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

[Bailey C. <bcu...@gm...>]

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.

Bailey C