Initial data commit

Task/Entropy/Picat/entropy.picat

@@ -0,0 +1,15 @@
+go =>
+  ["1223334444",
+   "Rosetta Code is the best site in the world!",
+   "1234567890abcdefghijklmnopqrstuvwxyz",
+   "Picat is fun"].map(entropy).println(),
+  nl.
+
+% probabilities of each element/character in L
+entropy(L) = Entropy =>
+  Len = L.length,
+  Occ = new_map(), % # of occurrences
+  foreach(E in L)
+    Occ.put(E, Occ.get(E,0) + 1)
+  end,
+  Entropy = -sum([P2*log2(P2) : _C=P in Occ, P2 = P/Len]).