Re: [Libmesh-users] EquationSystems::init() takes an enormous amount of time with scalar variables

[John P. <jwp...@gm...>]

On Tue, Jul 3, 2018 at 8:16 AM, Bailey Curzadd <bcu...@gm...> wrote:

> Hi John,
>
> Thanks for the advice. I looked into the alternatives you suggested, but
> discretizing the LMs as a field variable unfortunately causes me more
> headaches than it solves, so I’ve switched to the penalty method for now. I
> do have one suggestion to improve DofMap that should be relatively easy to
> implement. Since the MPCs are a recent addition to my code, I assembled the
> constraint equations separately from the stiffness section of the system
> matrix to avoid major changes to existing code. In doing so, I had to
> change the stiffness assembly to manually separate displacement DOFs from
> LM DOFs since, currently, the DofMap interface only allows requesting
> element/nodal DOFs for a single variable or all of them at once. I think it
> would be useful to have something like
>
> dof_indices(const Elem *const elem, std::vector< dof_id_type > &di,
> std::vector<const unsigned int> &vns)
>
> in order to select the DOFs associated with a reduced list of variables.
>

Hmm, yes, this seems like a reasonable extension to the existing
dof_indices() interfaces. I don't have time to work on it at the moment,
but feel free to open a GitHub Issue for this so it stays on our radar.

-- 
John