numerology.rb

module Numerology
  Standard = {
    '1' => 1, '4' => 4, '7' => 7,
    '2' => 2, '5' => 5, '8' => 8,
    '3' => 3, '6' => 6, '9' => 9,
    'A' => 1, 'J' => 1, 'S' => 1,
    'B' => 2, 'K' => 2, 'T' => 2,
    'C' => 3, 'L' => 3, 'U' => 3,
    'D' => 4, 'M' => 4, 'V' => 4,
    'E' => 5, 'N' => 5, 'W' => 5,
    'F' => 6, 'O' => 6, 'X' => 6,
    'G' => 7, 'P' => 7, 'Y' => 7,
    'H' => 8, 'Q' => 8, 'Z' => 8,
    'I' => 9, 'R' => 9
  }

  Chaldean = {
    '1' => 1, '4' => 4, '7' => 7,
    '2' => 2, '5' => 5, '8' => 8,
    '3' => 3, '6' => 6, '9' => 9,
    'A' => 1, 'J' => 1, 'S' => 3,
    'B' => 2, 'K' => 2, 'T' => 4,
    'C' => 3, 'L' => 3, 'U' => 6,
    'D' => 4, 'M' => 4, 'V' => 6,
    'E' => 5, 'N' => 5, 'W' => 6,
    'F' => 8, 'O' => 7, 'X' => 5,
    'G' => 3, 'P' => 8, 'Y' => 1,
    'H' => 5, 'Q' => 1, 'Z' => 7,
    'I' => 1, 'R' => 2
  }
  
  def self.calculate(str, mapping = Standard)
    sum = str.gsub(/[^a-z]/,'').upcase.split(//).inject(0) do |v,l|
      v += mapping[l] || 0
    end % 9
    
    sum == 0 ? 9 : sum
  end
end