fixing ambiguous call to log

cbaselib/MutualInformation.cpp

@@ -39,8 +39,8 @@ double MutualInformation::entropy ( size_t n1, size_t n2 ) const
   // daher
   // p_1 log 1/p_1 + p_2 log 1/p_2
   double sum = n1 + n2;
-  double log1 = n1 > 0 ? log(n1) : 0;
-  double log2 = n2 > 0 ? log(n2) : 0;
+  double log1 = n1 > 0 ? log( (double)n1) : 0;
+  double log2 = n2 > 0 ? log( (double)n2) : 0;
   double logsum = (sum > 0) ? log(sum) : 0;
 
   return - (n1/sum*log1 + n2/sum*log2) + logsum;