Add bin and edit workflow

bin/gems/facets-3.1.0/lib/standard/facets/math/kldivergence.rb

@@ -0,0 +1,19 @@
+module Math
+
+  # The Kullback-Leibler divergence from this array to that of +q+.
+  #
+  # NB: You will possibly want to sort both P and Q before calling this
+  # depending on what you're actually trying to measure.
+  #
+  # http://en.wikipedia.org/wiki/Kullback-Leibler_divergence
+  #
+  def self.kldivergence(array, q)
+    fail "Buggy."
+    fail "Cannot compare differently sized arrays." unless size = q.size
+    kld = 0
+    each_with_index { |pi,i| kld += pi*Math::log(pi.to_f/q[i].to_f) }
+    kld
+  end
+
+end
+