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20 lines
345 B
Ruby
20 lines
345 B
Ruby
class Array
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def entropy
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each_with_object(Hash.new(0)) do |i, result|
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result[i] += 1
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end.values.inject(0, :+) do |count|
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percentage = count.to_f / length
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-percentage * Math.log2(percentage)
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end
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end
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end
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module ArrayClassification
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refine Array do
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def classification
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collect(&:last)
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end
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end
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end
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