module Dls:sig
..end
Direct Linear Solvers operating on dense, banded, and sparse matrices.
include Sundials_LinearSolver.Direct
type'm
jac_fn =(Sundials.RealArray.t Cvode.triple, Sundials.RealArray.t) Cvode.jacobian_arg ->
'm -> unit
Callback functions that compute approximations to a Jacobian
matrix. In the call jac arg jm
, arg
is a Cvode.jacobian_arg
with
three work vectors and the computed Jacobian must be stored in jm
.
The callback should load the (i,j)
th entry of jm
with
$\partial y_i/\partial y_j$, i.e., the partial derivative of the
i
th equation with respect to the j
th variable, evaluated at the
values of t
and y
obtained from arg
. Only nonzero elements need
be loaded into jm
.
Raising Sundials.RecoverableFailure
indicates a recoverable error.
Any other exception is treated as an unrecoverable error.
arg
nor the matrix jm
should
be accessed after the function has returned.type'm
linsys_fn =(Sundials.RealArray.t Cvode.triple, Sundials.RealArray.t) Cvode.jacobian_arg ->
'm -> bool -> float -> bool
Function to compute the linear system matrix $M = I - \gamma J$ or an approximation of it. Offers an alternative to evaluating the Jacobian of the right-hand-side function.
In addition to those shared with the Jacobian function, the arguments of this function are
m
, storage for the computed linear system matrix,jok
, indicates whether the Jacobian-related data needs to be
updated, andgamma
, the scalar in the formula above.The function should return true only if the Jacobian data was recomputed.
Raising Sundials.RecoverableFailure
indicates a recoverable error.
Any other exception is treated as an unrecoverable error.
m
should be accessed after the function has returned.val solver : ?jac:'m jac_fn ->
?linsys:'m linsys_fn ->
('m, Sundials.RealArray.t, [> Nvector_serial.kind ] as 'a, [> `Dls ])
Sundials.LinearSolver.t -> 'a Cvode.serial_linear_solver
Create a Cvode-specific linear solver from a Jacobian approximation function and generic direct linear solver.
The Jacobian approximation function is optional for dense and banded
solvers (if not given an internal difference quotient approximation is
used), but must be provided for other solvers (or Invalid_argument
is raised).
The linsys
argument allows to override the standard linear system
function that calls jac
to compute $M$ . This feature is only
available in Sundials >= 5.0.0.
val get_work_space : [> Nvector_serial.kind ] Cvode.serial_session -> int * int
Returns the sizes of the real and integer workspaces used by a direct linear solver.
real_size
, integer_size
)val get_num_jac_evals : [> Nvector_serial.kind ] Cvode.serial_session -> int
Returns the number of calls made by a direct linear solver to the Jacobian approximation function.
val get_num_lin_rhs_evals : [> Nvector_serial.kind ] Cvode.serial_session -> int
Returns the number of calls to the right-hand side callback due to the finite difference Jacobian approximation.