Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

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Document Table of Contents

dcgmrhs_init

Initializes the RCI CG solver with MHRS.

Syntax

dcgmrhs_init(n, x, nrhs, b, method, RCI_request, ipar, dpar, tmp)

Include Files

  • Fortran: mkl_rci.fi, mkl_rci.f90

Description

The routine dcgmrhs_initinitializes the solver. After initialization all subsequent invocations of the Intel® oneAPI Math Kernel Library (oneMKL) RCI CG with multiple right-hand sides (MRHS) routines use the values of all parameters that are returned bydcgmrhs_init. Advanced users may skip this step and set the values to these parameters directly in the appropriate routines.

warning:

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 dcgmrhs_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*nrhs. Contains the initial approximation to the solution vectors. Normally it is equal to 0 or to b.

nrhs

INTEGER. Sets the number of right-hand sides.

b

DOUBLE PRECISION. Array of size n*nrhs. Contains the right-hand side vectors.

method

INTEGER. Specifies the method of solution:

A value of 1 indicates CG with multiple right-hand sides (default value)

Output Parameters

RCI_request

INTEGER. Gives information about the result of the routine.

ipar

INTEGER. Array of size (128+2*nrhs). Refer to the CG Common Parameters.

dpar

DOUBLE PRECISION. Array of size (128+2*nrhs). Refer to the CG Common Parameters.

tmp

DOUBLE PRECISION. Array of size (n, (3+nrhs)). 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.