[Dune] A problem in dune-grid

[Christian Engwer]

Hi Shim,

welcome to dune :-)

On Tue, Sep 25, 2018 at 08:50:56PM +0000, Shim, Miseon wrote:
> Dear All,
> 
> I hope you are doing well!
> 
> 
> A problem was occurred when I used dune-grid via duneuro-py. The error message is as follows:
> 
> 
> RuntimeError: GridError [createGrid:/Dune/dune-grid/dune/grid/uggrid/uggridfactory.cc:275]: You have supplied 868420 parametrized boundary segments, but the coarse grid has only 119990 boundary faces!
> 
> What is the meaning of this error?

If you construct/read a mesh, you can assign a boundary
parametrization (the boundary segment) to each foundary face of the
mesh. In your case UG reports, that you have roughly 8 times as many
boundary segments as you have faces. This sound pretty much as if your
mesh is already invalid.

- Are you reading a gmsh file? Or how are you constructing the mesh?
- Can you provide the mesh file (or a minimal example)?

> Is there a limitation for the number of boundary segments?

If I remember UGGrid correctly, there is a limitation, but this is not
your problem here and I doubt that you will hit this limit.

> Should I reduce the number of segments?

Does this mean that you manually specify the segments?

Best
Christian