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did some renaming of main dirs (apps, libs, etc.)

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swaits committed 2005-05-09 22:53:48 +00:00
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rb/glicko2.rb
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#!/usr/bin/env ruby
#
#
# Copyright (c) 2004 Stephen Waits
#
# This software is provided 'as-is', without any express or implied warranty. In
# no event will the authors be held liable for any damages arising from the use
# of this software.
#
# Permission is granted to anyone to use this software for any purpose,
# including commercial applications, and to alter it and redistribute it freely,
# subject to the following restrictions:
#
# 1. The origin of this software must not be misrepresented; you must not claim
# that you wrote the original software. If you use this software in a
# product, an acknowledgment in the product documentation would be
# appreciated but is not required.
#
# 2. Altered source versions must be plainly marked as such, and must not be
# misrepresented as being the original software.
#
# 3. This notice may not be removed or altered from any source distribution.
#
#
# Glicko-2 Rating calculator class.
#
# This class implements the Glicko-2 rating system algorithm written by
# Professor Mark E. Glickman. All rating inputs and outputs are Glicko ratings,
# but internally everything is converted to and considered Glicko-2 ratings.
#
# Glicko-2 is an improvement on the original Glicko, which was, in turn, an
# improvement on the ELO system.
#
# The Glicko-2 system is specified on http://www.glicko.com/
#
class Glicko2
protected
# Glicko2 reprensentation (Glicko2 uses different scales from Glicko)
attr_accessor :g2rating, :g2deviation, :g2volatility
# a nested Class to hold a single result
Result = Struct.new(:opponent, :result)
public
WIN = 1.0
LOSS = 0.0
DRAW = 0.5
# Constructor with rating, rating deviation, and volatility optionally
# specified. If nothing specified, nitializes to a rating of 1500, a
# rating deviation of 350, and a volatility of 0.06.
def initialize(rating = 1500.0, deviation = 350.0, volatility = 0.06)
@dvolatility = 0.3
self.rating = rating
self.deviation = deviation
self.volatility = volatility
clear_results
end
include Comparable
# Comparison operator
def <=>(other)
self.rating <=> other.rating
end
# Get the current rating. This rating is a Glicko rating, not a Glicko2 rating.
# For details, please see http://www.glicko.com/
def rating
(@g2rating * 173.7178) + 1500.0
end
# Set Glicko rating. Internally this is converted to a Glicko2 rating.
# For details, please see http://www.glicko.com/
def rating=(r)
@g2rating = (r - 1500.0) / 173.7178
end
# Get the current rating deviation. This is a Glicko rating deviation, not a
# Glicko-2 RD. For details, please see http://www.glicko.com/
def deviation
@g2deviation * 173.7178
end
# Set Glicko rating deviation. Internally this is converted to a Glicko-2 RD.
# For details, please see http://www.glicko.com/
def deviation=(d)
@g2deviation = d / 173.7178
end
# Get the current rating volatility.
def volatility
@g2volatility
end
# Set rating volatility.
def volatility=(v)
@g2volatility = v
end
# Clear all results previously added via add_result(), add_win(), add_loss(),
# and/or add_draw(). This method is called automatically whenever update()
# is called.
def clear_results
@opponents = []
@results = []
end
# Add a result to this rating. Note that no calculation is performed until
# update() is called.
def add_result(opponent,result)
@results.push( Result.new(opponent.clone, result) )
end
# Add a win result to this rating. Note that no calculation is performed until
# update() is called.
def add_win(opponent)
add_result(opponent,Glicko2::WIN)
end
# Add a loss result to this rating. Note that no calculation is performed until
# update() is called.
def add_loss(opponent)
add_result(opponent,Glicko2::LOSS)
end
# Add a draw result to this rating. Note that no calculation is performed until
# update() is called.
def add_draw(opponent)
add_result(opponent,Glicko2::DRAW)
end
# Update rating based on current results list, and clear results.
def update
# util func
def Glicko2.g(deviation)
1.0 / (Math.sqrt(1.0 + 3.0 * deviation ** 2.0 / (Math::PI ** 2.0)))
end
# util func
def Glicko2.E(rating, rating_opponent, deviation_opponent)
1.0 / (1.0 + Math.exp(-Glicko2.g(deviation_opponent)*(rating - rating_opponent)));
end
# bail if no opponents set
if @results.empty?
