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 solver returns the correct result. It only reduces the chance of making a mistake in the parameters of the method. Skip this operation only if you are sure that the correct data is specified in the solver parameters.

The lengths of all vectors must be defined in a previous call to the dcg_init routine.

Input Parameters

n

INTEGER. Sets the size of the problem.

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. Gives information about result 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

Indicates that the task completed normally.

RCI_request= -1100

Indicates that the task is interrupted and the errors occur.

RCI_request= -1001

Indicates that there are some warning messages.

RCI_request= -1010

Indicates that the routine changed some parameters to make them consistent or correct.

RCI_request= -1011

Indicates that there are some warning messages and that the routine changed some parameters.