module EverydayCliUtils::KmeansUtil

Public Class Methods

f_test(clusters, means, cnt, avg) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 10
def self.f_test(clusters, means, cnt, avg)
  cnt2 = clusters.count { |i| !i.empty? }
  ev   = f_test_ev(avg, clusters, cnt2, means)
  uv   = f_test_uv(clusters, cnt, cnt2, means)
  (ev / uv)
end
f_test2(clusters, means, cnt) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 34
def self.f_test2(clusters, means, cnt)
  uv   = 0.0
  cnt2 = clusters.count { |i| !i.empty? }
  (0...means.count).each { |i| uv += f_test2_calc(clusters, i, means, uv) unless clusters[i].empty? }
  (uv / (cnt - cnt2))
end
f_test2_calc(clusters, i, means, uv) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 41
def self.f_test2_calc(clusters, i, means, uv)
  tmp = 0.0
  (0...clusters[i].count).each { |j| tmp += (clusters[i][j] - means[i]) ** 2.0 }
  tmp /= clusters[i].count
  Math.sqrt(tmp)
end
f_test_ev(avg, clusters, cnt2, means) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 17
def self.f_test_ev(avg, clusters, cnt2, means)
  ev = 0.0
  (0...means.count).each { |i| ev += clusters[i].empty? ? 0.0 : clusters[i].count * ((means[i] - avg) ** 2.0) }
  ev / (cnt2 - 1.0)
end
f_test_uv(clusters, cnt, cnt2, means) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 23
def self.f_test_uv(clusters, cnt, cnt2, means)
  uv = 0.0
  (0...means.count).each { |i| uv = f_test_uvi(clusters, i, means, uv) }
  uv / (cnt - cnt2)
end
f_test_uvi(clusters, i, means, uv) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 29
def self.f_test_uvi(clusters, i, means, uv)
  (0...clusters[i].count).each { |j| uv += (clusters[i][j] - means[i]) * (clusters[i][j] - means[i]) } unless clusters[i].empty?
  uv
end
find_outliers(avg, cs, i, sensitivity) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 65
def self.find_outliers(avg, cs, i, sensitivity)
  csi = cs[i]
  std = EverydayCliUtils::MapUtil.std_dev(csi)
  cnt = csi.count
  csi.select { |c| (normal(c, avg, std) * cnt) < sensitivity }
end
get_clusters(collection, means) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 48
def self.get_clusters(collection, means)
  clusters = Array.new(means.count) { Array.new }
  collection.each { |item|
    cluster  = false
    distance = false
    (0...means.count).each { |i|
      diff = (means[i] - item) ** 2
      if distance == false || diff <= distance
        cluster  = i
        distance = diff
      end
    }
    clusters[cluster] << item
  }
  clusters
end
normal(x, avg, std) click to toggle source
# File lib/everyday-cli-utils/safe/kmeans.rb, line 5
def self.normal(x, avg, std)
  exp = -(((x - avg) / std) ** 2.0) / 2.0
  ((Math.exp(exp) / (std * Math.sqrt(2.0 * Math::PI))))
end