September 2017 Update

Task/Entropy/Friendly-interactive-shell/entropy.fish

@@ -0,0 +1,21 @@
+function entropy
+    for arg in $argv
+        set name count_$arg
+        if not count $$name > /dev/null
+            set $name 0
+            set values $values $arg
+        end
+        set $name (math $$name + 1)
+    end
+    set entropy 0
+    for value in $values
+        set name count_$value
+        set entropy (echo "
+            scale = 50
+            p = "$$name" / "(count $argv)"
+            $entropy - p * l(p)
+        " | bc -l)
+    end
+    echo "$entropy / l(2)" | bc -l
+end
+entropy (echo 1223334444 | fold -w1)