Mark Reid mreid

Keybase proof

I hereby claim:

I am mreid on github.
I am mreid (https://keybase.io/mreid) on keybase.
I have a public key whose fingerprint is 0290 8892 E023 A876 460B D320 2B84 F83F 283D 58D8

To claim this, I am signing this object:

The INSTALL instructions that come with Vowpal Wabbit appear not to work on Mac OS X Lion. Here's what I did to get it to compile. You will need the developer tools that come with the XCode installation.

The only dependency VW has is the boost C++ library. So first, download and install Boost

To install Boost, do the following:

$ cp ~/Downloads/boost_1_48_0.tar.bz2 ./

	# Example implementation of simple arithmetic coding in Python (2.7+).
	#
	# USAGE
	#
	# python -i arithmetic.py
	# >>> m = {'a': 1, 'b': 1, 'c': 1}
	# >>> model = dirichlet(m)
	# >>> encode(model, "aabbaacc")
	# '00011110011110010'
	#

	# Example Huffman coding implementation
	# Distributions are represented as dictionaries of { 'symbol': probability }
	# Codes are dictionaries too: { 'symbol': 'codeword' }

	def huffman(p):
	'''Return a Huffman code for an ensemble with distribution p.'''
	assert(sum(p.values()) == 1.0) # Ensure probabilities sum to 1

	# Base case of only two symbols, assign 0 or 1 arbitrarily
	if(len(p) == 2):

	# A command-line noisy channel
	#
	# USAGE: python channel.py BLOCK_SIZE FLIP_PROBABILITY
	#
	# EXAMPLE:
	# $ echo "0000000" \| python channel.py 7 0.8
	# 0000100
	#
	# AUTHOR: Mark Reid <[email protected]>
	# CREATED: 2013-10-21

	# Hamming (7,4) Coding
	#
	# Reads binary stream from standard input and outputs Hamming (7,4) encoded
	# version to standard output.
	#
	# USAGE: python h74-encode.py
	#
	# EXAMPLE:
	# $ echo "0001" \| python h74-encode.py
	# 1000101

	# LZ78 Encoding
	#
	# Performs LZ78 encoding on the standard input and writes result to standard output
	# using algorithm described in MacKay textbook.
	#
	# Note:
	# - All input symbols are encoded using 7-bit ASCII.
	# - Pointer index is encoded using logarithmically increasing number of bits
	#
	# USAGE: python lz78-encode.py

	# LZ77 Encoding
	#
	# Simple implementation of Lempel-Ziv 77 (a.k.a. "Sliding Window") coding
	# as described in Section 13.4 of Cover & Thomas' "Information Theory".
	#
	# USAGE: python encode.py INPUT_STREAM
	#
	# EXAMPLE (from lectures):
	# $ python encode.py abbababbababbab
	# (0,a)

	Running Snow Leopard 10.6.7 on a 2.66 GHz Intel Core 2 Duo iMac.

	Installed XCode 4 from the App Store (previous had XCode 3 installed under 10.5).

	----
	$ uname -a
	Darwin iMac.local 10.7.0 Darwin Kernel Version 10.7.0: Sat Jan 29 15:17:16 PST 2011; root:xnu-1504.9.37~1/RELEASE_I386 i386

	$ gcc --version
	i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5666) (dot 3)