Module: RetrievalLite::Vector

Defined in:
lib/retrieval_lite/vector.rb

Class Method Summary collapse

Class Method Details

.cosine_similarity(scores1, scores2) ⇒ Float 



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# File 'lib/retrieval_lite/vector.rb', line 5

def self.cosine_similarity(scores1, scores2)
  length = (euclidean_length(scores1) * euclidean_length(scores2))
  if length == 0
    return 0
  else
    dot_product(scores1, scores2) / length
  end
end

.dot_product(scores1, scores2) ⇒ Float 



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# File 'lib/retrieval_lite/vector.rb', line 17

def self.dot_product(scores1, scores2)
  raise "document vectors are not of same length" if scores1.size != scores2.size
  
  sum = 0
  for i in 0...scores1.size
    sum += scores1[i]*scores2[i]
  end

  return sum
end

.euclidean_length(scores) ⇒ Float 



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# File 'lib/retrieval_lite/vector.rb', line 30

def self.euclidean_length(scores)
  sum = 0

  for i in 0...scores.size
    sum += scores[i] * scores[i]
  end

  Math.sqrt(sum)
end