Normal vector of the boundary fehlt noch

The normal vector of the boundary can be calculated in the following way

   Variable<double>  X1(grid), X2(grid), X3(grid);

   ...

   Normal_vector(X1,X2,X3);  // This function calculates the normal vector
   // Now (X1,X2,X3) is the normal vector of the boundary
Handbook

Last modified: Fri Feb 11 09:18:59 MET 2000