Class: AdaBoost::WeakClassifier

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(feature_number, split, alpha = 0.0, error = 0.0) ⇒ WeakClassifier

Returns a new instance of WeakClassifier.



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# File 'lib/adaboost/weak_classifier.rb', line 8

def initialize(feature_number, split, alpha = 0.0, error = 0.0)
  @feature_number = feature_number
  @split = split
  @error = error
  @alpha = alpha
end

Instance Attribute Details

#alpha ⇒ Object (readonly)

Returns the value of attribute alpha.



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# File 'lib/adaboost/weak_classifier.rb', line 6

def alpha
  @alpha
end

#error ⇒ Object

Returns the value of attribute error.



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# File 'lib/adaboost/weak_classifier.rb', line 5

def error
  @error
end

#feature_number ⇒ Object (readonly)

Returns the value of attribute feature_number.



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# File 'lib/adaboost/weak_classifier.rb', line 6

def feature_number
  @feature_number
end

#split ⇒ Object (readonly)

Returns the value of attribute split.



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# File 'lib/adaboost/weak_classifier.rb', line 6

def split
  @split
end

Instance Method Details

#classify(sample) ⇒ Object 



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# File 'lib/adaboost/weak_classifier.rb', line 19

def classify(sample)
  sample[@feature_number] > @split ? 1 : -1
end

#classify_with_alpha(sample) ⇒ Object 



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# File 'lib/adaboost/weak_classifier.rb', line 23

def classify_with_alpha(sample)
  return classify(sample) * @alpha
end

#compute_alpha ⇒ Object 



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# File 'lib/adaboost/weak_classifier.rb', line 15

def compute_alpha
  @alpha = 0.5 * Math.log((1.0 - @error) / @error)
end

#increase_error(amount) ⇒ Object 



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# File 'lib/adaboost/weak_classifier.rb', line 27

def increase_error(amount)
  @error += amount
end