2016 Update

Task/Probabilistic-choice/Elixir/probabilistic-choice.elixir

@@ -0,0 +1,27 @@
+defmodule Probabilistic do
+  @tries 1000000
+  @probs [aleph:  1/5,
+          beth:   1/6,
+          gimel:  1/7,
+          daleth: 1/8,
+          he:     1/9,
+          waw:    1/10,
+          zayin:  1/11,
+          heth:   1759/27720]
+
+  def test do
+    trials = for _ <- 1..@tries, do: get_choice(@probs, :rand.uniform)
+    IO.puts "Item      Expected   Actual"
+    fmt = " ~-8s ~.6f  ~.6f~n"
+    Enum.each(@probs, fn {glyph,expected} ->
+      actual = length(for ^glyph <- trials, do: glyph) / @tries
+      :io.format fmt, [glyph, expected, actual]
+    end)
+  end
+
+  defp get_choice([{glyph,_}], _), do: glyph
+  defp get_choice([{glyph,prob}|_], ran) when ran < prob, do: glyph
+  defp get_choice([{_,prob}|t], ran), do: get_choice(t, ran - prob)
+end
+
+Probabilistic.test