Python Install libraries

Installing numpy, scipy, matplotlib and Basemap on Mac OS X can be challenging.

Installation using homebrew

This installation path should work for all versions of Mac OS X, because every library involved and the python interpreter is self-compiled. Make sure to use the system compiler to be compatible to system libraries.

1. Install homebrew using the default settings.

   ruby -e "$(curl -fsSkL raw.github.com/mxcl/homebrew/go)"

2. Install necessary libraries and python.

   brew install gfortran python geos freetype

   brew link --force freetype

3. Install numpy via the python package manager pip which homebrew installed automatically with python.

   pip install numpy

4. Install scipy

   pip install scipy

5. Install matplotlib

   pip install matplotlib

6. Install ipython (not necessary, but recommended replacement for the standard python shell)

   pip install ipython

7. Install the python-imaging library, which is required for Basemap.

   pip install PIL

8. Basemap itself is unfortunately not available via pip, so you have to compile and install yourself. Download and extract the source code from the sourceforge repository. Then in the extracted directory run

   python setup.py build

   python setup.py install

Testing your installation

Open an python or ipython shell and type

1. to import and test numpy:

   import numpy as np

   np.test()

2. to import and test scipy:

   import scipy as sp

   sp.test()

3. to import and test matplotlib

   import matplotlib as mpl

   mpl.test()

4. to import Basemap

   from mpl_toolkits.basemap import Basemap

There should be no errors during the imports and during the tests.

De-Installation

Follow the above commands in the opposite order and replace install by uninstall.

Common pitfalls

• Make sure you have no other version of gcc installed. Check the output of

  which gcc

  to make sure to use the system compiler.

• Do not mix pre-compiled (installed by a *.dmg- or *.pkg file) and self-compiled libraries.