Dear all, What I found out so far is that the problem in my example is related to having a cycle in the constraints. If there are no cycles in the constraints, all constraints can be resolved before they are applied so that each constrained_dof_index (which is a row index) never appears as a constraining dof (which is a column index). In this case, the matrix C has a zero column at the constrained_dof_index, so that C^T*K*C has zero rows and columns for all constrained_dof_indices. This means that inserting unit rows for the constrained_dof_indices afterwards produces a symmetric constraint matrix. In case of a cycle, the columns of C at the constrained_dof_indices can also be non-zero as in my example so that the final result is non-symmetric.
I ran into that issue in opt mode, so I wonder if there is any error checking in place that looks for cycles in the constraints? Best, Jonas ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
