interpreter&vm: handle multi-iterator

[nit.git] / lib / counter.nit

diff --git a/lib/counter.nit b/lib/counter.nit
index 818264e..9a539e6 100644 (file)
--- a/lib/counter.nit
+++ b/lib/counter.nit
@@ -254,6 +254,32 @@ class Counter[E]
                end
                return (sum / map.length.to_f).sqrt
        end
+
+       # The information entropy (Shannon entropy) of the elements in the counter (in bits).
+       fun entropy: Float
+       do
+               var res = 0.0
+               var sum = self.sum.to_f
+               for k, v in self do
+                       var f = v.to_f / sum
+                       res = res - f * f.log_base(2.0)
+               end
+               return res
+       end
+
+       # Prints the content of the counter along with statistics
+       #
+       # Content is printed in order (if available) from lowest to highest on the keys.
+       # Else, it is printed as-is
+       fun print_content do
+               var a = keys.to_a
+               if a isa Array[Comparable] then default_comparator.sort(a)
+               var subtotal = 0
+               for i in a do
+                       subtotal += self[i]
+                       printn("* ", i or else "null", " = ", self[i], " => occurences ", self[i].to_f / sum.to_f * 100.0, "%, cumulative ", subtotal.to_f / sum.to_f * 100.0, "% \n")
+               end
+       end
 end
 
 redef class Collection[E]