Contents

class Array
  def central_moment(k)
    if k < 0
      nil
    else
      mean = self.mean

      (1.0 / self.length) * self.map{ |x| (x - mean) ** k }.sum
    end
  end

  def raw_moment(k)
    if k < 0
      nil
    else
      (1.0 / self.length) * self.map{ |x| x ** k }.sum
    end
  end

  # def l_moment k
  #
  # end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
rstat-0.1.2	lib/rstat/core_ext/array/descriptive_statistics/shape/moment.rb
rstat-0.1.1	lib/rstat/core_ext/array/descriptive_statistics/shape/moment.rb