Method: RubyUnits::Unit#root

Defined in:
lib/ruby_units/unit.rb

#root(n) ⇒ Unit

Calculates the n-th root of a unit if n < 0, returns 1/unit^(1/n)

Parameters:

  • n (Integer)

Returns:

Raises:

  • (ArgumentError) —

    when attemptint to take the root of a temperature

  • (ArgumentError) —

    when n is not an integer

  • (ArgumentError) —

    when n is 0



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# File 'lib/ruby_units/unit.rb', line 900

def root(n)
  raise ArgumentError, "Cannot take the root of a temperature" if self.is_temperature?
  raise ArgumentError, "Exponent must an Integer" unless n.kind_of?(Integer)
  raise ArgumentError, "0th root undefined" if n.zero?
  return self if n == 1
  return self.root(n.abs).inverse if n < 0

  vec = self.unit_signature_vector
  vec =vec.map { |x| x % n }
  raise ArgumentError, "Illegal root" unless vec.max == 0
  num = @numerator.dup
  den = @denominator.dup

  for item in @numerator.uniq do
    x = num.find_all { |i| i==item }.size
    r = ((x/n)*(n-1)).to_int
    r.times { |y| num.delete_at(num.index(item)) }
  end

  for item in @denominator.uniq do
    x = den.find_all { |i| i==item }.size
    r = ((x/n)*(n-1)).to_int
    r.times { |y| den.delete_at(den.index(item)) }
  end
  q = @scalar < 0 ? (-1)**Rational(1, n) * (@scalar.abs)**Rational(1, n) : @scalar**Rational(1, n)
  return RubyUnits::Unit.new(:scalar => q, :numerator => num, :denominator => den)
end