Class: Statfeed

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

Constant Summary collapse

VERSION = 
"1.0.1"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(decisions, options, heterogeneity: 0.1, accent: 1.0) ⇒ Statfeed

Returns a new instance of Statfeed.



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# File 'lib/statfeed.rb', line 5

def initialize decisions, options, heterogeneity: 0.1, accent: 1.0
  @decisions = decisions
  @options = options

  # This will eventually be the result of applying statistical feedback
  @choices = Array.new(@decisions.size, nil)

  # Vector of heterogeneity values for each decision
  @heterogeneities = Array.new(decisions.size, heterogeneity)
  # Vector of accent values for each decision
  @accents = Array.new(decisions.size, accent)
  # Vector of statistic for each option
  reset_statistics

  # Fill matrix of random values
  populate_randoms
  # Fill matrix of weights
  populate_weights
end

Instance Attribute Details

#accents ⇒ Object

Returns the value of attribute accents.



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# File 'lib/statfeed.rb', line 3

def accents
  @accents
end

#choices ⇒ Object

Returns the value of attribute choices.



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# File 'lib/statfeed.rb', line 3

def choices
  @choices
end

#decisions ⇒ Object

Returns the value of attribute decisions.



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# File 'lib/statfeed.rb', line 3

def decisions
  @decisions
end

#heterogeneities ⇒ Object

Returns the value of attribute heterogeneities.



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# File 'lib/statfeed.rb', line 3

def heterogeneities
  @heterogeneities
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/statfeed.rb', line 3

def options
  @options
end

#randoms ⇒ Object

Returns the value of attribute randoms.



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# File 'lib/statfeed.rb', line 3

def randoms
  @randoms
end

#size ⇒ Object

Returns the value of attribute size.



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# File 'lib/statfeed.rb', line 3

def size
  @size
end

#statistics ⇒ Object

Returns the value of attribute statistics.



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# File 'lib/statfeed.rb', line 3

def statistics
  @statistics
end

#weights ⇒ Object

Returns the value of attribute weights.



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# File 'lib/statfeed.rb', line 3

def weights
  @weights
end

Instance Method Details

#expected_increment(decision, option) ⇒ Object 



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# File 'lib/statfeed.rb', line 55

def expected_increment decision, option
  (@accents[decision] + (@heterogeneities[decision] * @randoms[decision][option])).to_f / @weights[decision][option]
end

#increment_statistics(decision, option) ⇒ Object 



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# File 'lib/statfeed.rb', line 83

def increment_statistics decision, option
  @statistics[option] += true_increment(decision, option)
end

#normalization_value(decision) ⇒ Object 



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# File 'lib/statfeed.rb', line 63

def normalization_value decision
  @accents[decision].to_f / @weights[decision].inject(0.0, :+)
end

#normalize_statistics(decision) ⇒ Object 



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# File 'lib/statfeed.rb', line 87

def normalize_statistics decision
  @statistics.each_with_index.map do |statistic, m|
    if @weights[decision][m] > 0.0
      statistic - normalization_value(decision)
    else
      statistic
    end
  end
end

#normalize_statistics!(decision) ⇒ Object 



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# File 'lib/statfeed.rb', line 97

def normalize_statistics! decision
  @statistics = normalize_statistics decision
end

#populate_choices ⇒ Object 



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# File 'lib/statfeed.rb', line 29

def populate_choices
  @decisions.each_index do |decision|
    vals = scheduling_values(decision)
    @choices[decision] = sort_options(vals).first
    increment_statistics decision, sort_option_indices(vals).first
    normalize_statistics! decision
  end
  @choices
end

#populate_randoms ⇒ Object 



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# File 'lib/statfeed.rb', line 39

def populate_randoms
  @randoms = Array.new @decisions.size do
    Array.new @options.size do
      rand
    end
  end
end

#populate_weights ⇒ Object 



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# File 'lib/statfeed.rb', line 47

def populate_weights
  @weights = Array.new @decisions.size do
    Array.new @options.size do
      1.0 / @options.size
    end
  end
end

#reset_statistics ⇒ Object 



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# File 'lib/statfeed.rb', line 25

def reset_statistics
  @statistics = Array.new(options.size, 0.0)
end

#sample ⇒ Object 



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# File 'lib/statfeed.rb', line 101

def sample
  # Accumulator value
  acc = 0.0
  # Map the cumulative weights
  cdf = @weights.map { |w| acc += w }
  # Get a random number between 0.0 and the last value
  r = rand(cdf.last)
  # Gets the first number that's less than the random number
  index = cdf.find_index { |c| c > r }
  
  @weights = @weights.map { |w|
    # Increment the full thing by a total of 1.0
    w += (@weights[index].to_f / (@weights.size-1.0))
  }
  @weights[index] = 0

  if block_given?
    yield index
  else
    index
  end
end

#scheduling_values(decision) ⇒ Object 



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# File 'lib/statfeed.rb', line 67

def scheduling_values decision
  (0...@options.size).map do |m|
    @statistics[m] + expected_increment(decision, m)
  end
end

#sort_option_indices(vals) ⇒ Object

Feed the scheduling values into this (step 2)



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# File 'lib/statfeed.rb', line 79

def sort_option_indices vals
  (0...@options.size).to_a.zip(vals).sort_by(&:last).map(&:first)
end

#sort_options(vals) ⇒ Object

Feed the scheduling values into this (step 2)



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# File 'lib/statfeed.rb', line 74

def sort_options vals
  @options.zip(vals).sort_by(&:last).map(&:first)
end

#true_increment(decision, option) ⇒ Object 



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# File 'lib/statfeed.rb', line 59

def true_increment decision, option
  @accents[decision].to_f / @weights[decision][option]
end