Class: Rational

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

Overview

When mathn is required Rational is changed to simplify the use of Rational operations.

Normal behaviour:

Rational.new!(1,3) ** 2 # => Rational(1, 9)
(1 / 3) ** 2            # => 0

require ‘mathn’ behaviour:

(1 / 3) ** 2            # => 1/9

Instance Method Summary collapse

Instance Method Details

#**(other) ⇒ Object

Exponentiate by other

(1/3) ** 2 # => 1/9



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# File 'lib/mathn.rb', line 138

def ** (other)
  if other.kind_of?(Rational)
    other2 = other
    if self < 0
      return Complex(self, 0.0) ** other
    elsif other == 0
      return Rational(1,1)
    elsif self == 0
      return Rational(0,1)
    elsif self == 1
      return Rational(1,1)
    end

    npd = numerator.prime_division
    dpd = denominator.prime_division
    if other < 0
      other = -other
      npd, dpd = dpd, npd
    end

    for elm in npd
      elm[1] = elm[1] * other
      if !elm[1].kind_of?(Integer) and elm[1].denominator != 1
        return Float(self) ** other2
      end
      elm[1] = elm[1].to_i
    end

    for elm in dpd
      elm[1] = elm[1] * other
      if !elm[1].kind_of?(Integer) and elm[1].denominator != 1
        return Float(self) ** other2
      end
      elm[1] = elm[1].to_i
    end

    num = Integer.from_prime_division(npd)
    den = Integer.from_prime_division(dpd)

    Rational(num,den)

  elsif other.kind_of?(Integer)
    if other > 0
      num = numerator ** other
      den = denominator ** other
    elsif other < 0
      num = denominator ** -other
      den = numerator ** -other
    elsif other == 0
      num = 1
      den = 1
    end
    Rational(num, den)
  elsif other.kind_of?(Float)
    Float(self) ** other
  else
    x , y = other.coerce(self)
    x ** y
  end
end