Index: mttroot/mtt/lib/cr/hh/frictionfactor.hh
==================================================================
--- mttroot/mtt/lib/cr/hh/frictionfactor.hh
+++ mttroot/mtt/lib/cr/hh/frictionfactor.hh
@@ -1,11 +1,10 @@
 #ifndef FRICTIONFACTOR_HH
 #define FRICTIONFACTOR_HH
 
 #include <iostream>
-#include <math.h>
-#include <string>
+#include <cmath>
 
 #include "constants.hh"		// ReL, ReT
 #include "fade.hh"
 
 inline double