use it

Device/Histo/DiffUtil.cpp

@@ -42,7 +42,7 @@ Datafield* DiffUtil::relativeDifferenceField(const Datafield& dat, const Datafie
     std::vector<double> out(dat.size());
     for (size_t i = 0; i < dat.size(); ++i)
         out[i] = Numeric::relativeDifference(dat.valAt(i), ref.valAt(i));
-    return new Datafield(dat.frame().clonedAxes(), out);
+    return new Datafield(dat.frame().clone(), out);
 }
 
 //! Returns sum of relative differences between each pair of elements: