Data update

Task/Entropy/SETL/entropy.setl

@@ -0,0 +1,16 @@
+program shannon_entropy;
+    print(entropy "1223334444");
+
+    op entropy(symbols);
+        hist := {};
+        loop for symbol in symbols do
+            hist(symbol) +:= 1;
+        end loop;
+        h := 0.0;
+        loop for count = hist(symbol) do
+            f := count / #symbols;
+            h -:= f * log f / log 2;
+        end loop;
+        return h;
+    end op;
+end program;