Data update

Task/Entropy/FutureBasic/entropy.basic

@@ -0,0 +1,34 @@
+include "NSLog.incl"
+
+double local fn Entropy( array as CFArrayRef )
+  CFMutableDictionaryRef count = fn MutableDictionaryNew
+
+  for CFStringRef element in array
+    if ( count[element] )
+      count[element] = @(fn NumberIntegerValue( count[element] ) + 1)
+    else
+      count[element] = @(1)
+    end if
+  next
+
+  double       entropy = 0.0
+  NSUInteger     total = fn ArrayCount( array )
+  CFArrayRef valuesArr = fn DictionaryAllValues( count )
+
+  for CFNumberRef value in valuesArr
+    double p = fn NumberDoubleValue( value ) / total
+    entropy -= p * log(p)
+  next
+  return entropy / log(2)
+end fn = 0.0
+
+void local fn DoIt
+  CFStringRef string = @"1,2,2,3,3,3,4,4,4,4"
+  CFArrayRef characters = fn StringComponentsSeparatedByString( string, @"," )
+  double result = fn Entropy( characters )
+  NSLog( @"Entrophy of \"%@\": %.15f", fn StringByReplacingOccurrencesOfString( string, @",", @"" ), result )
+end fn
+
+fn DoIt
+
+HandleEvents