return nil
end
# compute variance
#variance = 0.0
#@results.inject(0.0) do |variance,r|
# g_i = Glicko2.g(r.opponent.g2deviation)
# e_i = Glicko2.E(@g2rating,r.opponent.g2rating,r.opponent.g2deviation)
# g_i ** 2.0 * e_i * (1.0 - e_i)
#end
variance = 0.0
@results.each do |r|
g_i = Glicko2.g(r.opponent.g2deviation)
e_i = Glicko2.E(@g2rating,r.opponent.g2rating,r.opponent.g2deviation)
variance += g_i ** 2.0 * e_i * (1.0 - e_i)
end
variance = 1.0 / variance
# compute delta
delta = 0.0
@results.each do |r|
delta += Glicko2.g(r.opponent.g2deviation) * (r.result - Glicko2.E(@g2rating, r.opponent.g2rating, r.opponent.g2deviation))
end
delta *= variance
# determine new volatility
new_volatility = 0.0
a = Math.log( @g2volatility**2.0 )
x = 0.0
x_new = a
while ( (x - x_new).abs > 0.0000001 )
x = x_new
d = @g2deviation**2.0 + variance + Math.exp(x)
h1 = -(x - a)/(@dvolatility**2.0) - 0.5*Math.exp(x)/d + 0.5*Math.exp(x)*(delta/d)*(delta/d)
h2 = -1.0/(@dvolatility**2.0) - 0.5*Math.exp(x)*(@g2deviation**2.0+variance)/(d**2.0) + 0.5*(delta**2.0)*Math.exp(x)*((@g2deviation**2.0) + variance - Math.exp(x))/(d**3.0)
x_new = x - h1/h2
end
new_volatility = Math.exp(x_new / 2.0)
# update the rating deviation to the new pre-rating period value
pre_deviation = Math.sqrt( @g2deviation**2.0 + new_volatility**2.0 )
# update the rating and deviation
new_deviation = 1.0 / (Math.sqrt( 1.0/(pre_deviation**2.0) + 1.0 / variance))
new_rating = 0.0
@results.each do |r|
new_rating += Glicko2.g(r.opponent.g2deviation) * (r.result - Glicko2.E(@g2rating, r.opponent.g2rating, r.opponent.g2deviation))
end
new_rating = new_rating * new_deviation**2.0
new_rating += @g2rating
# wipe our result lists
clear_results
# copy new values
@g2deviation = new_deviation
@g2volatility = new_volatility
@g2rating = new_rating
end
end
A = Glicko2.new(1500.0, 200.0, 0.06)
B = Glicko2.new(1400.0, 30.0, 0.06)
C = Glicko2.new(1550.0, 100.0, 0.06)
D = Glicko2.new(1700.0, 300.0, 0.06)
A.add_win(B)
A.add_loss(C)
A.add_result(D,0.0)
A.update()
print "rating ", A.rating, " deviation ", A.deviation
rb/xmlrate.rb
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require "rexml/document"
file = File.new( "../py/data/hockey-2005.xml" )
doc = REXML::Document.new(file)
# each rating doc
doc.elements.each("ratingdoc") do |root|
# each player
root.elements.each("player") do |player|
name = player.elements["name"].text
rating = 1500.0
deviation = 350.0
variance = 0.06
# TODO: find better "Ruby-esqe" way of doing these
if player.elements["rating"]
rating = player.elements["rating"].text
end
if player.elements["deviation"]
deviation = player.elements["deviation"].text
end
if player.elements["variance"]
variance = player.elements["variance"].text
end
puts name,rating,deviation,variance
puts
end
# each rating period
root.elements.each("period") do |period|
# each regular game
period.elements.each("game") do |game|
puts "home",game.elements["home"].text
puts "away",game.elements["away"].text
puts "result",game.elements["result"].text
puts
end
# each race
period.elements.each("race") do |race|
race.elements.each("competitor") do |c|
puts c.text
end
puts
end
end
end