Plotting & iGraph on Lion and Mountain Lion

Note: this was previously posted at, but I am in the process of (re)organising my technical notes and tutorials.

After giving up on Gephi (again, I really should learn), I decided it was time to get to grips with Python and iGraph since I really need to produce multiple iterations of a graph. The matmos at CASA have, of course, been touting Python for ages, but I’ve just not had the time/incentive to install and, more importantly, actually get around to using it… until now. Of course, like all such migrations, there has been a bit of a learning curve, so I’m documenting this to save you (and me) the trouble later because it turns out that Lion and Mountain Lion aren’t 100% iGraph friendly out of the box.

iGraph itself is easy to install, you can just download and run the installer from SourceForge but the supporting libraries to enable plotting have some issues. Below is what I adapted from information provided by the people at  ffMpeg.

You will need to start by grabbing xz, which is (yet another) compression/decompression library promising better performance than the venerable gz or bzip:

make && sudo make install

You need xz so that you can decompress glib, but before you can compile glib, you will also need the latest version of gettext. Furthermore, per the instructions you will need to manually edit one of the files to get it to compile on Lion or Mountain Lion. Namely, open:


and change it such that you have added a line reading:

#undef stpncpy

just before the line reading:

#ifndef weak_alias

From there, it’s your usual:

make && sudo make install

Now you can finally move on to installing glib, which will be need for compiling Cairo properly. Note that this is the point where you have to start passing in more and more command line arguments to configure:

xz -d glib-2.33.10.tar.xz
tar -xvf glib-2.33.10.tar
cd glib-2.33.10
LIBFFI_CFLAGS=-I/usr/include/ffi LIBFFI_LIBS=-lffi ./configure; make && sudo make install

Phew, we’re getting there. Now it’s time for pkg-config:

GLIB_CFLAGS="-I/usr/local/include/glib-2.0 -I/usr/local/lib/glib-2.0/include" GLIB_LIBS="-lglib-2.0 -lgio-2.0" ./configure --with-pc-path="/usr/X11/lib/pkgconfig:/usr/X11/share/pkgconfig:/usr/lib/pkgconfig:/usr/local/lib/pkgconfig"
make && sudo make install

I was able to skip straight to installing pycairo because I had already installed Cairo as part of my last update to QGIS. The excellent KyngChaos has a handy set of installers to keep things simple.

And finally it’s time for pyCairo (you probably want py2cairo since OSX is using Python 2.7):

./waf configure
./waf build
sudo ./waf install

You may also care to add this line to your



export PYTHONPATH="/usr/lib/python2.7:$PYTHONPATH"

(You may also not want to add python2.6 or python2.5 to your Python path since this will give you some interesting errors… as I discovered.)