Python modules

There a several modules which are already included in the standard Python distribution:

• http://docs.python.org/modindex.html

Other modules have to be installed seperately, e.g. Numpy, Scipy, Pylab, etc.

• http://www.scipy.org/

• http://www.pythonxy.com/ Python(x,y) is a scientific python distribution with many modules included

Over 8000 special purpose modules and scripts can be found in the Python Package Index:

• http://pypi.python.org/pypi

It is important to know where to find the functions that you need. We will go through some useful examples.

Numpy, Scipy and Pylab

Numpy

Numpy is the core library for multidimensional array objects (ndarray) and linear algebra. Most other scientific modules use the numpy array object. Numpy arrays and standard Python sequences have important differences:

• Numpy arrays have a fixed size at creation, unlike Python lists
• Numpy arrays facilitate mathematical operations on large numbers of data efficiently

The User's guide PDF provides a good introduction.

Scipy

The scipy module uses the numpy array

functionsPylab (aka Matplotlib) uses scipy and numpy and offers high-level functions that are similar in the name and syntax to those offered by Matlab.

User guide and references

• http://docs.scipy.org/doc/

• http://docs.scipy.org/doc/numpy/user/ (start reading this user's guide) PDF

• http://matplotlib.sourceforge.net/

Recommended book

• http://www.springer.com/math/cse/book/978-3-540-73915-9 Python Scripting for Computational Science

Importing Scipy

The statement

from pylab import *

imports the most important functions/objects for numerical computation and plotting.

Slides for teaching

• http://heim.ifi.uio.no/~hpl/scripting/all-nosplit/index.html (some are outdated)