Re: [Libmesh-users] BoomerAMG/hypre with CG for elasticity

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

On Sat, 1 Feb 2014, Jens Lohne Eftang wrote:

> I used these arguments for 3D elasticity and they seemed to work well
> also in combination with DirichletBoundary (why does that break symmetry?)

When you constrain your element matrix and vector (any constraints,
but including the heterogenous constraints from DirichletBoundary),
the default argument "asymmetric_constraint_rows=true" causes your
matrix to be left in an asymmetric state.  The advantage is that in
this case the linear solver can handle your constraint equations for
you; the disadvantage is an asymmetric state.
---
Roy