simplerandom 0.5.0

Simple random number generators

Author:

Craig McQueen

Contact:

http://craig.mcqueen.id.au/

Copyright:

2010 Craig McQueen

Simple pseudo-random number generators, from George Marsaglia.

Intro

The simplerandom package is provided, which contains modules containing classes for various simple pseudo-random number generators.

The algorithms were obtained from a newsgroup post by George Marsaglia [1]. The algorithms were specified in C in the newsgroup post. For the purpose of prototyping software in a high-level language such as Python, before writing it in faster C, it is useful to have identical algorithms implemented in both Python and C.

One module provides Python iterators, which generate simple unsigned 32-bit integers identical to their C counterparts.

Another module provides random classes that are sub-classed from the class Random in the random module of the standard Python library.

References

[1] (1,2)

Random Numbers for C: End, at last?

George Marsaglia

Newsgroup post, sci.stat.math and others, Thu, 21 Jan 1999

Modules Provided

Module	Description
simplerandom.iterators	Iterator classes, which generate unsigned 32-bit integers.
simplerandom.random	Classes that conform to standard Python random.Random API.

Usage

Iterators

>>> import simplerandom.iterators as sri
>>> rng = sri.RandomKISSIterator(123958, 34987243, 3495825239, 2398172431)
>>> next(rng)
21111917L
>>> next(rng)
1327965872L
>>> next(rng)
2128842716L

Random class API

>>> import simplerandom.random as srr
>>> rng = srr.RandomKISS(258725234)
>>> rng.random()
0.30631872435766117
>>> rng.random()
0.43903576112750442
>>> rng.random()
0.69756297733927486

Supported Python Versions

Currently this has been tested on Python 2.6 on Ubuntu 32-bit. It will most likely work on Python 2.7.

The pure Python code is expected to work on 64-bit platforms. The Cython version of simplerandom.iterators should work on 64-bit platforms, but has not been tested.

Some preliminary testing has been done on Python 3.x support. It seems to work after conversion using 2to3, but this hasn’t been incorporated into the Python package yet.

The plan is to support Python >= 2.5 and 3.x.

Installation

The simplerandom package is installed using distutils. If you have the tools installed to build a Python extension module, run the following command:

python setup.py install

If you cannot build the C extension, you may install just the pure Python implementation, using the following command:

python setup.py build_py install --skip-build

Unit Testing

Basic unit testing of the iterators is in simplerandom.iterators.test. It duplicates the tests of the C algorithms given in the original newsgroup post [1]. It should print seven lines, all containing 0.

To run it on Python >=2.5:

python -m simplerandom.iterators.test

Alternatively, in the test directory run:

python test_iterators.py

Documentation

No documentation is yet written, apart from this README.txt. The plan is to write documentation using Sphinx, and provide it online at:

http://packages.python.org/simplerandom/

License

The code is released under the MIT license. See LICENSE.txt for details.