Added average keyword

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@14278 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/compute_msd.h

@@ -33,7 +33,9 @@ class ComputeMSD : public Compute {
   void set_arrays(int);
 
  protected:
-  int comflag;
+  int comflag;   // comflag = 1 if reference moves with center of mass
+  int avflag;    // avflag = 1 if using average position as reference
+  int naverage;  // number of samples for average position
   bigint nmsd;
   double masstotal;
   char *id_fix;