    --with-clang \
    --enable-roofit \
    --enable-cocoa \
    --enable-c++11 \
    --with-python-incdir=/opt/local/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7/ \

The last to lines ensure that the MacPorts version of Python 2.7 is used. If you want to do the same, make sure Python 2.7 is the active version via

sudo port select python python27

Set up

Once the installation is finished, you can set up ROOT by running

cd /opt/ROOT/5.34.18
source bin/

Afterwards, typing


should start the interactive interpreter.

  *                                         *
  *        W E L C O M E  to  R O O T       *
  *                                         *
  *   Version   5.34/18     14 March 2014   *
  *                                         *
  *  You are welcome to visit our Web site  *
  *            *
  *                                         *

ROOT 5.34/18 (v5-34-18@v5-34-18, Mar 14 2014, 16:29:50 on macosx64)

CINT/ROOT C/C++ Interpreter version 5.18.00, July 2, 2010
Type ? for help. Commands must be C++ statements.
Enclose multiple statements between { }.
root [0]

You can exit by typing .q.