Add tasks for all the new languages

Task/Entropy/EchoLisp/entropy-1.echolisp

@@ -0,0 +1,18 @@
+(lib 'hash)
+;; counter: hash-table[key]++
+(define (count++ ht k )
+(hash-set ht k (1+ (hash-ref! ht k 0))))
+
+(define (hi count n )
+	(define pi (// count n))
+	(- (* pi (log2 pi))))
+	
+;; (H [string|list]) → entropy (bits)
+(define (H info)
+	(define S (if(string? info) (string->list info) info))
+	(define ht (make-hash))
+	(define n (length S))
+	
+	(for ((s S)) (count++ ht s))
+	(for/sum ((s (make-set S)))  (hi (hash-ref ht s) n)))
+	

Task/Entropy/EchoLisp/entropy-2.echolisp

@@ -0,0 +1,12 @@
+;; by increasing entropy
+
+(H "🔴")  → 0
+(H "🔵🔴") → 1
+(H "1223334444") → 1.8464393446710154
+(H "♖♘♗♕♔♗♘♖♙♙♙♙♙♙♙♙♙") → 2.05632607578088
+(H "EchoLisp")  → 3
+(H "Longtemps je me suis couché de bonne heure") → 3.860828877124944
+(H "azertyuiopmlkjhgfdsqwxcvbn") → 4.700439718141092
+(H (for/list ((i 1000)) (random 1000)))  → 9.13772704467521
+(H (for/list ((i 100_000)) (random 100_000))) → 15.777516877140766
+(H (for/list ((i 1000_000)) (random 1000_000))) → 19.104028424596976

Task/Entropy/FreeBASIC/entropy.freebasic

@@ -0,0 +1,34 @@
+' version 25-06-2015
+' compile with: fbc -s console
+
+Sub calc_entropy(source As String, base_ As Integer)
+
+    Dim As Integer i, sourcelen = Len(source), totalchar(255)
+    Dim As Double prop, entropy
+
+    For i = 0 To sourcelen -1
+        totalchar(source[i]) += 1
+    Next
+
+    Print "Char    count"
+    For i = 0 To 255
+        If totalchar(i) = 0 Then Continue For
+        Print "   "; Chr(i); Using "   ######"; totalchar(i)
+        prop = totalchar(i) / sourcelen
+        entropy = entropy - (prop * Log (prop) / Log(base_))
+    Next
+
+    Print : Print "The Entropy of "; Chr(34); source; Chr(34); " is"; entropy
+
+End Sub
+
+' ------=< MAIN >=------
+
+calc_entropy("1223334444", 2)
+Print
+
+' empty keyboard buffer
+While InKey <> "" : Wend
+Print : Print "hit any key to end program"
+Sleep
+End

Task/Entropy/Nim/entropy.nim

@@ -0,0 +1,8 @@
+import tables, math
+
+proc entropy(s): float =
+  var t = initCountTable[char]()
+  for c in s: t.inc(c)
+  for x in t.values: result -= x/s.len * log2(x/s.len)
+
+echo entropy("1223334444")

Task/Entropy/Oforth/entropy.oforth

@@ -0,0 +1,8 @@
+: entropy(s) -- f
+| freq sz |
+   s size dup ifZero: [ return ] asFloat ->sz
+   ListBuffer initValue(255, 0) ->freq
+   s apply( #[ dup freq at 1+ freq put ] )
+   0.0 freq applyIf( #[ 0 <> ], #[ sz / dup ln * - ] ) Ln2 / ;
+
+entropy("1223334444") .

Task/Entropy/Sidef/entropy.sidef

@@ -0,0 +1,10 @@
+func entropy(s) {
+  var counts = Hash.new;
+  s.each { |c| counts{c} := 0 ++ };
+  var len = s.len;
+  [0, counts.values.map {|count|
+    var freq = count/len; freq * freq.log2 }...
+  ]«-»;
+}
+ 
+say entropy("1223334444");

Task/Entropy/jq/entropy-1.jq

@@ -0,0 +1,10 @@
+# Input: an array of strings.
+# Output: an object with the strings as keys, the values of which are the corresponding frequencies.
+def counter:
+  reduce .[] as $item ( {}; .[$item] += 1 ) ;
+
+# entropy in bits of the input string
+def entropy:
+  (explode | map( [.] | implode ) | counter
+    | [ .[] | . * log ] | add) as $sum
+  | ((length|log) - ($sum / length)) / (2|log) ;

Task/Entropy/jq/entropy-2.jq

@@ -0,0 +1 @@
+"1223334444" | entropy # => 1.8464393446710154