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examples
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examples
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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.
