Data update

Task/Entropy/Pluto/entropy.pluto

@@ -0,0 +1,22 @@
+do  -- Shannon entropy - translated from the Lua sample
+
+    local function log2 ( x : number ) : number return math.log(x) / math.log(2) end
+
+    local function entropy ( X : string ) : number
+        local N, count, sum, i = X:len(), {}, 0
+        for char = 1, N do
+            i = X[char]
+            if count[i] then
+                count[i] += 1
+            else
+                count[i] = 1
+            end
+        end
+        for n_i, count_i in pairs(count) do
+            sum += count_i / N * log2(count_i / N)
+        end
+        return -sum
+    end
+
+    print( entropy( "1223334444" ) )
+end