Had to break this out for universal access through the code base.

lib/Lexicographic.h

@@ -0,0 +1,32 @@
+#ifndef GRID_LEXICOGRAPHIC_H
+#define GRID_LEXICOGRAPHIC_H
+
+
+namespace Grid{
+
+  class Lexicographic {
+  public:
+
+    static inline void CoorFromIndex (std::vector<int>& coor,int index,std::vector<int> &dims){
+      int nd= dims.size();
+      coor.resize(nd);
+      for(int d=0;d<nd;d++){
+	coor[d] = index % dims[d];
+	index   = index / dims[d];
+      }
+    }
+
+    static inline void IndexFromCoor (std::vector<int>& coor,int &index,std::vector<int> &dims){
+      int nd=dims.size();
+      int stride=1;
+      index=0;
+      for(int d=0;d<nd;d++){
+	index = index+stride*coor[d];
+	stride=stride*dims[d];
+      }
+    }
+
+  };
+
+}
+#endif