Class: TrueSkillObject

Inherits:
Object
  • Object
show all
Defined in:
lib/TrueSkill/TrueSkill.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(mu = MU, sigma = SIGMA, beta = BETA, tau = TAU, draw_probability = DRAW_PROBABILITY) ⇒ TrueSkillObject

Returns a new instance of TrueSkillObject.



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# File 'lib/TrueSkill/TrueSkill.rb', line 12

def initialize(mu=MU, sigma=SIGMA, beta=BETA, tau=TAU,draw_probability=DRAW_PROBABILITY)
  @mu=mu
  @sigma=sigma
  @beta=beta
  @tau=tau
  @draw_probability=draw_probability
end

Instance Attribute Details

#beta ⇒ Object

Returns the value of attribute beta.



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# File 'lib/TrueSkill/TrueSkill.rb', line 4

def beta
  @beta
end

#draw_probability ⇒ Object

Returns the value of attribute draw_probability.



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# File 'lib/TrueSkill/TrueSkill.rb', line 4

def draw_probability
  @draw_probability
end

#mu ⇒ Object

Returns the value of attribute mu.



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# File 'lib/TrueSkill/TrueSkill.rb', line 4

def mu
  @mu
end

#sigma ⇒ Object

Returns the value of attribute sigma.



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# File 'lib/TrueSkill/TrueSkill.rb', line 4

def sigma
  @sigma
end

#tau ⇒ Object

Returns the value of attribute tau.



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# File 'lib/TrueSkill/TrueSkill.rb', line 4

def tau
  @tau
end

Instance Method Details

#build_factor_graph(rating_groups, ranks) ⇒ Object 



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# File 'lib/TrueSkill/TrueSkill.rb', line 48

def build_factor_graph(rating_groups,ranks)
  ratings=rating_groups.flatten
  size=ratings.length
  group_size=rating_groups.length
  rating_vars=[]
  size.times { rating_vars << Variable.new}
  
  perf_vars=[]
  size.times { perf_vars << Variable.new}
  
  teamperf_vars=[]
  group_size.times { teamperf_vars << Variable.new}
  
  teamdiff_vars=[]
  (group_size-1).times { teamdiff_vars << Variable.new}
  
  team_sizes=_team_sizes(rating_groups)
  get_perf_vars_by_team=lambda do |team|
    if team > 0
      start=team_sizes[team-1]
    else
      start=0
    end
    endv=team_sizes[team]
    return perf_vars[start,endv]
  end
  
  build_rating_layer=lambda do
    Enumerator.new do |yielder|
    
      rating_vars.zip(ratings).each do |rating_var,rating|
        yielder.yield(PriorFactor.new(rating_var,rating,@tau))
      end
    end
  end
  build_perf_layer=lambda do
    Enumerator.new do |yielder|
    
      rating_vars.zip(perf_vars).each do |rating_var,perf_var|
        yielder.yield(LikelihoodFactor.new(rating_var,perf_var,@beta**2))
      end
    end
  end
  build_teamperf_layer=lambda do
   Enumerator.new do |yielder|
     teamperf_vars.each_with_index do |teamperf_var,team|
        child_perf_vars = get_perf_vars_by_team.call(team)
        yielder.yield(SumFactor.new(teamperf_var,child_perf_vars,[1]*child_perf_vars.length))
     end
   end
 end
 build_teamdiff_layer=lambda do
  Enumerator.new do |yielder|
    teamdiff_vars.each_with_index do |teamdiff_var,team|
      yielder.yield(SumFactor.new(teamdiff_var,teamperf_vars[team,team=2],[+1,-1]))
    end
  end
 end
 build_trunc_layer=lambda do
  Enumerator.new do |yielder|
    teamdiff_vars.each_with_index do |teamdiff_var,x|
      size=0
      rating_groups[x,x+2].each do |group|
        size+=group.length
      end
      draw_margin=calc_draw_margin(@draw_probability,@beta,size)
      
      if ranks[x]==ranks[x+1]
        v_func,w_func=$v_drawFunc,$w_drawFunc
      else
        v_func,w_func=$vFunc,$wFunc
      end
      yielder.yield(TruncateFactor.new(teamdiff_var,v_func,w_func,draw_margin))
    end
  end
 end
 
 return Array(build_rating_layer.call),Array(build_perf_layer.call),Array(build_teamperf_layer.call),Array(build_teamdiff_layer.call),Array(build_trunc_layer.call)
end

