bloom.py:

Demonstrates the implementation of a Bloom filter, see:

http://en.wikipedia.org/wiki/Bloom_filter

compress.py:

Demonstrates how the bz2 module may be used to create a compressed

object which represents a bitarray

decoding.py

Bitarray's decode method is implemented in C. Since the C code

might be hard to read, we have implemented exactly the same

algorithm in Python. It is about 20 times slower than it's

C counterpart, since (recursive) function calls are more expensive

in Python than in C.

huffman.py

Demonstrates building a Huffman tree. Given an input file,

calculates the number of occurrences for each character;

from those frequencies, a Huffman tree is build; and by traversing

the tree, the Huffman code is evaluated.

Also allows encoding and decoding of a file, see -h option.

mandel.py

Generates a .ppm image file of size 8000x6000 of the Mandelbrot set.

Despite it's size, the output image file has only a size of slightly

over 6 Million bytes (uncompressed) because each pixel is stored in

one bit.

Requires numpy and scipy (see http://scipy.org/).

Not supported by Python 3.x.

ndarray.py

Demonstrates how to efficiently convert boolean data from a bitarray

to a numpy.ndarray of dtype bool.

Requires numpy.

pbm.py

Defines a simple class called PBM (Portable Bit Map) which allows:

- addressing pixels by their coordinates

- storing and loading .ppm (P4), which is the same as .pbm, files

sieve.py

Sieve of Eratosthenes is a simple, ancient algorithm for finding all

prime numbers up to a specified integer. In this exmaple, the algorithm

is implemented using the numpy ndarray as well as the bitarray object.

Thanks Steve for emailing this example.

smallints.py

A class is defined which allows efficiently storing an array of

integers represented by a specified number of bits (1 through 8).

For example, an array with 1000 5 bit integers can be created,

allowing each element in the array to take values form 0 to 31,

while the size of the object is 625 (5000/8) bytes.

Thanks to David Kammeyer for the idea to apply a bitarray in this way.