Atlas of Lie Groups and Representations

These pages are under construction, 25 September 1066

linux installation  Mac installation  Main installation page

Compiling atlas for the Mac using gcc

The main point is that you need a "true" gcc compiler, at least gcc 4.4. The versions supplied with Xcode (at least up to XCode 7.2.1) will not compile atlas (as explained here). But using the XCode compiler, there are many ways to get a true gcc compiler. If you are not able to follow our recommended MacPorts installation, you are on your own. We hear good things about Homebrew.

We will retain here old instructions based on Compiling gcc 4.6.2 on Mac OSX Lion.

The idea is to install gcc (not llvm-gcc, see mac C compilers) in a custom directory, safely away from all XCode and other C libraries.

(1) Create a directory my-gcc in your home directory username/my-gcc.

(2) Install the XCode C compiler. If you already have XCode installed, go to step (3) (XCode is not installed by default).

The XCode package is huge, and includes a lot of unnecessary tools. We recommend downloading and installing just the XCode command line tools, which have everything you need. Alternatively install the entire Xcode package. In either case you will need a (free) Apple ID.

Once you have installed XCode, or just the command line tools, you will have a C compiler /usr/bin/gcc

(3) install gmp from Double click on gmp-5.0.2.tar.bz2, to extract the library into your Downloads folder. Open a terminal window, and do the following:

cd Downloads
cd gmp*
mkdir build
cd build
../configure --prefix=$HOME/my_gcc

If all goes well this will install the gmp libraries in your my-gcc directory.

(4) Follow similar steps to install mpfr from

(5) Follow similar steps to install mpc from

(6) Follow similar steps to install gcc from This takes a long time.

(7) Follow similar steps to install readline from
It may be necessary to use

make static

(there is a bug that prevents dynamic linking)

(8) Give the command

export PATH=$HOME/my-gcc:$PATH

to add my-gcc to your path environment variable.

(9) Edit the atlas makefile to read:

#the default compiler
CXX = my-g++

Proceed to Step (6) in the MacPorts installation process.

linux installation  Windows installation  Main installation page