Get the absolute value of a phone number.

abs_phone.rb

# Get the absolute value of a phone number
def abs_phone(phone)
  abs = []
  phone = phone.gsub(/[^a-zA-Z0-9]/, '').downcase
  phone.each_byte do |b|
    case b
      when 0..96
        abs << (b - 48)
      when 122
        abs << ((((b-97).to_f/3.0)+1.0).round)
      when 115..121
        abs << ((((b-96).to_f/3.0)+1.0).round)
      else
        abs << ((((b-95).to_f/3.0)+1.0).round)
    end
  end

  abs.join('')
end