## [Libmesh-users] where to get additional DOFs from ?

 [Libmesh-users] where to get additional DOFs from ? From: Mark Blome - 2005-02-25 09:01:24 ```Hi everybody, I am currently working on a finite element application where I need to introduce additional degree of freedoms that are not associated to the mesh. I need them to approximate the region exterior to the finite element mesh. I already posted an email about this some weeks ago. Now I think I know (well more or less) how to create the matrix, in principle it looks something like: | Ke 0 | | x | = | Fe | | 0 K2 | | A | | 0 | where Ke*x=Fe are the usual FEM equations and matrix K2 are additional entries and the vector A are the additional DOFs I need. Would it be a stupid idea to introduce something like a "large virtual finite element" that geometrically does not exist but has all the additional DOFs A associated to it? How could I do this? Is there any other more elegantly way of doing this in libmesh? I would be very happy about any comments on this, Mark ```

 [Libmesh-users] where to get additional DOFs from ? From: Mark Blome - 2005-02-25 09:01:24 ```Hi everybody, I am currently working on a finite element application where I need to introduce additional degree of freedoms that are not associated to the mesh. I need them to approximate the region exterior to the finite element mesh. I already posted an email about this some weeks ago. Now I think I know (well more or less) how to create the matrix, in principle it looks something like: | Ke 0 | | x | = | Fe | | 0 K2 | | A | | 0 | where Ke*x=Fe are the usual FEM equations and matrix K2 are additional entries and the vector A are the additional DOFs I need. Would it be a stupid idea to introduce something like a "large virtual finite element" that geometrically does not exist but has all the additional DOFs A associated to it? How could I do this? Is there any other more elegantly way of doing this in libmesh? I would be very happy about any comments on this, Mark ```