Module Idas_bbd

module Idas_bbd: sig .. end

Parallel band-block-diagonal preconditioners for IDAS (requires MPI).


type parallel_bsession = (Nvector_parallel.data, Nvector_parallel.kind) Idas.Adjoint.bsession 

Alias for sessions based on parallel nvectors.

type parallel_preconditioner = (Nvector_parallel.data, Nvector_parallel.kind)
Idas.Adjoint.Spils.preconditioner

Alias for preconditioners based on parallel nvectors.

type bandwidths = Ida_bbd.bandwidths = {
   mudq : int; (*

Upper half-bandwidth for the difference quotient Jacobian approximation.

*)
   mldq : int; (*

Lower half-bandwidth for the difference quotient Jacobian approximation.

*)
   mukeep : int; (*

Upper half-bandwidth for the retained banded approximate Jacobian block.

*)
   mlkeep : int; (*

Lower half-bandwidth for the retained banded approximate Jacobian block.

*)
}

The bandwidths for the difference quotient Jacobian operation.

type local_fn = Nvector_parallel.data Idas.Adjoint.bresfn_args ->
Nvector_parallel.data -> unit

Functions that approximate backward residual functions using local computations only. They are passed the arguments:

The approximation is allowed to coincide with the actual backward residual function.

Raising Sundials.RecoverableFailure signals a recoverable error. Other exceptions signal unrecoverable errors.

type comm_fn = Nvector_parallel.data Idas.Adjoint.bresfn_args -> unit 

Functions that perform the interprocess communication necessary for the execution of Idas_bbd.local_fn.

Raising Sundials.RecoverableFailure signals a recoverable error. Other exceptions signal unrecoverable errors.

val prec_left : ?dqrely:float ->
bandwidths ->
?comm:comm_fn ->
local_fn -> parallel_preconditioner

Left preconditioning using the Parallel Band-Block-Diagonal module. The difference quotient operation is controlled by ?dqrely, which specifies the relative increment in components of y, and Idas_bbd.bandwidths.

val reinit : parallel_bsession -> ?dqrely:float -> int -> int -> unit

Reinitializes some BBD preconditioner parameters. In the call, reinit s ~dqrely:dqrely mudq mldq, dqrely is the relative increment in the components of y, and mudq and mldq are, respectively, the upper-half and lower-half bandwidths of the difference quotient Jacobian approximation.

val get_work_space : parallel_bsession -> int * int

Returns the sizes of the real and integer workspaces used by the BBD preconditioner.

val get_num_gfn_evals : parallel_bsession -> int

Returns the number of calls to the right-hand side function due to finite difference banded Jacobian approximation in the setup function.