Class: Pedicab::RANK::KNN

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

Instance Method Summary collapse

Constructor Details

#initialize(strings) ⇒ KNN

Initialize with a collection of strings



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# File 'lib/pedicab/rank.rb', line 5

def initialize(strings)
  @strings = strings
end

Instance Method Details

#rank(id, query, k = 5, method: :levenshtein) ⇒ Object

Find k nearest neighbors to the query string Returns array of hashes with :string, :distance, and :similarity



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# File 'lib/pedicab/rank.rb', line 11

def rank(id, query, k = 5, method: :levenshtein)
  a, t = id.split("-") 
  return [] if @strings.empty?
  
  # Calculate distances for all strings
  distances = @strings.map do |str|
    dist = levenshtein_distance(query, str)
    {
      book: id,
      author: a,
      title: t,
      string: str.strip,
      distance: dist,
      similarity: 1.0 / (1.0 + dist)
    }
  end
  
  # Sort by distance (ascending) and take k nearest
  distances.sort_by { |d| d[:distance] }.take([k, @strings.length].min)
end