Contents

module Enumerable
  def sum
    reduce(:+)
  end

  def mean
    sum.to_f / length
  end

  def variance
    m = mean
    reduce(0) {|accum, item| accum + (item - m) ** 2}.to_f / (length - 1)
  end

  def stdev
    Math.sqrt(variance)
  end

  def percentile(pc)
    sort[(pc * length).ceil - 1]
  end
end

Version data entries

25 entries across 25 versions & 1 rubygems

Version	Path
madvertise-ext-0.2.0	lib/madvertise/ext/enumerable.rb
madvertise-ext-0.1.3	lib/madvertise/ext/enumerable.rb
madvertise-ext-0.1.2	lib/madvertise/ext/enumerable.rb
madvertise-ext-0.1.1	lib/madvertise/ext/enumerable.rb
madvertise-ext-0.1.0	lib/madvertise/ext/enumerable.rb