This patch wraps the HYPRE_Destroy functions for the HYPRESolvers in a
functtion that checks if the pointer is NULL before calling the Destroy
function. While this makes sense on it self, it also makes it possible
to override a finalizer by adding a second one that sets the pointer to
NULL. This is utilized in the set_precond(::Hybrid, p) function, since
the Hybrid solver currently frees the provied preconditioner too.
This patch stores the MPI communicator in the solvers structs. The
default communicator is changed from COMM_WORLD to COMM_NULL, for
BiCGSTAB, GMRES, and PCG, since their respective HYPRE_Create functions
simply ignore this argument.
This patch adds the following methods:
solve( ::HYPRESolver, ::PSparseMatrix, ::PVector)
solve!(::HYPRESolver, ::PVector, ::PSparseMatrix, ::PVector)
which automatically converts to/from HYPRE(Matrix|Vector).
This patch adds a function
solve(::HYPRESolver, ::HYPREMatrix, ::HYPREVector) which initializes an
output vector initialized to 0 and pass it to solve!.
Settings are passed as keyword arguments, just like BoomerAMG. The
Precond argument (corresponding to PCGSetPrecond) is handled separately,
and lets you pass another solver directly, instead of the solver
pointer, the setup and solve functions, as in the SetPrecond C function.
Example:
precond = BoomerAMG(; options...)
solver = PCG(; Precond = precond, options...)
This commits contains the solver interface:
A = HYPREMatrix(...)
b = HYPREVector(...)
x = HYPREVector(...)
solver = HYPRESolver(; options...)
solve!(solver, x, A, b)
where the abstract type HYPRESolver is replaced by a concrete solver
implementation (this commit includes the concrete
implementation/wrapping of BoomerAMG <: HYPRESolver).
Solver settings are passed as keyword arguments to the solver
constructor, cf. SetXXX functions in HYPRE.
For example, to create a BoomerAMG solver, and setting the tolerance:
solver = BoomerAMG(Tol = 1e-7)
Keyword argument names correspond directly to the solvers SetXXX
function in HYPRE; passing Tol corresponds to
HYPRE_BoomerAMGSetTol(solver, 1e-7).