following-follower.rb

require 'rubygems'
require 'twitter'

def get_friends(twit, page = 1)
  r = twit.friends(:page => page)
  (r.size == 100) ? r.concat(get_friends(twit, page + 1)) : r
end

UID = 'your_twitter_id'
PASSWORD = 'your_twitter_password'

auth = Twitter::HTTPAuth.new(UID, PASSWORD)
twit = Twitter::Base.new(auth)
friends = get_friends(twit)

h = Hash.new(0)
open("friends.txt", "w") do |f|
  friends.each do |friend|
    if friend[:friends_count] > 0
      rate = friend[:followers_count].to_f / friend[:friends_count].to_f
      log = ("%.1f" % Math::log10(rate)).to_f
      f.puts "#{'%.1f' % log} #{friend[:screen_name]} #{friend[:followers_count]} / #{friend[:friends_count]}"
      h[log] += 1
    end
  end
end

open("data.csv", "w") do |f|
  h.keys.sort.each {|key| f.puts "#{key},#{h[key]}" }
end