#make_as_global ⇒ Object 



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# File 'lib/TrueSkill/TrueSkill.rb', line 31

def make_as_global
  return setup(nil,nil,nil,nil,nil,self)
end

#Rating(mu = nil, sigma = nil) ⇒ Object 



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# File 'lib/TrueSkill/TrueSkill.rb', line 21

def Rating(mu=nil,sigma=nil)
  if mu.nil?
    mu=@mu
  end
  if sigma.nil?
    sigma=@sigma
  end
  return Rating.new mu,sigma
end

#run_schedule(rating_layer, perf_layer, teamperf_layer, teamdiff_layer, trunc_layer, min_delta = DELTA) ⇒ Object 



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# File 'lib/TrueSkill/TrueSkill.rb', line 128

def run_schedule(rating_layer, perf_layer, teamperf_layer,teamdiff_layer, trunc_layer, min_delta=DELTA)
  [rating_layer,perf_layer,teamperf_layer].flatten.each do |f|
    f.down
  end
  teamdiff_len=teamdiff_layer.length
  (10).times do |x|
    if teamdiff_len==1
      teamdiff_layer[0].down
      delta=trunc_layer[0].up
    else
      delta=0
      (teamdiff_len-1).times do |x2|
        teamdiff_layer[x2].down
        delta=[delta,trunc_layer[x].up].max
        teamdiff_layer[x].up(1)
      end
      (teamdiff_len-1).step(0,-1) do |x2|
        teamdiff_layer[x2].down
        delta=[delta,trunc_layer[x].up].max
        teamdiff_layer[x].up(0)
      end
    end
    if delta<=min_delta
      break
    end
  end
  teamdiff_layer.first.up(0)
  teamdiff_layer.last.up(1)
  teamperf_layer.each do |f|
    (f.vars.length-1).times do |x|
      f.up(x)
    end
  end
  perf_layer.each do |f|
    f.up
  end
end

#transform_ratings(rating_groups, ranks = nil, min_delta = DELTA) ⇒ Object 



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# File 'lib/TrueSkill/TrueSkill.rb', line 165

def transform_ratings(rating_groups, ranks=nil, min_delta=DELTA)
  rating_groups=validate_rating_groups(rating_groups)
  group_size=rating_groups.length
  if ranks.nil?
    ranks=Array(0..group_size-1)
  end
  sorting=ranks.zip(rating_groups).each_with_index.to_a.map {|x| x.reverse}.sort { |x,y| x[1][0] <=> y[1][0]}
  sorted_groups=[]
  sorting.each do |x,g|
    sorted_groups << g[1]
  end
  sorted_ranks=ranks.sort()
  unsorting_hint=[]
  sorting.each do |x,g|
    unsorting_hint << x
  end
  layers=build_factor_graph(sorted_groups,sorted_ranks)
  run_schedule(layers[0],layers[1],layers[2],layers[3],layers[4])
  rating_layer,team_sizes=layers[0],_team_sizes(sorted_groups)
  transformed_groups=[]
  ([0]+team_sizes.take(team_sizes.size - 1)).zip(team_sizes).each do |start,ending|
    group=[]
    rating_layer[start,ending].each do |f|
      group << Rating.new(f.var.mu,f.var.sigma)
    end
    transformed_groups << Array(group)
  end
  unsorting=unsorting_hint.zip(transformed_groups).sort { |x,y| x[0]<=>y[0]}
  output=[]
  unsorting.each do |x,g|
    output << g
  end
  return output
end

#validate_rating_groups(rating_groups) ⇒ Object 



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# File 'lib/TrueSkill/TrueSkill.rb', line 34

def validate_rating_groups(rating_groups)
  rating_groups.each do |group|
    if group.is_a? Rating
      group=[group,]
    end
    if group.length==0
      raise "each group must contain multiple ratings"
    end
  end
  if rating_groups.length<2
    raise "need multiple rating groups"
  end
  return rating_groups
end