Re: [Libmesh-users] Setting boundary ids on structured grids

[Roy S. <roy...@ic...>]

On Tue, 9 Mar 2010, Vikram Garg wrote:

> Roy/John,

I'll Cc: to libmesh-users, too, in case someone else has any ideas.

>               I am trying to create a mesh and specify its boundary
> ids for a rectangular domain. I had previously done this with an
> unstructured grid and everything had worked fine. But now when I try
> to do the same for a structured grids, I am getting an assertion
> failure while writing out the mesh in xda format.
> 
> Assertion `n_bcs == n_bcs_out' failed.
> [0] src/mesh/xdr_io.C, line 735, compiled Mar  2 2010 at 09:52:55
> terminate called after throwing an instance of 'libMesh::LogicError'
>   what():  Error in libMesh internal logic
> Aborted
> 
> The code works when I just create and write out the mesh without
> trying to set boundary ids. I am guessing that there must be
> something wrong in boundary id setting on structured grids. Is there
> anything different about setting ids for a structured mesh ? Any
> suggestions ?

The only difference I can think of is that a structured mesh output
from build_square/build_cube/whatever already has some boundary ids
set.  Is it possible that you're setting new boundary ids without
clearing the old?  IIRC we wanted to support multiple ids on a single
boundary side, but the support isn't all there yet, so perhaps you're
successfully adding an additional id but we're not able to write it
out.
---
Roy