module DocumentSimilarity

Constants

VERSION

Public Class Methods

similarity(document, another_document) click to toggle source

# File lib/document_similarity.rb, line 5
def self.similarity(document, another_document)
  document_words = document.downcase.split(' ')
  another_document_words = another_document.downcase.split(' ')
  all_words = (document_words + another_document_words).uniq
  document_vector = self.document_vector(document_words, all_words)
  another_document_vector = self.document_vector(another_document_words, all_words)
  cosine_similarity = document_vector.inner_product(another_document_vector) / (document_vector.norm * another_document_vector.norm)
  cosine_similarity
end

Private Class Methods

document_vector(document_words, all_words) click to toggle source

# File lib/document_similarity.rb, line 17
def self.document_vector(document_words, all_words)
  Vector.elements(all_words.map { |word| document_words.select { |document_word| document_word == word }.size / document_words.size.to_f })
end