Shylu is a package for solving sparse linear systems. it can be used either as a preconditioner, or as a solver. currently, we recommend using it as an ifpack preconditioner. shylu uses a hybrid direct/iterative approach based on schur complements. the goal is to provide robustness similar to sparse direct solvers, but memory usage more similar to preconditioned iterative solvers. shylu was designed as a node-level solver. it can use both mpi and threads in several ways. shylu was designed (a) to solve difficult but medium-size problems, and (b) to be used as a subdomain solver or smoother for very large problems within an iterative scheme. it is a purely algebraic method so can be used as a black-box solver. shylu has been particularly successful in electrical circuit simulation (xyce).

this package provides headers.