dcg_check

Syntax

Include Files

The Fortran interface is specified in the mkl_rci.fi include file and the C interface is specified in the mkl_rci.h include file.

Description

The routine dcg_check checks consistency and correctness of the parameters to be passed to the solver routine dcg. However this operation does not guarantee that the method gives the correct result. It only reduces the chance of making a mistake in the parameters of the method. Advanced users may skip this operation if they are sure that the correct data is specified in the solver parameters.

Warning

Users can modify the contents of these arrays after they are passed to the solver routine only if they are sure that the values are correct and consistent. Basic check for correctness and consistency can be done by calling the dcg_check routine, but it does not guarantee that the method will work correctly.

Note that lengths of all vectors are assumed to have been defined in a previous call to the dcg_init routine.

Input Parameters

n

INTEGER. Contains the size of the problem, and size of arrays x and b.

x

DOUBLE PRECISION array of size n. Contains the initial approximation to the solution vector. Normally it is equal to 0 or to b.

b

DOUBLE PRECISION array of size n. Contains the right-hand side vector.

Output Parameters

RCI_request

INTEGER. Informs about result of work of the routine.

ipar

INTEGER array of size 128. Refer to the CG Common Parameters.

dpar

DOUBLE PRECISION array of size 128. Refer to the CG Common Parameters.

tmp

DOUBLE PRECISION array of size (n,4). Refer to the CG Common Parameters.

Return Values

RCI_request= 0

The routine completes task normally.

RCI_request= -1100

The routine is interrupted, errors occur.

RCI_request= -1001

The routine returns some warning messages.

RCI_request= -1010

The routine changes some parameters to make them consistent or correct.

RCI_request= -1011

The routine returns some warning messages and changes some parameters.