Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 3/31/2023
Public

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Document Table of Contents

dcg_init

Initializes the solver.

Syntax

dcg_init(n, x, b, RCI_request, ipar, dpar, tmp)

Include Files
  • Fortran: mkl_rci.fi, mkl_rci.f90
Description

The routine dcg_initinitializes the solver. After initialization, all subsequent invocations of the Intel® oneAPI Math Kernel Library RCI CG routines use the values of all parameters returned by the routinedcg_init. Advanced users can skip this step and set the values in the ipar and dpar arrays directly.

CAUTION:

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

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 the 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= -10000

Indicates failure to complete the task.