MFEMLORLinearSolverBase

Summary

Base class for mfem::Solver objects used as linear solvers or preconditioners in MFEM problems that support variants for solving low-order-refined (LOR) problems.

Overview

Classes derived from LORLinearSolverBase<T> represent preconditioners and/or linear solvers that have LOR solver variants to accelerate the solution of high-order problems. Use of these variants is controlled by setting the low_order_refined parameter to true. LOR solvers work by taking a problem and casting it onto a spectrally equivalent one with lower polynomial order and more refined mesh. Due to the scaling properties of the computing time with respect to polynomial order and mesh size, this change will often result in a significant performance improvement, which tends to be more pronounced at higher polynomial orders. More details can be found here.

Any LOR-capable MFEM solver T must inherit from LORLinearSolverBase<T>. Provided methods are targeted towards LOR solver variants described by mfem::LORSolver<T> objects; if this is not appropriate for the desired LOR-based MFEM solver (for instance, if additional setup is required or if building an mfem::LORSolver<T> object is unnecessary), the developer is free to specialize LORLinearSolverBase<T>::UpdateEquationSystemContext() as required. With the low_order_refined variant set to false (the default), the wrapped MFEM solver will be of type T and LOR functionality will be disabled.